Dog Bone and Rear Shock Bearings

[trapezeartist]

In a moment of madness I decided to pull apart the rear suspension of my '21 ePure Race. Not surprisingly I found a few seized bearings, namely one of the dog bone ends and the lower end of the rear shock. Poor things, living on a diet of mud and water with the occasional bit of dust thrown in.

Two questions really, so hopefully someone can prevent me from making any silly mistakes.

1. I thought the whole rear suspension came from Sherco, but the dog bone bearings I found on the internet are plain teflon bushes and the EM bearings are needle rollers. Are they unique to EM, or am I looking in the wrong place?
2. The dog bone bearings are a seriously tight fit and using a couple of sockets and whacking with a big hammer has not done a thing. Eventually I'll get them out, either by warming the arms or by grinding through the outer race. Then I have to fit the new ones. Will they tap in or do I have to find myself a press?
3. I've never touched a rear shock bearing before and don't really know what is in there. There appear to be a pair of spacers a bit like wheel bearing spacers which have so far resisted my efforts to remove. I haven't tried that hard yet so hopefully I will find a way. Then pretty much the same questions as the dog bones.

OK, so that was three questions. Any thoughts on how to go forward or do I just suck it and see?

None of the required parts feature on the Inch Perfect online shop so I will probably have to phone them tomorrow, unless I can find Sherco parts somewhere else.

[stpauls]

Just done my 1922 Sherco 125.  Completely disassembling the entire rear shock system.  Checked and lubricated everything.  Put it back together this afternoon.  The frame seems to be mostly the same frame as yours, apart from the front down tube and likely the engine mounts and a few other brackets. 

The only roller bearings that I saw were inside of the rear shock eyes.  These are sealed with O rings, but I took them apart to check anyway.  They were perfect.

All the other bearings were just plain linear bushes - no Teflon coatings anywhere.  I lubricated them with Red "N" Tacky Grease.

Those big "spacers" on the two dogbones don't come out!

I didn't need to use a hammer or explosives to get it all out/apart and I don't think you will need to either!  If something is seized then spray it with Plusgas or a similar penetrating fluid.

Thought: I wonder if electrolysis is an issue with electric bikes?

Edited February 17, 2023 by stpauls

[trapezeartist]

The dog bones are marked EM-L and EM-R so perhaps they are different from Sherco to accommodate the (presumably) larger OD of the needle rollers. Shame they didn’t include seals as well. I’ll talk to Inch Perfect tomorrow.

I don’t think electrolysis is an issue because I haven’t seen any aluminium corrosion anywhere.

[trapezeartist]

On 2/17/2023 at 5:26 PM, trapezeartist said:

 

1. I thought the whole rear suspension came from Sherco, but the dog bone bearings I found on the internet are plain teflon bushes and the EM bearings are needle rollers. Are they unique to EM, or am I looking in the wrong place?
2. The dog bone bearings are a seriously tight fit and using a couple of sockets and whacking with a big hammer has not done a thing. Eventually I'll get them out, either by warming the arms or by grinding through the outer race. Then I have to fit the new ones. Will they tap in or do I have to find myself a press?
3. I've never touched a rear shock bearing before and don't really know what is in there. There appear to be a pair of spacers a bit like wheel bearing spacers which have so far resisted my efforts to remove. I haven't tried that hard yet so hopefully I will find a way. Then pretty much the same questions as the dog bones.

Well I can now answer my questions myself.

1. The bearings do seem to be unique to EM. In the end I got them from a local factors which was quick, easy and cheap.
2. I warmed the dog bone with a heat gun ( to about 100 deg I would guess) and the bearings tapped out easily. The new ones went in the same way.
3. I didn't have any luck with removing the rear shock bearing, but while I was working at it and squirting in lots of WD40 the bearing freed up. So I cleared as much of the WD40 as possible with an airline and re-lubed it with chain spray. It now moves easily and smoothly.