Gearing

[CallumZuma]

I have now tested mine with a gps on stock 14t.

Across the range its over reading by 10 percent 

[Robell]

So at an indicated 60 mph the true speed is 54 mph, slightly worse than I guessed.
The legal limit is +10%, so it's right on that limit

[CallumZuma]

OH WOW!

did mine today. tu250 15t sprocket. massive difference. also tested speedo with gps. its out by like 1 or 2km now. so at 50km/h on the dash your doing 48/49kmh. and i found doing 62 on the dash i was doing 60 on the gps. i think 1 maybe 2 teeth on the rear wouldnt be to bad. and i think 1 would make the speedo perfect.

so much nicer to ride with this change :D

[CallumZuma]

im thinking i might go down 2 teeth on the rear. the 15t front made a big change but i feel that the bike would still pull a 16t very easily. if anything i think the bike is faster with the 15t front. it pulls a lot better. like its staying in its optimum torque range.

http://www.motorcycleraceparts.co.uk/product.php/4859/suzuki-inazuma-250-2012---2013-renthal-rear-sprocket-

they offer different ones. any of the uk boys care to comment on the site?

there is a chance of me doing 160km of highway riding a day in the very near future so im more so looking to drop the highway rpm by a fair bit. i also feel that getting into 5th or 6th around the suburbs is just wrong. 6th should only be for the highway and 5th should be for main roads.

but maybe im just weird.

[CallumZuma]

so i picked up a 39t rear sprocket today from a gsv650 that apears to have the same part numbers. looks the same to.

will drop the final drive ratio down to 2.6 from the 3.067 it was at with the 15t front.

estimating i will be around 6150rpm in 6th at 110km/h. which i will be much happier with.

one thing im thinking though is i may have trouble with the chain length. going down 7 teeth on the rear may be an issue. not sure where i would find a short chain for one.

[Robell]

Originally Posted by CallumZuma

  i also feel that getting into 5th or 6th around the suburbs is just wrong. 6th should only be for the highway and 5th should be for main roads.

but maybe im just weird.

My thoughts exactly - I was exiting some islands already in 6 th gear !

If you've gone up a tooth at the front, I'd think the standard chain would be ok if you lose a couple at the rear 

Originally Posted by CallumZuma

OH WOW!

did mine today. tu250 15t sprocket. massive difference. also tested speedo with gps. its out by like 1 or 2km now. so at 50km/h on the dash your doing 48/49kmh. and i found doing 62 on the dash i was doing 60 on the gps. i think 1 maybe 2 teeth on the rear wouldnt be to bad. and i think 1 would make the speedo perfect.

so much nicer to ride with this change :D

Making the speedo more accurate, sounds a good reason to gear up to me 

How did you get on aligning the new sprocket ?

[CallumZuma]

New front one was easy.

Rear however. I ended up getting a 39t. 7 teeth down from stock. And the chain is to long for it. Have a chain breaker on the way. If my math works out. 15 and 39 puts the final drive around 2.6 giving you around 6000rpm in 6th. Being that the gears are nice and close I would assume 8000rpm in 4th. At 110kmh that is. So I shouldnt get over 4th arpund the streets. And 5th only fprain roads. 6th will be strictly highway. This will put the speedo out. But ill fix that.

Also... topped out 6th on sunday. Holding around 9.5k at one point speedo kept counting. I think its a little slow to read. But had me at 110kmh at 10k rpm for a moment.  Was very confusing.

[Robell]

Blimey, that sounds quite a change.
Hope it works ok, if you have to shorten the chain to try it.

[CallumZuma]

haha when you put it that way. i hope it does to hahahaha

[CallumZuma]

Ok so finnaly found some time to do it. I now have a 15 tooth front and 39t rear. And let me just say. Why didnt the bike come with this. Its faster.  The gears are much more usable. This is how the bike should be. I got 60kmh before I topped out first haha. But cruising through the streets at 50km in 4th is good. 5th is around 4k rpm. 6th is a no go. I dont think 6rh now has a use under 70kmh... which is more like most things..  the 39t is from a sv650. I also put a gold series chain in. Looks great.