Critique this performance velomobile idea

General Discussion about electric bicycles.
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Chalo   100 GW

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Re: Critique this performance velomobile idea

Post by Chalo » Sep 03 2016 6:38pm

That looks like a pretty typical failure at a combined stress riser/heat affected zone. Changes in stiffness and cross-section should be gradual so that they don't focus the stress right at the point of transition.
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The Toecutter   1 kW

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Re: Critique this performance velomobile idea

Post by The Toecutter » Sep 03 2016 7:35pm

I'm glad I didn't get pulled underneath it. The end of one of my crank arms is chewed up from scraping the gravel at speed. It was fun while it lasted, and has made me a bit stronger.

Accelerating in this heavy, lossy thing is not easy. I would let random strangers ride it, and most of them struggled to get it above a 6-8 mph, roughly jogging pace. The healthier ones could do 15-16, but even then it was a struggle. It wasn't rolling right, ever, although some times were a lot better than others. I used to have a favorite 400-foot stretch of 9-10% grade uphill on Winnebego St that I'd stop at the base of then sprint up, sometimes reaching 9-10 mph at the crest(maybe had a good tailwind), but even 7-8 mph at the crest of the hill still nearly wears me out, and 3-4 mph would be a comfortable cruising speed if this hill were to go on for miles. That level of exertion probably did my frame no favors, nor did those 25+ mph sprints on the flat.

I'm tempted to try to top the Raleigh out again to see how much stronger using this Thunderbolt as my daily rider has made me over the last few months, but I have a lot of reasons not to do that. The Raleigh has seen more than its fair share of use and everything on it thanks to me, and is thoroughly worn out. At one point early this year, I was looking for a cheap used bike to replace it with, since it then made funny noises of multiple kinds at about 28 mph and over even after repeatedly adjusting everything, and with the causes originating from multiple sources all requiring replacement, some of which could cause a life-threatening failure at an inopportune moment. Derailleurs, bearings, shift levers, brake levers, cables, freewheels, sprocket sets, chain, are all worn out. Even the freewheel pawls sometimes like to lock up and make the bike pedal itself. The bike has more than 5 years of almost-daily use and somewhere over 20,000 miles on it. I bought the bike as a classic, already 22 years old, as a replacement for a twice stolen once recovered Taiwan-made steel Schwinn Traveller I had(It has a story too...). The Raleigh was owned by some dude's wife who had purchased it new in 1989 and had ridden it only twice. The seller wanted $75, but had no change and I only had $20-bills, so I paid $80, I loaded it into the trunk of my 300 SDL and was now biking again for my main source of transportation. Everything looked shiny and new when I bought it. About $50 for a new seat and some brake pads to get it riding, and $250 worth of cables, pads, rims, spokes, chains, tubes, slime, and tires along the way for those 5 years, I more than got my money's worth. That's less than $0.02/mile, not counting accidents(Accidents can quickly make costs exceed that of using a car on a per mile basis). Over the duration of my usage, the bike had seen its share of bumps and potholes and going unintentionally airborne at 20+ mph. It's been through a lot. I've broken chains from pedaling it too forcefully, and more than once have almost fallen sideways by accident putting in too much force. It was well-maintained. Today, the frame, being composed of two dissimilar bonded metals, could fail at any time while in use, especially when a road imperfection is hit at speed. It's not worth fixing up to a usable restored condition, but I suppose I cold turn it into a custom “fixie” that is marginally safe to operate at under 15 mph and sell it for a small profit. It's otherwise doomed to collect dust and grime, and it seeing use again may be the one ride that something critical fails. It could become worth a small fortune as the decades roll on, so I'd like to keep it relatively unmolested though should I keep it, as it was a great design on part of its producers as far as bicycles of that era went.

That KMX I'm going to order will become my main transportation source, so I will have to build on it in a way that minimizes downtime.

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Chalo   100 GW

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Re: Critique this performance velomobile idea

Post by Chalo » Sep 03 2016 8:27pm

The Toecutter wrote:That KMX I'm going to order will become my main transportation source, so I will have to build on it in a way that minimizes downtime.
That criterion sure suggests "normal bike" rather than "recumbent trike". Don't let me talk you out of something important to you, but availability is likely to be much higher with a bike that uses proven, interchangeable commodity parts rather than proprietary stuff that's being developed and vetted by you and other end users.
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Re: Critique this performance velomobile idea

Post by The Toecutter » Sep 03 2016 9:43pm

Chalo wrote:That criterion sure suggests "normal bike" rather than "recumbent trike". Don't let me talk you out of something important to you, but availability is likely to be much higher with a bike that uses proven, interchangeable commodity parts rather than proprietary stuff that's being developed and vetted by you and other end users.
All true.

I've spoken with various builders of KMX frame kit trikes. Their reliability seems better than any bicycle I've ridden.

One of them has placed thousands of miles on theirs, typically moving around 25-30 mph on electric assist for miles at a time, but has seen 60 mph. He's using bicycle parts with a middrive. He also has a front suspension kit, which probably helps greatly to this end. Before installing the front suspension, he broke steering knuckles from hitting debris and potholes at 30 mph, and has had thousands of problem-free miles since installing it, still having hit debris and potholes unintentionally. His build didn't work well for mixing the human and electric power, but it moves well under either alone, and thus his chain lasts for thousands of miles in a powerful, high-revving 6kW mid-drive, and it spins the front cog well faster than any reasonable rider cadence.

My chain is due for another cleaning/lubing and shows little evidence of wear. I'm hoping it can stand up to 1.5 kW of motor plus me pedaling hard anywhere from 60-140 rpm when I put it in a KMX. I do not know how much torque the chain and components can withstand. I will probably need a thicker chain than 3/32" for this, but we'll see how durable this KMC "Gold" really is.

Availability of exotic parts to me only matter insofar as to whether the parts are "bulletproof" for my application or not. I need to find a system that isn't going to fail, and/or carry spare parts of critical systems to the vehicle's continued operation that could fail. I can only carry a limited number of parts, so the largest/heaviest components need to be the strongest, and the smaller, weaker parts need to be minimized. The Rohloff may be very specialized, and if it fails, I need to have standard components to replace it with(thus the tools to re-build the rear wheel). I will be carrying spare chains, tires, and tubes for sure, unless I go with those specialized solar car tires from Schwalbe(1 spare should suffice).

I do intend to travel long distances, after all. I might also be living out of it for a period. I had a lot of fun with my previous trike and it was comfortable enough to sleep in. If I had such a vehicle with a body shell on it that can also store tools/camping gear/clothes/food/water, I could do a lot with it.

I also don't want it to leave me stranded. Whether the parts were proprietary or not at that point may not be relevant if something critical fails ten miles out of Toadsuck, TX. I need something that is strong enough not to fail for my application.

A KMX frame is very solid. I could see myself purchasing an internal-geared Rohloff hub sometime next year or whenever the current 7spd pieces currently on the Thunderbolt break while used on the KMX, but in the meantime, I'm just going to use what I have. I'd like to add a motor/body sooner rather than later, as I figure I've waited long enough. The Thunderbolt just wasn't going to work. I really like the Cyclone mid-drives from what I've read so far.

The components that mount the wheels/brake calipers, otoh, are proprietary and not as strong as I would like. The front suspension kit with an added gas shock should dramatically reduce wear and tear on them, and so far it seems to be a very reliable system according to those who have installed it. I have yet to hear of any negatives other than cost(and you won't find anything as good for under $4k anyway), so if anyone knows of any, please share!
Last edited by The Toecutter on Sep 04 2016 2:56pm, edited 1 time in total.

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Re: Critique this performance velomobile idea

Post by docnjoj » Sep 04 2016 10:33am

Used to be you could get a Steintrike Full Suspension frame for about 2800 USD. It had shocks, springs etc. You just needed to add wheels, gears etc to make it run. Wildfire HPV or Velo Verde are suppliers and there may be more.
Steel frame.
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E-bike stable at our house

Steintrike Mad Max full suspension trike rear Cute 100H going on: Whoops, Cute wheel broke but I fixed it.
Sun USX delta trike EbikeKit small geared front wheel sort of front suspension for wife

Agniusm/A123 AMP 20 36 volts on the Steini has been taken off.
2x16000 Multisport from HK now gone as they died after 2 years
New Luna 10S bottle battery 13.6AH now on mine
Relatively New 10S4Px2 for wife's bike giving 20ah @ 40 volts home made Panasonic from Tumich. BMS's rule.

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Re: Critique this performance velomobile idea

Post by The Toecutter » Sep 04 2016 2:53pm

docnjoj wrote:Used to be you could get a Steintrike Full Suspension frame for about 2800 USD. It had shocks, springs etc. You just needed to add wheels, gears etc to make it run. Wildfire HPV or Velo Verde are suppliers and there may be more.
Steel frame.
otherDoc
I checked them out. They are fairly light. The cost seems excessive when I can get a KMX framekit for $900 plus adam333's front suspension kit for another $800. For $2800, I think I'd be making a go at a fully custom built from exotic materials.

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Re: Critique this performance velomobile idea

Post by The Toecutter » Sep 05 2016 6:36pm

During a search, I came across a velomobile kit for the KMX called El Loco:

http://www.velomobiles.de/html/el_loco.html

At only 7 kg, it is very light. It's body style is not exactly what I'm looking to do though, as I want to be able to keep myself out of the elements, and I will need storage space. I became interested in it because it has now proven to me that even with the KMX direct steering, it is possible to seal the rider from anything the wheels/tires might throw up from the pavement, without posing a clearance issue with the steering.

Since I don't have a KMX in my possession to take measurements on, doing mockups and getting to the task of drawing up a compatible floorpan and shell are not yet possible.

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Re: Critique this performance velomobile idea

Post by The Toecutter » Sep 07 2016 9:22pm

The KMX frame kit is ordered. I will probably order a front suspension kit in a month or two, but I look forward to setting this up and riding on 3 wheels again. I expect this will be much faster than my old Thunderbolt, probably similar to the Cattrike I tested a few months ago.

I may swap out the front tires from the Maxxis Hookworms to the Schwalbe Tryker at a later date. On my Hookworms, the criss-crossed fine diagonal pattern has worn off of the middle of the tread where the contact patch with the road is established, but the pattern is fully in-tact on the sides, and the larger round grooves in the tire are still well-established and are nowhere near worn, if at all. This is with more than 700 miles of use. My rear tire shows no signs of wear yet.

I look forward to building something for this platform(especially a body). Maybe it will be worthy of replicating and selling.

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Re: Critique this performance velomobile idea

Post by The Toecutter » Sep 14 2016 8:31pm

I contacted utahtrikes about the status of my order being that it hasn't arrived yet. It is scheduled to arrive on Friday. Should it arrive Friday, I am intent on putting it together Saturday.

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Re: Critique this performance velomobile idea

Post by The Toecutter » Sep 16 2016 10:46pm

The frame kit has arrived. Hopefully, I can put it together tomorrow. I expect it to be an 8-10 hour job. We'll see. A friend helped me get my Thunderbolt over to the designated work space so that I can strip it for parts to use on my KMX.

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Re: Critique this performance velomobile idea

Post by The Toecutter » Sep 19 2016 11:08pm

I got it about halfway put together over the weekend, over a total of about 7 hours, a good 3 hours or so of that spent trying to pry the tires and tubes off the old wheels, and another 2 disassembling the Thunderbolt. I'll keep at it after work, and may have it put together before this weekend.

The quality of the components that the kit came with is excellent. As long as I don't break any of the components beforehand, the addition of a front suspension should practically make this thing "bulletproof".

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Re: Critique this performance velomobile idea

Post by The Toecutter » Oct 22 2016 10:24pm

I've been riding it around a bit. I would have responded sooner, but I have moved and temporarily had no internet access for roughly 3 weeks.

Anyhow, in comparison to the Thunderbolt:

1) The KMX is much easier to pedal. It rolls without anything rubbing, its parasitic losses minimized. With 30+ lbs of weight reduction over the Thunderbolt, I can spin the rear tire in the 32T granny gear just using my legs(It helps that the rear tire doesn't have much in the way of traction). I am much faster on it than the Thunderbolt, but I have not yet done a top speed run. I think 30+ mph is very doable right now with it(although will require a high cadence, see the below paragraph).

2) After cleaning my previous chain with alcohol, it ended up rusting to a state of uselessness. I used the 1-spd chain that came with my frame kit. It will work with my rear derailleur/cogset, but not my front ones. I'm using the middle 38T front cog and due to a clearance issue with one of the rear frame bolts going to one of the seat mount posts, I have locked out the 7th gear on the rear cog(It now functions as a 32T-16T 6 spd). It still is easier to pedal up steep hills than the Thunderbolt was, and cruising all day long at a steady 15 mph at 82 cadence is no problem. That being said, my gearing will limit me to 25 mph or so top end at 135 cadence. Next year sometime, I may be getting a Rohloff hub, if I choose a middrive.

3) The KMX frame has a 5.5” ground clearance at its lowest point and the chain's lowermost point is just in front of the rear derailleur at 5” above the ground. While riding the Thunderbolt, I feared any speedbumps or road imperfections scraping the bottom of the trike with its frame's 2.25” ground clearance and with the chain almost touching the ground at any given time. The rear suspension in the Thunderbolt kept me comfortable even over potholes, but the KMX has a wonderful seat mesh that absorbs vibrations well, even better than the seat I built out of vinyl webbing for the Thunderbolt. The KMX feels unsafe over potholes compared to the Thunderbolt, as if I am going to fall off. In the Thunderbolt, I could recline back and the top of my head would be 31” from the ground. With the KMX, I adjusted my seat as low as possible without the rear mudgaurd rubbing the rear tire while adjusting my boom for optimal pedal stroke length, and the top of my head is 39” from the ground. I am going to need to be careful in my placement of EV components to get the center of gravity right.

4) I need to order and install a front suspension kit. This thing has a noticeably higher center of gravity than my Thunderbolt, mainly due to the elevated ground clearance and rider position. The elevated ground clearance of the KMX was much needed for safely traveling at speed, but its cornering is unsafe compared to the Thunderbolt, and the small KMX seat makes me feel like I'm going to fall off in a sharp turn, whereas the oversized seat on the Thunderbolt held me in very well. I don't think anything over about 0.4-0.5G lateral acceleration is a good idea in the KMX until I get a front suspension. The Thunderbolt was a lot more stable in the corners.

5) I hate the direct steering with a passion. I will need some kind of damper. The steering feels very unsafe over 20 mph, and the slightest twitch will send me into another lane. Hard pedal strokes induce an unavoidable steering change. The front suspension might help correct these issues to an extent, but I still think some sort of damper will be necessary for my application, especially if I will be cruising at 30 mph in traffic over crappy roads or accelerating hard at a stop light. The Thunderbolt felt plenty stable at 25 mph even over bumpy roads, by comparison.

6) The Thunderbolt looked a lot better, aesthetically. This won't matter once a body is on it, but I do appreciate the KMX for its functionality.

7) The KMX frame is much sturdier than the Thunderbolt and I highly doubt this frame will ever fail.

8) The Thunderbolt was much more fun to ride while intoxicated. It felt stable and solid. The KMX feels twitchy and dangerous, and will be kept to sober riding only until its issues are resolved.

Overall, I am satisfied with my purchase of the KMX and this build will continue as parts are ordered and arrive.

ABS plastic sheeting is on the way. I won't bother doing much with it until the front suspension is installed though.

The ordering of the Rohloff 500/14 Speedhub can wait, as it will be almost useless until I have a body on it anyhow, and I don't think it will work if I decide to use a hubmotor, and I'm going to want a front cogset with a 150mm crank to go with it all to make my pedal strokes more efficient. If I go with a single-speed in the front for reliability, I would want to gear the Rohloff hub's teeth and/or front cog to allow ~4 mph at 60 cadence up a steep hill in the lowest gear, and at the highest gear roughly 30 mph at 90 cadence cruising on the flat with a top end of about 45 mph approaching 140 cadence. I think this would be a good, balanced approach with the intent of making this build a practical form of transportation, with a bit of ass-hauling capability on the side. The less failure points, the better, and not needing a front cogset and front derailleur would be nice.

That being said, I'm still considering a variety of different drive configurations.

-A Monster Clyclone XL would be delicious overkill, and I think it offers a 44T ring when engaged, and both a 44T and 32T one when not. Getting this to work with a Rolhoff 500/13 could give me a range of 3 mph at 60 cadence up to 50 mph at 140 cadence. It would be able to go up the steepest inclines, whether the battery has charge or not, thanks to the gearing range available for pedal-only input. I do not think there exists a bicycle chain that could handle both my torque plus the power/torque coming from the internal gearing of the Monster Clyclone motor if I try to get as much out of the motor as possible, so I might have to restrict the motor after the power/torque is transformed by the gearing to producing maybe 100 lb-ft up to 140 cadence, which yields about 2 kW mechanical power from the motor, plus my pedal input. I'd be heavily under-using this motor and I would like to think it would provide tens of thousands of miles like this. I think I would be hard-pressed to get any bicycle chain to last that long.

-A smaller 3000W Cyclone would be more appropriate for a middrive that doesn't kill my chain over and over again. I'm still not sure if the most durable KMC ebike-specific chains could handle this, but if they can, this amount of power would be a good compromise.

-Going to the opposite extreme, figuring out how to fit a Lynch/Agni/Etek motor to work in this as a pedalec would be a very interesting, and ballzy, exercise/ It's not only a highly efficient motor, but it would provide a dangerous amount of ass-hauling capability, and set up as a hubmotor, bypasses the chain issue. I would be forced to use front/rear cogsets/derailleurs to get the gearing range I need though. It is very heavy too, and it would be nice if lighter versions of this motor were available, say, in the region of 7-10 lbs. I tried 4 lbs of ballast on the Thunderbolt's rear wheel as an experiment, and rotational inertia heavily penalizes acceleration/uphills when operating the vehicle on pedal-only, so a heavy lynch motor would make that quite a problem during circumstances where the vehicle has to be operated with no assist. If I set it up as a middrive, I would probably need a separate chain and sprocket that isolates the pedal crank output from the motor output, and adds them together with a sort of clutch or split-broach spine.

I still haven't decided on a motor/controller/battery just yet as this new build is radically different from my old Thunderbolt. Its low weight/high strength opens up a lot more design possibilities than the Thunderbolt had. A bottom bracket torque sensor will be needed, and those aren't cheap.

I want to build up some moped rims and get a set of Schwalbe energizer DOT-rated 60 mph capable tires on them. The idea of never having a rim fail when hitting a pothole or debris at speed plus almost never any tire failures, while maintaining the requisite low-rolling-resistance to function well as a bicycle when the motor is unable to be used, all appeals to me.

Pictures of my KMX are below.
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KMX 1.JPG
KMX 1.JPG (52.85 KiB) Viewed 1903 times
KMX 2.JPG
KMX 2.JPG (52.77 KiB) Viewed 1903 times
KMX 3.JPG
KMX 3.JPG (60.67 KiB) Viewed 1903 times

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The Toecutter   1 kW

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Re: Critique this performance velomobile idea

Post by The Toecutter » Oct 24 2016 10:10pm

I went airborne from a pothole while cornering at 22 mph today. I once again got lucky since there wasn't a vehicle or obstacle occupying the space I veered into, and I regained control.

I imagine that the suspension will do wonders for its stability, because I wouldn't trust mine over 20 mph on even the smoothest roads unsuspended... One little bump could become a medical emergency.

I don't know how xenodius managed to handle his non-suspended KMX at 60+ mph, but I have immense respect for that feat now that I know the character of this trike.

So much damned fun though. I've put 34 miles on it in the last 48 hours. No body. No motor. Maintaining 15 mph on the flat is no problem. I really wonder what it will feel like to ride at 45 mph with a suspension, body and drive system installed and the center of gravity optimized by component placement. I've never ridden an electric velomobile before, so unless I get a chance to try one out sometime before this one is ready for testing, my own build will be my first time riding one.

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Re: Critique this performance velomobile idea

Post by Triketech » Oct 26 2016 11:46am

You may want to look this over:
Power Assist Made Easy

Granted the wide selection of components is anything but easy.

The only way any constabularies in Texas are going to challenge your power level is if you call attention to yourself by presenting an obvious danger. They have more real crimes to deal with and the complexity of enforcing e-bike codes is probably the lowest priority of all.

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Re: Critique this performance velomobile idea

Post by The Toecutter » Nov 05 2016 6:09pm

Triketech wrote:You may want to look this over:
Power Assist Made Easy

Granted the wide selection of components is anything but easy.

The only way any constabularies in Texas are going to challenge your power level is if you call attention to yourself by presenting an obvious danger. They have more real crimes to deal with and the complexity of enforcing e-bike codes is probably the lowest priority of all.
Thanks for the link. I wish they would have discussed other mid drive options than the BBS02.

I need a middrive that can put out at least 750W, can accept input from a torque-sensing bottom bracket, functions with a Cycle Analyst, and weighs under 15 lbs. Preference will be given towards a middrive whose motor can be mounted under the seat and for higher levels of power.

I will also need a chain strong enough to reliably and regularly handle all of the motor+rider torque generated. I am still considering the purchase of a Rohloff 500/14 Speedhub.

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Re: Critique this performance velomobile idea

Post by dozentrio » Nov 07 2016 10:47pm

The guy who runs this channel
http://www.youtube.com/user/ChrisyLuxembourg
aka LOWRACER

built a DIY carbon fully faired forced-air cooled hub motor trike. With suspension? I can't remember. But he took down the videos of it. Very sad. I suspect the legality of it was in question. Anyway, maybe you can contact him for some info. If he responds, let me know because I want his construction video on that! Someday, it's my dream to do a cross-country trip in something like what you're working on.

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Re: Critique this performance velomobile idea

Post by The Toecutter » Nov 22 2016 8:51pm

I've put 186 miles on my KMX within the last month. It's much more reliable than the Thunderbolt. Nothing has needed adjustment until today. I'm about to replace the brake pads and set the calipers back up again, because the pads are worn out from the abuse placed on them by my previous Thunderbolt trike.
dozentrio wrote:The guy who runs this channel
http://www.youtube.com/user/ChrisyLuxembourg
aka LOWRACER

built a DIY carbon fully faired forced-air cooled hub motor trike. With suspension? I can't remember. But he took down the videos of it. Very sad. I suspect the legality of it was in question. Anyway, maybe you can contact him for some info. If he responds, let me know because I want his construction video on that! Someday, it's my dream to do a cross-country trip in something like what you're working on.
Was this it?

http://tiltingvehicles.blogspot.com/200 ... racer.html

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Re: Critique this performance velomobile idea

Post by The Toecutter » Nov 30 2016 11:32pm

I look forward to installing and testing the front suspension kit once it arrives. I'm considering painting the exposed portions of those screws to ward off any corrosion of them due to exposure to salt(being that I live near the coast and salt/moisture is in the air here). I'd like them to last at least as long as my KMX frame.

The first real test will be going over Staples St at 25 mph with all of the construction and deep potholes that such a street entails. Right now, I wouldn't try it at anything over 20 mph, lest I break the steering knuckles or damage the handlebars or their mounting, or hurt myself.

Of course, I'm sure it would be able to comfortably cruise at much higher speeds on that road if I had enough power or aerodynamic efficiency to reach it.

Being that mine is non-motorized as of yet, and given that I have a limited gear range(had to lock out my 7th speed 13T cog due to a clearance issue between the chain, the 13T cog, and a seat-stay mounting bolt, and am stuck with a 6th gear of 16T), 26 mph is about as much as I can reach thus far at 140 cadence, but it is below my natural top speed if I had taller gearing. I haven't done a proper top speed run, because I need taller gearing to reach it. I keep it in the 38T front ring due to no front derailleur, and the slightest bump knocks the chain from the 48T front ring to the 38T one.

I've still not decided on a motor, but a few more items have caught my interest.

-LightningRods Utah trike middrive kit: I am assuming(but not sure) that this is based on the 2.8 kW big block kit. With a 48T single-speed cog up front, Rohloff 500/14 speedhub with a stock 16T rear cog, I could go 3.8 mph up steep hills at 60 cadence, comfortably cruise on the flat at 30 mph at 89 cadence, and reach 47 mph at 140 cadence going all-out. The chain would be the weakest link in the system. I would preferably want a chain that could repeatedly and reliably handle me pedaling with all my strength PLUS using all 2.8kW of the motor in a possibly jerky PAS setup, but I do not know of any bicycle chain that can fit with bicycle sprockets that can handle this. My acceleration would be very car-like under full throttle from pedaling at max power.

-MAC8T internal-geared hubmotor: I've read up on these a bit and the more I read, the more I like. They are small enough to be hidden in the center of the rear wheel by a disc brake and can be completely decoupled with a polymer clutch that lasts 1000s of miles and is about $60 to replace. They can fit up to a 9-speed freewheel, and I would need one with a wide range. Does anyone know if they could fit a 9-speed cassette instead? I would love a 42-11T setup in the rear with a 44T front in conjunction with this. This would allow me to go up hills at 4.8 mph at 60 cadence in the 42T rear ring, cruise at 30 mph on the flat in the 11T rear ring at 98 cadence, and going all out reach 42.9 mph at 140 cadence on the flat in the 11T ring. Easy to set up with a PAS and Cycle Analyst. Since the chain is only stressed by the rider alone, I don't need to worry about its durability nearly as much. Further, if the chain breaks, I could use a throttle switch and have the motor/controller set up to reach 20 mph top end and still get me to a safe work space to repair it. If the clutch on the motor breaks, I can still pedal it as a bike, with no motor cogging. When everything is working, it would certainly provide enough power in its rpm range to add meaningful assistance at any speed from 0 to 40 mph. The downsides are the peak power isn't all that great, 1200W at 48V/25A which would yield mediocre acceleration(very usable in traffic, but still boring). The efficiency kind of sucks, about 75% for cruising at 15-30 mph. It would also have a poor hill climbing capability that would necessitate frequent stops to avoid overheating in mountainous regions. I would also have 8 lbs of dead rotating weight, increasing inertia losses. Overall, this would be a very effective, reliable, versatile, and inexpensive option, not requiring an expensive internal gear hub or a potentially unobtanium chain to work for my specific application. But it all hinges on having a gear range that may not be compatible with this motor. I need to be able to go up steep hills on a dead battery, as well as cruise at 30 mph on the flat with a reasonable cadence. There is also the unsolved issue with regard to the chain clearance in the rear.

Thoughts?

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The Toecutter   1 kW

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Re: Critique this performance velomobile idea

Post by The Toecutter » Dec 08 2016 7:38pm

The front suspension kit has arrived from adam333. I might get it installed this weekend.

I'm wondering how a MAC6T geared hub motor would do at 60V/35A in terms of reliability? It would certainly give me a level of acceleration performance that I would be pleased with, but I don't want to be having to rebuild the motor or replace the clutch every few hundred miles. If I could get it to last at least 5,000 miles before major replacement of parts, that would be acceptable. I intend to be a bit conservative on any controller ramp function so as not to destroy things.

Here's a video of a MAC10T with a 9speed freewheel:

https://www.youtube.com/watch?v=Bmp_sIC1c9U

A Sunrace 11-40T 9sp freewheel is cheap and could work with the 6T as well. Once I get a body set up on the trike, it will be time to order a motor, and I may end up ultimately going with the MAC6T. The 9sp freewheel will also necessitate new shifters, cable, chain, derailleur, rear wheel, along with a THUN torque-sensing bottom bracket, cycle analyst, batteries, and charger. It's looking to be a $4,000 project when all is and and done(more if you count the previous Thunderbolt trike), but if I went the middrive route, it could go over $5k.

Piece by piece it's coming together.

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Re: Critique this performance velomobile idea

Post by The Toecutter » Feb 11 2017 12:03am

I installed the front suspension almost 2 months ago, but have not ridden it until tonight. The trike sat unused because I didn't have the necessary pump to fill my gas shocks. A friend of mine ordered one for his business and planned to let me use it, which would spare me the expense of purchasing it. This was in December. It never arrived, he got his money refunded, and had to order it from a different supplier.

Today, it finally arrived.

I carried the trike 1 mile over to his shop and got the shocks aired up to 90 psi.

I rode a total of 3.31 miles after doing so. It feels like a floating couch at 20 mph. Tomorrow, I'm going to test some cardboard mockups of body pieces and see if they have proper clearance with the components on the trike.

Attached are pictures from 2 months ago when I installed the suspension.

I'm very interested in the Leafmotor as of late. I think that with a 72V/150A Sabvoton would work well... I'd limit it to around 4 kW peak, get 0-30 mph in under 6 seconds like that... It's advantages over a MAC for my application are in all categories except for weight. I'm tempted to order these components soon, but my research is far from complete. There's so many component choices it's ridiculous, and none of the motors I've found are 100% ideal for my application, even if some of them have come very close.
Attachments
KMX Suspension 1.jpg
KMX Suspension 1.jpg (46.47 KiB) Viewed 1586 times
KMX Suspension 2.jpg
KMX Suspension 2.jpg (48.61 KiB) Viewed 1586 times
KMX Suspension 3.jpg
KMX Suspension 3.jpg (43.83 KiB) Viewed 1586 times

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Re: Critique this performance velomobile idea

Post by The Toecutter » May 23 2017 7:10pm

Here's some pics I got of off my old burner phone some time back. I didn't get more recent pics of the support pieces, the top, or the roll bar, but it is now close to completion.These pics were taken at about 1/3 of the way complete. I plan to share more when I replace my computer. This first body shell is open-wheeled, inspired by the Lakester salt flats racers of the 40s and 50s, the Rumpler Tropfenwagen, and the LeMans velomobile. I decided to go for as little drag as possible retaining the open wheeled layout(the wheels are going to account for the majority of the air drag), given that I need to be able to fit it in and out of my doorway so that it doesn't get stolen or vandalized. I'm hoping for a CdA of under 0.15 m^2 and I think it is doable if I get the drag coefficient to 0.28 or less. I won't know what it is until I can mount the body and do some coast down testing.

I have some drawings I still need to post also, but in due time.
Attachments
Body 6.jpg
Body 6.jpg (22.73 KiB) Viewed 1392 times
Body 7.jpg
Body 7.jpg (45.71 KiB) Viewed 1392 times
Body 8.jpg
Body 8.jpg (48.7 KiB) Viewed 1392 times

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Re: Critique this performance velomobile idea

Post by The Toecutter » Jul 12 2017 9:57pm

I have more pics stored on other devices to post, but since adam333 asked, here are some taken from a phone some months back. I have more than this, and I haven't been posting much as of late in effort to get this body finished so that I can use it.

I wasn't able to get my Epson 3940 scanner to work with my Linux machine, even after using the command prompt and then in desperation, writing my own scripts, in vain(I gave up after tinkering with it for 5 hours), so my drawings remain unposted. I've made more drawings since. I have some major plans for my second body(which won't be made of coroplast), especially after studying closely both the Milan SL and the LeMans velomobiles, but I will need to set up a sort of rack and pinion steering to allow for the body to be sufficiently narrow because the direct steering that I currently have requires a width of 680mm(and full turning radius of the unfared KMX is still not retained, but the wheels won't rub, at least).

But I still need to finish and permanently mount my first body before I can even bother constructing the second one. The top pieces, support brackets, roll structure, and the rest aren't shown in these old pics. I will be having some of them made out of aluminum anyway because it's too wobbly and I would rather the body crumple and tear, instead of come off and cut my head off, in the event of a wreck. The top piece not shown is designed to lift up and come off, and is held with teflon straps with a few strategically placed velcro strips.
Attachments
052617 1.png
052617 1.png (198.09 KiB) Viewed 1269 times
052617 2.png
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052617 3.png
052617 3.png (212.03 KiB) Viewed 1269 times

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adam333   100 W

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Re: Critique this performance velomobile idea

Post by adam333 » Jul 13 2017 11:04am

This is quite a nice project you have initiate there. :D

I initially planned to have a closed body fairing for my KMX, but I gave up the idea as when I saw the amount of work it take.

I will follow your developments.

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Re: Critique this performance velomobile idea

Post by The Toecutter » Jul 13 2017 6:36pm

adam333 wrote:I initially planned to have a closed body fairing for my KMX, but I gave up the idea as when I saw the amount of work it take.
If I get my first prototype to work right, my second one will go for the lowest possible drag for its particular size/utility as well as accommodate a larger range of rider sizes. Given the width of the KMX when the suspension is installed, I think open-wheeled is the way to go. The KMX needs an affordable aftermarket body made that a buyer could obtain for a few hundred dollars in kit form and bolt it up to the KMX with just a few hours of work, and the El Loco, while light, pretty, and seemingly straightforward to install, is way too damned expensive and it leaves a lot to be desired in terms of sealin the drivetrain from the elements and in terms of aerodynamics. There's no aftermarket rack and pinion steering for the KMX either, although it would benefit greatly from such a thing.

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Re: Critique this performance velomobile idea

Post by The Toecutter » Jul 20 2017 8:04pm

Last weekend, I decided to take a break from the body and make some wheel disc covers to reduce the drag generated by the spokes. My cruising speed increased from about 15 mph to 16 mph and my top speed increased from roughly 26-27 mph to a consistent 28 mph(reached after work today twice, didn't check the wind. I reached 27 mph with just the front ones and a slight tail wind last weekend). These were not scientific tests(kind of hard to do in a very windy area), but there is a small but noticeable impact. Note that the covers were done slightly convex to extract as much efficiency as possible from them. I decided to leave the right side of the rear wheel with a concentric open circle in it due to the fact that I was using zip ties to install it and needed access, and that happened to be the side with the rear freewheel and clear plastic chain guard covering the center of the spokes.
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072017 1.jpg
072017 1.jpg (163.07 KiB) Viewed 1198 times
072017 2.jpg
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072017 3.jpg
072017 3.jpg (204.45 KiB) Viewed 1198 times
072017 4.jpg
072017 4.jpg (192.29 KiB) Viewed 1198 times

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