BRAKE JOB potential problem with caliper bracket bolts

[gungadin]

OK. I just spent a day on a caliper rebuild on my '75.
I'm installing the caliper and bracket assembly back onto the forks.
I noticed that the lower caliper bracket bolt was protruding thru it's hole and into the raceway where the rotor should only occupy.
OH! That doesn't look right.
I thought well I had some spare brake parts from a '78 and maybe I got something mixed up. So I removed all the bolts and looked them over.
Apparently there are long ones for the upper mount and VERY SLIGHTLY SHORTER ones for the lower mount. An I mean really slight. You could find one short and one long and the difference is like two threads.
Look I thought this would be important so I just stopped and took some pics of the calipers mounted both ways and pics of the bolts. So have a look.





the longest and the shortest of the whole lot. Most were more nearly the same.
I know some of the pictures are a bit blurry or dark but hey I was in a hurry.

[Annie's Boyfriend]

Very usefull info there, it is always wise to check and then double check again.

Your brakes are so inportant, they should always work perfect....

[gungadin]

Messed up the first two pics. See I was in a hurry. I'll try again.


These are what it should look like with the end of the bolt slightly recessed in the threaded hole.
These pictures are in my gallery if it helps get a better look. I think they are bigger there.
If anyone needs a better picture I'll try again but hurry I'm going back together.

[RebelRouser]

Edited Those First Two For You

[gungadin]

Thanks Reb!
Well now that I've got the whole brakes back together it's tough to take a picture of it but If I take one of the long bolts and forget the washer it definately comes within a mm of touching the inside web spokes of the rotor. Add a freak bolt to the mix and your day is wrecked. I can see it could be interfering/touching in a corner with brakes.
Another variable might be a sloppy bearing.

[octane]

Hi Gungadin

...just checked those bolts, as I'm removing them on my daily wing
to get to the fork oil seals.
Anyway I measured them, and they are all the same lenght.
Also checked my parts book.
Upper and lower have same #.
10 x 50mm

well I had some spare brake parts from a '78 and maybe I got something mixed up

so I checked the 78-79 parts# as well. Same #.

I guess yours (the longer ones) comes from an even younger wing.

Best regards
Octane

[gungadin]

When I first posted this there was a post just prior from someone who had just put it on the street and in the first corner experienced a grinding or vibration in the front end that sounded scarey. Coincidentally I discovered these funny bolts on mine.
Worth looking at once the calipers are installed to make sure they don't/can't interfere with the rotor. I think the stars and planets would have to line up but I think they could if you had an accidental long bolt and sloppy bearing and whatever flexing might occur.