Rear Rotor Rubbing Issue

I own a 2013 St1 Platinum and the rear rotor is rubbing. I took it in for it's yearly service and they told me they could not get it to stop rubbing because the caliper hits the frame. Do all ST1's have this issue, or should I look into this further? When I spin the rear wheel it doesn't even make one revolution......
 
The shop said they couldn't move the caliper over enough to center the rotor because the caliper was hitting the frame. I'm not sure why that is like that, but I will put the bike on the work stand tomorrow and see if the rotor is warped, or if I can move the caliper over enough to center the rotor. The other thing is the rear wheel was taken off and maybe not put back correctly into the frame.
 

opimax

Well-Known Member
I had to replace the brakes on wife's ST1. Great support by magura. They sent me some upgraded calipers that ran out space to adj properly and I took the Dremel grinder to them and all good. The originals should not be rubbing and your guess of the wheel not installed properly sounds appropriate to me. If it was fine before what would have changed?

Aside from the brakes wife's bike has been near perfect, runs great. Took it in for a new tire and I was told I needed a new wheel since he could not tighten the wheel! luckily for for me Stromer stepped up and is replacing the wheel no charge. The bike is past warranty. You may want push back at the shop it didn't have that problem till you worked on it.
 
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I was not aware that my rotor was rubbing before, but it might have been. How many turns of the rear wheel is average for a ST1? I have never spun my rear wheel like I do on our non-Ebikes becuase the wheel motor has always felt to have a little drag - maybe that has always been my rotor?
 

opimax

Well-Known Member
I cant pick up the rear of my bike and spin, too hard my old back. There is resistance in the wheel form the motor and the magnets, cogging, that is normal. There are 2 torx screwa that hold the caliper in place , if you remvoe the caliper and gently set it down in a safe and secure manner, then spin the wheel there is no brake involved. If you do this test, place something inside the caliper the will prevent it form closing too far. If the handle is accidentally pushed. and the caliper travel to far the caliper will need to be replaced, be very careful!

I edited my above post to say I received new calipers not rotors which now should make better sense to others that read it
 

JoePah

Well-Known Member
There should be no noticable resistance from the brake disc when you spin the wheel.

Something changed and the difficult part is identifying what part got dinged, bent warped.

shoot a video down the brake caliper with the wheel spinning.

If it were me, I'd remove the brake pads first, then spin the wheel and see if there's a rub. Inspect the pads, measure the distance from the disc to the caliper on each side.

Then I'd remove the caliper from the frame, leaving the hyd line intact and look for something out of sorts.

And to your point, measure the distance between the tire and the frame on each side to see if the wheel is centered
 
I cant pick up the rear of my bike and spin, too hard my old back. There is resistance in the wheel form the motor and the magnets, cogging, that is normal. There are 2 torx screwa that hold the caliper in place , if you remvoe the caliper and gently set it down in a safe and secure manner, then spin the wheel there is no brake involved. If you do this test, place something inside the caliper the will prevent it form closing too far. If the handle is accidentally pushed. and the caliper travel to far the caliper will need to be replaced, be very careful!

I edited my above post to say I received new calipers not rotors which now should make better sense to others that read it
I tested my Stromer by leaning it against the kick-stand and slightly lifting the rear wheel off the ground. I will put it on the stand today to do it correctly.
 
There should be no noticable resistance from the brake disc when you spin the wheel.

Something changed and the difficult part is identifying what part got dinged, bent warped.

shoot a video down the brake caliper with the wheel spinning.

If it were me, I'd remove the brake pads first, then spin the wheel and see if there's a rub. Inspect the pads, measure the distance from the disc to the caliper on each side.

Then I'd remove the caliper from the frame, leaving the hyd line intact and look for something out of sorts.

And to your point, measure the distance between the tire and the frame on each side to see if the wheel is centered

I will try loosening the caliper bolts first, then if that doesn't help I will pull the wheel and brake pads.
 
I forgot to add - the brakes were just bleed at the shop - could that have had something to do with this issue? Could they be overfilled causing the pads to not retract enough?
 

JoePah

Well-Known Member
I think this is a shop Eff up. And they overfilled the master cylinder so you cannot push the pads back.. I would try squeezing the brake pads back on the rubbing side, then remove and re install them.

If that doesn't work you need to bleed some fluid at the handlebar master cyling... And that is easy to screw up.

Try researching on line for those brakes.
 
Thanks for all the advice and suggestions. I'm heading down to the garage and putting it on the stand. I'll let you know what I find.
 
I put the bike on my stand and spun the rear wheel - quarter turn or so. I pulled out the brake pads and it spun about a revolution and a half. I noticed the side that was rubbing had the thicker pad on it, so I put the thinner pad on that side and now it spins much better. I'm not sure if there is too much brake fluid in there, but I will ride it like this until it needs pads. Thanks for all the help and advice from everyone here!