new sprockets and chain

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marty125

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hey guys i'm about to order a new 17t front and 37t rear sprockets and a new DID or RK chain for my pitpro 140xr should i get 420 or 428 pitch?? obviously i'll get the sprockets in the same pitch as the chain. thanks in advance.
 
Don't risk the damage a busted chain can do -- Go for the 428
The photo is of 428 gearing 16/32 that I use at the drags-- Small rears are available on Net at ooracing.com-- $61 delivered
 

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i gotta ask why have you chosen 17/37?
my 140xr came stock with with 16/41 so I went to 16/37 to get more speed, wouldn't 16/41 to 17/37 make little to no difference? you're lower the speed with the 17 then upping it with 37 :confused:
 
oh yea don't get a shitty KMC chain, go for RK or D.I.D. they don't stretch/break as easily and will last you allot longer
 
Im pretty sure Changing the Front sprocket does the oppisite to the rear sprocket. so going bigger in the front is like going smaller in the back
 
twit:p did you drop out of school in like yr 4?

whats 41/16? 2.5625

whats 37/16? 2.3125

whats 37/17? 2.17647059

so the 17/37 combo is higher than either 16/41 or 16/37

its not really that hard:p

now pitch wise, 420 and 428 are the same pitch, but 428 being slightly wider means less pressure on the rollers and tooth face, which then means less wear, so the 428 will last slightly longer. but then, other factors like maintenance and brand also come into play...

its your wallet, so your choice...and 428 may be too wide for things like engine cases and swingarms...

just dont use an o-ring chain, its absorbing about 10%of your power, so if youve got ten at the output shaft, you only have 9 at the wheel... try plain chain on a big bike with 70 or more horses and notice the difference:eek:

once again maintenance....
 
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oh yea! I wasn't thinking properly, damn pain killers mixed with booze:eek:
 
excuses, excuses:p and im running 17/34 just so the maths is easy:)

id go 16/32 but the chain will chew out my swingarm...

see, changing sprockets isnt just about size, theres all these other little gremlins that start having a party when you modify something... another gremlin and ima gunna have a fifinella:eek:
 
i got 17/32..... with 428 RK HD.....cruizing speed is achieved.
 
the 17/37 is a pretty good gearing there marty...what da bomb has is less than 2;1 thats all. so he has even higher gearing.

bomb, do you get it to redline in 4th?

i get almost faster in third than fourth with my gearing, but you got a 140, so....
 
disregard everything I said mate, I was confused and got it wrong ;)
 
actually o rings lube better than regular chains and last longer, better wear on sprockets, how do you figure you loose horse power? sure they might not be worth the price difference, but loosing horse power? what do you think about x and t-ring chains? i know they are more drag cause of size, but that cant be much, but you got some dynos on this?
 
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the 17/37 is a pretty good gearing there marty...what da bomb has is less than 2;1 thats all. so he has even higher gearing.

bomb, do you get it to redline in 4th?

i get almost faster in third than fourth with my gearing, but you got a 140, so....

something like 130k, my mass tyres put out my speedo :)
 
From my timed Drag strip runs 17/37 is exactly 70mph (old money) red lining in top with a yx150 and 120/70 Motard wheels
 

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From my timed Drag strip runs 17/37 is exactly 70mph (old money) red lining in top with a yx150 and 120/70 Motard wheels

i have the exact same gearing, what size wheels is 120/70? i have a 12 inch rear rim, so i guess i shud get around 120kph.

what time did ure bike run down the strip?
 
120/70 is the Tyre size of my 12 inch Motard wheels, I ran best of 17.5 secs & tried 16/32 gearing but only ran 17.9secs. at 70mph -- not enough power yet too pull the taller gearing.
 
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