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Old 02-27-2009, 09:56 AM
bobber bobber is offline
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Default Wheel & gearing question

First, I would like to thank you in advance for responding with helpful information. Its great that I can come to this site and get info that helps me enjoy my toys.

I have a mini bike bobber & would like to put a larger tire on the rear. It currently rides on a 15x6.00-6. I would like to go to a larger size to make it look more proportional. I was thinking more like a 10" rim. I don't want to get any wider. Any help would be great.

The other thing I would like to change is the lack of low end power. It is pretty slow off the line and I would be willing to sacrifice top end for more pick up. It has a 54 tooth rear & a 10 tooth front. I rode next to a friends truck and on his speedo I topped out at 28 mph. It has a 3 hp Briggs which soon will be replaced by a 5 hp Briggs. The 30 MPH range is plenty for my neighborhood.

When I increase the wheel size I am guessing I will increase the top end & decrease the low end.
Any suggestions on how to gear it so it doesn't feel like I'm standing still when I take off?

I'm also am replacing the over sized seat.

Thanks.







Last edited by bobber; 02-27-2009 at 10:26 AM. Reason: More info
  #2  
Old 02-27-2009, 11:23 AM
Cotmullion's Avatar
Cotmullion Cotmullion is offline
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That bike is brilliant!!! I love the handlebars. About the gearing: If you increase the tire and the sprocket you will barely gain anything, so you need to increase the tire size and increase the sprocket even more, to get better low end torque and acceleration.
  #3  
Old 02-27-2009, 04:54 PM
Kenny_McCormic Kenny_McCormic is offline
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Nice build!
Rule of thumb is you cant run over 15" of tire on a cent clutch. With the 5hp ungoverned and that gearing/tire it should do around 35
  #4  
Old 02-27-2009, 06:03 PM
bobber bobber is offline
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Thanks. I saw a big Scag mower at a shop today that had a 8" wheel. It was nice because it was tall and narrow. It was the wrong size hub though.
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Old 02-28-2009, 07:22 AM
bobber bobber is offline
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Kenny,

I just took a second look at your reply. You said the tire I have on it is the max height I should run with a cent clutch.
I want to put a TAV-2 on it but not right away. I was going to do the engine swap then the wheel swap. I was going to add the TAV-2 later.
I guess I should rethink more order of attack?

Thanks
  #6  
Old 02-28-2009, 09:19 AM
Kenny_McCormic Kenny_McCormic is offline
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Engine swap
TAV
Tire
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Old 02-28-2009, 12:10 PM
Scorch3 Scorch3 is offline
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Quote:
Originally Posted by Kenny_McCormic View Post
Engine swap
TAV
Tire
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