gearing question


12 replies to this topic
  • disastergrafix

Posted July 05, 2008 - 10:37 PM

#1

I have a 07 wr450 with all the mods done to it for power. It is plenty fast and I don't get the chance really to go full speed, so I was thinking what would it be like if I added one more tooth on the rear sprocket to increase the low end power? I cant do wheelies in third gear, in the dirt, but have no problem in 1st and 2nd. Everywhere I ride I am usually in second gear whether it is on the track or the trail. Now I still have the stock gearing. I notice when going down steep hills that my bike likes to shut off when in second and slide, so I have to get into third to keep bike running. So what would happen to the performance of my bike if I went ahead and got one more tooth on rear sprocket? I have re jetted it with gytr smog removal kit, and changed jet for dr.d complete exhaust setup, pulled grey wire, pulled rubber air constrictor under seat. So what do you think, will it let me get into third sometimes, and pull wheelies in third no problem? Or will it not make much of a change? Let me know what you would do. Thanks guys.

  • 123BigcoopDawg576

Posted July 05, 2008 - 10:50 PM

#2

it will help but you probably wont notice very much of a change...:thumbsup:

  • tribalbc

Posted July 06, 2008 - 06:51 AM

#3

I run 13/52 on my 07 It rules for the tight stuff
You'll generally find yourself riding everything 1 gear higher than you normally would

  • disastergrafix

Posted July 06, 2008 - 12:14 PM

#4

If i remember right changing one tooth on the front is like changing 4 on the rear. so you have basically changed 6. I am not sure what to do. Did this mess up your top speed? Is it kind of slow top end? I still want to kind of go fast on straights, but sure would like the low end to pop the front up in third in the dirt. what do you guys think?

  • swede426

Posted July 06, 2008 - 01:17 PM

#5

1 tooth change in back sprocket makes 1,42mph
1 tooth change in front sprocket makes 5,65mph
this calculated from this page; http://www.cosportbi.../SpeedCalc.html

  • tribalbc

Posted July 06, 2008 - 07:25 PM

#6

13 is stock up front. I added 2 teeth to the rear. And yes you're right 1 tooth up front = 4 in the rear.
I probably only lose about 3-4 mph top speed but who holds it pinned in 5th gear that often.

I also have all the free mods and a yz exhaust. Before the exhaust I ran 12/50. With all the extra low end and quick revving of the exhaust I had to raise my gearing to where it is now.

I do ride very tight gnarly woods though. 95% of my time is spent in first to third gear

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  • swede426

Posted July 06, 2008 - 09:15 PM

#7

13 is stock up front. I added 2 teeth to the rear. And yes you're right 1 tooth up front = 4 in the rear.
I probably only lose about 3-4 mph top speed but who holds it pinned in 5th gear that often.

I also have all the free mods and a yz exhaust. Before the exhaust I ran 12/50. With all the extra low end and quick revving of the exhaust I had to raise my gearing to where it is now.

I do ride very tight gnarly woods though. 95% of my time is spent in first to third gear

What bike you ride?
12 in front, wont it wear a lot on the svingarmplastics?

  • tribalbc

Posted July 07, 2008 - 05:45 AM

#8

07, 13/50 is stock. No issue with wear running a 12 tooth all last summer.

  • chevytrkn1

Posted July 08, 2008 - 05:37 AM

#9

13 52 is what i plan on using, Just ordered a new Moose rear sprocket for mine, Needed a little lower gearing for the tight gnarly trails. Glad to hear people like this setup

  • WR450FGreg

Posted July 08, 2008 - 02:46 PM

#10

If i remember right changing one tooth on the front is like changing 4 on the rear.


I think you'll find the rule of thumb is 1:3.
That's what we always work off in roadracing anyway.

Greg

  • projected

Posted July 08, 2008 - 10:56 PM

#11

I've always heard that one in the front is 2.5 in the rear. It's easy to figure out with a gear ratio chart.

  • disastergrafix

Posted July 10, 2008 - 08:32 PM

#12

Well I just looked at my front sprocket and there is a 13 on it. When I was on renthals website checking out their chainrings (before I went outside to look) they show 14 tooth being stock for my 07wr450. Crazy. I havent actually counted the teeth because it is night and there is a plastic guard over my front sprocket, but whatever....lol....I am going with what you guys say...I think I am going to go with a blue 52 tooth rear. I hope this helps me, I have never messed with my gearing before, and am not sure what to expect from this 2 tooth change.

  • taycam

Posted July 16, 2008 - 05:46 PM

#13

I've always heard that one in the front is 2.5 in the rear. It's easy to figure out with a gear ratio chart.


just divide in number of teeth on the front sprocket into the number of teeth on the rear sprocket eg: 15 frt 45 rr = 3 so one tooth change on the front is like 3 teeth change on the rear




 
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