The F3: "N minus one"

[MattyCiii]

Quick updates:
1) Carbon fiber parts to cover belt drive arrive Monday. Too bad I leave Sunday for 2 week work trip.
2) Speaking of the work trip. I'm taking the laptop, work clothes and some off-hour clothes in some small bags, strapped to the folding bike. Bike and I board Amtrak in Providence RI, get off 500 miles later. Then ride 40 miles to my hotel. I'm charging up the helmet cam as I type this to get some nice back-road ride footage.
3) To make room for all this baggage, I had to remove my LiPo from the trunk bag and (for a very short time) duct tape it to the frame. I'm torn whether or not this will lead to more - or less, calls to the "See something, say something" hotline than the previous arrangement.
4) Using nurserts, a 3/8" drill bit, hammer and wrenches, I'm upgrading the drive mount from hose clamps to some real durable hardware. Hope to finish before I leave. Damn I wish I brought my camera. Pics of the finished product will follow I promise.
5) Back to duct tape. I used a piece of cardboard and some "Duck Tape" that is surprisingly well color matched to my bike's paint job to cover the running gear (FW, motor, most of the left side drive chain). Mostly for stealth, not sure if it's making things better or worse, but I've been thinking maybe I should just grab a bigass Romney sticker and put it on there, make people think "It's a mount point for a political ad" vice "There's something behind that duct tape that'll blow my mind."
6) Using a Recumpese built Magura throttle-servo tester-BEC for now till I get the CAv3 set up right (I was doing it wrong). Great system, well modulated. Maybe I'll sticky-tape my 4s modules to the top of the frame tomorrow and go 10s2p. Woot!
7) This shit's a lot of work, but a lot of fun

 

[MattyCiii]

I decided to take a bit of a risk, and use the MENSTRUAL Cycle as my primary means of transport during a work trip. This is good for the taxpayers, because it's military temporary duty and if not for the bike I'd have had to rent a car.

I hopped Amtrak in Providence RI with the folding bike and just what it would carry. Working in uniform is great, as long as you have a coin op laundry nearby you can go indefinitely on 2 changes of clothes & plenty of underwear. Amtrak took me as far as Fredericksburg VA, then I rode to Colonial Beach VA (about 35 miles away, by the route I took). I'm working at a Navy facility in Dahlgren VA, but the hotel there is booked till Thursday and there's no barracks, so I'm commuting 13 miles each way each day.

This is the inaugural deployment of this bike - been using the bike a long while but the electric assist is new. Yesterday morning's commute was 13 miles in 35 minutes, or an average of 22MPH. That's funny considering at 6s, the bike's top speed is 20 MPH. I accept the difference since I can do 20MPH uphill, but downhill I'm definitely going faster than 20. There's a hill right at the end of the ride so long and steep I swear I'd exceed 40mph if I didn't tap the brakes a bit on the way down (the bike's geometry and construction are not capable of >40, scares me to death).

It's supposed to hit 100 deg F today with high humidity. I really appreciate the "uphill breeze" option available through the turn of the wrist.
More on this trip later...

 

[fractal]

great story Matt! Carrying your own means of transportation in your «pocket» is a good way to travel!

 

[MattyCiii]

great story Matt! Carrying your own means of transportation in your «pocket» is a good way to travel!

The folding bike has been great. I've taken it from Providence to Worcester to meet friends (by bus), Worcester to Boston (in trunk of car), then home to Providence by train. That's a big 180 mile triangle, never had to drive a mile but always had wheels. Another trip, Providence to NYC by train, 3 days work & fun in three of the boroughs, then out to Long Island on commuter train to visit family, then to to Orient point/ferry to CT, then train home. Never stuck in traffic, not for even a minute.

Adding power assist to the bike will double its utility. I can still carry it up 2 flights of stairs, bike, electrics, batteries and what little cargo I can pack. I can fold it just about as small as if it had no e-assist. But 20MPH uphill, and "gliding" to cool off/dry the sweat before arriving at my destination... PRICELESS!

 

[crossbreak]

I can fold it just about as small as if it had no e-assist. But 20MPH uphill, and "gliding" to cool off/dry the sweat before arriving at my destination... PRICELESS!

My bike is not foldable, but here in Germany almost any train has got a bicycle cabin. But the bike weights about 20kg (original it was about 12kg, so 8kg were added by motor, gear-hub, stronger fork etc.) so it's not always fun to carry it up stairs at stations if I also carry a heavy backback. The idea about mounting a hub motor as middrive to a folding bike that I posted earlier in this thread was abandoned because of the weight penalty. I will sell the motor and go for an RC-Motor solution like you did. I will also stick back to derailleur cause I noticed that 30 percent of the additional weight is cause by the gear-hub. I use an SRAM I-Motion-9, which btw lasts the additional load quite well. The thing I don't like with RC-drive is noise. My tongxin middrive bike is almost silent, the loudest thing is the clicking of the gearhub. So I'll try to get the RC drive as silent as possible. Are you still running only 6s lipo on your ASTRO Motor? That would be a way I would go too, keeping speed low will make it less noisy. It would be nice if you could measure how load the bike is for comparison. Sadly my bike does not make enaugh sound for an accurate measurement, my cheap multimeter says it has about 74dB at 1m distance from the crank (which is too much sound pressure, IMO it is less noisy). I'll try to measure again with a more accurate tool.

thanks for your inspiration. I hope you can finalize your project soon. I'm waiting keen for pics of the belt cover etc

 

[MattyCiii]

Thanks for your continued interest in my little project, Crossbreak and everyone else!

My bike is not foldable, but here in Germany almost any train has got a bicycle cabin.

That's awesome. Here, folding bikes are a concession between the motorist masses who might happen to take a commuter train/bus, and the bicycling lobby, who can at times be loud and obnoxious enough to get small compromises.
That said, I love the utility of the folding bike, it fits in the back seat or boot of nearly any car.

...it's not always fun to carry it up stairs at stations if I also carry a heavy backback.

I'm 44 years old and in average shape. Most train stations have an elevator - an extremely slow elevator - or an escalator. I'll take the escalator as my primary option, then if that's not an option it's a toss up between the fast/difficult climb, or the slow elevator. Here in the USA, the elevator is usually full of fat people with no outwardly visible disability apart from fatness. People who could benefit from 2 flights of stairs. There are lots of 'em. So the elevator usually has a queue. While I carry my bike up the stairs I think my bike is lighter than the fat they carry, and as hard as it is it affirms my desire to stay in good shape.

I will sell the motor and go for an RC-Motor solution like you did. I will also stick back to derailleur cause I noticed that 30 percent of the additional weight is cause by the gear-hub.

I really like being able to pedal, which at my age means I like having gears to pedal through. I prefer the NuVinci, but a derailleur is lighter and more efficient, and serves the same purpose. The Recunpense RC drive is great... With 6s2p, reduction and motor on the bike that's like maybe 5kg total. Can't beat it.

The thing I don't like with RC-drive is noise. My tongxin middrive bike is almost silent, the loudest thing is the clicking of the gearhub. So I'll try to get the RC drive as silent as possible.

I complained somewhere - here or another thread - that my drive was noisy. And it was. But it's quieter now, and I would not want it much quieter. It's quieter because I have the chain-line perfected now, I have a 16t Vs. 13t drive FW (BIG difference!), I have some shielding over the drive FW and chain, and it's "broken in". Oh and I have the belt drive tension lower, it was too tight originally.
I would not want it quieter because presently I can hear the drive over ambient noise. I love how I can - using e-drive on the left side and pedal drive on the right - combine power to get more workout, more speed, more stealth, whatever, all based on pedal cadence, current speed and pedal cadence. If my drive was much quieter, I'd probably over throttle and shock the system coming up to speed too fast, or not get power when I want it coming up to speed too slow. That belt "grind" noise is currently just right.

Are you still running only 6s lipo on your ASTRO Motor?

I've been jumping between 6s and 8s. My commute has the most hostile drivers at the end of the morning ride... so I rigged for 6s for the first 10 miles, then stopped and rewired for 8s. I hit a bump soon after, it twisted my wrist and I wheelied a bit! (had to change pants when I got to work). This bike is outright dangerous at much above 8s. I think I'll rig it for 9s, and depend on training myself, and using CAv3 throttle ramping, to tame that beast. The motor and controller will take 12s, but I fear that 10s and above is just too much for this wheel base.

I'll definitely post pix of the CF belt drive enclosure as I can. It'll be a slow process, I have a lot of parts to print on the Makerbot!

 

[MattyCiii]

Some pix from this trip:

Route 218 is really nice, has good tree canopy shade, but like all roads around here, has like 3" of pavement to the right go the white line.

Here's the route I travelled on my arrival day. Got off the train then went 36 miles on two battery sets: 6s2p then 8s1p. Pedaled the whole way, had battery assist when I needed it, but I drained both packs.

I like this pic a lot:

 

[crossbreak]

Here in the USA, the elevator is usually full of fat people with no outwardly visible disability apart from fatness. People who could benefit from 2 flights of stairs. There are lots of 'em. So the elevator usually has a queue.

The elevators are meant for people with luggage or handicap. I guess these people who carry around to much weight have both. That's symptomatic for our societies.

Your trip looks nice. I hope streets will get more than 3 inch sidewalks in the future, around my town there are multiple building sites for them, caused by the increased bicycle traffic and crashes.

With 6s2p, reduction and motor on the bike that's like maybe 5kg total. Can't beat it.

I guess so, too. The problem with most derailleur drives that use sprockets with less than 14 teeth is, they don't last the stress of an e-drive. To get the right cadence with 14T on the rear shaft I would have to mount a 60T chainring in the front which is just not possible. A Schlumpf drive or a speed-up-jackshaft would solve this, but that penalties weight again. :?

Your thoughts about noise encourage me best wishes and EV-Grin. I had to cancel my weekend trip yesterday because the final drive chain was sucked in between the chainrings and got stuck, I don't have a redundant drive so I had to walk home

 

[MattyCiii]

Here in the USA, the elevator is usually full of fat people with no outwardly visible disability apart from fatness. People who could benefit from 2 flights of stairs. There are lots of 'em. So the elevator usually has a queue.

The elevators are meant for people with luggage or handicap. I guess these people who carry around to much weight have both. That's symptomatic for our societies.

My friend's wife as a cardiac doctor, and a tell-it-like-it-is person (She's a Canadian import; we used to grow this type oaf person here domestically). A fair number of her patients will ask for a handicap placard. For those that are fit but fat she looks 'em straight in the eyes and says "No, in fact you need to park as far away from the store as possible from now on". Love it!

With 6s2p, reduction and motor on the bike that's like maybe 5kg total. Can't beat it.

I guess so, too. The problem with most derailleur drives that use sprockets with less than 14 teeth is, they don't last the stress of an e-drive. To get the right cadence with 14T on the rear shaft I would have to mount a 60T chainring in the front which is just not possible. A Schlumpf drive or a speed-up-jackshaft would solve this, but that penalties weight again. :?

Well of course with the e-drive, weight means very little except when it comes to lifting the bike. These past 10 days I've had plenty of that. The first two hotels gave me second floor rooms, no elevator.

I've found that the ATS Speed Drive works great on this bike. That, plus the NuVinci N360 (which I am a big fan of). The ATS in 1:1, I can pedal the bike no matter how heavy I load it up the steepest hills I've encountered (at very slow speeds). This is with a 20t cog and a 43t chainring. With the e-assist, I just pop the ATS into 1:1.6 overdrive and I can pedal along anywhere from low to high throttle. It's a great combination.

 

[crossbreak]

"No, in fact you need to park as far away from the store as possible from now on"

Thats exactly the opposite what these people wanna hear. It's all the same. Our EU-Politicians still say, that our economy has to grow to get rid of our debt. But there has hardly been any growth in the past 20 years (if one calculates right, including income and inflation), no matter how hard they tried (in terms of even more debt).
But that's just not what people wanna hear. It's like with cardiac doctors, the "patient" just changes his doc if he/she doesn't tell what he should to get even more fat. what ever...

So you can use 360%*1,6=576% gear spread, plays in the league of a Rohloff Hub, also the price, but a Rohloff is lighter (ok, I always have sth. to argue about). Both is too expensive for my needs. There are well organized lock picking gangs out there. Theft is a great issue here.

My 9-Speed gear hub has 340% but I only use the gears 3 to 9, so only 255% but I don't pedal up the steep hills without e-support. I can go 45km/h or 28mph at 90-crank-rpm, so I do not go slower than 17km/h the steepest hill i go up. that's possible with only 500Watts, because I run the motor power through the gear hub an get 2.55 times the torque at a steep hill, so my motor feels like a 1275Watt motor.

The more power the e-support has, the less spread I need. A simple and cheap 7-speed 14T-34Tsprocket cassette would almost serve my needs (34/14=2,42). It should if I use a 1000Watt motor in my next bike. What is your opinion? Would it be ok for you to swap the ATS drive for a single large chainring, or would it fail at a steep hill?

 

[MattyCiii]

What is your opinion? Would it be ok for you to swap the ATS drive for a single large chainring, or would it fail at a steep hill?

Are you still looking at a folding bike? If so I'd go with the ATS Speed Drive. Otherwise, a single large chainring, or a double chainring with a front derailleur, is a better choice.

There's no question in my mind whether the ATS can handle the torque load of pedaling up a steep hill in low gear.

ATS drive on a folding bike: pro's and con's
+ Simpler chain line than a front derailleur
+ Smaller diameter of front chainring - especially important considering the 20" wheels.
+ One less cable to run pas the center hinge and handlebar hinge to the hand grips. Those cables are a pain.
- Cost (~$300)
- Installation

To me, those advantages are well suited for a folding bike installation. That was a decision maker for me.

Note that I used to run a 60t front chainring on a folding bike similar to the one pictured here (It was a Dahon - no suspension, 20" wheels). My fixit riding friend called it the Pie Plate...

 

[crossbreak]

Thanks for your statement. If I calculate right, I need a ratio of 4.2:1 te get a cadence of 90rpm at 45km/h ord 29mph. That's what scares me. If I run power through the transmission I can't go down further on the rear sprocket than 13T, so I would need a 55T chainring even on a 26 inch bike :? I'd really like a folding bike, but the difficulties fall with wheel diameter. A 26" folding bike would be nice, but I can't find a nice frame that's affordable. I think I will first try to develop my electric drive, then search for a new frame. ATM I sadly don't have time for both

 

[MattyCiii]

My trip was an unqualified success!
As I write this I'm on the Amtrak back to Providence after 2 weeks working in Dahlgren VA. I put about 225 miles on the bike during the last 2 weeks, including about 24 miles this morning. I'll be another 6 miles to home once I arrive in Providence, but I can do that with or without e-assist. It's great knowing I can get away with going on an extended trip with nothing but what I can carry on the bike.

I'm glad to be heading home - and not just because I have a pile of new parts waiting for me!

 

[MattyCiii]

Carbon fiber pr0n!

I can see myself reflected in its finish. Niiiiiice!
This is the outer piece people will see when they look at the bike.

This is an inner piece, people won't see much of it - but it's about being thin, strong and rigid. Pretty is just the bonus.

Frankly it will take a while to get this all mounted. I have to design and print all the side pieces on the MakerBot, and that will take quite a while.

 

[MattyCiii]

OK, hopefully by next weekend I'll have my drive mounts upgraded.

Remember this?

That's right, I'm just one broken hose clamp away from getting the chain sucked into my rear wheel at speed, ruining my whole day and likely my pretty face too. I'll be upgrading my drive mount with real steel nuts and bolts.

Lookie here:

and...

The button head socket caps bolts are fixed into nutserts. Those rod-ends are 1/4" x 20, and will have nice lock nuts on the far end. I found some steel drawer slide hardware laying around with a very nice "C" channel shape, they will be nice and flat against the square aluminum but with those flanges will be very strong against bending. I'll take and post pictures of the install, but again that'll wait till next weekend, I have too much going on to start this job today.

Oh and of course my safety supervisor, sleeping on the job as usual...

 

[MattyCiii]

OK, the MENSTRUAL cycle is - temporarily - going e-power free
I went to install the new motor mounts today and realized my rod-end bolts are about 10mm short. I thought about putting the system back together with the hose clamps, but that's just flirting with disaster. No, time to get this thing done up right.

While the drive is off, I'll be:
1) Ordering/waiting for/installing the new rod ends,
2) Building a decent battery bag. Up till now I've simply had my LiPo duct taped to the bike's down tube, and we all know that's not a long term solution
3) Building and installing my belt drive enclosure.
4) Test-fitting the V4 drive on my other build


So while I'm sad to have removed the e-drive, this is for the best. If I didn't, the above safety related improvements - 1 through 3 above - might be put off longer leading to mishap.

 

[MattyCiii]

Progress on the belt drive enclosure. In fact, it's ready to mount back on the bike.

First, I designed a "side wall" to print on the MakerBot and hold the carbon fiber covers in place

I had to slice the part up so it was small enough to build...

Here you see a spacer in the center with an earlier version of the side wall

Lots of tedious printing later... a complete enclosure!

ABS plastic comes in many colors, I should have gone and printed this in black. But it takes color well from magic marker pen, so I'll go with that (see I have started to color it already on the small radius).

 

[Alan B]

Very nice. I have one of those printers on my list. I heard they have one that will print houses.

 

[crossbreak]

Nice work! Thx for posting! Which software do you use?

I have one of those printers on my list. I heard they have one that will print houses.

You can also order printed 3D parts online, for example here: http://www.fabberhouse.de/

 

[MattyCiii]

A quick update:
Life has been very busy lately!
I've shelved the belt drive enclosure for a while, my final product was too tall and would not fit! I won't try to fix it (specifically, I won't print new side wall parts) until I get a new supply of ABS plastic - this time I've ordered black.

The drive is back on the bike. I'm building up a battery box that straps on with velcro and detaches easily. It has a tough yet thin plastic box with a dense 1/4" foam inside layer, to prevent punctures. As I find time, I'll be sewing up a corder/nylon outer fabric layer, to make the bike look "less electric" or at least "less like a bomb".

 

[MattyCiii]

Update:
1) Received black ABS plastic for the MakerBot, so I can print new belt drive enclosure sides.
2) I finally got rid of the hose clamps and installed real steel bolts. When fixed firmly in place this drive is nice and reliable.
3) I have a pretty good system for holding batteries. Two LiPo bricks fit one in front of the other slung under the front half of the top tube. I tried doing this with two pairs side -by-side but it was too wide. I might try two pairs, one over the other, but for now I'm only using 2 bricks (10s1p).
4) I've done some tweaking... used a hack saw to cut the motor shaft shorter. Concurrently, installed a 5" drive shaft between the large belt pulley and the freewheel. I was at the extreme far end of what one can get out of a 4" shaft. This gives me a bit of play for belt and chain alignment.

 

[stoney]

I am enjoying this build

 

[The fingers]

Related to my Torquey AMped Pedal Or Not.

 

[MattyCiii]

Related to my Torquey AMped Pedal Or Not.

Hahahaaa! I laughed out loud at that.

Thanks for the continued looks, I need to get my camera out and post some detailed updates, soon. But of course, as the bike fun & reliability factor goes up, the rate and quality of thread updates drops!

 

[MattyCiii]

Update:

UPGRADE #1:
Spent some time yesterday on the rear brake. It's a Magura HS-33 hydraulic rim brake, I bought as a means of (1) learning about hydro brakes, and (2) because I thought a hydraulic e-brake cutoff switch would be more durable/reliable than an external, home-built hall effect or micro mechanical switch solution (shaky assumption to be sure).

For months I've had a hydro cutoff installed, but never working well. Attempt #1 brought me a switch that was too twitchy. It would activate from time to time with my hand nowhere near the brake lever. So, I'd lose power at speed... Needless to say that meant leaving the cutoff switch unplugged (deactivated). See thread: http://endless-sphere.com/forums/viewtopic.php?f=2&t=42390

Yesterday I got that fixed. I had a second pressure switch and decided to replace the original. This meant getting replacement brake hose, since my first install left too-short of a hose between brake lever and switch. Installing a new 5" section of hose on the brake handle was difficult. My LBS wouldn't touch the work. So I had to upgrade my tools and skills to get that section of hose replaced (hint: soften the tube by heating it. I tossed it into a pan of boiling water for a few minutes). Then I had to bleed the system twice to get it right and I nearly ran out of new fluid. But now it works like a champ - good, solid brake feel, and the e-brake cutoff works perfectly. I don't know if the first switch is defective, or if I just installed it poorly.

UPGRADE #2:
My drive chain line has been marginally acceptable for some time. The 16t freewheel driver to 53t drive sprocket left like 1mm of clearance on the top and bottom stays of the rear triangle. This meant I got chain slap on bumps, and the chain had started to wear away some of the aluminum tubing. Not good. For this upgrade, I replaced the 16t driver with a 13t freewheel, and the sprocket went from 53t to 52. This was almost exactly one full chin link shorter than the previous - and left me with the drive freewheel centered/ positioned better for both top and bottom clearance (i.e., the smaller diameter freewheel alone improved chain line, but moreover having the drive FW more centered improved chain line by creating more distance to the bottom chain stay).

As an extra side benefit, the drive reduction goes from 3.3:1 to 4:1. I haven't run numbers through a simulator or anything like that, but I sense that increasing reduction will reduce stress on critical parts of the drive, notably the motor, controller, and primary belt drive.

The bench test was a resounding success - I'll be doing a road test later today.

Wish me luck!