Freakin out a little.

[dougfollett]

Thought I'd work a bit more on the front end of my 1989 R100RT and see if I could figure out the torque settings for the two large hex nuts that hold the brake calipers on. I have the two inch thick Clymer's manual but being a bit slow I couldn't find a specific torque setting for them so I decided to use a short ratchet wrench and just snug them up. The top one went well but the second one seemed to get soft towards the end as I was tightening it. That surprised me because it seemed that something like that should take a lot of torque being that it held the brake calipers in place. I backed the bolt out and gave it a second start. This time it didn't take much pressure at all and the it bottomed out and kept turning. I backed the bolt out and noticed that the threads from the female side had been pulled out by the bolt. I could hold them in my thumb and index finger and unscrew them from the bolt. I realize I just stripped the threads but do you think it could have been stripped previously and this was a repair? What do I need to do to repair this? I feel like such an idiot. :banghead

Doug

[donbmw]

You should be able to use a thread insert for the repair.

Don

[crazydrummerdude]

Yeah, the Clymer likes to say "Secure the bolts," "tighten securely," etc.

Well, what the heck is "secure"?!

[26667]

did you just pull out smeone else's helicoil? no biggie if you did. that ought to be a "fix" you can re-fix.

i've decided it's ez to feel like an idiot when you don't have all the shop tools and some decent level of training and experience. and experience may be the main thing. if you've seen it before, had it explained, watched it repaired, it's ez.

pardon me if i'm being master of the obvious, but i'm getting tired of doing that "idiot" thing to myself. i want to be more zen-ey about all these kind of things that seem to come up w these machines. I hope i'm being helpful. So many people here have helped me.

[The_Veg]

Did what came out with the bolt look like it's own piece of metal, or like something that was shredded loose?

[kbasa]

Try to find a place that will sell you a Timesert.

They stay in better. FWIW, it sounds like a fresh strip. A helicoil is somewhat more substantial than the little winding it sounds like you got.

[AntonLargiader]

Thought I'd work a bit more on the front end of my 1989 R100RT and see if I could figure out the torque settings ...

Ouch. The M502 (second edition) Clymer I have does list the correct torque: 32 Nm. But for the ATE brakes the value it lists for the end cover is about 50% too high. That manual is just dangerous.

If it pulled out at 32, you had bad threads to begin with. Regardless, a Helicoil is a perfectly fine repair method for this and is pretty simple.

Brake calipers actually don't have monster torque values associated with them. They went as high as 40 Nm and then came down again as the bikes got lighter and rotors got larger. Now they're using smaller bolts than your bike has.

[AntonLargiader]

Another thing... especially with such a short fastener, it's critical to drill & tap the hole for the thread repair accurately. Put a very long bolt with a locknut into the other caliper bolt hole, and use that as a visual guide to make sure you are drilling parallel to it. Some people prefer to do this work in a drill press or a mill for better control, but if you're careful you can do a good job right on the bike. That's how I fix 'em.

[535is]

Brake calipers actually don't have monster torque values associated with them.

+1

Too many folks think, "If it's brakes, they gotta be Ape**** tight!" When you think about the stresses on these bolts, you should be able to see that surprisingly low torque will hold them on perfectly well.