Noob question about sprockets

annguyen1981 · December 27, 2005, 11:42:17 PM

From what I understand, changing the sprockets will give more kick of you get one with more teeth... Is this correct?

I understand the RPM will be wrong and the speedo will be 100% correct.

What advantage does changing sprockets do besides more kick?
Any disadvantage?

makenzie71 · December 27, 2005, 11:49:23 PM

Chainging sprockets can give you a "kick" but you got to know where to put it.

On the GS, changing the sprockets has no effect on the speedo. RPM per speed is altered but that's given when you chainge the final drive ratio.

Most people move to a lighter chain and go up one or two teeth in the back. That's enough to give you a noticeable change, but not enough to hinder driveablillity. Altering the front sprocket has a more direct effect becuase adding or removing one tooth is typically the same as 3 or 4 in the rear (speaking for TL1000 experience).

Hit up sprocket specialists and browse for your bike. They have what you need, whatever it is that you need.

jake42 · December 28, 2005, 12:48:38 AM

A common mod here is to drop the front sprocket by one tooth from 16 to 15. It does give it a little more off the start, but nothing really to write home about. You're not going to suddenly start pulling throttle wheelies with it or anything. It does cut down on your overall top speed, and you end up cruising at higher rpm's to maintain speed.

Jake

scratch · December 28, 2005, 12:53:07 PM

A 40 tooth rear (39 is stock) does very little in change, but increase my fuel consumption by about 5mpg (I used to get 65mpg regularily, now I average 60mpg; jetting to srinath standard may have helped do that, too).

marc · December 29, 2005, 09:39:24 AM

Sprocket modding depends on the desired effect you require.

Replacing a 16 teeth sprocket with a 15 teeth one, you will have the
benefit of faster accelerations, but will lose in top speed. Your cruising
speed will be lower too.

Replacing a 16 teeth sprocket with a 17 teeth one, you will feel your
bike lazier. Accelerations will be slower, but your top speed will increase
and your cruising speed will be higer too.

I use to cruise at about 6000rpm. With the 16 teeth sprocket, it is
about 120KM/h. With the 17 teeth sprocket, it is 135Km/h.

Alphamazing · December 29, 2005, 10:15:46 AM

Quote from: marcReplacing a 16 teeth sprocket with a 15 teeth one, you will have the benefit of faster accelerations, but will lose in top speed.

Ah yes, but since the GS is power-limited to its top speed, gearing down will not change your top speed. Instead you'll just hit your top speed in a higher gear or higher RPM.

scratch · December 29, 2005, 11:08:06 AM

You will hit your top speed sooner with shorter gearing (15tooth), which means you will not be going as fast as you would if you had stock gearing.

Alphamazing · December 29, 2005, 01:41:44 PM

Quote from: scratchYou will hit your top speed sooner with shorter gearing (15tooth), which means you will not be going as fast as you would if you had stock gearing.

Yeah you would... wouldn't you? You'd be going top speed, except you'd get there sooner due to the better acceleration.

Oh wait, I think I get what you're saying. You're saying that in a given gear at a given RPM you hit a top speed, but if you were in that same gear at the same RPM with stock gearing you'd be going faster. I gotcha.

Problem is the GS can't redline in 6th, so even if you are hitting top speed in 6th gear at 9000RPM with a 15T front sprocket you couldn't even get there with stock gearing. That's just an example, though.

RVertigo · December 29, 2005, 02:36:01 PM

Top Speed is useless anyway... You don't need it.

A 15T front sprocket is better than a 16T unless you do the majority of your riding at 70+ MPH... Then you could even use a 17T for the better gas mileage.

At 60 MPH, a 16t or a 17T has to be down-shifted to do anything... the 15T doesn't.

You have to shift more often in the city, but you can run a little higher RPMs and stay near the speed limit...

I like the 15T... 100 MPH is plenty (too) fast. I have no need or desire to go 110.

Alphamazing · December 29, 2005, 04:09:52 PM

Quote from: RVertigoTop Speed is useless anyway... You don't need it.

When I ride with my sportbike club I hit my top speed at least 2 or 3 times every ride. We do a lot of high speed sweepers, so entering turns at 70 and coming out accelerating into the top speed, then getting passed by the guys on supersports is kinda annoying, especially when I go faster through the turns than they do.

RVertigo · December 30, 2005, 12:46:52 PM

100 MPH is a respectable top speed... Buy a SS if you want to go 200 MPH. :dunno:

makenzie71 · December 30, 2005, 01:24:05 PM

100mph being a good top speed doesn't make it a smart idea. It's going to wreak havoc on the rest of your gearing.

RVertigo · December 30, 2005, 01:56:36 PM

What is? Having a 15T front? It only changes things about 7%... Not really havoc...

Or do you mean going 100 MPH? Going 200 MPH is really havoc...

makenzie71 · December 30, 2005, 02:09:24 PM

Quote from: RVertigoWhat is? Having a 15T front? It only changes things about 7%... Not really havoc...

Or do you mean going 100 MPH? Going 200 MPH is really havoc...

a 100mph top leaves you cruising at 7700rpm just to keep you with traffic...god forbid you want to pass someone. It's not going to be good on the bike or the rider to spend the entire time there.

RedShift · December 30, 2005, 02:11:50 PM

Okay boys, if you're not in Montana, how's about sticking to the speed limit...

makenzie71 · December 30, 2005, 02:12:29 PM

...to add, most bikes, regaurdless of displacement, are geared to top out at around 150 to 185. Very few bikes ever came from the factory with tall enough gearing to achieve 200mph, and very few bikes or riders actually have the abillity to move that quick. A GS500 certainly isn't in any kind of danger to go that quickly.

Also, it usually goes along the lines of 96, 97, 98, 99, 100, 101, 102...etc. Not 98, 99, 100, 200...

RVertigo · December 30, 2005, 02:15:58 PM

Quote from: makenzie71a 100mph top leaves you cruising at 7700rpm just to keep you with traffic...god forbid you want to pass someone. It's not going to be good on the bike or the rider to spend the entire time there.

Not at all... 7700 RPMs puts me around 82 MPH (ind)...

60 MPH (AKA the speed limit) runs around 5500 RPMs... Pretty much "in the pocket" as far as power for passing... 5500 is right about the low end of the power-band.

But, yes... Going 90 MPH with a 15T is pretty rough... 100 MPH is really rough...

But, my point is... Going really f%$king fast on streets or highways is for really f%$king stupid people.

makenzie71 · December 30, 2005, 02:20:10 PM

Quote from: RVertigoNot at all... 7700 RPMs puts me around 82 MPH (ind)...

Then you won't gear out at 100mph. At 11,000rpm you'll be moving about 118mph. Nearly a 20% difference.

The speed limit in most places is 70mph on open roads and hwys.

QuoteBut, my point is... Going really f%$king fast on streets or highways is for really f%$king stupid people.

Abillity doesn't mandate action.

Alphamazing · December 30, 2005, 02:20:28 PM

Quote from: RVertigoBut, my point is... Going really f%$king fast on streets or highways is for really f%$king stupid people.

Our rides take place in the Texas Hill Country along roads where there is nary a car for miles around. On one of our rides we saw literally three cars the whole time. These are well paved back roads that just aren't travelled much, especially on Sundays when most people are with their family. It isn't like we're going this fast around traffic.

RVertigo · December 30, 2005, 03:37:12 PM

Quote from: makenzie71Then you won't gear out at 100mph. At 11,000rpm you'll be moving about 118mph. Nearly a 20% difference.

The speed limit in most places is 70mph on open roads and hwys.

QuoteBut, my point is... Going really f%$king fast on streets or highways is for really f%$king stupid people.

Abillity doesn't mandate action.

You're right... For most people... But, there are plenty of people that ride in the triple digits.

The stock GS is theoretically capable of going 120 MPH, but it doesn't actually do 120... It does about 110-115 (indicated by an inaccurate speedometer)... Take the difference a 15T sprocket makes (about 6%) and you end up with a top speed of about 103-108... round up or down... Roughly 100 MPH

I live in a city, the highway speed is 60 MPH for 50+ miles in each direction.

But, again... Neither of those things matter... The exact top speed of the GS is unimportant, the point is that going faster than that isn't the most intelligent thing to do... Regardless of traffic, the potential for serious injury or death is higher when you increase your speed to the point of being faster than your reaction time... By the time you see something stationary when you're going 100 MPH, it's already too late to do anything about it. Even at 70 MPH, you have to have fast reflexes to avoid something that's not moving...

So... My whole point is this:

A 15T front sprocket is better than a 16T unless you do the majority of your riding at 70+ MPH... IMO :dunno:

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Noob question about sprockets