How much clearance please!?

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Donut 77
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How much clearance please!?

Post by Donut 77 »

Starting to reconstruct the back end. It’s had new bearings, seals and rear disk. I’m as certain as I can be that everything is in the correct place. I haven’t torqued the rear nut yet, but there is only a fag paper between the inner side of the new brake disk and the alloy plate which the calliper fixes to. There is about 3mm on the outside of disk (see pic) This makes me suspect it should be more central, but I can’t see how? If anyone gets a minute, would you mind measuring yours (ie can you get more than a sheet of paper in the inner gap) please.

Much appreciated as always. The wheel does turn freely, so it may be correct??

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Kev L
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Re: How much clearance please!?

Post by Kev L »

Could it be the wheel spacers in the wrong way round? Left one in the right and vice versa. I seem to remember them being different thicknesses.
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Donut 77
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Re: How much clearance please!?

Post by Donut 77 »

I wondered that but I’ve just checked the diagram and they are a different shape (4 & 5 in the pic) so can only go one way - I think. Over the whole axle, there are 4 spacers, 3 bearings a washer and a nut. They are all squeezed tight together, so the lateral position of the wheel (and therefore the disk) cannot change. Nor can the calliper mounting bracket! It could be that it’s designed that way because under braking load it pulls into the gap? I can’t see how though?


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sirch345
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Re: How much clearance please!?

Post by sirch345 »

You may find when you torque up the rear axle nut the disc will be sitting more central :eh:

Chris.
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Donut 77
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Re: How much clearance please!?

Post by Donut 77 »

I thought that too but it didn’t.

Its position seems to be 0.5mm inside clearance, 2.5mm outside.

Looking back at old photos, it’s how it was, and I don’t see how it can be put back any other way?

Maybe it’s designed to be close to scrape the crap off the inner disk? I think the problem is that I don’t actually understand its purpose.. ie why have a hook over the disk? Why not just the bit at the top for the slide pin?

There must be a reason! But then, they wouldn’t accidentally machine it off centre either.. 🤷‍♂️
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sirch345
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Re: How much clearance please!?

Post by sirch345 »

The things you have to do for a fellow biker :lol: :lol:

I couldn’t get to the point you want to know about without removing the caliper complete with pads first. I would have preferred it was a front caliper as the rear are fiddly to refit lol.

The distance on my bike is approximately 1mm gap behind and 2mm at the front, so not that different to yours. It could be you have an aftermarket disc that doesn’t sit in the exact position as a genuine OEM part does. As long as you have clearance that is the main thing:
IMG_1311.jpeg
IMG_1310.jpeg

HTH,

Chris.
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Donut 77
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Re: How much clearance please!?

Post by Donut 77 »

Wow, Chris you’re an absolute Saint. Thankyou so much.

I hadn’t really considered that it wouldn’t be easy for others to measure, as I’ve got no calliper in the way, but of course it isn’t.

I really appreciate you doing this.

It does look as though it is down to the disk - but as you say.., a gap is a gap!

👍👍
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sirch345
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Re: How much clearance please!?

Post by sirch345 »

Donut 77 wrote: Tue May 02, 2023 4:01 pm Wow, Chris you’re an absolute Saint. Thankyou so much.

I hadn’t really considered that it wouldn’t be easy for others to measure, as I’ve got no calliper in the way, but of course it isn’t.

I really appreciate you doing this.

It does look as though it is down to the disk - but as you say.., a gap is a gap!

👍👍
:lol: :lol:
You're more than welcome, at least you now know you haven't put something back together in the wrong place :thumbup: :thumbup:
Good on you for noticing it really :clap:

Chris.
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