I have just bought a Giant Reign 2 and look to swap my XT’s over for the Avids,The rear seems to swap straighforward but the front is causing some grief…
I had to shuffle about the spacers as the rotor was hitting the calliper,now when i allign the brakes the rotor is rubbing on the calliper when i spin the wheel.every time i loosen the bolts and pull on the brake lever and tighten the bolts same thing,rubbing!!!
Am i doing something wrong?the brakes were fine on my Rockrider when i fitted them,it had hayes rotors,203 on front and the Giant has 180,it post mount as the Rockrider was is mount but all im doing is attaching the calliper so it should be a straight swap??

Thanks for any advice..

Craig

Your brakes will not be a straight swap.

180 rotors and 203 rotors are a different size and need different adapters. So you need a new adapter for the Reign to cope with the different size rotor and the different change from IS to Post mount.

you need a post to IS adapter…most likely +20mm
also the method if aligning the caliper you are using is for post mount brakes. dont use this method! use some caliper shims to makes sure the caliper is aligned over the rotor then tighten up. if the caliper is aligned correctly you should be able to see an equal gap on either side between the rotor and pad, if not add/ remove a shim to each bolt. it could also be that your rotor is slightly warped.

Ah I’m not using the adapters from my old bike its basically just swapping the brake over and attaching it to the set up on the giant….so the calliper is being attached to the adapter for the 180 rotor.i knew the adapters were different as its is to post mount on one bike and post to post 180 on another I just can’t figure out why the rotor is rubbing on the side of the calliper

What you’re doing sounds correct, perhaps the caliper moves slightly when you torque the bolts fully? If he normal method doesn’t work, you’ll have to adjust it manually by working out where it’s rubbing and moveing the caliper a bit to compensate.

Thanks Paul…i knew i was setting up correct i just couldnt figure out why it was rubbing,one piston seems to be out more than the other so it my be causing the problem when alligning…need to get some mineral oil and see if i can free it off,

If you look carefully, the torsional force of tightening a brake bolt will move the caliper. Make sure you hold it exactly where you want it when tightening.

Also, are you sure the caliper is far enough out to stop the outer edge of the rotor rubbing? Maybe you need a washer to move the caliper out more. I have had this issue before when changing rotor makes ie shimano are 180, avid 183

Loosening the bolts, squeezing the lever and re-tightening the bolts is a rubbish method that has never worked for me. Remove the brake pads, push the pistons back in, and then align the caliper by eye over the disc. Get the disc dead central, once everything is tight you can then stick the pads back in and pump the lever to set the pistons/pads against the disc.

@dantsw13 it must be whats happening but any time i needed to re-align before i used the pulling on the brake method but looks like i need a new approach.looking at the bike details online it says 180mm front but will look at the rotor to see if its 183,i have the washers that were on the avid set up.just took the caliper off old bike and swapped it to new bike,tried without the washer and rotor clipped top end of caliper,

spooky i will have another look tomorrow,isnt it better to allign with the pads in??will have a good footer about with it tomorrow,might need to bleed the brake aswell as its a bit soft,

1. fully reset the pistons on the calipers
2. bolt mount to bike. tighten to correct torque
3. bolt caliper to mount. tighten then unscrew quarter of a turn
4. looking from the top or side make the disc sit in the center of the caliper and tighten
5. as you pull the leaver one piston might move towards the disc faster than the other, you want to slow this piston down with a very small flat screwdriver so the pads come into contact with the disc at the exact same time.

If you do this and the rotor is still rubbing then its warped. so replace rotor and repeat.

cheers watsontony done all this today,lined up by eye,lined up by pulling lever,think it might be moving slightly due to the washers as the are flat and rounded?
Also the bike is 2 days old so would hope the disk isn’t warped as it rode fine with the Avids yesterday…
One of the pistons does move more than the other so will try the screwdriver thing tomorrow…

[video]https://www.youtube.com/watch?v=akIWGqEE0PY[/video]

As said, don’t do the squeeze and tighten method. I think you may have hit on something with rotor diameter too. Avid do 185 as well as 180 and I think it’s Hope that does 183. Shimano do 180.

Avid mounts tend to have cup and cone alignment washers, Shimano didn’t used to but sometimes do now. This affects things a bit more in terms of mounting but sounds like you’ve got this sorted.

Tightening the allen key will twist the caliper to turn in towards the rotor unless you stabilise it with a hand until one of the bolts is tight. Even then it can tweak things out of place 😡

So:

1. Pads out, pistons back, align as above.
2. Put it all back together and check alignment.
3. Tighten when happy that both pads are working evenly and the rotor is not flexing when the brake bites.

Be careful not to pull the brake when there are no pads in as you can pop your pistons out, leading you into a world of pain (unless you’re making subtle adjustments like the screwdriver thingy). Additionally a screwdriver will be too hard if you have ceramic pistons (newer SLX & XT). A plastic tyre lever is a better thing to use to nudge the pistons with.

@herman i just checked and the rotor says 180 so that is one thing i can overcome,might just need to buy a shimano 180 post to post mount and hopefully that solves the issue,as said before the shimano bolts are like half the size of the avid ones,and dont have the washers,
Its new xt’s so ceramic pistons and i use tyre lever,but i might need to find some plastic to lodge between the pads and rotor to allign…

Don’t fill the gap while aligning, it’s not necessary. I see I’ve confused things a bit:

Get your pistons back in, put the pads in with the gap still wide.

Align the calliper so the rotor is dead centre (the split in the calliper is pretty much central), pull the lever a few times paying attention to the piston/pad movement: is it even?

If yes, good! If all’s hunky dory you’ll be able to lock the brake where the calliper is without flexing the rotor. If you get the pads in a bit and it’s clearly biased in/out then adjust accordingly and continue to fiddle until you have even pad movement and a flex-free bite.

The new Shimano PM to PM annoyingly has cup and cone washers (they add fuss in my opinion) and long bolts. It sounds like the Avid mount should work, maybe a washer’s ended up where it shouldn’t?

I’ve looked online at superstar 180adapter and its totally different from the shimano 180 one
The avid one when I mounted it at 1st I had a bit of rubbing from the top of the calliper on the rotor so I moved one of the washers from outside the calliper to Inbetween the calliper and adapter and its stopped fouling the rotor but ill footer about with it tomorrow to see if I can get to the bottom of the problem

So did Dales come up trumps then ?

hey iainc got the reign for 1800,so all is good and 1 happy rider….

Nice one 🙂

I’ve just thought of something not so obvious; is the adapter the right way up? I think you could fit a PM adapter upside down by accident (if it’s a 2 bolt only type) which would bring it too close to the rotor.

If it’s not working after the next fiddle, put a pic up.

Herman good shout,the arrow is pointing down with the writing on the outside….

yep turn that mount around. and if it need washers between the caliper and mount it will need the same under each bolt. your nearly there. keep trying

I think there are two problems in that pic:
1. The adaptor is upside down (arrow should point up, at least that’s the case on a Shimano adaptor).
2. The cup and cone washers shouldn’t be needed on the upper bolt, between the adaptor and caliper.

We got to the bottom of it 😀

My Shimano PM-PM adapter (same brake) is set up: adapter, calliper, washers, bolt. If you have a longer bolt it will go in the top hole.

Nearly there!

Ecky-thump,Herman shake and watsontony thanks guys,adapter swapped round so arrow pointing up and its now on the inside.is that right??
I put that washer in because the 1st time it was fouling the top of the caliper but all seems well now….just need the snow to do 1 and i can go out and have some fun….oh and be able to stop like i want 😯
Thanks for your input guys…much appreciated!!!

Glad its sorted 😆

Yep, right way round 🙂