Cute85 Front Hub StokeMonkeyish Recumbent

[evblazer]

I know it is a hub motor but I'm not using it as a hub?
This bike currently has a roller (friction) drive and the drive works very well but I really don't like the bike. I figured I would use it as a test platform to come up with something that would work on one of my nicer bikes.
I ordered a cute85 front motor with a disc mount (6 hole only ) and then used an old steel bb retainer which I notched with a angle grinder for the 6 bolts and welded the retainer "nut" to the threaded part to create a freewheel mount.

I also picked up a tandem crank cheap on ebay which will use the same BB all my recumbents have so I could easily swap it out and pull the drive off and the bike is back to normal if all works out.
View from the side of my swing boom fwd recumbent with the test mount. I kinda threw this together to try and ride it around pedaling unpowered to see if I would get any interference with my legs. I had the aluminum and it is easier to machine and drill but I don't know if it would work under power. So far it looks and fits well but I"m really thinking about hanging it off in the front of the wheel under the crank because it is really close to my left leg.

Note: The chain I just ziptied on to see if there was any interference which is why it might look really off.

Here is a picture from the front. I think I"m going to have to find a new place for the lights it is really tight in there with all the stuff on the front end.

This is how the temporary mount is on the left side. 1/4 aluminum threaded for an m5 bolt holding down a 1/16" piece of steel.

On the right side I used 2 1x1/4" aluminum to make two dropouts that fit the axle. I then faced them towards eachother and bolted them together.

I'd really really love to be able to make something like the stokemonkey mount I just don't think I have the skill

Is that mount possible with just some hand tools or am I hosed? Anything deathtrapish I'm missing besides the motor rotating and grinding my left calf off in the chain hm I really think I gotta not put that next to my calf.

 

[spinningmagnets]

I'd say it has more in common with a Cyclone layout, but good job so far!

There are several threads similar to this and I am watching them all to help me avoid problems you have discovered about using a hub as a non-hub drive. I believe they have a lot of potential, and I also think non-hubs will boom when fuel prices spike up, and hub-kits are immediately sold out and back-ordered.

Once the drive-line is figured out and installed, there are a variety of motors that can be used even if you first choice is unavailable. Also, adaptation kits can be made by local machinists here when China is too-swamped with E-bike work.

 

[evblazer]

I think I'm going to take a shot and order these clamps to hold the motor mount to the bike. It has to be better than the ubolts to attach it where it is going.

http://www.drillspot.com/products/632970/zsi_t034m040_surface_mounted_2_hole_cushioned_clamp?s=1
I'll use 2 to hold a flat piece or maybe c-channel up to where the motor hangs. To clamp it I'll make sure the motor mount only hits the rubber and then have another piece of metal connect to the bolts and sandwich it together.

I know they may twist a bit but with a max load of 400lbs holding power they should be strongish and the insert will give solid no crushing contact to my bike. Maybe?

 

[spinningmagnets]

One option is to slice a section of steel pipe lengthwise to make one or two saddles to spread the load out. That can give you a solid clamping with no flex, while also not crushing the bike frame tubing. Once the saddle threads have been cut off, its been de-burred, and primered/painted, it wouldn't look bad at all.

A section of inner tube between the saddle and frame can even protect the bikes paint. Here's a pic of project with those:

 

[evblazer]

I'll see what I can find for a 2 1/8" ID pipe locally. For now I ordered the rubber mounts since they were only ~$15 total for two. It took seeing your picture but I figure I can use a ubolt of proper size for the cushioned ones too to give it a more rigid wrap if the metal isn't strong enough on the cushioned clamps.

 

[spinningmagnets]

If you can't find exactly the diameter you want, you may be able to spread a smaller diameter pipe section slightly, I have spread brass pipe saddles to make a spacer so I could put a small-ID handlebar onto a big-diameter quill-stem. Since I didn't care about the bike paint, the U-bolt being tightened down did the spreading.

Brass is cheaper and stronger than copper, stronger than aluminum. For strength its about halfway between aluminum and the softer grades of steel found in common plumbing pipe. In the hardware store the 6" or shorter sections of pre-threaded pipe are called nipples, but only a hand-milking dairy-man could have thought that they looked like that.

Or, you can get a slightly bigger diameter pipe. Then, smear waxy lip-balm on the frame, and put JB-weld (metal epoxy) between the saddle and frame. the wax will keep it from attaching to the frame and keep the saddle removable. Once cured for 24-hours, JB is similar to aluminum, and can be filed to pretty up the edges.

 

[evblazer]

Couldn't find anything big enough at the depot but after some testing found I really couldn't have the motor where I put it. Put together another prototype on the test bike to see how it would work.

I definately need to shorten that chain and I do have a chain tensioner on the way too but I find it works pretty well. I will need to do a new prototype from scratch before I ride it very far with power hooked up but I think I found I want a little flex. Instead of twisting like it was before when power was applied the motor now bucks a little up like it's on a diving board with no twisting.
I will be getting up to speed before applying power in practice but it seems like a nice little feature.

I also got the bmsbattery controller working and it is pretty smooth. More than half the wires are disconnected and don't seem to do anything if I link them together. The Cycleanalyst was reporting 37mph in the second highest gear while it was up on the rack need to make some adjustments to get to the 11tooth. The ratio on the motor to crank is 16 to 42 so if the motor has alot of topend left I may try a 53 on the chainring since I have a few spares laying around.

Edit: Actually I don't think I'm going to put a bigger chainring on it. The motor with the current ratio will at max give me a cadence of 110 which is what I often do sprinting on the bike it will end up on after testing is done. The final bike as 20" wheels so won't be going 37 top speed so it should work quite well.

 

[evblazer]

Tightened up the chain a bit

and then I took it for a ride. I definitely need to stiffen the mounting arm and install a chain tensioner but I guess I already knew that. The chain would pop off if I tried to apply any real power.
Tomorrow I might try to bolt on a piece of 1/8" x 2" angle along the length to see if it relieves some chain issues by making the arm flex less. It did run pretty smoothly until it popped the chain off. So far I think it would be pretty easy to switch the final mount and motor over to my preferred commuting bike.

Stealthy looking it certainly is not. Maybe I can get a small front fairing and hide it a bit if that becomes an issue.

 

[evblazer]

Went out and got a 1 by 1/8" aluminum tube to strengthen the mount.
Chain tensioner came in early. Would be better on the return side but I can't easily get it down there with the current setup.
Between the two it is much improved. I think the chain tensioner acts as a nice guide too since it is so close to the drive sprocket and will stay in alignment regardless of any momentary twist or bouncing.

Now to find another crank spacer so the right crank won't hit the chainstay.

 

[evblazer]

Took the bike out on the road tonight hoping all was well. The drive performed pretty well actually I was able to use the cruise control to up the assist to a good point into a comfortable cadence so from that perspective it is a success.
Unfortunately the drive really makes the original problem I had with the bike 10x worse. Since it is a swing boom and the crank and whole front end turn with the steering having the cute motor hanging way out there with a bunch of aluminum makes it even harder to start and control. I actually can't start at all with the slightest incline and have to flinstone start on a slight decline or the flat because the front end is so heavy. I guess it's time to retire the bike and to put it on my fixed front end bike.

 

[evblazer]

Scrapped the on paper good ebike (Dual 26" wide tires, dual suspension, disc wheels) and fixed up my mount onto the following. Shown behind my wifes prius so you can see how tiny the bike looks. Wind I don't feel any wind

Found my magura hydro rim brakes have alot of grab when testing the mount oops.
Brakes: 1
Cheap beatup old freewheel: 0
Guess the cute85 has a little bit of oomph at slow speeds when it taps the battery for 350 watts

Got a new freewheel and will be putting it on today and adjust the mount to better suit the hurricane and the clamps I got shown above. Since the mount is now under the crank instead of over it the idler actually works for the return side due to the change in angles so that worked out just as planned :wink:

 

[evblazer]

Moved the mount over and found there were already two holes in the boom I could use which I hope will make a nice addition to the setup.

The clamp I got is a really nice fit and using one with the two bolts into the boom/frame will hopefully be enough to hold the mount steady but not harm the bike itself. I had to move it a bit forward from the original position to get it to clear the chain crossing. Where it is located now it just in front of where the pedals cross when they are all the way back.

In case anyone noticed them yes I love my q-rings. They allowed me to put in a few 1000 mile months in a row last year without any problems and after a 260 mile ride my legs muscles were toast but no pain at all

With the mount on the bottom it creates a better chainline and allows the idler to take up slack on the return side. So far it runs really smoothly but due to the monsoon outside I can't take it anywhere. The idler clears the hub motor by just a few mm.

They say partial sun tommorow so hopefully I can get out there. Not much room on the handbars so I don't know where I'm going to put the throttle that I can reach it easily :?

 

[spinningmagnets]

It appears that when the motor is turning your feet must also turn? Most geared hubs have a freewheel, so if this is like the others, you can pedal without having your feet drive an un-powered motor?

I'm most interested in the top speed achieved on flat ground? What volts, amps are used to get that speed? which winding this model is? sprocket tooth-counts and driven wheel diameter? Thanks in advance!

 

[evblazer]

I must pedal if the motor is going. I'm ok with that and considering that I'm using a pretty weak motor it shouldn't be a problem.
The motor freewheels well I found it easier to turn the cranks when I had a freewheel on instead of a track hub. I might not notice it when I was actually pedaling but by hand I could notice a slight difference.

Setup
8S thundersky 20 amp cells
Cute 85 Front hub with Disk Brake mount
-24 Volt
-16" wheel size was the request
-~305 rpms no load at full speed
Bottom bracket cup mounted to disk brake mount with 16 tooth freewheel
42 tooth left side chainring
No load max crank speed ~115 rpms
53/39 right side chainrings
11-25 9 speed cassette
406x1.35 20" wheel
Max assist speed will be 30mph with current gearing

I can pedal the bike that fast on the flats for a pretty limited time on certain surfaces. I do not think the controller has the power to get me up to near that speed since it'll peak at 250 watts but I have a few good loops or somewhat long flat streets I'll pedal up as fast as I can then see how fast it'll keep me going without putting any pressure of my own on the pedals I'm guessing it might hold me at 23 at full power.

I may get an igh sturmey archer 8 speed which would give me possible assist up to a speed of 40mph if I could go that fast but the controller doesn't have near enough power to do that on it's own. Those hubs are really built for little wheels like mine from what I understand and I've always wanted an igh.

 

[evblazer]

First longish test run.
Same setup as above.
Temps 102 in the shade ugh..

8 miles
Lotsa pedaling trying to figure out how to set the cruise control to a good spot where I can pedal and it helps not sure I have figured it out yet.
Cycle analyst showed <1 amp/hr total
2.? watts per a mile (again lots of pedaling)
Avg speed 18 mph

The controller peaked at pulling just over 300 watts but I tried to keep it around 100 when I needed it. When it drops to 40 I don't think it is doing much as it uses about 20 just to spin itself. Hopefully I get some better testing tommorow. I did find it really just doesn't help much past 25 and the watts really drop off. Honestly that is fine with me it probably ended up just where I wanted it.

The brake kicks off the cruise control well. Since I have magura hydro rim brakes I drilled a 3mm hole in the brake handle and then tapped it. I then took one of the extra cateye magnets I have then re threaded that to 3mm and screwed it in. Zip tied an old cateye wheel speed sensor to the handlebar wired it as a switch to the lv brake cutout and that was it.

What I really hope I can figure out is how to wire the CA into the circuit to limit amps so I can more easily use the cruise control and keep the amp draw low without minding it so much. Maybe a switch to wire it in and out of the circuit if I want to go faster and bypass the amp limit.



Edit: After posting figured that wouldn't work. The CA plays with the throttle to limit amps and if I use cruise control on the controller touching the throttle is just going to dump it out. I'll need to use a switch to hit full throttle and use the CA to limit amps that way. Maybe.. I may just take a few more ride the way I have it.

 

[evblazer]

About 18 miles pedaling using 3 ah. Dropped the chain on some really rough cobblestone so I have to work on that before I take it out in commuting traffic but I might be ready to try and take it to work after that. At least a test run on saturday.
The only place I can really tell it is working in on hills when it is maxing out and then I turn it off so it is helping a little. It's also pushing alot of weight around. 50lb bike + 25lbs battery/controller/motor/mount/CA/wiring (estimated) + 275lb rider so 350 lbs. Freaking gained a ton of weight when they wouldn't let me ride for a long time, or do anything else, bah.

Still the more I ride it or the other electric I had before briefly the more I wish I just got a bionx If I had found a realiable way to bypass the battery back when I was first looking I probably would have. 1300$ on ebay for a new battery OMFG. I'm just having trouble getting in sync with the motor to get assist except on hills. I find on the flats cutting power to the motor doesn't seem to affect my speed or make it harder to pedal I only notice it on hills which may be all it's good for which is ok I guess. I'll need a few commutes to see if my avg speed is over what I used to be able to do or if haling around the extra weight is actually overall slowing me down

 

[evblazer]

Took my test ride into work today. I had redone the mount a little so took a quick spin around town first. Basically just shortened it a bit, put a few more rivets in and changed the pulley so it forces the chain down instead of up. About 26 miles with the short test ride and ride to work using 4.2 ah. Charged at work for 3 hours with a 1.2ah charger while sending out some emails and then rode home 22 miles using 4.3 ah.
Overall 48 miles using 8.4ah 223 wattshr. Not bad for some pedaling pulling a 350lb overall rig with no shade and a heat index of 102 which is kinda cool for this time of year
Hopefully I'll be able to ride it at least once next week and more the following weeks. Seems to have held up very well on some rough pavement. I don't think I rode any faster today but I haven't ridden my commute since december or so and have barely put in any miles since then so I guess just making it was a good thing.

 

[evblazer]

Finally got camera privileges.
Took a side shot of the mount in it's current configuration. Shows how I flipped the chain tensioner the opposite of before. It has worked flawlessly in this orientation for about 100 miles vs dropping the chain every bad section of road the way I originally had it.
old

new

Closeup of the pipe hanger mount I used to lock the aluminum to the boom. It has worked really well so far. I do eventually need to weld up a mount from steel instead of the riveted aluminum to get ride of some flex if I try and use too many watts at low speed.

Right now I'm running my MCE Flashlight on 4P 18650s and a home made dual Soell p4(?) with eliptical lenses powered from the main pack through a dc/dc set to 5 volts. I plan on getting a magicshine for the front to replace them both and then set the dc/dc to magicshine voltage to run both my front and rear lights.

This is the aerotrunk I run for commuting duty. It is a pretty big bag and has served me well for many thousands of miles.

I also found that the laptop pocket perfectly fits my 8S thundersky pack if they are put in lengthwise. Keeps them nice and tidy and up close to the rear of the seat. I do not plan on carrying my work laptop on my electric bike like I used to pre-electrifying. I rarely did it then so no big loss I just don't want to push my luck.

I did go back to round rings.. I stil am having high rpm problems with them but I figure if I'm going to wear out rings on a chain powered bike theyshould be cheap ones.