Katana Owners Club U.K.

Might just be me but here's my dilema.
Some of you might have allready done this

As a wider rear wheel is fitted with a 180 tyre, now the proper spacers are made and fitted, the chain run was off by 18mm so machined down sprocket carrier by 8mm, then fitted offset front sprocket and chain is now straight.
But 630 offset sprockets like hens teeth

So while i'm ok at the minute was thinking of getting a 530 chain conversion for next time, but as i have offset 17 tooth front and plenty of 530 chain, its the rear thats doing my head in , do i buy a 47/48 tooth to keep the 2.80 ratio undestandind i'll end up with a longer chain.

Or should i just replace both sprockets 15/42 but in 530 (can still get 15 offset front)

So if anybody has done it please point me in the right direction


oops sorry many thanks in advance

If you run 15/42 in 530 size the chain will eat through your swingarm in no time, you need bigger sprockets, 18/50 in 530 is about right i think, you could also run 17/48 for similar gearing, i'm running 17/48 on the race Kat but in 520 size which has the same pitch as 530 but it's lighter and more narrow, also got an 18 front but need to have a 50 made up from Talon. I didn't need an offset front though as only running a 130 tyre. You will need a longer chain, i think i fitted 114 links on mine, can't be sure but it was something like that.

Had thought of that arnica and measured the sprocket differences, the 17 530 is 2.5 mm slimmer than the 15 630 at the shallow part of the working surface, which equals 1,25mm above and bellow the swingarm.
Looked on the ratio charts and standard gearing works out at 2.80, using 17 530 with 47 ratio is 2.76 and 48 is 2.82 so probably go for 48 should give about 1mph more top end

17 / 45 is a nice compromise i've found...

cheers Sparki might have to order a 45 as ordered a 48 but will try that 1st, if i'm right should accelerate a fraction quicker