Chain derailers, making a two speed

So where do I get a derailer for a moped sized chain? I figure you could make a two speed or maybe three before the chain would be running at to much of an angle. Also a rear sprag would be needed.

Actually a three speed hub like from an old bike would have the sprag already in it, just relace the spokes to your rim and its all good, O-- accept for the rear brakes. Maybe centerpull style like a bike?

I'm leaning tward the three speed hub, those things rock!

Re: Chain derailers, making a two speed

i was thinking about this a while back... would be really cool to see someone do it!

Re: Chain derailers, making a two speed

There's a reason motorcycle transmissions are designed as they are. You can't put that much force through a deraileur system.

Re: Chain derailers, making a two speed

^ Seriously, not enough tesion from a derailer on the chain to keep it from slipping.

Re: Chain derailers, making a two speed

this thread happens every couple of weeks. search next time so you dont make the millionth duplicate. everybody had this idea at some point or another, but most people realized it would not work for very long.

Re: Chain derailers, making a two speed

you can however put a derailleur on the pedal crank side, and it will work

Re: Chain derailers, making a two speed

♣Slew Foot♣ /

i have seen errr heard of, a puch maxi \

can with a puch ten speed back sprocket

but thats not the drive side just pedals easy

Re: Chain derailers, making a two speed

Conrad Conrad /

Yeah i remember that ten speed. It was a bright green maxi. There was a thread about it a couple months back.

Re: Chain derailers, making a two speed

bigblockfiero /

I actually think it would work quite well and also because I built a souped up radio flyer wagon powered by a chain saw motor.

I welded a sprocket to the clutch that ran the chain. Discarded the bar. Then built a jackshaft that incorporated a three speed hub, then to the rear axle with a derailer for high and low range.

This thing ripps pretty good. I rev it to ten grand in low range and first gear then without letting go of the throttle I nail secound gear on the three speed hub. It yanks the front wheels. I really beat the crap out of this thing and it keeps wanting more.

Re: Chain derailers, making a two speed

I want to see the radio flyer.....&...the big block fiero....

Re: Chain derailers, making a two speed

chainsaw powered radioflyer

3 speed chainsaw powered radioflyer.

did i read athat right????

Re: Chain derailers, making a two speed

Yeah man! I wanna see the Radical Radio Flyer too! :P

Re: Chain derailers, making a two speed

I'm not doubting your skills at all, but pics or it didnt happen!

Re: Chain derailers, making a two speed

Bike components are not up to mechanized use, my 2 cents worth. Would not want a bike brake on a moped. Best of luck, try not to die.

Re: Chain derailers, making a two speed

I know this guy builds some seriously rad two stroke shit I just want pictures.

Re: Chain derailers, making a two speed

try this:

http://farm3.static.flickr.com/2061/1508433832_ba422b8d73.jpg?v=0

you would have to manually shift it while the bike is stopped, though.

Re: Chain derailers, making a two speed

a nuvinci hub can take up to five horsepower.

Sturmey Archer hubs can easily handle a moped's one to three horsepower _in gear_ but it's the shifting part that's hard.

If you try to shift a Sturmey, Shimano, or Sachs three-speed hub while your wheel is turning at speed, nothing will happen at first. Then, it will shift sort of suddenly, and the hardened teeth of the internal gears will make gradual contact at a few thousand RPM.

You can do that a few times before you grind it all to powder.

So, three speed hub is your best bet, but you have to stop the rotation of the rear sprocket, change gear, and then give it power. You need not only a clutch, but some kind of chain brake.

Re: Chain derailers, making a two speed

This was my solution as mentioned above.

This works great; I can peddal it comfortably up to around 18 mph. It did require a lot of modifications to the swingarm and wheel spacers.

Re: Chain derailers, making a two speed

man, gear lower if you have that much pedal assistance capability!

i wanna see the other pictures of that bike again, that thing was a masterpiece.

Re: Chain derailers, making a two speed

nuvinci hub = new school variator

Want to post in this forum? We'd love to have you join the discussion, but first:

Login or Create Account