Gathering Ideas For A Build

[to the beach]

Found a great $35 deal on a 1993 Fuji SandBlaster, designed in USA, made in Taiwan, 4130 Cromoly, 3 x 7 speed Shimano 100GS components. I added Kenda K838 street tires and Planet Bike full MTB fenders for another $60.

Not headed off road and don't want the added weight of suspension. Weatherproofing is part of my plan, if at all possible. Just want an efficient E-bike that will cruise 25MPH and still climb moderate hills at 20MPH. I like the stealth look of a gear hub in the rear but don't know how one will hold up since I weigh 245 and the gears are usually nylon. Also, I wouldn't mind another Yescom (this time rear kit though) but don't like how conspicuously large the direct drive motors are. No question about battery type, definately LiFePo4 mounted in the triangle, either in a frame bag, or what I really like, the bottle cage mounted Thermos looking thing they sell on Ebay. I can't figure out how I should set controls up. Current shifters are trigger and I'd like to convert to rear disc brake at the same time. I've got around $150 per month to put into this and would like to be done for next summer, unless I sell my current E-Bike.

 

[Drunkskunk]

That looks like a great bike. If it's one of the lugged frames, It ought to be an excellent rider.

At 245lbs and with the mountians of NH, you're kind of on the line with motors. If you go for a geared, its going to need to be a MAC/BMC, and thats only if you don't have any long climbs. Otherwise, a Direct Drive will be needed.

A frame bag seems like the obvious answer for that bike. But the black on black look is kind of clasic.
I think if that was my bike, I'd get an old leather briefcase (ebay for very cheap) and cut/re-stich one corner so it would fit in the triangle.

As for the throttle, you could fit a thumb throttle between the brake and the twist shifter if you can stand those things. Or replace the brakes with a set of Shimano Rapidfires and have trigger shifters and room for a normal twist throttle.

 

[to the beach]

I'm still looking for input/ideas for this build, please chime in.

drunkskunk: They are trigger shifters and the frame is not lugged though the welds look nice enough. Dropouts are thick but could be beefier....I think they'll hold up fine for my purposes.

 

[d8veh]

The forks look a bit thin and the brakes look a bit weak for 25mph cruising, so you need to keep the weight down. If you don't have steep hills, you could use a pair of high-speed light-weight motors like the Q100. The 201 rpm ones do about 15mph on the road, so run them at 48v for about 22-23mph. The 328 rpm ones will get you cruising at 25mph (just), but the controllers will get hot if you enclose them too tight. They'll be drawing maximum current a lot of the time. The 2WD spreads the load around the frame, so much less stress. You don't need any special torque arms. The standard ones that you get from BMSBattery are more than adequate. Installation is straight-forward. You can make a double throttle or use a Cycle Analyst to split the throttle signal for the two controllers. It all sounds complicated, but it's no more difficult than installing a lightweight hub-motor twice. Here's one I dis with twin Q100s, It's for off-road, so 201 rpm motors give 15mph. Traction is unbelievable and it only weighs about 23kg. click on the image to see the whole thing.

 

[dogman dan]

Hmm, a fine old bike, but for a few reasons maybe not the best thing. Best thing you might find for that price, you bet, but not the best thing.

I had one very similar btw. The canti brakes really weren't that great, but with the right pads, serviceable for 25 mph. The front forks are a bit weak for a motor. My very first ebike ride lasted a half mile, then the front motor blasted right out of those weak dropopouts. No torque arm at the time though.

It's going to be 1" steer tube, so upgrading the forks will be a problem, if you wanted to at any point. But, for a rear motor, you can use that bike and be OK. Great triangle space of course.

On to the real problem. At 245 pounds, not many hubmotors that cruise at 25 mph are going to get you up any hills at 20 mph. Not one hubmotor, unless its a really big one. Your best bet to get close to that on a 28mm rotor, will be a slow winding motor, that is run on 72v. A dd motor from EM3ev is available in 10t. This motor, with 72v 20 amps controller, will just reach 30 mph, and might climb the milder hills at 20 mph. But only the really mild hills. To move that weight up 5% grades, you'd need 3000w. If brief enough, you can get away with 72v 40 amps. But really, unless you are climbing pretty mild hills, you will end up climbing them closer to 15 mph.

Two of these 10t motors would work. With a very strong battery, you could run 72v 20 amps each, and have a bike that would climb anything, possibly at 20+ mph.

Hell, once you go two motors, you might be able to use nearly any hubmotor to get er done. Two typical winding 48v motors with 20 amps controllers gives you 2400w max. That would do er.

That brings us back to that somewhat weak dropout fork. Two torque arms should suffice to fix that.

Damn, that's getting pretty complicated. Time for you to start looking at really big motors, and be done with it. Look at the crown, the hubzilla, the cromotor. Oh, and forget looking normal.

 

[dogman dan]

Hmm, a fine old bike, but for a few reasons maybe not the best thing. Best thing you might find for that price, you bet, but not the best thing.

I had one very similar btw. The canti brakes really weren't that great, but with the right pads, serviceable for 25 mph. The front forks are a bit weak for a motor. My very first ebike ride lasted a half mile, then the front motor blasted right out of those weak dropopouts. No torque arm at the time though.

It's going to be 1" steer tube, so upgrading the forks will be a problem, if you wanted to at any point. But, for a rear motor, you can use that bike and be OK. Great triangle space of course.

On to the real problem. At 245 pounds, not many hubmotors that cruise at 25 mph are going to get you up any hills at 20 mph. Not one hubmotor, unless its a really big one. Your best bet to get close to that on a 28mm rotor, will be a slow winding motor, that is run on 72v. A dd motor from EM3ev is available in 10t. This motor, with 72v 20 amps controller, will just reach 30 mph, and might climb the milder hills at 20 mph. But only the really mild hills. To move that weight up 5% grades, you'd need 3000w. If brief enough, you can get away with 72v 40 amps. But really, unless you are climbing pretty mild hills, you will end up climbing them closer to 15 mph.

Two of these 10t motors would work. With a very strong battery, you could run 72v 20 amps each, and have a bike that would climb anything, possibly at 20+ mph.

Hell, once you go two motors, you might be able to use nearly any hubmotor to get er done. Two typical winding 48v motors with 20 amps controllers gives you 2400w max. That would do er.

Two small gearmotors would be more discreet, like the pic above. But likely best if each ran at only 15 amps, so likely a less than 20 mph hill climb. Change your needs to 15 mph up the hill, and it gets a LOT easier to do.

That brings us back to that somewhat weak dropout fork. Two torque arms should suffice to fix that.

Damn, that's getting pretty complicated. Time for you to start looking at really big motors, and be done with it. Look at the crown, the hubzilla, the cromotor. But that throws discreet and lightweight out the window. It works though, John in CR flies up hills on his bikes, with his hubzilla.

 

[to the beach]

I set my goals based on the performance of my current E-Bike. Avg. speed per cycle computer is 20 MPH, not trying to climb any steep hills, just moderate climbs. I figured if I could adapt this performance to an incognito bike built with lighter components and LiFePo4 instead of SLA, I would reach my higher goal. I don't beat on my bikes and always steer around bumps in the road, or at least slow down for them. The roads around here aren't hellacious, unless you consider the distracted drivers that don't respect the shoulder.

d8veh: Nice bike! I'm sure I would enjoy off road too, I'm just commuting from work and on short trips to the stores a few miles away currently.

dogman: 2wd sounds expensive, I plan to spend two thirds of my budget on a ping 48v20ah battery pack. A geared hub in the back might be all I need, if I can find a 700-800 Watt or overdrive a nice quality 500 Watt. Also, I lost 5 pounds so now I'm 240 and dropping.

 

[to the beach]

drunkskunk, upon closer inspection, the frame IS lugged, however it's only at the top of the seat tube where the crossbar meets...at least there's something.

 

[D A Snyder]

Here is my friend riding up a very steep hill. http://california-ebike.com/product/sierra-climber-high-torque-geared-motor-kit/. He's 63 and loves to ride so he does make it look easier than it really is.
The kit I would recommend would be the Sierra Climber geared hub. http://california-ebike.com/product/sierra-climber-high-torque-geared-motor-kit/
Give me a call if you have any questions.
Good luck!

 

[to the beach]

Thanks Mr. Snyder, looks like quality, real-world merchandise, from what I have read in your website's content. I would have to consider your products, especially the higher wattage Sierra Hill Climber geardrive hub motor which I have never before seen. Is the composite gear material a trade secret, or could you share more info?