Stock vs. 18 Tooth Sprocket

[Kieran]

Got my 2001 this weekend and love it. The owner had an 18 tooth front sprocket but switched back to the original because:
1- The original has some rubber on each side. The replacement lacks that and according to him, makes the bike much louder. Also creates some vibration.

2- Acc to him the improved performance isn't worth the tradeoff in fuel economy

I can't comment on #1 and don't agree with #2. It seems to me that the ideal power band for this engine is going to be 4000 to 8000 rpm. At that RPM in 3rd Im doing 70+. Is getting higher RPM in all gears (not just off the line) another argument for the switch to 18 teeth? Any comments on additional noise or vibration?

[dolson]

I have had no vibration, MPG issues what so ever. The math is easy to run but you end up with a 500 rpm increase for any given speed. At 70 indicated with the 19 I was running 3500 rpm now it's 4000 with these motors, pzzzt. You are not buzzing the crap out of it.

You get more thrust in any gear and it will put more pep in it's step without going nutz.

I have never seen less than 47mpg and the other day on a 200 mile jaunt loafing along between 70-90mph I got 56.7 mpg.

That's probably one of the two cheapest things you can do to better the driveability of these things.

Don

[thfwsf]

On 2004-08-16 12:42, dolson wrote:
At 70 indicated with the 19 I was running 3500 rpm now it's 4000 with these motors,

That's funny, on my '01 with stock sprockets, I'm running 4k rpm in 6th at 70mph. About 4.5k rpm at 80mph.

Tom
'01 Sprint ST (red and CF pipe enhanced)

[shawboy]

Ditto Tom's RPM's on my 2003 with the stock set-up.

[dolson]

Well guys, My 2002 came with 19/43 new. I was hitting 70 3500 rpm in 6th. I changed to an 18 and now get 4000 at 70.

What can I say?

Don

[ikonoklass]

I just went to 18/43 this weekend. I agree that it's the easiest way to dramatically improve the bike. Runs great now, haven't paid attention to the mileage yet.

[SpiderTex]

I have stock set-up.
I do daily commute of a small 20Km (12.5 miles) highway slabbing. And tend to cruise at 5000rpm = 140km/h (87.5mp/h) on speedo in 6th gear.

In week-end's I do most of the time twisties and an increase of 500rpm sounds attractive, but I do (try) to do 2 long haul trips a year where I always end up with some long connecting stretches of highway which I like to mill down at 160km/h (100mp/h) on such moments, IMHO, the increase of 500 rpm would get annoying.

So I'll stick to the stock one. The Sprint has enough grunt for me down under as it is..

just call me lazy :razz:

[ This message was edited by: SpiderTex on 2004-08-17 02:34 ]

[REGULATOR]

so just how hard is it to swap?
I've already decided to do it. just want to know what to be prepared for.
I know i need a new folding washer but what else?

[garry]

A large socket and a torque wrench. A helper to stand on the rear brake is good too.

[thfwsf]

On 2004-08-16 22:26, dolson wrote:
Well guys, My 2002 came with 19/43 new. I was hitting 70 3500 rpm in 6th. I changed to an 18 and now get 4000 at 70.

What can I say?

You said it all!! :razz: I've read that they weren't consistent on what size sprockets came with the sprints. You must have gotten the special edition!

Based on my riding, if I would have been turining 3.5k at 70mph, I would have switched out to a different sprocket also. My sprint really likes the 4k to 5k range. Though it doesn't have an issue reving up a little higher!! Though it will pull ok from about 2.5, it doesn't like to cruise at a consistent speed at less than 3k to 3.5k rpms.

Tom