Lower Sherman Jumper
- Thread starter skiplie
- Start date
Too bad you don't want to go to your LBS. They're a great resource, especially when you eventually screw up. Have you researched anywhere else or do you want us to spoon feed you the info?
wow, a bit harsh. Theres a thread on this from a while ago, it links you to some other site. And I really doubt you'd find an LBS anywhere that has experience lowering a sherman jumper......
That's not harsh... That's just tough love. Harsh is having to drop a deuce mid ride and finding out all you have to wipe your hole with is the pile of pine needles next to you. Now that's harsh.
OK FINE. Here's my advice. Don't lower it. You'll easily surpass the cost of buying a good used fork with all the necessary parts to do it right.
New spring (for the ride height you want)
New stanchions (for the ride height you want)
The Lowers should be the same but you'll need new seals to match the new stanchions.
Snap ring plyers, fork oil, and the specs and instructions on how to take your fork apart, change the stanchions, and how much oil to add.
+ time, mess, and frustration
If this is your first time, it'll be a long but fruitful learning experience.
OK FINE. Here's my advice. Don't lower it. You'll easily surpass the cost of buying a good used fork with all the necessary parts to do it right.
New spring (for the ride height you want)
New stanchions (for the ride height you want)
The Lowers should be the same but you'll need new seals to match the new stanchions.
Snap ring plyers, fork oil, and the specs and instructions on how to take your fork apart, change the stanchions, and how much oil to add.
+ time, mess, and frustration
If this is your first time, it'll be a long but fruitful learning experience.
dont need new stanchions at all, don't need new lowers, dont really "need" new spring, he probably wants it stiff anyways. All you really need are some spacers, tools and oil. Playing around with the fork is a good learning experience anyways, frustration=learning.
Yes it is long, but it is worth. The enduro fork seals site has a good walk through on ripping apart shermans.
BTW here's the link for lowering sherman jumpers
http://www.streetsteeze.com/forum/viewtopic.php?t=9
and the RM thread its from (search = friend, but it takes practice
)
Yes it is long, but it is worth. The enduro fork seals site has a good walk through on ripping apart shermans.
BTW here's the link for lowering sherman jumpers
http://www.streetsteeze.com/forum/viewtopic.php?t=9
and the RM thread its from (search = friend, but it takes practice
)
if the jumper is anything like firefly as far as the way the fork is set up, then it's under pressure...so if you go by that guys method, make sure before you take your fork apart, you release all the air out of the fork...otherwise you'll get a set of lowers shot at your face or across the room
I dont think the fork is under pressure, ive taken off the lowers before and they didn't shoot off at all. Thanks for the link, I think I will try it tomorrow. I just have one question though, how do you put the spacers in? There are the big black spacers and the top out spring, but they don't come off of the rod, or can I just put the spacers on without taking off the big black ones?
its not under pressure, i've taken mine apart a dozen times (still doesn't feel perfect :'( ). Anyways for the spacers You gotta like take apart one of the rods from the stanchions and put them like on top of the top out spring or something. Its been awhile since I tried to do it. But i remeber taking the rod out of the stanchions (compression side i thinkg)
i found the outer diameter for hose spacers were just a tad too small. Try something else maybe? Or maybe "better" spacers.
I tried to do it yesterday, but I couldn't put on the spacers because there is a spacer at the top near the bottom of the lowers, and there is a spacer at the bottom on top of the top out spring. So I have no way of puting the spacers on because of the spacers on either end of the rod. How do I put them on?
Just cut the springs down to the length you want. In a Jumper 2004(I had the same on and lowered it) I actually ordered a super stiff spring for it, then cut it. The preload spacers were then to short. So after some ghetto-rigging, we used then handle of a screw driver.
You should not need to buy one new thing and get it done.
You should not need to buy one new thing and get it done.
the preload spacer is something that fits inside the spring on top. It does not matter what it is, as long as something is pushing on the top cap against the spring... a loaf of bread could work as long as it puts pressure on the spring and the top cap. I understand the fork being to soft, I will try and find the link for you to where I got my super stiff spring. The ride height is already super low. Try a lower bar, or moving spacers, or even a lower stacked headset. Making a fork stiffer is pretty easy.
1) Cut the spring to the ride heigth you want
2) Grind it down to make a flat surface
3) Find some object or a preload spring to fit inside the spring, and is roughly the same size as the portion of the spring you cut off
4) Reassemble
Taddaaaa! a Super stiff fork! Sure, it will void the warentee, but making any alterations to a fork will do it anyways.
When you cut the spring, it will lower it. Use a smaller pre-load spacer and it will lower. It's that simple.
Nobody that has posted yet has a clue what their talking about. I've done this twice now including once about two weeks ago. It's clear to me that none of them know a thing about the Sherman internals. It's also clear none of them have searched for this before.
If you need disassembly tips let me know but you sound like you'e gotten that far.
After you pull the lowers off pull the 20mm plastic "nut" off the bottom of the spring side. You will have the spring compression assembly. The bumper and washers on the bottom should slide right off. Take the plastic nut with the top-out spring off and you'll have the rod with the piston on the end and a little o-ring next to the piston. Just pull the O-ring off. You don't need it. Put vinyl hose seals on against the piston a little over the height you want to lower it. The more you add the more PITA it will be to put it back together. I recommend you put no more than 8-10. Get a metal washer that fits on the rod (I don't remember the size but there's a metric washer that fits perfect) and put it on top of the hose seals. Throw the nut back on so you have (in this order) piston, hose seals, washer, top-out spring, nut (attached to top-out spring). Pull the top cap off so you don't have to fight to compress the whole assembly. Screw the plastic nut in about halfway. Now fight the top-cap to compress the whole assembly and screw the cap on at the same time. You want to do it from the top cap so you don't screw up the plastic piece. After you get it in a little ways screw the plastic nut back in all the way then the top cap. throw the bumper and washer back on and put it back together.
If you need anymore help feel free to pm me.
If you need disassembly tips let me know but you sound like you'e gotten that far.
After you pull the lowers off pull the 20mm plastic "nut" off the bottom of the spring side. You will have the spring compression assembly. The bumper and washers on the bottom should slide right off. Take the plastic nut with the top-out spring off and you'll have the rod with the piston on the end and a little o-ring next to the piston. Just pull the O-ring off. You don't need it. Put vinyl hose seals on against the piston a little over the height you want to lower it. The more you add the more PITA it will be to put it back together. I recommend you put no more than 8-10. Get a metal washer that fits on the rod (I don't remember the size but there's a metric washer that fits perfect) and put it on top of the hose seals. Throw the nut back on so you have (in this order) piston, hose seals, washer, top-out spring, nut (attached to top-out spring). Pull the top cap off so you don't have to fight to compress the whole assembly. Screw the plastic nut in about halfway. Now fight the top-cap to compress the whole assembly and screw the cap on at the same time. You want to do it from the top cap so you don't screw up the plastic piece. After you get it in a little ways screw the plastic nut back in all the way then the top cap. throw the bumper and washer back on and put it back together.
If you need anymore help feel free to pm me.
Then feel free to tell me why the few times I've done it, it has worked for over two years of hard riding, and under two different riders.
He asked how to lower it and preload it not just preload it. BTW there is no reason to cut the spring and risk bind to add preload. All you have to do if that's what you want is add a spacer on top of the spring (or the bottom) and close it up.