Shock Rebuild

Appears I missed this whole section out, probably due to the pandemic kicking in. So as mentioned previous when I took the spring off the shock it proceeded to dump its oil and gas, sigh.

As with everything else on the bime it was covered in road debris and was in need of a full rebuild. This is a bit tricky as CCM didn’t provide any info on the shock, so after hours looking at paerts diagrams I decided the closest match is either a KTM 640LC shock or KTM 65, both use many identifcal parts to the CCM. This meant getting parts would be easier than expected.

I stripped the shock and then started sourcing parts, one important piece of info here is to get hold of a manual to help with disassembly – google WP 4614, which is close enough to guide you through the process, as I damaged a seal thinking it came out in one direction when it actually came out in the other.

It was also the seal inside the piston, which is not a part you can buy from KTM on its own, you have to buy the whole piston which in the UK was £105. I did try to order one but after weeks of waiting was told it had been superceeded and the new part was £150. So gave up briefly and worked on other things.

After more research I discovered the seal was an X-ring and has a PTFE backup ring to support it.

The photo below shows most of the parts and their part numbers.

I bought the piston inner bush from K-Tech suspension and found the X-Rings at part no – QR113. The most difficult part to source was the PTFE backup ring, so in the end I found someone on eBay (Therma-tec) offering laser cut PTFE washers to custom sizes, so I had some made to my dimensions – 18.5 OD x 14.2 ID x 1.5 (all mm). All other parts came from my local KTM dealer.

If you decide to strip your shock ENSURE you depressurise it using the screw on the remote reservoir, very CAREFULLY!!

There is also a detailed rebuild here

Ok , so rebuild didn’t quite go to plan followed the manual and the shock ended up pissing out oil, WTF!

Time for some RTFM slowly, ah light bulb! I’ve knocked up a quick diagram to explain, so anyone following this doesn’t make the same mistake. Its obvious when you see it, but not when you’re just following the manual.

Other than that issue, the instructions are pretty good and I fitted a schrader valve conversion to make gas filling easier. Also bought some of the factory tools to make life easier. They weren’t that expensive and save me having to make things.

T110S is the piston rod and T144S is the breather bottle, they cost approx £50 for the pair.

Other things to note –

Compression adjuster is held on with a small allen bolt and its a pita to get out, mine was stuck on the two o-rings, also make a note of how it comes apart to ensure it goes back together the same. Otherwise the adjuster won’t work properly.

Keep the shim stacks in order, I put a cable tie through each one.

The piston isn’t symmetrical, so make a note of the orientation when disassembling.

Have lots of clean cloths and brake cleaner handy.

Just waiting on white paint for the spring.