View Single Post
Old 12-28-2011, 02:51 PM   #22
Beastly Adventurer
ER70S-2's Avatar
Joined: Sep 2009
Location: SE Denver-ish
Oddometer: 7,261
Rear Brake Grease Zerk

I've never liked that the rear brake pedal has to be removed to grease it. There's no bushing, wear is permanent in the frame. So I've done this to several of my previous bikes. I usually drill and tap a hole in the frame, but there isn't a good place for the zerk. This idea was from another member earlier in the DR thread, once he said 10mm zerk, I figured out what he meant. He hammered in a wood plug on the backside, I did this.

My pegs are down and back 1", this puts my heel nearer the zerk, but it hasn't broken off in the last 7k miles, so there is enough room. I didn't have a 10 x 1mm bolt so I used a 10 x 1.25 (the zerk is 10 x 1mm). This means that I used two different taps.

The pedal is upside down in the pic, the wear is on the bottom side and that's where you want the grease. I drilled the grease hole the same size as the cotter pin.
Cut the head off of your bolt, notch with a hacksaw or cut-off wheel and test fit.

Make sure the plug goes in far enough to completely clear the cotter pin. It's hard enough to get that pin in there, no reason to make it a tight fit.
Remove plug, Loctite, re-install, yer done. Disclaimer: this will make a mess down at the pedal, but it's better than the wear.
Next time I have it apart, I'll shim the 'in and out' play tighter, I think it's about 1/16" and lets grease flow through easily.

Edit: I'll put an O-ring over the shaft, between the frame and pedal.

The zerk is 10 x 1mm thread, and it's easy to see the size difference.


Adding the o-ring(s): The first attempt was with a 1/16" o-ring, which wasn't much better than before. So I headed over to the local Ace Hardware to look at o-rings. Although individual clear plastic packaging costs more per piece, it made looking at my options much easier. Any time someone asked if I needed help: "Nope, just engineering, thanks." So I bought a range of 'guesstimated' sizes and headed home.

This is where I ended up:

If you look closely, there is a slight bulge in the o-ring on the left side (end of weld bump). It's what makes this o-ring work. That bump makes the o-ring try to slide off; lightly pressing it against the pedal, becoming a second seal.

The idea works because the smaller o-ring on the pedal shaft is lightly compressed; this is the clamp I used to do that. The split clamp design allowed the shaft to press through the frame and I was able to push the cotter key in by hand.

Here's what you need to know (the right package says 3/4 x 9/16 x 3/32):

I was really pleased because it takes a bit of pressure with the grease gun, no more 'free-flow'.
2004 DR650: 62,605 miles
2013 WR250R

Originally Posted by Threewheelbonnie View Post
"BTW, I don't do style. It's a dirt bike, not some girlie dress-up thing." -

ER70S-2 screwed with this post 04-01-2013 at 10:27 PM
ER70S-2 is offline   Reply With Quote