Just changed my forks to recons and had to change the rotors to 160 mm from 180 mm,is there a performance issue I should be aware of before I go out tomorrow,,when I changed my wheels I had to put 160 mm on the rear wheel as well so I’ve got both wheels on 160 mm now,also can I get a spacer to go back to 180 mm if there is an issue?

Eh? Of course you can use 180 rotors. Why did you ‘have’ to change to 160?

Smaller rotor equals smaller mechanical advantage, so a slightly less powerful brake.

If they’ve not been used before they will perform badly until they’ve had a chance to bed in too.

There’s a different fixing on the back of the forks,the old forks are tora’s and there was a bridge spacer,sorry for the confusion glasgowden but the spacer won’t fit on the new forks hence the change.

The old standard for disc brakes was international standard (IS), where the bolts went from the side thru clearance holes in the forks, into a mount/adapter. Different adapters allowed use of 160/180/200mm rotors. The new standard is post mount, where the bolts thread directly into the fork leg from behind. Usually, 160mm rotors require no additional mounts, but 180/200mm rotors can still be used via post-post adapters, like this.

Thanks Dave that’s what I’m looking for,can I use them for front and back brakes?

Certainly can, though most back brakes are still IS standard, and front and back adapters are different. I’m guessing here, but I’d say you need a Post-post 180/185mm for the front (as linked above) and an IS-post 180/185mm for the back, like this. Hopefully the whole adaptor thing should make a bit more sense from my description so have a good look at what you’ve got. Superstar mounts are OK and cheap.

As said above, smaller discs = less powerful braking, but also they’ll tend to heat up quicker and therefore fade quicker. 180 front and 160 rear is fairly standard though if you’re an average rider of average weight. I run 200 front 180 because i am rad (lol, actually because my fork can’t take anything smaller, because i’m fat and because ive got poor technique so tend to drag the back brake!)

I’ll probably just get one for the front then,try to stay off my brakes as much as I can now,I wa dragging the brakes also and realised in the end it was just down to habit that started just after a bad fall I had last summer,noticed my brakes were wearing down quickly a swell so that’s another reason I’m laying off the brakes,thanks for the advice Dave been a big help 🙂

No worries.