Tell me if you will, is it better to increase the size of the rear sprocket rather then the easier route of decreasing the size of the front sprocket? Tell me the good and bad of both.

Thanks

 

There is a difference in the feel. I prefer to go bigger in back, when possible.

If you go bigger in back, you may not have room for the bigger sprocket to clear the skid plate, etc. Plus, your chain may come up short.

If you decrease the front, usually all you need to do is take up the chain slack.

 

It is better to go up in size on the rear sprocket. This said b/c when you go smaller on the front you get frictional and static horsepower loss due to the chain having to go around a smaller rotating circumference. ex. if you could go up from a 10 on the front and 20 on the back to a 20/40 even though you would not be changing the ratio you would actually pick up fractional horsepower gain due to the above stated facts. just my $.02

 

I have gone from a Front 17tooth to a 15t now to a 14t and it just does not feel right even though the bottom end and the top end is pretty much where they need to be. It seems in each gear the power peaks and then kind of falls off before the peak rpms is obtained. Does that make sence? Could this be because of the small front gear and if it were a bigger rear sprocket it would just feel better?

 

Going smaller in front, will also put more strain on the drivetrain. I always prefer to go bigger in back when possible.

You may have other issues, like just a plain lousy powerband to start with????

 

Changing the gear ratio is not an exact sience. It depends on what you are looking to get out of the machine and what is availlable sprocket weise
I do agree going bigger in the rear is best. But you do loose ground clearance also chain guard issues come up
Going smaller in front is the biggest change
I have 2 Honda 400EX 03 sprockets stock 15-38
Changed to 14-38 due to allot of trail riding not need allot of topend
Then added 39 to rear when purchased 22" paddles for running the dunes Big improvment
Lost top end but Rev Chip made up
Difference
My 400 stock with sprocket changes and rev chip 22" paddles spark arrestor modified to 1-18" id on 50/50 race gas mix
Buddys 400 with 14-38 sprocket race exhaust 22" paddles no rev chip 91 octaine Loud
I pass no problem pulling the hills at Glimas no problem
I have just installed a 13 tooth front sprocket now 13-39 tried much better trail riding cannot wait to try at the dunes
Biggest reason for me is now if pulling big dunes Me no need to drop into first gear due to not enough HP lower gearing keeps engine rpm's up
Harder to hit Neutral when 3/4 way up big dune ( happens when least expect loose all momentum forward buddys laugh )
Buddys all buying 450R bikes now me happy with 400EX can only go so fast anyway
Change gearing makes good sense
But it depends what you are looking to get out of it
It don't hurt to try
Sprockets cheep easy to change someting to try between rides in camp small change makes difference
Just my thoughts
Thanks
Ray

 

<div class="FTQUOTE"><begin quote>Originally posted by: outofline

I have gone from a Front 17tooth to a 15t now to a 14t and it just does not feel right even though the bottom end and the top end is pretty much where they need to be. It seems in each gear the power peaks and then kind of falls off before the peak rpms is obtained. Does that make sence? Could this be because of the small front gear and if it were a bigger rear sprocket it would just feel better?</end quote></div>

when changing gear ratios to a lower gearing(higher numerically) you will pass through your gears faster. Sometimes on less powerful machines a gear change will not really be able to be felt in "the seat of the pants" it does make a difference. Dragstrip et's/mph are what really show the difference, along with top speed. In reference to your statement about the power peaking and falling off before peak rpms, this is normal on any engine. As the rpms reach the upper end of the spectrum horsepower starts to decline and on some engines it drops at 6k some at 10k. BTW what kind of machine are you working on? Anyhow an example of my first statement i had a 1972 honda sl 70. I wanted harder acc. out of it so i changed the back sprocket from a 40 to 44 not very noticeable, just dropped the top end down. Then again on my z400 i went from 14/38 to 13/44, huge difference. Over the years on all the machines i have worked on, the biggest difference can be felt in the biggest bores, although you can feel a difference on any machine, you just have to have a well trained rear end:-)

 

I went 1 tooth smaller in front on my 450R. The R's are geared tall stock anyway, so the change isn't that dramatic. Even though this is a desert quad that gets ridden mostly in open country, I like the extra low end grunt, and a more torquey throtle response. No problem with it becoming wheelie happy...