Reducing travel on '04 Sherman?
I have an '04 Sherman Firefly that I used to run on my Xc bike. I want to reduce the travel from 135cm to around 90cm so I can put it on my DJ bike and get rid of my heavy dj1. Anybody have any experience doing this?
90mm, not cm.
You space out the negative travel spring (part of the travel adjust assembly). Do a search for one of my write-ups. It's been covered several times.
I just rebuilt a Minute today. Very easy to work on. I didn't put the metal washers for the bottom of the rod back in. I didn't really see a purpose in them. I guess we'll see what happens.
Here's what I did.
Pulled off the Rapid Travel adjuster knob, the foot nut on the bottom of the left side lower, and the 20mm top cap on the left leg.
Removed the spring assembly. There's a little plastic wedge that turns to extend the metal "wings" at the bottom of the spring, I did not put this back in when I reassembled the fork.
Since I was doing a rebuild anyways. I removed both the adjusters on the right leg. Use a 8mm allen wrench and turn clockwise to unthread the dampener from the lowers. Removed the 20mm top cap and dampening assembly. This is the part where all the oil pours out or hits you in the face.
Pull the lowers off.
To access the travel assembly unit in the left leg, you will need to unscrew the assembly from the stanchions.
After you pull the assembly off, make sure the metal "wings" aren't extended. Then space out the assembly. I used rubber washers from garden hoses. Just stretch them out over the top of the assembly. Use as many as you would like to reduce the travel by. 30mm of spacers = 30mm less travel and 30mm lower axle to crown height.
Thread this assembly back into the left side stanchion.
Slide the stanchions back into the lowers, but not all the way. Before you thread the uppers and lowers back together, fill the semi-bath oil. 16ccs of oil in each lower leg. This oil is not for the dampener. So you can use any type of light oil. I also packed a lot of Manitou Prep-M grease under the new seals.
Thread the 11mm footnut back into the left leg.
Use something to push the rebound assembly to the bottom of the right leg. Turn your 8mm allen wrench counter-clockwise to thread it back in. Make sure it's nice and snug. Thread the rebound knob back on.
Grease the shi!t out of the spring. Drop the spring back into the left leg and thread the 20mm top cap on. On the 65mm fork, I used a 80mm spring. On the 100mm for, I used a 130mm spring. It was a pain in the ass to get it all the way down. But I did it. Shermans are notoriously undersprung anyways. If you really need to, you can always just lop off a bit of the spring. Remember to measure and think things through before you cut. Make the spring slightly longer than it has to be. The spring is slightly longer than it has to be when it comes with the fork too.
Add oil to the dampener side. I used a more viscuous oil to slow down the rebound in order to compensate for the added preload.
I was about 2.3 inches from the crown. Compress the fork regularly, oil will suck down into the rebound assembly. Oil heights are subjective. As long as it feels good, you're alright. Pop the 20mm top cap back on. After a few rides, check the oil height again.
I think that's it.
WOW!!! That's more than I was expecting, thanks for the info! I'll do it this weekend and report back.
I have chimed in on this in the past as well. Usually just adding onto one of Will's posts. His instrux are right on. The only thing I'd add is that Will has had good luck with the hose washers and I didn't. I ended up using a bmx bb spacer which fits perfectly. Just pop the plastic end cap off the bottom of the rod and slide the spacer on, replace the cap and bingo. The cap (or boot) takes a little force to remove but will come off with no tools.
Originally Posted by 2w4s
though hope is frail, it must prevail - Taj Weekes
betam eh-wud-eh-HA-lehu yeh-nay Ityopia!
yo B! I got a 47mm BB spacer that i dont need. ill bring it up today.