Rear Sprocket

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Old 01-11-2020, 08:30 AM
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Default Rear Sprocket

Just wondering what size you can go up to w/o having to move/change the chain guides/rollers etc.
Currently running 13:42.
Would a 48 or 51 make it rev too hard at 60mph?
 
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Old 01-11-2020, 03:06 PM
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your going to be around 7000 rpm probably higher with a 13 front tooth
 
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Old 01-11-2020, 07:05 PM
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Originally Posted by philgoodklx
...w/o having to move/change the chain guides/rollers etc.
Very good question! I've wondered the same myself.

Irrespective of engine RPM at any given speed, what will the stock/OEM hardware allow for?
 
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Old 01-11-2020, 10:57 PM
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You can put a 13 FS on it and not change the chain.
 
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Old 01-12-2020, 07:46 AM
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Any chance of an answer to my original post? Sorry for appearing rude but it is frustrating.

Just wondering what size you can go up to w/o having to move/change the chain guides/rollers etc.

Currently running 13:42.
Would a 48 or 51 make it rev too hard at 60mph?
 
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Old 01-12-2020, 10:41 AM
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Current setup 13:42 … sorry I missed that.
Proposed setup 13:51
Net change 51/42=1.21 …..did you have algerbra in HS?
The rpms would be the same as if you were driving at 73mph now.
Go out and see if you think it is too fast.
You can run the motor up to redline –500rpm all day. Is it going to wear more… yes!
 
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Old 01-12-2020, 11:15 AM
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I ran I think a 45/13 no changes with any guide stuff. I will say it would pull without any issue in deep sugar sand up in Michigan. I don't know if I'd get much value from much lower gearing. I will say I've never been a hill climber if that's part of the plan. Never saw the sense in running up hills going tougher and tougher until I'd have to toss the bike and watch it slide and slither to the bottom or worse yet, cart wheel down. So it's mainly trail gearing and I felt it was plenty low. But that's my opinion. I think I've seen where up to a 47 is possible. From what I've goofed with I'd think anything over a 47 is stepping into trials riding gearing.

If you want a gearing/tire diameter spread sheet to do some comparisons I made up a sheet with the ability to do side by side. I did it for gearing and for diameter comparisons when I was looking at doing supermoto wheels on my 650. Made up another for the 2009 and up 250 (different 6th gear) using it for a pre-09 would require finding out what the gear tooth count is for the earlier version. I will try attaching a copy to this message. If you can't open and save a copy you can email me at the cam chain tensioner email address to get a copy sent. kriegercct@clems-garage.com It allows change for engine rpm, gearing, and tire diameter, so you can see what speed the bike will be going at a given rpm for a given tire.


 
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  #8  
Old 01-12-2020, 03:52 PM
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Thanks durielk and klx 678.
Will have a study of your advice tomorrow.
If I am at 7000rpm doing 60mph with 13:42 do I multiply rpm by 1.21 for 13:51 durielk?
 
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Old 01-12-2020, 04:09 PM
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Originally Posted by philgoodklx
Just wondering what size you can go up to w/o having to move/change the chain guides/rollers etc.
Currently running 13:42.
Would a 48 or 51 make it rev too hard at 60mph?
47 tooth will fit without interference. “Rev too hard” is personal preference.Experiment with this link if you want to know actual numbers:

https://www.gearingcommander.com/
 
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Old 01-12-2020, 04:13 PM
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Thanks Osavip.
Is there a thumbs up for thanks?
 


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