F800GSA Front wheel / brake dragging - BMW F800 Riders Forum & Registry



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  1. #1
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    Hi. Have searched this forum and the Internet for an answer but can't seem to get good info. Bike was on centre stand and I noticed the front wheel does not spin freely. Turns 3/4 to 1 rotation when spun before it stops. Decided to flush brake fluid as it was due in any case. Also greased the calliper sliding pins with Copper Eze as they were not moving smoothly. Discs aren't warped and brake friction is consistent across a full rotation. Checked the bobbins and they have enough play for the floating disc.

    What is normal? Should the wheel spin freely? I recall the dirt bikes I had spun a few rotations before stopping but these had single disks. Called BMW and got two opposing answers.

    Thanks in advance for any feedback.

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  3. #2
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    Sounds like you might benefit from cleaning the caliper and exposed portion of the caliper pistons.

    The following is a little video posted by Delboy on YouTube. He's a time served motor cycle technician who explains his method using his winter hack as an example.

    https://youtu.be/FNz00OTRLzM

    It's not a BMW but the principal is the same for other bikes.

    If you've managed to change your brake fluid with no issues then you should be able to follow this but decided for yourself for safety's sake.

    Ride safety.

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  4. #3
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    Thanks for the reply. I have already followed those steps to clean the calipers and rotor bobbins. Did not make much of a difference. When I watched the article again, I noticed that at the end he spins the wheel and it also doesn't complete a full rotation. Maybe that's normal then. Will take the bike for a ride and not use the front brake to see if the rotors heat up.

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  6. #4
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    You'll need to clean the pistons, pads and caliper. The pistons need to be able to move freely to retract and not cause the pads to drag on the disk.

    To keep his video short, he skipped cleaning the second caliper. That is why his wheel didn't spin as freely as it should do at the end of his video. He should have mentioned this but must have assumed that the viewer realised that his machine had two front caliper, both of which needed cleaning.

    Rid safety.

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  7. #5
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    Are these BMW factory brakes, or aftermarket?
    BMW F800ST, 2010, Black, Fuzeblock, Sat Nav, BMW Tank Bag, Givi Touring Screen, Denali Spotlights, Denali CANSmart, Wunderlich Crash Bars, 62K Miles & counting 

  8. #6
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    First thing I did was to clean it all out - callipers, sliding pins, brake pad pins, pistons, pads and rotors. Pistons can be moved with fingers without too much force. Only things I have not changed, are the seals.

    What I am after is to find out what normal is. Is one rotation enough or is that still too much drag for twin discs?

  9. #7
    Richard230's Avatar
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    Quote Originally Posted by Neilm View Post
    First thing I did was to clean it all out - callipers, sliding pins, brake pad pins, pistons, pads and rotors. Pistons can be moved with fingers without too much force. Only things I have not changed, are the seals.

    What I am after is to find out what normal is. Is one rotation enough or is that still too much drag for twin discs?
    I think what you are experiencing is typical for disc brakes. They do tend to drag a lot while you spin them with your hands in your garage. However, once rolling along the road any slight drag goes away. But just to be sure, ride your bike at high speed and then come to a stop using only your rear brake. Get off the bike and feel your brake discs. If they are not hot, then the pads are not dragging and there is nothing to worry about.

    BTW, the front brake disc of my Royal Enfield also drags like yours. But the rear wheel, which has a drum brake, will spin several rotations after turning it by hand. Sometimes I think I could balance the rear wheel without taking the wheel off of the bike, there is sot little friction.
    Richard - Current bikes: 2016 BMW R1200RS, 2018 16.6 kWh Zero S, 2011 Royal Enfield Bullet 500 Classic, 2009 BMW F650GS, 2020 KTM 390 Duke, 2002 Yamaha FZ1 (FZS1000N) and a 1978 Honda Kick 'N Go Senior. 

  10. #8
    BoxerBits's Avatar
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    Quote Originally Posted by Richard230 View Post
    ...just to be sure, ride your bike at high speed and then come to a stop using only your rear brake. Get off the bike and feel your brake discs...
    Interesting approach, would work as a diagnostic test , might end up with a dose of gravel rash but ...

    How does the machine feel when you push it around, is it more difficult than usual to do so i.e. does it feel like it's resisting your efforts to push it around as if the brake is applied?

    Can you hear any rubbing when you spin the wheel or push the bike around?

    Any discoloration of the disk surfaces?

    Is the ware on all the pads even across all pads?

    When the calipers are removed, does the wheel spin freely with many more rotations than when you try with the calipers and pads installed? (Or do you have to apply a lot more effort to spin the wheel the second time?)

    You' may well answer your own question by trying some of the above.




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  11. #9
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    How easily can you push the pistons back into the calipers? Should be able to do it with your thumb. If you press one in and another pops out that doesn't count. Some 800s have an issue where master cylinder piston doesn't retract far enough to fully expose the port and an adjust may be needed. The wheel should spin relatively freely even with the light contact inherent to disk brakes.

  12. #10
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    Thanks for all the comments and suggestions. I took the bike for a 15km ride at 90 to 100km/h. Measured the temperature of the brake rotors before and after I stopped (without using the front brake). Starting temperature was 19C and after the ride, the right disc went up by 2C and the left disc by 4C which is negligible. Double checked with fingers and they were still cold to the touch 🙂 I am happy with the result of this test and will now accept the amount of drag on the wheel. Thanks for all advice, much appreciated.

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