T100 2007 Revs High At Top Speed

Hello and welcome to the forum Guy.

 

If I were you I would be checking both sprockets, but particularly the front one. Count how many teeth it's got and replace it with a sprocket 1 tooth more. This will reduce your cruising speed revs by about 500 rpm at 100 kph.

So for example if the current front sprocket has 16 teeth, change it for a 17 tooth jobby. Available from Ebay or TEC europe for about £12-15.

Just an example as I don't know what local suppliers you have :

https://shop.tecbikeparts.com/products/19-tooth-gearbox-sprocket

 

To reduce revs revs you can either INCREASE the front sprocket or REDUCE the rear sprocket.

Increase front sprocket by one tooth gives the same effect as reducing the rear sprocket by 3 teeth.

Or you can do a little of both, however on my T100 I went from 18 to 19 teeth on the front sprocket only, and it dropped revs at 100 kph by about 500 rpm.

You've changed the rear tyre, but for what size? Std. or different ?

 

If you changed both sprockets simultaneously you may have substantially the same final drive ratio. Increasing one tooth on the gearbox will drop cruising revs by 250-300 rpm at slight cost to acceleration.

However, have you got clutch slip?

 

Hi Guy, that sounds just bizarre !!!! The limits in adjusting bike gearing are almost limitless!!!

 

Hence me wondering if the problem ain’t gearing!

 

In my mind, you need to establish exactly where you are now, with your bike. So what chain and sprockets gearing to you have? What tyre sizes do you have? Are you running in top (5th) gear when you talk about 4500rpm at 100 kph.

However, as Callumity asked, do you have any clutch slip, or are the revs constant when going through the gears and when accelerating in top?

 

You can play with this then you know what to buy;
https://www.gearingcommander.com/

 

Doesn’t this depend on where the speedo is driven from rather than the gearing.
It might think you’re doing 100k a 4500 but the gearing changes may be completely different.
Ride with a friend to see where your speedo is really at

 

OEM is 18/43 on a 130/80 17 rear I believe mate.