sprockets

[kivmax]

For more acceleration when short on funds.....
What do you do? Down 1 tooth in the front? Or up 2 or 3 on the back sprocket? My wife said no to new pipes....Too much money.
What are the pro's and con's of changing sprockets?

[TusherTLR]

Pro: lower gearing (I went down on on the front) = MUCH better accel
: One of the best bangs for the buck...HIGHLY recommended!

Con: Speedo is off (I don't find that it is a big deal though)
: This also provides less fuel economy (not a big deal)
: some people have had the chain mash the spacer

[kivmax]

Originally posted by TusherTLR
Pro: lower gearing (I went down on on the front) = MUCH better accel
: One of the best bangs for the buck...HIGHLY recommended!

Con: Speedo is off (I don't find that it is a big deal though)
: This also provides less fuel economy (not a big deal)
: some people have had the chain mash the spacer

I heard that about going down in the front, have you had any problems with the spacer? Seems to me 1 tooth wouldn't hurt.
And how much could it possible affect gas mileage?

[SDTLR]

It will chew down the chain guide in a year or two. Just ask sweets

41t rear

[TusherTLR]

I haven't had any problems with the spacer...although, I must admit that I haven't removed the cover to check it out. I just haven't heard anything out of the ordinary.

The fuel economy will be a negligible difference...for me, it was an 'all encompassing' thing...I did the front sprocket at the same time I put on a TFI box. Man, does that thing add fuel. Not to mention...once you change the sprocket, and feel that wicked acceleration....you tend to want it all the time. Thus...I have been on the throttle a lot!

[kivmax]

How many teeth on the stock back sprocket? Is it 39?

[TusherTLR]

Originally posted by SDTLR
It will chew down the chain guide in a year or two. Just ask sweets

41t rear

I heard that from different people too...but theoretically...wouldn't decreasing the diameter (by going down on tooth) actually pull the chain away from the spacer? Soooooooo...shouldn't this actually 'help' the spacer? I could see if it was going up a tooth...

The other school of thought is that the hard acceleration stretches the chain at a greater rate, and therefore get sloppy quicker...maybe this is what happens?

dunno

[TusherTLR]

I think you are right...17/39 stock... the gearing is different on a Tillis though. If memory serves me correctly (and I am sure that numberous Tillis owners are willing to jump down my throat if I am wrong on this one), I think it is 17/38...anyone?

[TusherTLR]

Changing the front sprocket is very easy...I would highly recommend using an impact though. It came off like butter. The whole job can be done in less than an hr! 1/2 hr if you are good

[dgyver]

An exhaust by itself doesn't really add too much to accelleration anyway.

My front sprocket came off with just a regular wrench. Good thing that there is a safety washer there. Doesn't going down a tooth in the front cause extra chain wear by turning a smaller radius?

[TusherTLR]

I think you're right

[N2wheelies]

for my tls - 1/4 acceleration improvements

one tooth in the rear = micron slip ons

that is my bike turns the same times with micron slip ons and stock 17/38 gearing
or
stock exhaust and 17/39 gearing

[KBOlsen]

Going down one tooth in front will not hurt anything, and you won't need to add/subtract any links in the chain.

Go down one in front first, then add teeth in the rear if you want. The "optimal" setup will depend on your objectives. For example, the top speed of my bike has been somewhat reduced in the interest of being able to accelerate harder/faster in a shorter distance. If you like to do a lot of high-speed, straight-line, roll-on stuff, then my gearing (currently 16/46) would not be good for you.

[Steve TLS]

Originally posted by dgyver
Doesn't going down a tooth in the front cause extra chain wear by turning a smaller radius?

It's late, so I'll keep it short, a smaller front puts more stress on the chain in tension too.

For example if you go for a 6% chain in final drive ratio by dropping the front, you increase the stress on the chain by 6%.

If you alter the final drive ratio by 6% by going up on the rear, you have the same torque applied to the rear wheel as dropping the front but for a zero increase in chain stress.

If wear is linear with stress and 20K miles is normal for std ratio, we are only talking about 18,800 miles of life now, no big deal. But is it linear? And do you want to put the chain under more stress by choice?

But for the guys who go samller on the front and run a 520 chain IMHO

[N2wheelies]

i agree with steve on the chain stress #