14/39 or 15/42

[Luddite]

Originally Posted by billy 192

I just saw this vid



This shows what I am saying. He removes the the big bracket holding the front and rear foot rest and gear shift, then, and then only there is room to move the sprocket and chain in one piece.

I note the guy in the video doesn't lift the chain from the rear sprocket. If he did, then I don't believe he would have needed to remove the footrest.

Still, whatever gets the job done!

Let us know your opinion of the lower gearing once you've had a chance to try it.

[Ron1000]

Originally Posted by billy 192

I think I have confused you re fron t sprocket removal.

when i say there is not enough play i meant sideways not length ways

I just saw this vid

https://youtu.be/p9lHBeVJuqI

This shows what I am saying. He removes the the big bracket holding the front and rear foot rest and gear shift, then, and then only there is room to move the sprocket and chain in one piece.



just like the vid. lol

I am not getting a new chain just to use the 43 rear.

Billy

Worst comes to the worst you can take the master link out the chain the buy and fit a new one after the sprocket is fitted

[Mr Gazza]

You must complete the entire procedure using ONLY your right hand.

[Doggy]

100 mile ride today with the 14t fitted. I think I like it and will keep it fitted. Going to get a new chain as it looks minging against the new wheels, also rental rear sprocket and new carrier.

well changed the front from 15 to 14 and the result is brilliant. I do like it . i did the front coz i did not bank on the rear needing a diff carrier and sprocket also the chain would need to be longer.

Billy

[Goofle]

Originally Posted by Mr Gazza

You must complete the entire procedure using ONLY your right hand.

And not tighten the bolts holding the plate to the new front sprocket to anything more than finger tight too before ‘throwing everything back on’!

[Chriswilly]

Ended up on 15 x 38 and found a it lot easier in traffic..
This suits a 'standard' chain I believe (wahtever that is) - can't remember.

[Ron1000]

15,38? That’s making the gearing longer! Like higher stop speed less quicky quicky!

Seems an unusual way to go! But if you like it you like it.

15, 39 = 2.6 ratio
14, 39 = 2.78 ratio
15, 42 = 2.8 ratio
15, 38 = 2.53 ratio

I believe standard chain is 104 link 525 pitch. Bigger rear sprockets require a 106 link

[slob]

https://www.gearingcommander.com/

[chris.p]

Check out the chart on the JT Sprockets web page.

http://www.jtsprockets.com/catalogue/model/s4230/

And there full chart

http://www.jtsprockets.com/fileadmin...tgearratio.pdf

[Darkness]

With a 19 tooth on the front, and a 30 tooth on the back wheel, it looks like I’ll get my M900 over 200 mph!

[Mr Gazza]

Originally Posted by Darkness

With a 19 tooth on the front, and a 30 tooth on the back wheel, it looks like I’ll get my M900 over 200 mph!

Not until the sprocket has eaten away the front of the swinging arm, you won't..

[slob]

Originally Posted by Darkness

With a 19 tooth on the front, and a 30 tooth on the back wheel, it looks like I’ll get my M900 over 200 mph!

In a vacuum

Originally Posted by Mr Gazza

Not until the sprocket has eaten away the front of the swinging arm, you won't..

at least the chain will be well lubed, when it's eaten away an equal amount of crankcase

[Darren69]

If like my S4 the standard and even DP fuel map is crappy at 30mph then moving the gearing either way will make some improvement? I left mine standard as I like the gearing just didn't like the fueling so I had it re-mapped. I know the later 696/796 suffer more because of the Lambda sensors making the mixture even leaner. So get those disabled and re-map would be the best way to go imho, then it wouldn't matter what gear ratio you had you could change it to how you wanted, but the standard is usually ok at least with the 6 speed close ratio box on the S4 its fine.

[Mr Gazza]

Originally Posted by slob

at least the chain will be well lubed, when it's eaten away an equal amount of crankcase

Yes nicely lubed chain, but it would probably chop through the clutch pushrod too, so it would interesting when the engine seized at 200mph!
Is there a calculation for the length of skidmark from 200mph with a freshly lubricated rear tyre?