Binding brake - MOT fail?

Binding brake - MOT fail?

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ccr32

Original Poster:

1,970 posts

218 months

Wednesday 23rd July 2014
quotequote all
Afternoon all.

I know that a binding brake will fail a bike MOT test, though was wondering how bad it has to be?

My front brakes have started dragging a bit, more than what I would consider to be normal (a bit of noise from the pads 'zinging' against the discs when you spin the wheel) to the point where the wheel stops relatively quickly when spun. It doesn't require any significant force to turn the wheel though, so doesn't affect normal operation.

Would this fail the MOT?

I have tried cleaning up the calipers/pistons in situ, though it's still not great and a caliper strip-down will be required to get any better results, though was hoping to dodge having to do this before the bike needs to be tested.

Thanks.

moanthebairns

17,939 posts

198 months

Wednesday 23rd July 2014
quotequote all
don't they need to spin the wheel to check the bearing, if a binding brake stops them being allowed to do this isn't it a fail.

ccr32

Original Poster:

1,970 posts

218 months

Wednesday 23rd July 2014
quotequote all
Purity14 said:
Does it have floating discs? Have you cleaned/freed up the bobbins? - it might be sitting wonky.
Err, I think it does... but I don't think this is the sole cause - taking the calipers off last night, they were gripping the disc a bit (but not tightly).

Good point though about the bobbins - I'll get some brake cleaner in and around them too.

ccr32

Original Poster:

1,970 posts

218 months

Wednesday 23rd July 2014
quotequote all
moanthebairns said:
don't they need to spin the wheel to check the bearing, if a binding brake stops them being allowed to do this isn't it a fail.
I have no idea, though that makes sense - as I say, you could spin the wheel at the moment, but it will stop pretty quickly. The rear however (for instance) will keep spinning a while longer with the same amount of force applied...

moanthebairns

17,939 posts

198 months

Wednesday 23rd July 2014
quotequote all
how many revolutions

Prof Prolapse

16,160 posts

190 months

Wednesday 23rd July 2014
quotequote all
As MTB says you spin it. If you don't get more than a few full rotations it needs done. But I don't think there's definitive guidance.

http://www.motinfo.gov.uk/htdocs/

For it to be the bobbins I would have thought it would spin freely for a portion of rotation then slow down as it hit the misaligned section(s) of disc(s) rather than a constant light drag. I'd still agree with doing it for routine cleaning if nothing else though.

Personally though I'd just fix the calipers. There's no sense waiting for them to fail entirely when they're so cheap and easy to maintain.







ccr32

Original Poster:

1,970 posts

218 months

Wednesday 23rd July 2014
quotequote all
I will get barely one full rotation when spinning the wheel, if that... so there's my answer I guess.

Have ordered a seal kit now anyway so will pull them off, take them apart, clean up and re-bleed. Will pay some attention to the bobbins on the discs too at the same time - may as well do a proper job!

Thanks for the help all.