New Front discs not aligned centrally in brake caliper body

Having Problems with your BMW R1200RT/R1250RT? or have some Maintenance and Service questions?
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hestbank frank
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New Front discs not aligned centrally in brake caliper body

Post by hestbank frank »

Hi Everyone
Just fitted new discs/pads (Brembo) on my 07 R1200 RT
Failed MOT due to part of caliper body (fin) nearly touching disc (0.2 mm gap) with good clearance on other side of disc ..say 3mm gap between disc and caliper fin
Checking other side of wheel and same issue with the other caliper/disc non centralisation (similar gaps)
It's as if wheel needs to move over 1-1.5 mm
Any ideas to help
Everything was put back as found during disc change but have no bike history
The new disc is 5.1mm thick
Is this correct? 
Last edited by hestbank frank on Sun Sep 09, 2018 2:04 pm, edited 1 time in total.
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pwbike
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Re: New Front discs not aligned centrally in brake caliper body

Post by pwbike »

Perhaps the discs are left and right sided and they've been fitted to the wrong sides of the wheel, or just flipped?
Peter
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David.
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Re: New Front discs not aligned centrally in brake caliper body

Post by David. »

hestbank frank wrote:Failed MOT due to part of caliper body nearly touching disc.
The disc sits in the centre of the calliper with the brake pad friction material plus the thickness of the pad back plate either side.

Don't understand how the disc can be anywhere near the calliper.

This video shows how to remove the pads, demonstrating the clearance described above, https://www.youtube.com/watch?v=kCTAgPHER0M

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Levisp
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Re: New Front discs not aligned centrally in brake caliper body

Post by Levisp »

Post some closeup photos so we can see the problem.
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pwbike
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Re: New Front discs not aligned centrally in brake caliper body

Post by pwbike »

What a terrible video, out of focus and shaky.
Anyway it did show that the disks are mounted with the bolt going through a bushing that had a thin flange.
Perhaps when fitting discs, the flanged bush has been put on incorrectly and has offset the discs from their correct position.
Either that, or the new discs are too thick.
Last edited by pwbike on Wed Sep 12, 2018 9:49 am, edited 1 time in total.
Peter
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David.
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Re: New Front discs not aligned centrally in brake caliper body

Post by David. »

RealOEM lists two alternative set ups for the front brakes on a 2007 RT, https://www.realoem.com/bmw/enUS/partgr ... 388_&mg=34

If EVO callipers are fitted, the discs are described as "offset", the others aren't.

Could be possible that the replacement Brembo discs are not correct for the bike, or the Brembo spacer & screw kit hasn't been used.
http://moto.brembo.com/en/detail/68B407 ... iscs/front
Last edited by David. on Wed Sep 12, 2018 8:55 am, edited 1 time in total.
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pwbike
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Re: New Front discs not aligned centrally in brake caliper body

Post by pwbike »

hestbank frank wrote: Just fitted new discs/pads (Brembo) on my 07 R1200 RT
Failed MOT due to part of caliper body (fin) nearly touching disc (0.2 mm gap) with good clearance on other side of disc ..say 3mm gap between disc and caliper fin...
Nearly a week gone by with no update, what's happening, what turned out to be the problem?
Peter
hestbank frank
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Re: New Front discs not aligned centrally in brake caliper body

Post by hestbank frank »

Planning on looking at it tomorrow with a bike mechanic friend
Been researching the problem
Looked at a few other bikes with the same caliper /disc arrangement (GS's also use the same components)
None of the other bikes have the disc central to the small caliper fins
Beginning to think the Honda garage i took it to got it wrong !
My view is if the disc is not touching any part of the caliper then it is OK
The gap can only increase as the disc wears
The new discs being Brembo have been checked to be 5.1mm thick
This has obviously made the gap smaller since the original discs were only 4.5mm thick
I suspect if i took the bike to any other MOT centre it would pass
I will let you all know the final outcome after tomorrow's full inspection
BMW main dealers currently have a half price MOT offer so once i am 100% happy that everything is in order then i will take the bike to them for the MOT when it will probably pass


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hestbank frank
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Re: New Front discs not aligned centrally in brake caliper body

Post by hestbank frank »

Problem caused by the new Brembo discs being thicker at 5.1mm as opposed to the original 4.5mm
Looked at a number of other bikes and none have the disc dead centre in the caliper body
Problem resolved by adding a 0.7mm shim adjacent to the axle spacer effectively moving the wheel over o.7mm
ABS gap still in spec
Thanks for everyone's comments/help
Now just to sort out the headlight problem
See my latest post
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