A 520 chain has slightly narrower rollers (1/4" vs 5/16"), is all. In theory, less powertrain loss.

Thanks for the info regarding chain length. I'm not trying to go faster, I just want to drop the revs a bit. At the moment, I'm always hunting for a seventh gear!
I'm an old bugger and the SVS is plenty fast enough for me.

Oldie

That was my feeling exactly (also an old scrote :oops: ). Sounds like going to 16T will do exactly what you're after. Since having the 16T on I can't recall ever having tried for 7th, but I did all the time when on std gearing.

I find myself looking for 7th quite often too. However, this is mostly around 20miles before the fuel light starts flashing, she just sounds to be revving higher because of more air in the tank, but it's a good indication of fuel levels. I don't only hear it, but also feel it.

And I've just gone up 2 on the back to get it quicker off the line :D

Std chain is a 525. For road use stick to this as the 520 conversion wont last as long.


Adding a tooth on the rear is like taking two off the front. More on the rear, more grunt. Less on rear more top end.

SV650Racer, I think you meant adding a tooth to the front is like taking 2 off the rear, in truth its more like taking 3 off, since 15/16 = 45/48.

a popualr mod for the aprilia 125s is drop it a tooth on both sprockets. has anyone tried this for an sv

by dropping a tooth at the back you'r almost cancelling out the tooth down at the front, 1 tooth down on the back would make things less harsh than with just 1 tooth down on the front, but to me seems a little pointless, unless it lets you keep the standard chain length?