Why not smaller chain?

orbit222 · #1 03-01-2009, 12:11 PM

I'm trying to minimize weight and the stock chain seams way too beefy. I know most experienced folks have switched to a #41 chain but I'm unclear what's the diference. Seems like it's quality not size. Is the #41 thinner along it's width? Has anyone tried to use bike chain? Can you get a smaller sprocket for the motor? How bout for the left side wheel drive? I know the impulse is to think you need a heavy chain for the tork but a single speed bike chain can take my 210lbs pushing as hard as I can from a dead stop and that is way more tork than my motor puts out.

**Dave31** · #2 03-01-2009, 02:52 PM

I posted pics side by side in this thread

http://motorbicycling.com/f3/replace...hain-1139.html

orbit222 · #3 03-01-2009, 04:57 PM

Thanks, I see the #41 looks better quality and I'll probably go with that. I'm still interested to know if anyone has tried or if it's possible to go all the way down to bike chain. It just seems better suited to the job. I think it would be smoother and lighter and you could use a nice chain tensioner (like the Kore clamp on). Is the sprocket on the motor a standardish part that could be swapped out?

orbit222 · #4 03-01-2009, 05:16 PM

Did a little more research and #410 (#43) Seems to fit all the same dimensions but is thinner and lighter- Why go with the heavier #41?

Azusa Engineering, Inc. Online Catalog - Roller Chain, Motorcycles, etc.

Outrunner · #5 03-02-2009, 06:33 AM

Orbit, I think that you have a valid point about the left drive chain,although a #41 chain is too wide between the plates (1/4")
A #42 chain has the correct dimensions; 1/2" between pins and 3/16"
width between the plates. That is the proper size to fit the front and
rear sprockets. The weight of the chain is really of little concern, but
the quality of the chain will make a difference.When a chain stretches,
it's stretching the side plates of the chain, and only on approximately
1/2 of the chains total length. This causes the chain rollers to try to
climb up the sprocket teeth instead of setting into the sprocket grooves. Besides creating noise, it wears the sprocket teeth very fast!

Home-made J · #6 03-03-2009, 12:09 AM

A bike builder here in Santa cruz runs a normal bike chain...he did this by grinding down the teeth on the stock drive cog till they fit, and he modified a normal chainring sprocket to bolt to the rear disc brake mount...he swears by it...a lot less drag when under leg power, and better accelleration and braking under motor power...I would have done this mod to my bike, but I had already spent $50 on an Andy's 34T that I love. But a normal bike chain is plenty strong...have you ever seen the micro chains that run pocket bikes? Those bikes pull way more RPM's and produce more torque, and the tiny chains hold up fine.

Whizzer Nut · #7 03-03-2009, 12:35 AM

I have been using a regular single speed bicycle chain on 2 different bikes with no problems. I Had done no mods. to sprockets & I thought the chains fit pretty nice. Less vibration & less drag. On most 2 stroke engines if you look at the output sprocket housing you can see where the 415 chain actually touches the housing at times as there are wear marks. The bicycle chain has more clearance. I also installed one on grubee 4 stroke kit & used chain idler from a tandem bike. that bike has over 800 miles with no issues.

orbit222 · #8 03-03-2009, 09:55 AM

Wow- No mods? On a China kit? I didn't even check to see if a bike chain would fit the stock drive and sproket- I guess the visual difference between the chain that comes with the kit and a bike chain faked me out. Just shows you: Assume makes ass out of u and me. When I get my new (warrantee replacement) motor from Chris Hill I'll give it a try. For me the weight issue is huge- and if it's smoother too all the better. Thanks Whizzer Nut.

ride65 · #9 03-03-2009, 10:33 AM

Why would you need a replacement motor from Chris Hill. I thought he sold higher quality motors?

orbit222 · #10 03-03-2009, 11:40 AM

I had a problem with power loss at high rpms. Chris helped me with trouble shooting all the usual suspects- bad mix, carb clip, etc. He's always prompt to respond. I finally figured out it was a leak in the case (see pic) which I diagnosed by spraying carb cleaner while the motor was running. I fixed it with rtf as suggested on a thread here and dropped Chris a note to tell him what was up. The motor was almost a year old at this point and he didn't hesitate to exchange it for a new one. I'll admit it was a pain, but once the problem became clear he really did come through. As far as his being a better motor, it's hard for me to say as I have no point of reference, this was my first kit and I've yet to meet any other riders here on Cape Cod. I'd recommend buying from him, if you can stand the shipping delays due to the canada customs.