Restricted Bike, Chain and Sprockets - SV650.org

12-02-06, 10:53 PM

Hello all!

My name's Ryan, I'm 19, from wee Norn Iron and I ride a 2001 Yellow SV650S. I got my bike when I was 17, and have 5 months left of 33BHP restriction (roll on August!!).

One of the most popular mods I've noticed people doing (especially on the US site) is going to a 520 conversion, with alot of people going up a few teeth at the rear sprocket. Would this have much of an effect on my bike's acceleration even though it's restricted? I'm also wondering that if the restrictor kit takes the power away top end, if I were to drop a few teeth at the back sprocket would this help to counter - act the restriction and give me a bit more 'umph' top end?

I'm a bit of a mechanical newbie, so am I just talking out of my @rse?!!

I'd really appreciate some advice!

12-02-06, 11:21 PM

Hello bud...

The sprocket size has a direct effect on the gearing of your bike. If you increase the number of teeth on the rear sprocket, this increases your acceleration & decreases your top end speed (also reduces your MPG too

)

e.g.

Going up 3 teeth on the rear sprocket (to a 47 tooth sprocket,) is the same as coming down 1 tooth on the front (from a 15 tooth, to a 14 tooth.) Going down 1 tooth on the front sprocket isn't advised though because it massively increases the chain wear!

Therefor, doing this in reverse (reducing your standard rear sprocket by 3 teeth (i.e. 44 tooth to a 41 tooth rear,) would have the opposite effect; reducing acceleration & increasing top speed (and improving MPG too

) Keeping the rear sprocket standard & increasing the front sprocket by 1 tooth would be a far cheaper & cost effective mod if this is what you wanted to achieve

Good luck with it

BTW, why don't you wait 5 months 'til you go full power & see what difference that makes before you start changing the gearing

12-02-06, 11:36 PM

Cheers Cloggsy!

I'm pretty happy with the bike off the mark. If you increase the rear to say, 47 teeth, from what I've read it will improve acceleration without sacrificing the top end all that much. So do you think by dropping 2 or 3 teeth at the rear that would improve top end without sacrificing acceleration too much?

Yeah, I probably should wait the 5 months, but I reckoned if I could improve acceleration without sacrificing top end speed, it would be worth doing. And then I started thinking if I could do the reverse, that would be worth doing! And now I dunno what to do!! lol

13-02-06, 07:26 AM

Ulster...Changing sprockets is a relatively cheap performance mod and is of course a compromise. Which ever way you go,there will pay a trade off. In reality the top end is going to be used so little that for sure the best option is as mentioned by Cloggsy.Go for a little more acceleration but definitely wait and try the bike in unrestricted form first.

Biker Biggles · 13-02-06, 01:48 PM

I think raising the rear sprocket by a few teeth is a great idea on a restricted bike.
Sinse your bike only has 33 BHP it can't pull top gear to anywhere near max revs,making it overgeared.You might as well make it get off the mark quicker and enjoy that aspect of the performance.

13-02-06, 05:56 PM

Cheers fellas. I'll go with my original plan then and go up a few teeth at the back and make the most of the bike as it is. I've been looking at sprockets for a while now and had settled on Vortex, so I'll just go for them. They don't seem to last long so by August they'll most probs need changed again anyway. I can decide then when the bike's derestricted whether I want to keep running 47 teeth at the back, or if I want to change things up.

13-02-06, 07:50 PM

Quote:

Originally Posted by UlsterSV

Hello all!

My name's Ryan, I'm 19, from wee Norn Iron and I ride a 2001 Yellow SV650S. I got my bike when I was 17, and have 5 months left of 33BHP restriction (roll on August!!).

hahahahaha i only have till june (well done for sticking it out)

chainging should help but not massivly, i went down (by mistake) 1 on the rear and there is no difference

13-02-06, 09:31 PM

Oi! No need to rub it in! :P

I prefer it restricted anyway...

One tooth probs wouldn't do much, but I'll try going up three and see. Will do no harm fiddling about with things.

14-02-06, 09:50 AM

well my friend got hers done early (ie swaped the ecu back) and it is not that much quicker, she is only had 112mph before she chickened out and i can beat her off the line

Viney · 14-02-06, 10:54 AM

Dont bother with doing the 520 conversion. If you do go up a couple of teeth on the rear spocket, make sure you buy a longer chain (110 links as on the nakedSV not the 108 on the S)

I dropped the front by 1 tooth to a 14. It is great fun, and didnt wear the chain as much as you/we are all lead to beleieve.

HTH

12-02-06, 10:53 PM	#1
UlsterSV Guest Posts: n/a	Restricted Bike, Chain and Sprockets Hello all! My name's Ryan, I'm 19, from wee Norn Iron and I ride a 2001 Yellow SV650S. I got my bike when I was 17, and have 5 months left of 33BHP restriction (roll on August!!). One of the most popular mods I've noticed people doing (especially on the US site) is going to a 520 conversion, with alot of people going up a few teeth at the rear sprocket. Would this have much of an effect on my bike's acceleration even though it's restricted? I'm also wondering that if the restrictor kit takes the power away top end, if I were to drop a few teeth at the back sprocket would this help to counter - act the restriction and give me a bit more 'umph' top end? I'm a bit of a mechanical newbie, so am I just talking out of my @rse?!! I'd really appreciate some advice!

13-02-06, 01:48 PM	#5
Biker Biggles Member Mega Poster Join Date: Jan 2005 Location: Barnet Herts Posts: 5,071	I think raising the rear sprocket by a few teeth is a great idea on a restricted bike. Sinse your bike only has 33 BHP it can't pull top gear to anywhere near max revs,making it overgeared.You might as well make it get off the mark quicker and enjoy that aspect of the performance. __________________ On a clear day we stand there and look further than the ordinary eye can see.

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12-02-06, 11:21 PM	#2
Cloggsy Guest Posts: n/a	Hello bud... The sprocket size has a direct effect on the gearing of your bike. If you increase the number of teeth on the rear sprocket, this increases your acceleration & decreases your top end speed (also reduces your MPG too ) e.g. Going up 3 teeth on the rear sprocket (to a 47 tooth sprocket,) is the same as coming down 1 tooth on the front (from a 15 tooth, to a 14 tooth.) Going down 1 tooth on the front sprocket isn't advised though because it massively increases the chain wear! Therefor, doing this in reverse (reducing your standard rear sprocket by 3 teeth (i.e. 44 tooth to a 41 tooth rear,) would have the opposite effect; reducing acceleration & increasing top speed (and improving MPG too ) Keeping the rear sprocket standard & increasing the front sprocket by 1 tooth would be a far cheaper & cost effective mod if this is what you wanted to achieve Good luck with it BTW, why don't you wait 5 months 'til you go full power & see what difference that makes before you start changing the gearing

12-02-06, 11:36 PM	#3
UlsterSV Guest Posts: n/a	Cheers Cloggsy! I'm pretty happy with the bike off the mark. If you increase the rear to say, 47 teeth, from what I've read it will improve acceleration without sacrificing the top end all that much. So do you think by dropping 2 or 3 teeth at the rear that would improve top end without sacrificing acceleration too much? Yeah, I probably should wait the 5 months, but I reckoned if I could improve acceleration without sacrificing top end speed, it would be worth doing. And then I started thinking if I could do the reverse, that would be worth doing! And now I dunno what to do!! lol

13-02-06, 07:26 AM	#4
Peter Henry Guest Posts: n/a	Ulster...Changing sprockets is a relatively cheap performance mod and is of course a compromise. Which ever way you go,there will pay a trade off. In reality the top end is going to be used so little that for sure the best option is as mentioned by Cloggsy.Go for a little more acceleration but definitely wait and try the bike in unrestricted form first.

13-02-06, 05:56 PM	#6
UlsterSV Guest Posts: n/a	Cheers fellas. I'll go with my original plan then and go up a few teeth at the back and make the most of the bike as it is. I've been looking at sprockets for a while now and had settled on Vortex, so I'll just go for them. They don't seem to last long so by August they'll most probs need changed again anyway. I can decide then when the bike's derestricted whether I want to keep running 47 teeth at the back, or if I want to change things up.

13-02-06, 09:31 PM	#8
UlsterSV Guest Posts: n/a	Oi! No need to rub it in! :P I prefer it restricted anyway... One tooth probs wouldn't do much, but I'll try going up three and see. Will do no harm fiddling about with things.

14-02-06, 09:50 AM	#9
Last Action Pimp Guest Posts: n/a	well my friend got hers done early (ie swaped the ecu back) and it is not that much quicker, she is only had 112mph before she chickened out and i can beat her off the line

14-02-06, 10:54 AM	#10
Viney Member Mega Poster Join Date: Jul 2003 Location: In the shadows to the left Posts: 7,700	Dont bother with doing the 520 conversion. If you do go up a couple of teeth on the rear spocket, make sure you buy a longer chain (110 links as on the nakedSV not the 108 on the S) I dropped the front by 1 tooth to a 14. It is great fun, and didnt wear the chain as much as you/we are all lead to beleieve. HTH