Front sprocket size

snobles · #1 (**permalink**) 05-25-2012, 03:09 AM

I have a 46 tooth rear sprocket. What size front sprocket should I run on my CFL, and where is the best place to get it from?

morrison100 · #2 (**permalink**) 05-25-2012, 11:33 AM

what size motor and what kind of beltdrive?probably a 23 tooth anybody that sells pbi sprockets.i have them in stock for a 200 bike or 140

cfl19692000 · #3 (**permalink**) 05-25-2012, 01:55 PM

Hey snobles

cfl19692000 · #4 (**permalink**) 05-25-2012, 02:09 PM

Snobles if you parts contact Devon at least he is honest

Captain America · #5 (**permalink**) 05-25-2012, 06:21 PM

I like to use this gear ration calculator, it's very accurate and you can then dial your bike into the RPM range that you want depending on your primary ratio, trans ratios, final drive ratio, and rear tire size...

Motorcycle gear/rpm/speed calculator

FRANKTHECRANK · #6 (**permalink**) 05-25-2012, 06:50 PM

Quote:

Originally Posted by snobles

I have a 46 tooth rear sprocket. What size front sprocket should I run on my CFL, and where is the best place to get it from?

Front sprocket that has been tried and true is a 23 tooth PBI sprocket. Part number 28123, with has a .500 offset,.....which works with the 1/2 inch offset the CFL frame has built in.

pushrod243 · #7 (**permalink**) 05-25-2012, 07:01 PM

Quote:

Originally Posted by FRANKTHECRANK

Front sprocket that has been tried and true is a 23 tooth PBI sprocket. Part number 28123, with has a .500 offset,.....which works with the 1/2 inch offset the CFL frame has built in.

I agree PM me i can hook you up

CloudDiver · #8 (**permalink**) 05-26-2012, 07:30 PM

I have a 21 tooth from Baker, .5 offset built in, my rear sprocket is a 48, PM doesn't do a 46... The thing to ask is what your first gear ratio is, then decide on you front tooth count.

snobles · #9 (**permalink**) 05-27-2012, 04:26 AM

Thanks guys, that was a huge help

axeychrome · #10 (**permalink**) 07-23-2012, 03:12 AM

I've always used the PBI fronts with a meganut. good parts.

I'd made a whole spreadsheet to try to figure out the gearing since i plan on using a Primo instead of BDL's like in the past.

i'll have a 6 spd/121" in it. what do you guys aim at for a good engine RPM at what speed?

i.e. i did several big engine bikes with gearing that is only 2500 RPM at about 70mph (BDL,6spd,24&51). It seems low, but i had one customer say he wanted it revving higher, and another saying he wanted it revving lower at that. another bike w/ just an 80" evo (BDL,5spd,24&50) had about 2850 rpm at 70 mph. comparatively, my old man's sportie revs about 3000 at 55-60mph, which seems way high to me, but...??

I'm assuming the calculations are right, as they match that gearing link Capt A posted below. (thanks for that!).

HellionsMC · #11 (**permalink**) 07-23-2012, 07:36 AM

Quote:

Originally Posted by FRANKTHECRANK

Front sprocket that has been tried and true is a 23 tooth PBI sprocket. Part number 28123, with has a .500 offset,.....which works with the 1/2 inch offset the CFL frame has built in.

I have the 23T PBI front sprocket and a 46T WCC rear sprocket...when I install the front sprocket on the gearbox, do I need to put any spacers behind it or is that the point of the offset built into the sprocket? I still need to pull off the pulley that came with the gearbox originally. And yes, I know about the left hand threads and loctite.

pushrod243 · #12 (**permalink**) 07-23-2012, 08:04 AM

There is offset built into the sprocket but you will have a sprocket spacer behind it that you can fine tune your offset if you need to.

BANGS · #13 (**permalink**) 08-02-2012, 05:36 AM

I have the ultima 6 speed and took the pulley off to put on a .500 offset sprocket. Problem I have is the spacer that sits on the main shaft behind the sprocket is .600 thick. Everyone says .500 offset sprocket for the CFL but with this spacer on pushes it way out. With the spacer off it's .500 from the face of the tranny but rubs against the big outer seal.
I'm sure there are plenty on here used the ultima in the cfl and converted it to sprocket, do I have to machine down the spacer?

coryhebert · #14 (**permalink**) 08-02-2012, 01:26 PM

It never ceases to amaze me how people focus on sprocket sizes, and never take their primary drive into account. Not all primary drives have the same ratio, and vary greatly from one manufacturer to another.

Folks, you have to count the teeth on all 4 pulleys/sprockets in question. Do yourself a favor and use my gearing calculator:
http://www.maindrivecycle.com/tech-gearing.html

axeychrome · #15 (**permalink**) 08-03-2012, 03:14 AM

Quote:

Originally Posted by coryhebert

It never ceases to amaze me how people focus on sprocket sizes, and never take their primary drive into account. Not all primary drives have the same ratio, and vary greatly from one manufacturer to another.

Folks, you have to count the teeth on all 4 pulleys/sprockets in question. Do yourself a favor and use my gearing calculator:
Maindrive Cycle gearing calculator

agreed on having to consider the primary too. looking at both vendor sites, appears the BDL's i used before were 47,72, while primo brute iv is 48,76. been playing with other tools out there and my own spreadsheet, but was trying to find somewhere that really tells a goal for the end ratio. with a primo belt drive and a 48 tooth rear sprocket, i was debating between a 22 and 23. yours shows i'd need closer to a 24. back to pondering a little...