Pusher-Trailer: A Bicycle-Frame Solution

Hi Lemlux; that would make sense. Using the bike frame puts the wheel behind the axle at least 14” (minimum clearance) + 30” (minimum length of frame from head to rear axle). :)

Brief status:
  • The project is officially moving forward with the purchase this week of quantity two of the 12 x 4110 MOSFET Extreme Modder Controller LYEN Edition. Also I ordered up another set of Rear LED Taillights and Turn Signals for the trailer; duplicates of what I have for the ebike.
  • I am close to placing my order with ChainReaction in the UK for the frame and associated parts; it’s free shipping if the amount is over $250, so I want to get as much in from them as possible. The sticking point is the Mavic EX271 rim:
    • I mistakenly bought the EX729 Disc rim and mounted a 9C 2806 FH to it, not realizing I have rim brakes. :roll: The order must have been placed on the day I skipped breakfast and subsequently spaced out. Thread: Rim Brake on a Disc Rim.
    • This has led to exploring if one can just swap out the cover and convert it to disc, although I fear it might be a lost cause. Otherwise the options are to either buy a disc hub motor or a Vee-Brake capable rim and then swap that out. Regardless it is a money pit: Whatever the outcome, I’ll still need to fetch a 9C 2806 RH; the only rear hub motor that I have was taken apart to stuff 10-AWG wires through it. Thread: DIY 10awg phase leads through axle in 9C hubmotor.
      Sadly I honed the hole out to make enough room to put the wires through and now I don’t trust the axle to handle the weight and shock. In the end, this mod was unnecessary because I am not pushing enough current into the motor to be worth it. Anyways, I’ll need a new RH. Already have the rim for it: Kris Holm 24” Mountain. That will be mated to a 24” Maxxis Hookworm (already stocked). So the wheel business is almost sorted.
  • The electrical system will be modified shortly. I have all the parts I need now – sans the two controllers which should arrive this week. Partial Thread: Advancing the state of Ebike Electrical Wiring. The difference here is that I will need to decide where the 2nd controller will live: On the trailer or on the ebike. If it’s on the trailer then I’ll need to pass all the signal wires and power over with connectors. Or if I leave the controller on the ebike, then it’s just 3-phase and Halls (as well as the brake/signals). The latter option pretty well keeps it simple.
  • Speculating: The VKP60M312 DC-DC converter puts out 60W total. I figure the 3.3V circuit driving the LED blinkies and headlights won’t take more than 2A, but let’s say it takes up to 3A/10W. That leaves 50W to drive the 12V circuits, LED brakes and signals. I am guessing that the 12V regulator on the controller does not push beyond the maximum limit at 1.5A each (times two), but if it did, that’s 3A @ 12V = 36W.
    The part that I don’t know is the current draw of the signals and brakes, though it can be measured. The question I have is what formula should I use to determine the proper capacitor size to assuage the voltage drop during signaling/braking?
The saga continues. KF
 
Found another frame style having several manufacturers offering variations upon the same theme.

Because-Simple-24-3frames.jpg

Product Link. This can be had for $300-390 range depending on the postage/insurance deal. Near as I can tell these are all made in China.
EDIT: Cropped a copy of the image from original source and colocated on my server for faster response.

What's interesting is that the "trials" bike frames are available in two models: no-seat & the "Street" (with seat) version. The Street version has a longer seat tube. Either way, in most cases the BB is up higher; having greater ground clearance. The price of these frames run close to parallel to what one might expect to performance bikes. The frame weights are about 3.5 lbs being made of Aluminum 6061. Not sure how that would pan out for overall strength, but I've seen video of what people are doing with them and I believe the frame can handle a 100 lb load as a trailer bike.

Caveats: One needs to pay close attention to the rear drop-outs; they should be parallel for better strength. Most accept 135mm wide, and also have integrated heads 110mm long; a very compelling geometry.

For a good list of what's out there, check out TartyBikes in the UK. There's also PinkBike and TopGears. :idea:

The question begs: What's the widest acceptable tire width? And should I go with the 24" or the 26" for a slightly longer wheelbase?
ADDENDUM 1: 4/24 - Just got an answer back on the frames above; they can accept a 2.5" wide tire.
ADDENDUM 2: Confirmed by rep that the Head Tube accepts 1-1/8th size steerer.

It's captured my fancy, KF :)
 
Oh man! Yeah, I think these frames can handle a little trailer action. Check this out; well produced film of Danny MacAskill...

[youtube]Z19zFlPah-o[/youtube]

Wow! KF 8)
 
Hey KF! He does the most incredible stuff I have ever seen on a bike. Maybe like the old Kevin Costner film we should nickname him "Dances with bikes"!
otherDoc
 
I’ve narrowed my new-&-revised search for a frame down to these two beauties:

Class: Trails Frame (seatless)
Both frames are within 5% of each other in terms of weight, length, and head rotation. Although I think that the Neon Wing is a better-built and stronger frame. The question though, is it worth $95 more? :?

Here’s the layout of the Because Simple 24” frame in CAD:

Because-Simple-24-CAD.rotated15.jpg

Note: Frame is rotated 15° CW in this view (the spec says the head is actually rotated 72° rather than 75°)

This class has the highest ground clearance when rotated. At 15° the BB still had about 8” of clearance with a 24” tire; that’s livable. The 26” frame will have lightly better clearance over the 24", and with the Neon Wing slightly edging out the Because Simple. The next step up in BB clearance becomes really pricy.

Kicking the tires, KF
 
Status:
Been quiet on this front although I have been very busy moving forward with acquisition of parts and supplies, advancing on design work, and generally setting myself up for a nice long 2000 mile trek. Items that have been sorted to date are:

  • Controller 12-FET LYEN, QTY-2
  • Hub Motor 9C 2806 FH
  • Hub Motor 9C 2806 RH
  • Mechanical Calipers; I may or not use these, but I have them nonetheless.
  • CA, Direct Plug-in; already had a spare, so total of 2.
  • Rims: Mavic EX 729 Disc, Qty-2
  • Rim: Kris Holm 24” MtB (rear pusher)
  • Hookworms, both 26” and 24” with tubes.
  • Crown & Steerer, Marzocchi 888 Flat: OK, I was going to snag a used one off of PinkBike but the experience has left me with a lot of wait and doubt. At the same time I am staring at my unused Marzocchi 888 DH fork thinking that I can just take the parts off of it for free. They can always be put back on or replaced later. So that’s about $136 saved. Also might as well reuse the Frame Protectors as well.
  • Connector, 6-way; on its’ way from Amazon.
  • Signal Lights
  • Rear taillight
  • Controller mods: R12 and caps upgrade on its’ way from Digikey.
  • Routes: All laid out on http://www.Bikely.com; it’s about 2000 miles round trip. BTW – I shall be passing through San Francisco and Portland for overnight on the return leg back up to Seattle/Redmond. The first and the last days will be the hardest and longest.

Left to do:
  • 26" Frame, MtB DMR Transition; leaning pretty hard on the 26” frame over the 24” due to the width of the Hookworm. Not yet ordered. I am still toying with having a frame builder make a custom from frame parts. Check out these guys: http://www.cycle-frames.com/
  • Headset, FSA Orbit BMX; not yet ordered.
  • Trailer Hitch: This is a custom designed part that I am working on that will integrate the double-crown steerer to my rear axle. The design is nearly perfected.
  • Rear Rack: I am hoping to use an off-the-shelf design; won’t know until I get the frame sorted.
  • Battery bags: The trailer-bike is designed to carry Qty-48 Zippy FlightMax 5S1P 5000mAh 15/2C. That’s 24 batts per side, likely in a 3x3x4 (tall) configuration in saddlebags over the tire, equaling about 75 lbs.
  • Faring: tbd.
  • Batteries: Not yet ordered. Though I anticipate it will be 36 + 6 (to replace 6 bloated batts). This will bring my total up to 72 batteries.
  • There’s one other mod that I am working on; the design is complete and I am negotiating with the machinist on price. The mod will allow me to mount a Campagnolo 53T triple chainring & derailleur onto my DH bike frame, allowing for a 53-11 ratio which I hope will allow sustained pedaling in excess of 35 mph with comfort. This mod is key to my success this year as it will allow me to increase my average speed by up to 10 mph over last year.
  • Steering Dampener/Stabilizer: tbd
  • Charger upgrade: tbd. Essentially I wish to raise the output from 700W to about 1200W, if possible. The present system is bulky, and I am not too keen on adding more to it for greater output.
  • Wiring: got plenty, it just needs doing :roll:

So the short story is “Yes” I am still moving forward with this project, and there is a lot left to do. If the employment gods are kindred to my plight then I should be able to take July off and complete the journey. Too bad there’s no room for my guitar. Prolly just as well; I play horribly – though well enough to amuse myself. <sigh>

Sawing away at the ball & chain, KF
 
Very eager to read and see more about your custom designed trailer hitch. I have focused on the BOB 28" hitch only because I'm not aware of anything better. I'm also planning on going the cheap route with the $20 cromoly Giant MTB frame I showed earlier. It would appear to require sticking the steerer tube up in the air and welding or bolting something below the bottom of the steerer tube and tilted backward to get appropriate ground clearance and the 80 degree angle.

Per your comments on another thread, I/m particularly curious about your TBD steering damper / stabilizer presumably somehow connected through the steerer tube.
 
Hello Lemlux :)

I placed the order yesterday for this: Streamline Steering Stabilizer 7 Way Rebuildable Black

StreamlineSteeringStabilizer.jpg


Search eBay; the seller is “atv_zone”. My total cost was $124.20 USD. It closely resembles the steering dampener that I had on my Honda Odyssey. Ultimately the desire for the 7-way adjustments and be rebuildable won out over the other device. Not sure if the clamps will be of use though. BTW - the seller was pdq on getting this order out first thing this morning and I already have a UPS tracking number 8)

Frame: Correction...
The frame will be a 26” Neon Wing Trials weighing in at 3.5 lbs. I’m nearly convinced this would be easier than trying to get someone to weld up a custom bike frame. If I did the welding route then the tubes would be either Aluminum 6061 or Steel Alloy 4130 – all thin wall stuff. However every frame builder out there looks like their minimum is $1200; I’m better off modifying from off-the-shelf. So this will likely get ordered this week.

NeonWingTrials.jpg


That's pretty flat! Any more and the price escalates rapidly :roll:

Hitch:
The present design has the hitch made from four elementary parts with some extra pieces; below is an analogy of one side. First, there is a design constraint with the rear axle on the right side where the derailleur is located; chiefly the location of the hanger restricts freedom of movement. Therefore a study was made to consider moving the trailer mounting point farther back behind the axle.

  • Custom Rear Axle: 12mm through the Hope Pro II MtB hub, transitions to 10mm flats through the frame, but is extra-long to accommodate the adapter described below. In this manner the axle is self-locking in relation to the frame for when I secure the axle nuts.
  • Axle Adapter : Moves the pivot connection behind the rear axle so the hitch assembly has better freedom of movement. The adapter will mate to the rear axle and use a shoulder screw as a pivot pin for the bracket.
  • Bracket: I’m still sorting this out; might make it from plate, might be a weldment. Plate is simpler, weldment lighter and stronger. The bracket mates to the adapter pin by way of a bronze bushing, and secured with washer and nut. That’s one half of the mounting problem done; bike to hitch. Now we resolve the hitch to trailer-bike connection.
  • Fork Clamp (2X/side): Basic C-Clamp designed to fit a 38mm steel tube and affix it to the other end of the bracket. The tube emulates the upper fork and is mated to the crown & steerer which follows using typical hardware.
  • The Frame protectors will go on the 38mm steel tubes.
  • A custom mounting is likely required to affix the steering dampener/stabilizer between the bike frame and the 38mm steel tube. We only need one, and I’ll put it on the right side.

That was as of last night. This morning I had an epiphany :idea: on how to simplify the design yet again, so it’s back to the drawing board. Actually I really enjoy engineering studies because ultimately the rewards are in the pocket :wink:

With crayons, KF
 
Frame Correction Part Duex:
Ack! The last couple of days have been fraught with naught! The seller of the 26” Neon Wing Trials was slow to get back and relate that the Disc option is no more; he's out and not getting anymore. Unfortunately there are few worldwide suppliers of this – apparently rare configuration – that sourcing a replacement was next to impossible :cry:

On top of that I have learned that BECAUSE, NEON, and BORN are all of the same manufacture, or at least in league with each other to covet/control the market (they share the exact same cookie-cutter website layout). With my options quickly running out, my choice was to forgo the Disc option altogether, perhaps entertaining the “Brake Therapy Disc Brake Conversion Kit”, or to move away from Trails Stock frames to hybrid 24” frames with Disc. Ultimately that’s what I did, reverting back to the Because Simple Trials White frame as previously suggested. With no domestic supplier, I went to http://www.TartyBikes.com and paid $442 after shipping and insurance.

bt_conversion343x343.jpg


Brake Therapy Disc Brake Conversion Kit: These run about $136. There was no guarantee it would fit the frame, rotor, brake, & hub, therefore I elected not to entertain the risk.


Because-Simple-24-3frames.jpg


24" Because Simple Trials: I snagged the white frame from TartyBikes in the UK.

Custom Widget:
The Revision-D passed muster with my machinist and he has provided a favorable quote this AM; we are proceeding forward with a prototype and I hope to have it in hand for testing shortly. The widget will allow me to mount a Campagnolo 53T triple chainring & matching derailleur onto my DH MtB frame.

Campy&PhilWood.jpg


The parts necessary for the potentially-fastest pedal ebike: 53T Chainring & custom Phil Wood BB 8)

Hitch:
Now that I know how the frame will be I can finally sort out the hitch details and get that off to the machinist as well.

Honorable mentions:
People running these sites were helpful in educating me on what I needed to know about the trials frames.


Moving forward, one day at a time, KF
 
Status

A great week for parts.

The 24" Because Simple Trials that was ordered on Tuesday arrived at 10:30AM on the nose Thursday from the U.K.; evidently TartyBikes shipped it to me expedited ~ no complaints, just big wide smiles! Inside the box was a nice large black T-Shirt from TartyBikes and a lower chain stay protector; very nice schwag! The frame is in great condition, feather-light, and built strong. My only concern are the drop-outs which look a bit thin on material. From the specs, my CAD drawing required very little modification after having the frame in hand. Overall, it is a very impressive bit of construction and I am quite pleased. :D

Steering Dampener: Arrived in good shape & reviewed.

90 Degree Valve Step Extension: Basic yet essential convenience for my ebike; reviewed.

Headset: Decided on only the best and ordered the Cane Creek 110 in Black from eBay for $91.49 total with shipping.

Charger Upgrade: I need an upgrade to keep pace with the time it will take to charge the large pack. The later postings on the How-To: Meanwell 63-84V CV/CC Charger thread discuss my findings, though suppose it couldn’t hurt to announce here that the unit selected and ordered is the HRP-600-24 and -48, one each to create a 63V 600W charging array. Cost was about $360; should arrive around Tuesday-Wednesday. $pendy, yesssss ~ I know. But then it is a crucial piece of equipment just as important as the trailer frame, and we can’t afford failure. The new assembly is roughly twice as powerful with less volume for the same weight. :)

Hubs: E-BikeKit says the front hubs arrived yesterday and mine will ship out Monday. These are the 9C 2806 Disc models, Front & Rear. My present FH is not disc; rim brakes are so noisy and I look forward to this upgrade. The new tire will be the 26”x2.5” Maxxis Hookworm. The rear tire will use the Kris Holm 24” MtB rim mated to a 24”x2.5” Maxxis Hookworm. I was sold on this rim after watching the guy perform some incredible feats!

[youtube]1uPznTbus3g[/youtube]

That’s all I knows from this front. More to come.
Dutifully, KF
 
Status
It’s been a week since my last post; here is what has changed.


  • Headset: Delivery delayed till Monday. I kinda need that to finalize my design this weekend; bummer.
  • Charger Upgrade: Done! Review: Meanwell HRP-600 Series & How-To: Meanwell 63-84V CV/CC Charger. This is a hug win as this upgrade literally cuts my charging cycle in half. I’m still not out the door though: There’s a tiny detail with cutoff that needs to be addressed to prevent overcharging. :roll:
  • Hubs: In transit and expected on Tuesday.
  • Custom Widget: Received from Machinist on Wednesday; looks sharp and hope to have it mounted this weekend.
  • Throttle: Replaced failed throttle with a similar HE throttle for now. I may or not upgrade to the Magura; depends on how the Lyen Controllers adapt when the time comes.

Custom Hitch:
I went round and round on this knowing that the machinist is the most expensive route and trying to create thrifty alternatives. Yet each time I have been frustrated by the lack of- or difficulty in finding appropriately compatible hardware.

I used BeamBoy extensively although I do not trust it to report cantilever solutions correctly, being off by a factor of 10. I probably went through five complete iterations before coming back full-circle to one that just makes the most sense. Sorting out my questions, I waited a day before fetching the parts and try to get my answers direct from the machinist in one fell swoop. And I am glad I did because his welder-partner was conveniently there as well.

Turns out that um… Fate has a hand on this tiller:
My machinist built an electric-powered Chevy Luv running off 12Vx10 car batteries two years ago, and he drives this to work. It only has a 20 mile range, but this truck is absolutely clean! I’ll try to get some pics next time I’m in. The welder-associate works across the street and fabricates racing frames for motorcycles for himself and others. They’re pretty excited about my ebike and I have to think that this is a match made in heaven!

Therefore I am redesigning the hitch to be a CrMo tubular weldment assembly for simplicity, fatigue-resistance, and strength. This whole assembly will include the new axle, bracket, faux fork tubes, and fork clamps. :wink:

What’s next
  • Torque Arms: Two sets; front and rear. In conceptual stage.
  • Battery Bag mounting brackets: tbd
  • Battery bags
  • Cargo bags
  • Additional batteries
  • Faring
  • Handlebar reorganization
  • And lots of little details.

Five weeks to go.
Methodically, KF
 
Was this the bike attachment you were thinking of

CIMG1192-300x224.jpg

from

http://troyrank.com/category/bikes/

here is a way to attach a complete kids bike, though it is not what you are looking for.

followme.jpg

http://clevercycles.com/products/accessories/child-seats/followme-tandem-coupling/
 
hekdude said:
Was this the bike attachment you were thinking of

<snip>
here is a way to attach a complete kids bike, though it is not what you are looking for.

followme.jpg

http://clevercycles.com/products/accessories/child-seats/followme-tandem-coupling/
The design will be similar to that except that I am using a DH fork crown with the forks removed, and replaced with a “faux fork” short tube that is long enough to engage the crown & steerer. The side brackets will mount to that. By removing the forks (or rather shortening the length) the bike frame rotates forward – creating a near horizontal platform for loading up batteries and cargo. Maybe I need to post a 3D model… wait, lemme get to that shortly for a picture is worth a thousand words :wink:

~KF
 
Status
I was distracted by work this past week and ended up commuting to Seattle and back several times – a 45 mile loop. Nice to know my present setup can do it at nearly WOT through hilly urban terrain: 15S6P @ 27.5 W/mi; batts never dropped below 54V. New charger restored the pack in less than 2 hours.

What’s changed
  • Headset & Hub Motors from E-Bikekit: UPS driver had his knickers stitched up past his ears and refused to leave my packages – two separate deliveries – with the designated terrestrial representative. Why do some Earthlings lack the capacity to follow simple instruction? Round and round we went with the driver leaving more sticky notes – and Customer Service that wasn’t. After close to a week delay – and on the second attempt to the Distribution Center I was able to fetch my packages. One appeared damaged…

    I dread biting the hand that feeds me but my hope is that a picture is worth a thousand words; this is not the way to ship product:

    9CHubsCrappyPackaging.jpg


    Regardless, I will actively use alternate shipping if given the choice henceforth.
  • Rear Hub: This is off to REI for mating with the Kris Holm 24” MtB rim & 24”x2.5” Maxxis Hookworm. I suspect this will take two weeks because the spokes are custom-order and my wheel-builder guy only works one day a week.
  • Front Hub: I have one mounted ready to go now except it doesn’t sport the disc brake covers. What to do. I could save some dough and just swap the cores. The center ring is not painted so it might look a bit peculiar. Regardless I hope to get that sorted shortly. The front brake will need to be replaced (parts already on hand) as will the Torque Arm arrangement which brings up a good point...

Custom Parts
Knowing that machining can be expensive I have gone round and round on the designs attempting to keep things simple; match materials with stock product dimensions to maximize utility and economy. Before I can mount the front hub I need the torque arms and that is a two-week lead. Designs have to go out tomorrow. There’s a lot to do, however the layouts are completed.

I am now focused on the trailer battery box. The design initially began with each side holding 24 batteries, though now I think it should be 30. The calculus:
  • Last summer on my last day with 15S12P I went 173 miles, climbing nearly 8000 feet and dropping 13000 – and averaging about 26.5W/mi overall which included a lot of pedaling. This year my most arduous day will be about 240 miles with matching ascent/descent of 12000 feet, hence the doubling of the batteries. That’s
  • 36 * 2 = 72. There are 18 batteries (15S6P) mounted now in the forward triangle. 72 – 18 = 54. Split that between left and right bags 54 / 2 = 27. This is rather an uneven number:
  • Stacking can be done by 2 or 3 deep. The study below shows the difference in width; 2 deep makes good sense being more streamlined. 27 / 2 = 13.5; not a convenient number, however 30 / 2 = 15, and 15 can be achieved by stacking 5 x 3. A box containing 30 LiPo bricks (Zippy FlightMax 5S1P 5000mAh 15/2C) measures roughly 17x9x4.5 and needs to withstand a static load of 38 pounds.

    SimpleTrailer0.png


    The red dashed line in the top view indicates the relative width using the pedals. My preference is to remain slim and slippery :)

    As such, mounting this box and its’ construction has my undivided attention. I looked at several off-the-shelf solutions but the weight was in excess of 5 pounds; I think I can do better with a simple framework and bag. Anyway – that plan is developing.
For the most part things are progressing well enough. I am concerned about my time now. The batteries will have to be ordered this week. It doesn’t leave me much room for road testing.

EDIT: Batteries ordered on this day. 36 + 5 replacements. This will be enough for road testing. I can always get more if field testing suggests the need. Amazing that the HK-USA shipping price was so low; < $25. I can't imagine USPS trying to deliver 52 lbs of batteries! :lol: I wonder if HK-USA does will call?

Four weeks to go.
Antsy, KF
 
Status
Things are picking up steam. I can’t believe it’s Thursday already and I’m still drawing; I’ve been heads-down drawing up my parts and going through permutations trying to figure out the best use of off-the-shelf stock sizes.

  • Front Hub – Sent this off to REI today to swap out the Rim-Brake hub for the Disc-Brake hub. The wheel is a 26” Mavic EX729 Disc rim with a Maxxis Hookworm. I hope to get that back on Saturday and finally swap out my front wheel, converting to disc brake at the same time. Required task.
  • Rear Hub – dropped this off a couple of days ago at REI. Kris Holm 24” MtB rim & 24”x2.5” Maxxis Hookworm. My wheel builder works again on Saturday; once he gives me the spokes lengths I’ll order them up from WheelBuilder.com. All my custom wheels use this spoke. The lead time could be up to 10 days before I get is back.
  • 24" Because Simple Trials frame at REI to be mated with the Cane Creek 110 Headset and Marzocchi Double-Crown-Steerer. Dropped this off today as well.
  • Batteries arrived yesterday in one 53 lb box. I haven’t inspected them yet but will do shortly.
  • Battery Box – I am evaluating a pair of Parallel Rib Cases from Melmat for use as a rugged battery enclosure. It is very difficult to source an enclosure of the proper size. These cases are wide and long enough but are a 3” taller than what I need. Regardless I am planning the deck of the trailer-bike to accommodate the batteries with or without the case.
  • Braking – I have looked at how to accomplish mechanical braking on the trailer and there are two paths:
    • Mechanical/Wire breaking will not be possible or practical. Neither is electric braking, as in electrical-actuated servo-braking. However there is a possibility of hydraulic braking. The risk here is that it would me scrapping the existing system which could be another $1000 when all said and done.
    • The other choice is to do nothing; to rely on trailer ebraking and the two existing mechanical brakes + ebrake on the ebike. My thinking is this will be enough. The trailer will only weigh about 100 lbs, and with four forms of braking my hope is that it’ll be covered well enough.
  • Brooks Saddle – After the initial lube-down the B17 Narrow Imperial was attached last week. I should probably do a review. Already the comfort level has bumped a notch or two towards complete bliss; I found myself daydreaming on the ride into work – the whole 23 miles. It rained on the way home; I let the saddle dry out and then slathered a second layer of their special rub onto it. My gawd! The next time I was out the saddle began to loosen up even more. My bum never had it so good. Clearly this will continue to break in more as time marches forward. I purchased a rain cover for protection.
  • Going to California 2011 thread started. Lots of great interest!
What’s left:
  • Need to finished detailing my parts and get them off to the machinist. Tomorrow tomorrow!!
  • Make fenders
  • Swap in new controllers
  • Rework handlebar controls and signal lighting
  • Replace mirrors
  • Create additional cargo bags for soft items.
  • Faring

Nap time, KF :wink:
 
Brief Status

Seems like I’ve been real busy. Fact is I’ve been heads-down scribblin’ away on my custom part drawings in an effort to appease my machinist. Neat guy, full of good advice on how to K.I.S.S. However - I hate to take up too much of his bandwidth although it’s definitely a learning experience that I enjoy. :)

  • Front Hub: Got this back from REI on Saturday. The only thing that prevents mounting is the new Torque Arm, and that is off to the Machinist; next week at the soonest.

    9C2806FH&Hookworm.jpg

  • Rear Hub: The spokes from WheelBuilder just arrived by FedEx. My wheel guy will sort this out next week when he returns from holiday.

    Spokes24inchHub.jpg

  • 24” Simple Trials Frame: The Cane Creek 110 Headset was installed last Saturday. Picked up a spare stem missing a few parts for cheap. I’ll use this to mount the steering dampener instead of having a custom fork clamp manufactured.

    trailer-headset-assy0.jpg

  • Braking: I think I said that I am forgoing brakes on the trailer, and instead using the eBrake.
  • HE Cable Replacement: I ordered up a set of USB Micro-B Extension cords to replace the HE cable connectors at the hub. The Micro-B connectors are small enough to fit through the M14x10 slotted torque Arm and M14 nut. The idea popped into my head during the design of the trailer torque arm when I figured out how to simplify the design by removing the clamping slot. The key feature allows for complete removal of mounting hardware for tire swapping; something I hope not to endure on the upcoming road trip – though must provision for the worst. The cables were delivered today by USPS.

    USB-Micro-B-Extension-TorqueArm.jpg


    The image shows the larger Female connector fitting tightly through the Torque Arm, and the smaller Male connector easily passing through the M14 nut: Perfect! :D
  • Balance Cables: Ordered a slew of JST-XHx6 parallel harnesses for the entire battery pack. This will greatly aid in keeping the cells in balance; a poor-man’s Balancer. This should be received any day now.

Custom Parts:
  • Hitch Assembly design is on Rev-B. The big change was to eliminate welding, thus shortening the lead time. I used BeamBoy extensively to calculate the loads and shapes; not exactly accurate – though good enough for ballpark engineering. This is off to the machinist.
  • Torque Arm assembly is on Rev-C; mainly converting to stock sizes and optional materials, and also sitting in the machinists’ ToDo bin.
  • Battery Box & Rack: In the queue. Lots of options, but faster if I can mod something off the shelf. The soft-bag version I fear may not provide enough support for a heavy load, therefore I am looking at marine-grade Baltic Birch Plywood or possibly Aluminum sheet. The Parallel Rib Case that I was considering is actually too large. So that’s where I am at; hopefully I’ll have this part concluded by Monday morning.

What’s Left:
It’s the same list as before except we’ve made progress on the above items, and there’s a short list of additional machining. Three weeks to go. I am hoping all parts are in within the next 10 days so I have time for field trials and mods.

Hungry, KF
 
Battery Box & Rack: In the queue. Lots of options, but faster if I can mod something off the shelf. The soft-bag version I fear may not provide enough support for a heavy load, therefore I am looking at marine-grade Baltic Birch Plywood or possibly Aluminum sheet. The Parallel Rib Case that I was considering is actually too large.

I think you said the ones you were looking at were about 3" too tall but unless there's a clearance issue, go with those. If nothing else you can fill them the rest of the way w/ clothes and snacks.
 
REdiculous said:
Battery Box & Rack: In the queue. Lots of options, but faster if I can mod something off the shelf. The soft-bag version I fear may not provide enough support for a heavy load, therefore I am looking at marine-grade Baltic Birch Plywood or possibly Aluminum sheet. The Parallel Rib Case that I was considering is actually too large.

I think you said the ones you were looking at were about 3" too tall but unless there's a clearance issue, go with those. If nothing else you can fill them the rest of the way w/ clothes and snacks.
The Parallel Rib boxes are still on backorder; I've cancelled it after sourcing this: 17-3/4" x 12-3/4" x 5-3/4" Aluminum Case.

image_365.jpg


There's a Harbor Freight in Bellevue; 15 minutes away by ebike :wink: right next to the Harley-Davidson dealership :twisted:

The only thing missing from this equation is the dragon tattoo :lol:

Seriously though, the width and height concern me. At present the battery pack on each side will be 3w x 5h x 2d; capacity for 30 bricks although I am only using 27. This means that the box inside dimensions could be as small as 4.5x10x17; can't seem to source anything close. It's been a bugger. Sheetmetal guys have a long lead time :cry: I might have been better off making my own box from plywood. :roll:

Regardless, I'm going to check out the toolbox before ditching outsourcing.

Best, KF
 
Crap. The Harbor Freight tool box was a bust. :( It is fine for light-duty consumer-oriented projects, however my needs would likely beat the hell out of it within 100 miles. :|

That said, they did have a small red-painted metal toolbox and that got me to thinking “outside the box!” Ha :eek: Sears is two blocks away, so I perused their tool center. Man, has that place changed from the glory days of my youth, but I digress… Didn’t find exactly a match, but definitely some food for thought. :idea:

Raced back home, broke open my layout and reworked the battery array to this: 1x4x7 = 28 (and we actually only need 27), results into 15.5w x 7.5h x 6d.

trailer-batt-layout-4x7.png


Sears did have one metal portable toolbox with similar dimensions: 16w x 7.5h x 7d. The Magenta box of that size is drawn around the batteries.

00959214000-1


It is a little bit wide, however the stack of batteries is lower and shorter, pushing the CG closer to the CL of the axle and frame; it will still be more than 50% above the axle – and we want that for proper trailing and balance. However there’s an issue with being too wide; the risk is that I am less than an inch narrower than the handlebars: My trailer would become a wide-glide fat fanny. :cry: :| :) :lol:

Ahh, but the hunt is on again; we mustn’t give up the ship! :wink:
Arrrg, KF
 
Craftsman 16'' Metal Hand Box

I went back to Sears today with my other battery pack that normally carries 12 to 14 bricks; in the past I’ve strapped this on for extending the range out to 100 miles at a modest clip. I took the Metal Hand Box and opened it up for inspection. The good news is that the tool tray is engineered to lay on top of the opened rim instead of resting on an intermediate bracket; I was a bit concerned because this might prove difficult to remove or modify – although my fears were gratefully unfounded. :)

The bottom corners of the box are not entirely closed (pin-hole sized); for the money why argue. The fact is I was going to put drain holes into the box to allow for moisture to escape. The sides appear to be flash-welded, soldered, or braised on; the black paint hides the technique, and yet it is very sturdy – even the hinge is well-mounted. The lid latch is matching in quality; though it is very budget-oriented the construction is a step above Harbor Freight et al.

Batteries were gently fitted into the Metal Hand Box. My layout drawing in the previous post is conservative; I was able easily fit a row 7 wide and a column 4 tall without issue. And there was room enough for a row of 8 wide with careful spooning; it’s a snug fit though not a bad one and quite possibly how I’ll end up packing them in. Plenty of room for cables above or to one side. The only caveat is attempting a stack of 4 x 8; the top row will peak at the rim about midway and there isn’t room for 8 across. Ultimately though I am pretty happy with the enclosure. :D

You can find this on the web cheaper than at the store; I elected to purchase mine direct from Sears online for $24.99 each (whereas the local store listed for $28.99) and saved an additional $5 off the total cost, however there was another reason and that is I am on my bike and there would not have been room for both boxes. The shipping will put it here in a week or so for < $10. Even then I still came out ahead. Total with tax for two was less than $60. There are also clones out there although they do not have the distinctive front panel where the Craftsman sticker is placed; these run about $3 less than Sears. Personally I’d rather have the warrantee.

Battery Platform
Early this morning I had an inkling that the Metal Hand Box would work out and began finalizing my layout to accommodate. The platform holding the Box will be constructed of two aluminum angle rails and probably ¼ inch (5-6mm) marine-grade plywood. I ran across these two sites and learned quite a bit.

Before today I had been looking for Baltic (Russian) or Finnish Birch as being the strongest, although the Okoume variety is rated quite high as well. To be honest I was sidelined for about an hour gazing over the Chesapeake Light Craft product catalog; other than biking I really dig sailing and I think it would be neat to build kayak (with a sail) and tow it behind my ebike to the lake. OK, I’d probably have to put an electric motor on it for when I want to troll for my dinner… :roll: :lol:

Back to work, KF
 
Screw the boat, Kingfish. That construction, especially the sew up type looks dynomite for a Velo! I also got lost in the catalogue too!
otherDoc
 
Thanks otherDoc :)

Perhaps it’s best if I update the layout of the present model:

From left to right, top to bottom, we are presented with three views, named Rear (technical Rear-Right Section), Right Profile view with bike facing forward to the right, and Top view looking down below it. For the layperson, between these three views I can generate any dimension required to make parts.

simpleTrailer1.png


Described:
  • The Simple Because frame is red and easily identified in the Right Profile view. It is tied to the rear axle of my ebike by way or the purple hitch through the steering crown; the Simple frame is rotated CW so that the vertical axis of the hitch is about 5-7 degrees forward. For comparison, most bike frames have their forks tilted 17-21 degrees backward. If the angle is too shallow instability occurs, and if it is too large the turning radius becomes unmanageable. Some tilt is required for the trailer to self-correct, otherwise it will wander when contributing to the forward thrust. I have rotated the frame as far forward as I dare; the bottom bracket matches the ground clearance of the BOB Ibex trailer which is represented by the horizontal magenta line.
  • The Rear view illustrates both the width of the BOB Ibex and the relative angle of clearance should the trailer lean over at 45 degrees. The illustration is fudged however because the Simple Because trailer tire is 24”, whereas the BOB is 16” in diameter - bringing the axle 4" lower, so the reality is that my trailer design actually has nearly twice the angular clearance – which is great should I ever take a corner so hard! :twisted:
  • The other red lines in the same view are the axle, and the lower clearance of the pedals represented as a dashed line. This is carried over in the top view as well. The goal of the layout was to remain inside the pedal width, but we can’t find a box off the shelf that is both cost-effective, rugged, and matching the requirements. With the top view, there are 3 dashed cyan lines: One is the center-line, and the other two designate the width of the handlebars. As you can see the trailer barely fits within this limit; not optimum, but good enough. I will need to be very careful in traffic if I need to squeeze by on the right.
  • The Battery boxes (yellow with green bricks inside) will be supported primarily by a tubular strut passing directly through the bottom bracket, with the other end affixed at the rear axle. I shall lay down two aluminum L-brackets (also called “angle iron”) parallel to the frame on each side, and topped with ¼” thk marine plywood. Upon this the metal box shall be mounted and strapped down. There is room for additional decking fore and aft, and I plan to use that space for light cargo or tools.
  • The faring will pretty much be a combination of stich and cloth, and HDPE. The main aspects are to reduce the wind resistance, and I plan on having a smooth surface beneath, as well as having tapered sides as partly indicated.
  • The ebike is displayed showing the Ortleib saddlebag, fender and crank clearances. The trailer is designed to pivot 30 degrees up or down relative to the ebike frame, and as previously discussed take a corner at 45 degrees, although not with either pedal down. Lastly the trailer is designed to be slightly top-heavy in partial matching to the Center-of-Gravity (CG) of the forward frame.
I have but a handful of parts left to design.
Two weeks to go: Will I make it? :shock:

Wagering, KF
 
Status

I have been really busy sorting out the details and ordering stuff. I guy can never have too much stuff, and well… I am full of stuff! At least – people have told me that I am full of stuff, so there it is. 8)

This week’s stuff is as follows:
  • Rear Hub: Kris Holm 24” MtB rim & 24”x2.5” & Maxxis Hookworm: Spokes were dropped off at REI and my wheel builder should have this completed on Saturday.
  • Speedict: In the queue, soon to be here. I have a special announcement with Speedict, however I shall save that for the Going to California: 2011 Thread, to be posted later this eve.
  • Battery Medic: Bought a unit recently and it is in the pipe 5x5. Related thread: A Question of Balance
  • Marine Plywood: Ordered up 4mm 2x4 Okoume A/B BS1088 from Boulter; in the queue.
  • Custom Parts: All design drawings are now at the Machinist. I am going through and creating layout plans as we speak on how to optimize the placement within the stock material, and setting up direct purchase from McMaster-Carr. The layouts will allow for better packing and less material costs, and – the Machinist will cut me some slack on the price if I do some of his planning & labor. It’s a lot of work; there’s about 60 hours of machining to do, and the race is on: Steel is being cut as of this evening. The custom parts are in four lots:
    • Custom Widget – Allows for mounting of the Campy 53-39-30 Triple; this work has been completed.
    • Front Torque Arm assembly – Parts are being cut as we speak. This will allow for the mounting of the 9C 2806 Disc hub with the Mavic rim and Maxxis Hookworm; in progress.
    • Trailer Hitch – Custom connection between the Felt Compulsion and the Simple Because frames.
    • Trailer Platform & Rear Torque Arm – An integrated assembly that supports about 100 pounds of batteries & dry goods.

It’s lot’s of stuff, with more stuff coming in.
Makin’ room for more stuff, KF :)
 
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