Trek 1.2 Lightweight High-power hybrid-unlimited pedal range

[rhitee05]

A suggestion for your throttle. Keep the pot wired in as a normal throttle would be, then add a pushbutton switch like Adrian was referring to. I'd suggest using a momentary NC switch wired between the pot wiper and ground. When you're not pressing the button the throttle will be shorted to ground, then when you press it the motor will come on at whatever throttle the pot is set to. That gives you some adjustability but also the safety of a dead-man switch configuration. I'd think you could find a way to place the button to use it without moving your hands on the grips.

Probably wouldn't hurt to wire in the brake cutoff, too, but if you place the button correctly you could probably make it impossible to press the button and pull the brakes at the same time.

 

[grindz145]

Not a bad idea Rhite. I think that might be an intermediary first step anyway.

 

[dogman dan]

29 pounds is pretty pedalable. My old school road bike weighs 28. Anything under 30 pounds back then was considered racing equipment. A schwinn varsity was something like 38 pounds.

29 pounds is not bad at all really.

Like the throttle idea above a lot! Low power like that, mostly you just need on off anyway.

 

[etard]

I like your bike! Why not go with a triangle frame bag for controller, do away with the CA ( too big For stealth IMO) and get a RC controller like the Castle Creations HV80. I think you can current limit them. I like the push button throttle idea, I also wonder if you couldn't just use the brakes as a throttle cutoff, maybe even set up the rear brake loose so you have a point that cuts throttle but does not yet brake, kinda like neutral.

 

[zukster]

Just a comment on the sensorless issues people have mentioned. Not sure if any really work for large series lipo packs. I have a couple of 350W Rear Bafang, 20 Amp Keywin sensorless controller, 20 Amp Keywin hall controllers. Configured with 10S and 15S packs. The 15S gives the sensorless setup stutter problems sometime less than 5km/h. Not bad but you can feel it. No issues with any other setup. I generally prefer the hall setup now.

 

[zukster]

Also a question re your lean and mean build. Why didn't you go with the Cute-85 front which is only 1.6 kg? I'm thinking of doing a light-weight power assisted XC Cross Country mountain bike. I have a Rocky Mountain Element to play with. I'm considering the Cute-85 front or the Cute-100 rear. I'm biased toward rear motors but I haven't really tried a front. I'm thinking this light front motor might be simple and adequate for this application...

 

[BATFINK]

interesting build, i have seen a very lightweight build from a company called cytronex and they seem to be able to keep the weight of there bikes quite low, any ideas on the exact setup these guys are using http://www.cytronex.com/

 

[BATFINK]

here is a better picture of the kit they sell http://www.cytronex.com/kit/index.html

 

[motomech]

Also a question re your lean and mean build. Why didn't you go with the Cute-85 front which is only 1.6 kg? I'm thinking of doing a light-weight power assisted XC Cross Country mountain bike. I have a Rocky Mountain Element to play with. I'm considering the Cute-85 front or the Cute-100 rear. I'm biased toward rear motors but I haven't really tried a front. I'm thinking this light front motor might be simple and adequate for this application...

I think Grindz's lightweight conversion must be on hold due to the weather, but he answered that question in another thread.
The Q85 motor is only available as a front mount, something he didn't care to try with his carbon fork.

But Grindz, I have a question[or several]about the 9-speed install.
Did you have to spread the drop-outs? Spacers?
Is it the aftermarket unit w/ the 11 tooth sm. cog.
Looking forward to seeing further refinements and results.

 

[zukster]

But Grindz, I have a question[or several]about the 9-speed install.
Did you have to spread the drop-outs? Spacers?
Is it the aftermarket unit w/ the 11 tooth sm. cog.
Looking forward to seeing further refinements and results.

The Cute 100 fits on the rear fine with a 9 speed DNP freewheel. No spreading needed.
I'll get my build pics up soon. Full Suspension Rocky Mountain Element. 32 lbs wth batteries Cute 100 on the rear. BMSbattery KU63 15 amp controller. 2x6S Zippy 4000s 20C.

http://ebike.ca/store/store_motors.php

Scroll down a bit.

 

[motomech]

Thank for the answer. How about a ride report as well?
I have a like-new Rocky Mountain Edge[love it to bits]and although I know I would have to lose the cassette, it would be nice to be able to retain the rest of the 9-speed components.

 

[zukster]

The Cute 100 rear delivers as much power to the road as my Bafang SWXH rear.
I ordered the Cute 100 with the 201 rpm option for more torque for a 26" wheel - more winds.
The kit came with all sorts of junk I didn't use.

http://www.bmsbattery.com/ebike-kits/426-250w350w-q-85100sx-motor-e-bike-kit.html

The Bafang is perhaps a bit better on a hill but the Cute 100 seems to go a bit faster. More on this later. I should really start a new thread for this but here it is for now.

Rocky Mountain Element Race 1999 19" Frame
2 x 6S Zippy 4000 mAH Lipo Batteries from HobbyKing
Methods LVC cell monitor battery protection boards with breaker board power cutoff.
BMSBattery Cute 100 Rear Kit includes:
Cute 100 Rear 201 rpm for 135mm drop out
KU63 15A Sensorless or Hall Sensor Controller. Good to about 15S/63V I think.
Waterproof Connector for Hall and Motor Phase wires - too cool.

I've run the Controller at 14S okay and BMS said it was okay. Haven't tried 15S/63V yet
but I suspect the limit is the 63V capacitors in the controller.

 

[motomech]

Your build definately deserves it's own build thread, you already have some great pictures.
And it would showcase a Rocky Mountain on a forum where the FS category is dominated by the likes of Trek, Giant and Specialized.
To me, these late '90's/early 2000's, open triangle FS bikes make a lot of sense for an E build.
Anyhow, thanx for the info and PIC.S.
Have you done any top speed runs?

P.S. I imagine you have read the reviews here,

http://www.mtbr.com/cat/bikes/bike-full/rocky-mountain/1999-element-race/prd_349810_95crx.aspx

 

[zukster]

I'm guessing about 40 km/h on a 12S / 50.4V Lipo Pack fresh off the charger on the flats. I'll be testing 15S / 63V max soon, which I'm almost sure the motor and controller will be fine with, and I'll post that when I get my new Lipo packs to test with.

I agree about the late 1900's/early 2000's bikes. I picked up the Element for 350 dollars. It was about 27 lbs. Then I added carbon handle bars, a lighter stem, Thomson elite seatpost, XTR rear derailler, maybe something else... Got the bike down to like about 25 lbs, then the hub motor, controller, and batteries, brought it to about 32 lbs (well around there). I weigh it at the bike shop later.

The 9 speed DNP freewheel did me in for weight. 600 grams or 1.3 lbs. I just bought a Suntour Microlite freewheel to try: 185 grams / 0.4 lbs.

 

[motomech]

Last[hi-jack]post

$350, a ganga for such a finely crafted bike. That's the beauty of these, they are dated for their original purpose[low price], but beautifully spec.'ed for Ebike.
The way I aquired mine is interesting. When the E-bug first bite, I went to a large "super store"of bicycles to ck. out possible donner-bikes. In the corner was this dusty, forlorn-looking MTB., a 2003 model. It had been lost in the warehouse for 8 years. I had them clean it up and bought it for $995.
Later, though research, I found out that Rocky Mountain had a recall on all their FS models of that period[your '99 as well], the chainstays could break at the "hanger hole". The Many were replaced by the factory, but I think mine was pulled off the floor for this reason. It still has the original, but I'm not worried as I don't plan on doing 10 ft. drops.
Have you thought about the EVFalcon bag? It's a very good fit on mine, even with the top shock mount. But my R.M is a 20.5" frame.

 

[spinningmagnets]

There was a thread a while back on full-sus frames that had a big triangle for battery pack placement. Just tried to find it, wanted to add this frame to it so they were all in one place...

 

[zukster]

I think this thread is dead other than us so don't worry about it. Interesting you mention the chainstay problem. If you look at the first picture of my bike you will see a green one behind it that is broken just as you described. I wonder if Rocky will replace that piece if I call them? I also have a Rocky Mountain Speed. One of the first full suspention cross country bikes. I use it as my work horse as it is a little heavier. It was over 4K new, but I got a deal like you. I pull my kids trailer with it and the Bafang hub motor.

I hadn't head of the "Edge." The Element also went under the names: Carve/Spice/Instinct/Fanatik ...

 

[motomech]

There was a thread a while back on full-sus frames that had a big triangle for battery pack placement. Just tried to find it, wanted to add this frame to it so they were all in one place...

this one?
http://www.endless-sphere.com/forums/viewtopic.php?f=3&t=32056&p=514724#p514724


I posted on that thread, listing most of the R.M. models with the open triangle.

 

[grindz145]

Also a question re your lean and mean build. Why didn't you go with the Cute-85 front which is only 1.6 kg? I'm thinking of doing a light-weight power assisted XC Cross Country mountain bike. I have a Rocky Mountain Element to play with. I'm considering the Cute-85 front or the Cute-100 rear. I'm biased toward rear motors but I haven't really tried a front. I'm thinking this light front motor might be simple and adequate for this application...

I think Grindz's lightweight conversion must be on hold due to the weather, but he answered that question in another thread.
The Q85 motor is only available as a front mount, something he didn't care to try with his carbon fork.

But Grindz, I have a question[or several]about the 9-speed install.
Did you have to spread the drop-outs? Spacers?
Is it the aftermarket unit w/ the 11 tooth sm. cog.
Looking forward to seeing further refinements and results.

Sorry I havent kept up with this thread, but I didn't have any trouble with th
e 9 speed at all, it's a snug fit, but not sretching was necessary. The 9 speed is the screw-on type from ebike.ca

 

[grindz145]

hey zuckster, where did you get that controller from? I'm definately considering going sensored with my build.

 

[motomech]

I think this thread is dead other than us so don't worry about it. Interesting you mention the chainstay problem. If you look at the first picture of my bike you will see a green one behind it that is broken just as you described. I wonder if Rocky will replace that piece if I call them? I also have a Rocky Mountain Speed. One of the first full suspention cross country bikes. I use it as my work horse as it is a little heavier. It was over 4K new, but I got a deal like you. I pull my kids trailer with it and the Bafang hub motor.

I hadn't head of the "Edge." The Element also went under the names: Carve/Spice/Instinct/Fanatik ...

The '02 and '03 Edge came mainly equipped with W/ Dirt Jumper II's[outstanding], Delore hydro's[equally outstanding], Fox Float R[very good] and Delore XT stuff[no great shakes]. The Slayer[R.M. has the best model names]of the same years was the same bike with higher end components. In '03, they went with sealed brg.s on all pivot points. I do get some creak with the cheap Race Face crank.
I really like the combo of heavy DJ forks on a X-country frame.

I rather doubt that R.M. would warranty your chain stay now, but they probably would sell you one. Their replacement chain stay became the one they used on the Slayer 70[starting in '04 ?]. I suspect it would cost more than what you payed for your Element.

 

[motomech]

Mucho gracias Grindz and Zukster for answering my questions.
I was in a quandry as to which wind Q100 to order. It seems like the 201 rpm will match my MXUS[22 to 23 mph].
Zukster, last question. You are using the 36V motor, right?

Dual mini's, 9-speed freewheel, 12S or 14S lipo in the frame, I'm jacked!

 

[zukster]

I bought 2 full kits from BMSbattery.com that included the KU63 controller, throttle, Cute 100 laced into a pretty good wheel with thick spokes, brake levers with cut-off signal, peddle assist sensor, all for 400 dollars shipped, so 200 per kits. I just had to get the batteries. This kit exactly:

http://www.bmsbattery.com/ebike-kits/426-250w350w-q-85100sx-motor-e-bike-kit.html

The KU63 has written on it 250W, 36V battery, current limit 15A, LVC 27.5V, fits 3-speed switch kit, for sensorless motor, for hall sensor motor.

It a pretty impressive controller. Its tiny. Smaller than a typical 20A Infineon. It packs a punch for its size at the higher voltages. Jack at BMS (I think he's like the President or Head Tech or something) told me that it was okay up to 14S which is 14 x 4.2V max = 58.8V. So the 36V is just its recommended usage. I hooked up 15S which is 15 x 4.2 max = 63V and nothing burst into flames. I opened it up and there are 63 volt capacitors inside, so this would be the absolute max to run through it. I did a test ride at 14S and it was fine and very fast. I only tried 15S on my test bench. I have some more Lipo batteries arriving next week and will try a 15S pack on the street. If that works, that's what I'll run. If I wreck the controller (which I doubt) a new one is 15 dollars from BMS.

I'm not sure if there's really a difference between a 36V and 24V motor.

Lots of good info on those Rocky frames here! I will check out that other thread. Thanks.

 

[grindz145]

O sweet, Yeah its similar to the Lyen controller I ordered, but I'm definately considering switching over to sensored, so that might not be a bad controller just to demo.

 

[motomech]

I bought 2 full kits from BMSbattery.com that included the KU63 controller, throttle, Cute 100 laced into a pretty good wheel with thick spokes, brake levers with cut-off signal, peddle assist sensor, all for 400 dollars shipped, so 200 per kits. I just had to get the batteries. This kit exactly:

http://www.bmsbattery.com/ebike-kits/426-250w350w-q-85100sx-motor-e-bike-kit.html

The KU63 has written on it 250W, 36V battery, current limit 15A, LVC 27.5V, fits 3-speed switch kit, for sensorless motor, for hall sensor motor.

It a pretty impressive controller. Its tiny. Smaller than a typical 20A Infineon. It packs a punch for its size at the higher voltages. Jack at BMS (I think he's like the President or Head Tech or something) told me that it was okay up to 14S which is 14 x 4.2V max = 58.8V. So the 36V is just its recommended usage. I hooked up 15S which is 15 x 4.2 max = 63V and nothing burst into flames. I opened it up and there are 63 volt capacitors inside, so this would be the absolute max to run through it. I did a test ride at 14S and it was fine and very fast. I only tried 15S on my test bench. I have some more Lipo batteries arriving next week and will try a 15S pack on the street. If that works, that's what I'll run. If I wreck the controller (which I doubt) a new one is 15 dollars from BMS.

I'm not sure if there's really a difference between a 36V and 24V motor.

Lots of good info on those Rocky frames here! I will check out that other thread. Thanks.

I believe the 24V models use compound gears, a la cute Q85, while the 36V use single plane planetary gears.
Strangely, I think the housings might be the same.