TM Racing 50mm Marzocchi Fork Rebuild
Posted 31 March 2012 - 05:57 AM
I was amazed at how easy this fork is to work on. I removed the bottom nut from the bottom of the fork (it takes a 21mm socket which I didn't have. So I used a 13/16 socket). Unlike a KYB, Showa or WP, when you remove the nut, the whole compression valve does not come out. It just frees the cartridge. I then removed the the fork cap.
You need a 4mm pin spanner wrench to remove the cap (available through Race Tech). Once you open the cap and pull the cartridge out the oil will drain out of the bottom of the fork. Put the cartridge somewhere safe! You do not have to bleed the cartridge or touch it to do seals in this fork.
Once all that is done its a pretty standard operation Pry the seal wiper down with a flat blade screwdriver. Then remove the seal retaining clip and slide hammer the the fork legs apart. Remove the bushings, seal washer (which doubles as bushing seat), seal and wiper. Clean everything up and get ready to put it back together.
Wrap masking tape around the top of the fork down past the bushing recess so you don't nick the seal when you reinstall. I use a little seal grease on the wiper as it comes dry. Slide the wiper, seal (the seal came from TM with grease on it), steel washer, and large bushing on to the lower leg. Remove the masking tape and clean the top of the leg. Slide the smaller bushing into it recess and slide the whole thing into the upper tube. Grab your seal tool (I use one from Motion Pro) and hammer the seal onto its seat. Install the seal clip and make sure it is seated in its groove.
Grab the cartridge and slide it into the outer tubes. Make sure the bottom of the cartridge is seated in the lower leg and reinstall the nut. I use an air tool to reinstall the nut as I do not have a cartridge holding tool for this fork yet. Pull the outer tube up to about 6" from the cap and pour in your oil. The stock recommendation is 310cc of 7.5wt. I wanted more bottoming resistance so I went with 330cc of 7.5 Silkolene Pro RSF. It is important to note that unlike the other fork manufacturers, you do not need to measure the oil level from the top of the tube. Just pour a specific amount in a cup and pour it in the fork. Way more simple!!! Pull up the outer tube to the cap and tighten it down.
Reinstall the forks on the bike and torque the triples down to 17f/lbs. Bolt the rest on and GO RIDE!!!!
The whole procedure took me about 20min per leg and another 15min to remove/reinstall. Not too bad for a first attempt. I was not familiar with the Marzocchi fork and it is really easy. Easier than any of the other forks I have worked on. The manual is excellent (although its 116 pages and in 5 languages)
When I do the oil in the cartridge I will post again. This is just for a seal or outer tube oil change. I hope you find this helpful.
The TM's are amazing bikes and out of the box I felt no need for valving or spring changes for me. I am a 200lb A/expert level rider that does mainly ECEA hare scrambles and moto with the occasional enduro thrown in for fun.
Posted 31 March 2012 - 10:11 AM
Only serviced the fork on my mountain bike before.. I was cautious doing that!
Posted 31 March 2012 - 01:22 PM
and the preload ring is easy to adjust too
Posted 01 April 2012 - 05:02 PM
Posted 02 April 2012 - 07:27 AM
Haha you know what?.....I think your right!!! Just remove the front wheel and handlebars and follow the rest of the procedure above!
Posted 02 April 2012 - 05:19 PM