Author Topic: Replacing the rear brake rotor  (Read 5740 times)

Offline frankenduck

  • Adrninistrator
  • ^ Quintessential Motobricker
  • Posts: 4965
Replacing the rear brake rotor
« on: June 17, 2011, 01:20:39 PM »
Replacing the rear rotor on a K bike is easy.  All you need to do is take the rear wheel off and then remove the two bolts that hold the rotor to the final drive.

BUT, and it's a very big but, oftentimes, due to corrosion and the Loctite used at the factory, the heads of those bolts can strip even if you've preheated them with a torch to burn off the Loctite.  In that case what you'll need to do is drill the heads off of the bolts, remove the rotor and then extract what's left with some Vice-Grips.

Here's an example where one bolt came out but the head on the other one stripped.  I drilled the head off with a 5/16" drill bit:

Then there will be enough of a bolt left to unscrew with some Vice-Grips.  Make sure that you get the Vice-Grips as tightly on the bolt as possible.  Otherwise when you turn the Vice-Grips you'll just strip metal off of the bolt. If on the bike then have the bike in gear when removing what's left of the bolt.  On the bench you can put in two of the lug bolts in and use a pipe to get some leverage and keep the final drive from turning:

The bolts can be replaced with countersunk M8x20 bolts from the hardware store.
Once I had a Collie pup. Dug a hole and covered him up. Now I sit there by the hour. Waiting for a Collie-flower.
New to K bikes? Click here.
K Bike Maintenance & Mods: Click here.
Buy parts here.

Offline robleyd

  • ^ Proficient Motobricker
  • Posts: 138
Re: Replacing the rear brake rotor
« Reply #1 on: May 14, 2012, 02:54:18 AM »
With a rotor down to 3.5 mm, I approached this job with some trepidation, not having a torch to heat the screws. I thought that I might try using an impact driver to remove the screws - the impact driver was designed for phillips and slotted screws, but has a 1/2" drive which I used with a hex socket.



Three or four sharp blows with a hammer and the screws loosened without damage to the heads. No heat, no fuss. Perhaps the deities of wielders of spanners were with me on this occasion :-)



As always, YMMV, but if you have an impact driver to hand, give it a try!
Motobrick member #70
1996 K1100 LT
1969 Triumph Bonneville

Tags: