41 tooth to 32 t sprocket

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sseisup

New Member
Feb 18, 2009
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mn
I got a BGFast 80cc that came with a 41 tooth and switched to a 32 tooth rear sprocket. I haven't got to ride it out much yet but now instead of 20mph in the middle of the rpms, it's really close to the start of the rpms. The quality isn't the best I guess, but it's running.
 

Bikeguy Joe

Godfather of Motorized Bicycles
Jan 8, 2008
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I had similar question...how fast do you have to go before releasing the clutch?

Also, I'd bet your top speed has decreased.
 

sseisup

New Member
Feb 18, 2009
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mn
Yeah, on a 26". It works great on the flat but any hill really knocks it out. The goal was less rpms at 30 mph. It does that well but takes more to start it off, not impossible to do. as for top speed I'm not brave enough to pas 30 yet on it, but considering how hills take it out I could see how the wind resistance would hurt. It was one windy night last night and sometimes the wind alone near stopped me. I'm gonna try a few more rides, but I guess I just gotta get used to high rpms.
 

Nikko

New Member
Jun 23, 2011
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hi im running a 44 tooth sprocket and ordered a 32 tooth, ino its a big jump but i want top speed, how fast do you have to be pedaling to release the clutch and realy start moving, also how fast can you go now and any advice for me before i make the decision to switch
 

mapbike

Well-Known Member
Mar 14, 2010
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I have a 34T on one of my bikes and a 36T on another one, with a good free flowing exhaust, a properly tuned carb. and a thinner head gasket or just sand a few thousands oof the head and both of these work great for me, I have hills I have to climb all around here and I never have to peddle on any of them, I top the hills still running 20+ MPH, 25-27mph on most of them, I weigh 200lbs.

I hade the stock muffler on one bike after installing the 34T sprocket and it would barely pull me on the bike, it was a real dawg.......until I put a SBP expansion pipe on it and then with only that one mod. it pulled the 34T just fine, I say just get a good free flowing exhaust even if you dont use an expansion pipe and it will make a world of difference in my experience.

Peace
 

Poe

New Member
Feb 27, 2013
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Arizona
I had a 18 tooth sprocket on my rear for a while. 700c tires. Had to pedal to about 15-20 to get the engine going and i could only get her up to about 35. but she felt awesome at such a low rpm. Only problem was the wind would stop me :( lots of pedaling involved and im switching to a 34 soon. On a 44 currently.
 

MotorBicycleRacing

Well-Known Member
Jul 28, 2010
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SoCal Baby!!!
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I had a 18 tooth sprocket on my rear for a while. 700c tires. Had to pedal to about 15-20 to get the engine going and i could only get her up to about 35. but she felt awesome at such a low rpm. Only problem was the wind would stop me :( lots of pedaling involved and im switching to a 34 soon. On a 44 currently.
Do you have a pic of that? :)

18 tooth sprocket is a crazy theoretical top speed of 81 mph on
29" tires at 7000 rpm.

You will get off the line much better and have a faster top speed
with a 34 tooth sprocket, 43 mph but you won't be able to pull it
with a stock bike.
A 36 tooth sprocket would be a better choice.
 

bairdco

a guy who makes cool bikes
Aug 18, 2009
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living the dream in southern california
smaller sprockets need more engine mods (and a lightweight rider helps... :) )

i run a 30t on my everyday 24" cruiser, a bunch of engine mods, and i weigh 135.

pulls me up hills great, can start from a standstill without pedaling (slowly,) and tops out at 45mph. (if you search "bairdco" on youtube and find the video "getting beer is uphill all the way" you can see me going up a 1/4 mile hill that's steeper than a 6% grade at speed...)

i ran a 28t on a 26" bike with heavy mods and gps'd it at 54mph.

then i blew it up drafting a truck at 62mph.

if you're scared to go fast, you don't need a 30t. sounds like a 36 would be the range you're looking for.
 

mapbike

Well-Known Member
Mar 14, 2010
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Central Area of Texas
I gotta Bikeberry 66/80cc on a 26" Giant with a Jaguar CDI, Pro-Jetpipe & 36T.

How much acceleration would i lose by running a 34T instead???????????
Anybody, thanks
Not much in my experience, but I had my 34T on a bike that has a well ported higher compression 66cc dax GenIV engine, I didn't realized any felt or seen difference between the 34T and the current 36T I have on it now, top speed may have been 1 mph faster with 34T ....:confused: but I haven't noticed any difference in power at low to mid speeds between the 34T and the 36T, I think the difference would show if I went down to a 32T from the 36T or had gone from a 32T up to a 36T.

Unless you have some good port work done and a well tuned carb along with a very free flowing exhaust id stay with 36T or larger sprocket, because it take a strong engine set up to pull a 32T or less on a 26" wheel and as Bairdco has said it also helps if your a light weight rider, I weight 220lbs and a 36T works good still for me but if I were to go to small my weight would create problems on hills even though my bike has a pretty strong engine that has run me down the road at 45+mph on the flat with a 36T sprocket on the rear, and currently cruises nice at 42mph.

The 36T is the best all around size if you dont weight to much and you dont have to many steep hils to contend with in my opinion, but if to many hills are involved and your a heavier rider then I like the 41-44T as a good choice for a 30mph bike with a well built up engine that is tuned right.

Peace, map
brnot
 
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