Sorry - Going to bore you with a sprocket question AGAIN!

[Tempest]

Been reading some of the talk here about sprockets.
Or to put it more exactly changing the sizes (no of teeth) for improved acceleration.

There have been lots of No's of teeth talked about here, and all got a bit confusing.

Is there any forum agreed ideal choice at the moment which you can do without changing the chain?

My VTR's Chain is quite new but does have some room for adjustment (mostly back wheel inwards) so it could take a larger rear.

As I understand it, the front is 16, and changing to 15 can make chain wear more, speedo read higher.

Also, is it, 1 less on front = 3 more on back (ratio)

Just wondering (from the many people who have played with sprocket sizes on both front and rear) Is there any ideal combination to go with?

Thanks

[Max]

There's no ideal combination, just a combination that you like.
I run 15/44 std chain length and its what I want for my storm but if you rode it you might want more speed as it quite low geared compared to std but accelerates a lot better.

[Tempest]

There's no ideal combination, just a combination that you like.
I run 15/44 std chain length and its what I want for my storm but if you rode it you might want more speed as it quite low geared compared to std but accelerates a lot better.

Thanks.

I've just spent the last 1/2 hour reading thru past questions about this, and (as you say) there's lots of different views.

From what I've read so far 15/44 would put you into "Nutter" terratory!

Some saying just drop 1 on the front (but more slack chain and longer wheelbase as back wheel goes back more)

So better to add 3 to the rear and leave front at 16 = less chain wear, and same effect as a 15 front, also shortens wheelbase, which is better.

You don't have to change the chain do you, (as long as it's long enough?)

Just wondering if you do drop the front to 15. How big does the rear have to go to compensate (chain length wise)

[Tempest]

Also, (never having bought a front sprocket before)

Does it have to be any particular spec?
Centre hole size?
Width?

[Tempest]

I think I'm gonna go down the bike shop on Monday and see what I can find.
Just want to make sure I get something good.

Else, will have to order

I see you can get hardened sprockets which sound good.

[Tempest]

Something has just crossed my mind.

Now perhaps I'm going mad, and have totally got this wrong.

But.................

What's the difference between changing sprocket sizes and just using a lower gear?

If you change sprocket sizes enough, will 2nd just be like 1st gear.
3rd like 2nd etc, so you end up with 6th like 5th?

I guess not (otherwise, why bother?)

Can anyone explain?

[Max]

You are confusing overall gearing with the difference through the gears, mine has a top gear similar to 5th but the real difference is when you run it up through the gears as they appear to be much closer and it always seems to drop back to the power in the next gear and go.
The sprockets are easy enough to get I got mine from my local bike shop. There are quite a selection to chose from.
Renthal do a variety
Front 14-17
Rear 40-46
JT ?? do a selection in steel as well
and if you want to go really wild have a word with zimr2006 (its 65 btw)


If you go here http://www.kamware.com/vtr1000f/shprograms.htm
you can down load a prog that will tell you what the speed will be when you change the sprockets.

[Tempest]

Thanks Max.

Must admit, I'm still a little hazy on the subject, but I'll take everyones word for it

I did wonder also if you need to bother with 1st, or can use 2nd as a 1st?

Main thing is I have no idea what to ask for at a bike shop.

Do I just go in and ask for a 43 or 44 tooth sprocket for a Firestorm, to be met with comments of that's the wrong sprocket for that bike.

I'm assuming things like Hole positions/width even? have to be correct.

Same as the front sprocket. Are there any Generic Specs you need to request. Like Inner hole dia, No of splines, etc etc.

[alan]

Tempest
the sprockets you order for your bike from your bike shop all dimensions and holes everything is specifically made for your bike you just tell them what number teeth you want thats it.

Only other thing you can choose is what make as Max said ie Renthal/Did/Afam/Regina.

The front sprockets are all made from hardend steel they do not make them in alloy only the rears.

Alan

[Tempest]

Tempest
the sprockets you order for your bike from your bike shop all dimensions and holes everything is specifically made for your bike you just tell them what number teeth you want thats it.

Only other thing you can choose is what make as Max said ie Renthal/Did/Afam/Regina.

The front sprockets are all made from hardend steel they do not make them in alloy only the rears.

Alan

Ahhh, OK.

I just wondered if there was a "Generic" sprocket design as it were.
So the same sprocket could fit dozens of bikes.

So it's just a case of asking for a Firestorm Sprocket of 43 (or whatever teeth) and leave it at that.
I have seen rear sprockets advertized as being hardened, which I assume is a good thing?

Any idea on the (approx) price of a rear as we have expensive shops round here.

I'm just wondering if anyone had done the maths as to, how many teeth up at the back = how much further forward the rear wheel moves.

[alan]

Hein Gereke do renthal rears and anodized for 35 pound near me and the fronts are about 17 pound.I always use alloy rears but its upto you really.

Alan

[chaz]

depends on what your chain is like, Ive seen c&s kits on ebay for £90 is that a good price?

[Tempest]

depends on what your chain is like, Ive seen c&s kits on ebay for £90 is that a good price?

My Chain (as I've been told) is not very old at all, and only fairly recently had a complete new Chain and Sprocket set fitted.

So I'm not changing the chain at the moment.

Just been trying to do the maths on a rear sprocket with 3 more teeth (44)

Rought measurment of current (41) sprocket was 105mm radius which is 660mm circumference.

The teeth seem to add 16mm per tooth to the circumference, so 3 more teeth make it 708 (ish) circumference.

Working back, that gives you a new radius of 113mm

Or in other words the wheel has to move 8mm forwards for the back of the sprocket to be in the same place.

but I think I'm missing something out here. We have the height of the sprocket too (not just the back) so I'm still unsure if a standard chain will go round a 44 rear and 16 front?

[Max]

std chain is a tight fit on 15/44 so I would be pretty sure it would not go on 16/44. unless anyone knows better

[Tempest]

std chain is a tight fit on 15/44 so I would be pretty sure it would not go on 16/44. unless anyone knows better

Thanks....

That's kinda what I wanted to know.

15/44 = tight, so (as you say) 16/44 ain't gonna fit

So, that's either staying with just a 43 on the back.

Or dropping the front to 15.

On the American site 15/43 seems a popular choice and I guess fits very well.

Just a bit unsure if that's going a bit too far.

Difficult (without trying) to know how much just 2 extra on the back will make (even noticable?)

I'm not after pulling a wheelie (I'd probably crap myself!) but I would like extra pull from just rolling on the throttle to overtake when in high gears.