Crank-Drive Subaru Build

[wileydavis@gmail.com]

Hello all,

Just thought I'd post a pic and a link to my current project. It's a motorized touring bike that i designed and built from scratch. The frame is 4130 steel, fillet brazed construction.

The drive system is a subaru EH035 mounted to a Staton 18.75:1 gearbox and driven through a left side crank. Yes, this means you have to pedal when using the engine (the engine acts like the stoker on a tandem) but since i like to pedal anyway, this isn't a problem.

At 6000 rpm this setup will give me my preferred 90rpm pedal cadence and a speed range of 4mph to 32mph depending on the gear i'm in. I just got the engine mounted up and running yesterday, so no word yet on how it rides. Hopefully by the end of the week I'll have it streetable. More pics on my blog here: http://practicalpedal.posterous.com

http://farm5.static.flickr.com/4043/4318979747_19367e5b15_b_d.jpg

http://farm5.static.flickr.com/4011/4318980573_5c23898f51_b_d.jpg

 

[give me vtec]

thats pretty cool... I like the way you think.

 

[professor]

Nice job!

 

[robin bird]

That is a great concept--nice job!!

 

[ibdennyak]

Nice design. Like the way the frame has space to mount the engine. Wonder if a freewheel crank could be adapted. I like it.

 

[wileydavis@gmail.com]

Freewheel pedaling

That's actually how I have it set up. It's a 16-tooth freewheel for 3/32 chain, so pedaling is pretty low-drag. Pedaling backwards is another story as there's quite a bit of resistance, but riding without the engine or when the clutch is disengaged, is like a regular bike or, more accurately, like pedaling a tandem without the stoker on the back.

As for the freewheeling capability (by driving on the right side) I decided against it for a few reasons. One, because I do like to pedal, and view the engine as an assist. Two, because this is intended for multi-state tours, I figure it's always better in the eyes of the law to be seen pedaling and this way I can't cheat and get caught by the police cruising by like a motorcyclist rather than a bicyclist. And three, I liked the fixed drive because it makes the bike trickier to ride and I enjoy machinery that takes awhile to master.

That said, if you wanted a freewheeling (at the cranks) drive, you could use the staton inside drive and drive to the right side instead of the left.

 

[robin bird]

As long as you dont lock your feet in !!

 

[mabman]

Montana doesn't have an automatic/no shift law but you may want to check in with the other states you plan to tour to for their regs if you are trying to apease the polease.

Nice looking bike though and have fun with it.

 

[Chris Crew]

That's a nice looking build and a very unusual piece of bicycle machinery.

 

[wileydavis@gmail.com]

It Runs

It runs, and well. Very fun to ride. Tops out at about 30mph with the gearing I have. I don't think the engine will give much more without some healthy pedal-assist, but it's a treat to ride.

I modified a gripshift shifter to use as a twist throttle. Much nicer that the cheapo twisters I've seen for motorized bikes and not so tall as a motion-pro or other motocross type throttle so I can get my thumbshifters to fit (plus it has lesss cable pull than those.)

That tank is a temporary thing. Planning to build a tank to go between the top tubes, but it won't be done in time for my trip to San Diego at the end of the month.

http://farm3.static.flickr.com/2756/4341436585_bb5da23837_b.jpg