How can I put a #35 chain size sprocket on a bicycle wheel?

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tjmortenson

New Member
Mar 22, 2012
3
0
0
Brainerd, MN
I'm trying to put the motor I took off my minibike on a bicycle. It is a 2.8hp Lifan 97cc from a doodlebug minibike, and I need to figure out how to get a 35 sprocket on my bike wheel. From what I have read, the clamp on ones that come with engine kits are regular bike size chain so they would be too small, but correct me if I'm wrong. any ideas for a sprocket?
Thanks!
 

Thud

New Member
May 26, 2010
205
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0
West Michigan
Hi,
What you are proposing is a fairly simple set up. #35 kart sprockets are cheap & durable (its all i use) & the geometry to layout a 6 hole pattern for the sprockets 5.25" bolt pattern & a 44mm bolt pattern for a disc brake hub is the same. I also have worked on mounting sprockets to a freewheel on the right side.
if you cant afford a new hub or the idea of building your own wheel seems too much. I can show you how to adapt a kart sprocket to a typical "rag" joint adapter.

here is a source for #35 sprockets:
http://stores.ebay.com/MM-Racing-Ka...b=1114699&_sid=74824662&_trksid=p4634.c0.m322
 

tjmortenson

New Member
Mar 22, 2012
3
0
0
Brainerd, MN
Ok, I think I might try to make my own rag joint adaptor. Would a 60 tooth sprocket be good for speed and power? My choices are pretty much 35 tooth or 60 tooth. I don't need a lot of speed, 25-30 mph is plenty, but I would like it to have some acceleration. The minibike it came off had a 70 tooth sprocket, so I should get a little more speed with a slightly smaller sprocket with the same clutch, correct?
 

Bikeguy Joe

Godfather of Motorized Bicycles
Jan 8, 2008
11,837
252
63
up north now
It's not really the number of teeth, but the reduction via the number of teeth on the drive sprocket vs. the driven sprocket. The number of teeth will vary with chain size for any given diameter.
 

Ibedayank

New Member
Oct 29, 2011
1,171
0
0
Columbia Tennessee
now is a good time to learn about gear ratios


use a gear ratio calculator program and find out what your gearing ratio is
you want between 12-14 to 1 final ratio
use to small of gear your clutch will never lock up and it will burn up to big of gears and you will go very slow at wot

to get useable gearing your going to have to build a jackshaft or run a CVT