SPROCKETS - Front, rear, one tooth equals?

[JackFlash]

Just wondering, is there a rule of thumb that says adding or removing a tooth on the front sprocket is the equivalent of removing or adding a certain number of teeth on the rear?

Just wondering about making an I-4 a little torquier or giving a twin more at the top.

Feedback?

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[mojocho]

-1 in front = +3 in rear.

For more precise info, go here:

http://www.gearingcommander.com/

[serpentracer]

just keep in mind not to go too small up front or it's hard on the chain to make that tight turn.

[ReconRat]

It's a variable ratio depending on the front/rear number of teeth that you start with. (stock)

Easiest way is with a calculator to crunch the numbers. Finding equivalent ratios. (Or a change in ratio.)

http://www.sprocketcalculator.com/

http://www.gearingcommander.com/

http://www.rbracing-rsr.com/calcsprocketdiam.html

edit: yeah, and it doesn't make torque, instead it applies torque more efficiently (or not). Similar result.

Edited November 22, 2012 by ReconRat

[jporter12]

What the enginerd above said...

[ReconRat]

I shouldn't have said variable ratio. It's an uneven ratio because of the original number of teeth front/rear. Like mine is 16F and 44R, which is a 1:2.75 ratio. So there really isn't a perfect changing of the front sprocket up or down one or two teeth that could possibly result in an exact match. But something close could be found.

So yes, on my sprockets if I wanted to go down one tooth in the front, then 3 teeth up in the back instead would be close. It would be slightly more "than one in the front", or basically 1.09 tooth in the front change. 10% more. Confusing enough?

Actually, I'd rather go up 2 or 3 in the back and keep my stock front sprocket. The rubber dampener on mine does kill vibration. I've noticed the difference between the two bikes I have. And I will switch it back some day. Not all bikes will be that way though. Liter I-4, probably so.

[Bubba]

Going smaller on the front is prolly the easier/cheaper option than going bigger in the back. Smaller front definitely puts more stress on the chain and may wear the chain guide excessively. Going bigger on the rear by more than 1-2 teeth prolly means buying not only the sprocket but a new longer chain as well, or minimally, adding a link or two to the old chain.

[blue03636]

Drop one down in the front and two up in the rear. They usually don't recommend going more than 1 in the front. If you do front and rear the chain you have should still fit if your not replacing it.

1 front tooth is about the same as 2-3 on the rear.

[Gixxus Christ!]

Now is the time on SPROCKETS ven vee dance.

[blue03636]

Now is the time on SPROCKETS ven vee dance.

would you like to touch my monkey?

[SWing'R]

Now is the time on SPROCKETS ven vee dance.

http://www.youtube.com/watch?v=QHZR9SA5pOg

[Gixxus Christ!]

Thread derailment level: master.

[SWing'R]

Thread derailment level: master.

It wasn't you, before I even read thru the thread my mind was already at the "SNL Sprockets"

just by the title of the thread, I was surprised anyone else knew what it was lol

[Moto-Brian]

What was echoed by others. You want to shoot for the best ratio between front and rear.

Think of it this way - what can you do to get as equal a diameter between the front and rear sprocket?

Don't fall for needing more teeth in the rear for better drive, either. It is a bandaid for low corner speed. Work on corner speed and the teeth come off the rear sprocket... You need drive so, yes - you will need to adjust the sprocket ratio. But, several guys are close to stock in terms of ratio...

[ReconRat]

Yes what Desmo-Brian said. There are compelling reasons to use stock gearing. The factory is pretty close to a "do all" gearing ratio. If you're doing something different than average, by all means experiment with ratios.

I've tried gearing up and down. I now avoid it. I did like one down front or 3 up in back for around town on a small bike, but many larger bikes don't need it at all.

And so far "gearing up for freeway" isn't too attractive either. Just too bogged down when in traffic.

[redkow97]

Yes what Desmo-Brian said. There are compelling reasons to use stock gearing. The factory is pretty close to a "do all" gearing ratio.

I disagree. I think a lot of bikes are geared with a top speed bias, because that's something squids care about.

No one needs a 150 mph street bike. Every 600 on the market could be geared -1/+3 and have more than enough speed for doubling highway limits. Better highway passing power too, which is one of the reasons I hear people wanting a liter bike for the street.

[ReconRat]

I disagree. I think a lot of bikes are geared with a top speed bias, because that's something squids care about.

No one needs a 150 mph street bike. Every 600 on the market could be geared -1/+3 and have more than enough speed for doubling highway limits. Better highway passing power too, which is one of the reasons I hear people wanting a liter bike for the street.

Good point. But then it's endless wheelies. Somewhere in between is a comfort zone.

[Moto-Brian]

I disagree. I think a lot of bikes are geared with a top speed bias, because that's something squids care about.

No one needs a 150 mph street bike. Every 600 on the market could be geared -1/+3 and have more than enough speed for doubling highway limits. Better highway passing power too, which is one of the reasons I hear people wanting a liter bike for the street.

If you need -1/+3 on a 600, you're doing it wrong. We run very close to stock gearing at a lot of tracks. If you need to hear to that type of ratio, you are lacking corner speed typically. Guys will ask is what gearing we run and I try and avoid it. Basically, they try gearing for a more experienced rider and they can't pull that gearing.

We are also moving to a lot of 5th gear gearing choices for a lot of tracks for example vs. 6th.

Point is that unless you wanna squid and pop tons of whoolies, -1 in front is about all you'd ever need. More than that and you need to work on other things and are simply covering up certain inadequate skills.

[redkow97]

I'm talking for street use. For track, I had stock and +1 gearing.

[Moto-Brian]

I'm talking for street use. For track, I had stock and +1 gearing.

I still don't see a reason to drop 1 and add 3 for street. RPM will be higher and no need.

I can see -1 for street, bit adding essentially 6 teeth for the rear is really silly.

[JackFlash]

Hey guys, Bellevue just called. They said to put down the funny cigarettes and come on back home or they are going to have to send the boys out with the long sleeve sweaters again to bring you back.

Now is the time on SPROCKETS ven vee dance.

would you like to touch my monkey?

Thread derailment level: master.

It wasn't you' date=' before I even read thru the thread my mind was already at the "SNL Sprockets"

just by the title of the thread, I was surprised anyone else knew what it was lol [/quote']

:nono:

I'm guessing that your names are most often mentioned in sentences that include the phrase, "the usual suspects."

.

[redkow97]

I still don't see a reason to drop 1 and add 3 for street. RPM will be higher and no need.

I can see -1 for street, bit adding essentially 6 teeth for the rear is really silly.

Sillier than having a 1000cc 160 horsepower commuter that is capable of triple the speed limit?

[Moto-Brian]

Sillier than having a 1000cc 160 horsepower commuter that is capable of triple the speed limit?

Just as silly as a current generation 600. You are saying that a 1000 is silly, but a guy taking and adding essentially 6 teeth on the back sprocket of said 1000 with 160 hp makes even more sense? You understand that the throttle response becomes MUCH more aggressive with the shorter gearing and adding the hp of said example is going to net what exactly?

The point is that you can compensate for inadequacies all anyone wants. OR, they can work on skills and become better riders where they don't need such changes. Again, -1 in the front is more than enough...

Plus, the example of a 160 hp 1000 allows a rider to be lazy moreso. The torque that is available from the 1000s is such that shorter gearing is VERY much a counter productive exercise. But, guys do it for the whooooolies so, that makes sense.

But, I cannot see why someone needs to shorten the gearing so much as you are leading folks to believe. It's really pointless and silly. It just doesn't make sense to do that aggressive of a gearing change...

[redkow97]

The OP has a GS500. -1/+2 isn't going to make his bike a wheelie machine.

[JackFlash]

...mine is 16F and 44R, which is a 1:2.75 ratio. So there really isn't a perfect changing of the front sprocket up or down one or two teeth that could possibly result in an exact match. But something close could be found.

So yes, on my sprockets if I wanted to go down one tooth in the front, then 3 teeth up in the back instead would be close. It would be slightly more "than one in the front", or basically 1.09 tooth in the front change. 10% more. Confusing enough?

Let's see. 44 / 16 = 2.75 One tooth lost on the front would be equal to 2.75 teeth added to the rear.

16 / 44 = 0.3636... One tooth added to the rear would be equal to 0.3636... teeth lost on the front.

Three teeth added to the rear would equal...

3 X 0.3636... = 1.0909... teeth lost on the front.

I just might have a handle on it.

.