Choosing a Rear Sprocket

[Cabinfever1977]

actually i could go faster than 35mph with my 44t but i dont want to have somebreak on bike at those speeds. not all these engines go the same speed and you have to account for diffrent bikes with diffrent tires and the big diffrence of the riders weight. and some people dont have there motors properly tuned up or installed right.

 

[TerrontheSnake]

I am running a 44t 66ccPowerKing and hit almost 30 on a smaller OCC rear wheel so obviously it would do way more potentialy on a 26.

 

[TerrontheSnake]

Takes a nice straight run about 300 ft then mine gets a second wind and kicks into high gear. I'm pretty sure I could get way more rpm out of it because I know I haven't even touched the top of the rpm range.

 

[xlite]

I am running a 44t 66ccPowerKing and hit almost 30 on a smaller OCC rear wheel so obviously it would do way more potentialy on a 26.

Not necessarily. Speed and torque are tradeoffs. I swapped 44t with 36t on that engine (same as bigger wheel) and top speed actually went down. It runs smoother with less vibration around 20mph though.

 

[burnclouds]

OK I got my 36T installed on my 80cc and I'm keeping it there.
Here are the details (YMMV):
I just swapped my 44T for the 36T.
The 44T topped out at 20mph on flat level ground.
The 36T tops out at 31.5mph on flat level ground.
Going up the steepest incline around here the 44T would get me going about 17mph, the 36T does 25mph on the same hill.
I only weigh 140 ± 5lbs.
All of this in using the Mountain Bike in my avatar (until i change it).

 

[soccerrj88]

Well I just took my new bike out for a spin this morning and hit 31 easily with a 44t stock set up... I'm still workin on breakin it in so I don't know if that was top speed or not but it was still excelerating. Given that, I would like to get a smaller sprocket just so i could cruise at a faster speed with lower RPM... What are the increments of the sprocket sizes you can get? I was thinkin a 40t would be a good compromise. I'm usin a 26" MTB. If Im running that now, what can i expect with a 40t or 36T?

 

[xlite]

OK I got my 36T installed on my 80cc and I'm keeping it there.
Here are the details (YMMV):
I just swapped my 44T for the 36T.
The 44T topped out at 20mph on flat level ground.
The 36T tops out at 31.5mph on flat level ground.
Going up the steepest incline around here the 44T would get me going about 17mph, the 36T does 25mph on the same hill.
I only weigh 140 ± 5lbs.
All of this in using the Mountain Bike in my avatar (until i change it).

I would expect a little more like 34-35mph and I weigh a LOT more than 140lb. 31 ain't bad though.

 

[Arnie]

I bought my 36 tooth sprocket for 10 bucks plus shipping, works nice.

 

[Alson]

I get 36 mph out of my 44t sprocket, I have 27 inch rims and a speedomater set for the rims, plus an expansion chamber from SBP Im thinking of going to a 40t gear. I was woundering if I had to shorting the chain when I went to a 40t

 

[The_Aleman]

Of course. When you run a smaller sprocket, you have the corresponding less amount of chain to run, because you are making it smaller. Yup. Think about it.

Also, this might help.

 

[decoherence]

this reminds me of when i was in the vespa forums & everyone said i couldn't do the 75-80mph that i claimed. so i posted 3 different speeding tickets. even had a cop pull me over doing 80mph but that is just because i was on I95 & able to draft.

back to topic. my 66cc 36t can hit 31mph on flats but four stroking like a mofo.

the rest of the stats are billet intake, upgraded carb & filter & expansion chamber. oh i weigh just short of 200#.

 

[F_Rod81]

I will only say that you should stick with the 36T since the engine will not like pull you with a 32T. It barely pulls with a 36.

I object. I have a "King's" 34T that does the job just fine. Plenty of hills and trails around. My weight is 181lbs; and I don't mind pedaling to 8mph. According to my gps I can get going close to 48mph on flat surfaces, and an average speed of 35.3mph with more rpm to go. Your tires and tuning are gonna make a huge difference. To **** with stock, go mods!!!

My bolt-ons:

- M.M. Ported intake
- SBP Air filter
- Properly jetted
- SBP expansion pipe
- SBP plug wire
- NGK BPR7HIX

 

[bobdeezy]

If that was true you would be at 8150 RPM with 26" wheels

How are you measuring that 35 mph?

my stock Products 80cc slant kit went a lil over 40 my first day out after the break in with a stock 44t sprocket. i dont have a tach so i couldnt tell u the rpms but it was screamin. i wont hit those speeds again till i replace my rear sprocket just cuz i dont wanna blow up this motor (yet) . but im sure with my lightweight 27" roadbike and lightweight a$$ ill be able to get a comfortable 40 with at least a 47 mph top. ill keep u posted.

oh btw ill be ordering my sprockets here Zoombicycles 36 Tooth 9 Hole Rear Sprocket (4-11C) | Accessories | Parts and Accessories | EHBC Distributors Ltd with shipping its the same price as bgf but ive heard alot of bad things about bgf