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I was trying to replace the piston band on my rebound piston in a showa tc fork. I got it on, but it was so streched out that it will not work. How do I get this band on without distroying it in the process?

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we use cones to install piston bands.

I guess the key is to stretch the band equally and maybe just for a very short time

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I was trying to replace the piston band on my rebound piston in a showa tc fork. I got it on, but it was so streched out that it will not work. How do I get this band on without distroying it in the process?

Warm up the piston band. You need to get the band started on the outer edge of the piston. then work it in little increments around and down on the piston. It takes the right amount of heat and feel. When it cools its snug on the piston..

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thanks guys, I will try that. I have already ruind 2. Good thing they are cheap.

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I was trying to replace the piston band on my rebound piston in a showa tc fork. I got it on, but it was so streched out that it will not work. How do I get this band on without distroying it in the process?

Okay...here's the deal.

Piston bands have to compressed after they are installed, in order to get the band down to the proper size. In other words, the job is only half way done after the band is placed on the piston.

So yes, you have to use a taper cone of sort to slip the band onto the piston with as little distortion to the band as possible.

Then the band has to be pressed or compressed down to the proper size before it is put back into service. This seals the band to the piston and makes sure that the band is not going to slip off of the piston as the piston is slipped back into the chamber.

So a band will stretch and a band will tighten or shrink when it's put under pressure.

We achieve this by using steel tapered cylinders that the piston can be ran through. We press them through, let it sit for a bit, then pop it out the other side looking sharp and clean and just like a new part from the factory. Here's what the cylinders look like.

Taper%20Band.jpg

Now...another trick to compress the band on involves wrapping the band super tight with electrical tape - as tight as possible for about 20 winds. Almost to the point that the tape snaps. Works very well. Just wrap it up, let it sit for a bit, then unwrap it.

You may need to mount a bolt into a vice and place the piston on the bolt, locked down, in order to get the right amount of leverage. You can't do this trick by holding the piston in your hand.

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Just when you think you have seen it all.........BAM!!! Right between the eyes with a 2x4!!

Glad my friends buy new bikes every year so I don`t have to do this procedure:ride: Great info Dudes!

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Here are some prictures of what Dave was talking about.

the tapered cone and at the right the piston band on it as well

pband1.jpgpband2.jpg

.

To push the band down we need some kind of cup:

pband3.jpgpband4.jpg

.

That's the sleeve which is tapered at the beginning:

pband5.jpg

.

The piston has to be pushed through the sleeve:

pband6.jpgpband7.jpg

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Very cool Frez! I could make an installation cone out of delrin on my little 3in1 lathe I guess. Perhaps a compression sleeve from aluminum.

That would be a fun project:ride:

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hey frezno, looks like the band on the pic at bottom left has been cut like a piston band. Is this on purpose or just a pic of a different band? I have change piston bands in my shock and it was pieced together like a puzzel, but I didn't think that would work in the fork sence you cannot compress the band with your hand. My cartrige rod had alot of side to side play in it. So, I replaced the cartrige seal and was changing the band to try and tighten the rod back up. Didn't think it would be this difficult.

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the band isn't cut. there's a marker line which might look as a cut.

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Okay...here's the deal.

Piston bands have to compressed after they are installed, in order to get the band down to the proper size. In other words, the job is only half way done after the band is placed on the piston.

So yes, you have to use a taper cone of sort to slip the band onto the piston with as little distortion to the band as possible.

Then the band has to be pressed or compressed down to the proper size before it is put back into service. This seals the band to the piston and makes sure that the band is not going to slip off of the piston as the piston is slipped back into the chamber.

So a band will stretch and a band will tighten or shrink when it's put under pressure.

We achieve this by using steel tapered cylinders that the piston can be ran through. We press them through, let it sit for a bit, then pop it out the other side looking sharp and clean and just like a new part from the factory. Here's what the cylinders look like.

Taper%20Band.jpg

Now...another trick to compress the band on involves wrapping the band super tight with electrical tape - as tight as possible for about 20 winds. Almost to the point that the tape snaps. Works very well. Just wrap it up, let it sit for a bit, then unwrap it.

You may need to mount a bolt into a vice and place the piston on the bolt, locked down, in order to get the right amount of leverage. You can't do this trick by holding the piston in your hand.

hey dave

i need to replace the piston band on the shock for my honda 450r...i'm a little leary about doing this myself...are you an outfit, i have the shock all broken down, although i haven't taken the piston off of the rod

looking for a place to send this to get this done, here in calif preferably

thanks

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I used to use th same type tools on Powersteering gear I used to overhaul. For the compression tool, tape does work but you can also put it in the freezer with tape on this works well.

MM

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I'm working on an 01' KX250 with KYB shock. I got the band on with no tools and currently have it wrapped tight with e-tape. How much interference fit do I want between shock body and piston band?

I guess my question is how far do I shrink it down?

Thanks,

Matt

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Thanks for the tips, needed this while working on some forks today. For some reason the rebound piston and band wasn't going back into the fork easily on a new yz250f, never had this problem on any other fork. What I had to do was wrap the band with electrical tape super tight, leave in the freezer for a while, then remove the tape, put back in the freezer for a few minutes, that did wonders cause the band was stretched out and nearly damaged from pushing too hard previously trying to get it into the fork. Then I heated up the fork cartridge, which was necessary, then the piston and band went into the cartridge fairly easily. Without the heat it still didn't want to go in easily. Had a little grease on the band too.

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On the shock you want it to be around 0.2mm bigger than the shock body

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The timing of this post could not be better. I just ordered these bands from Smart Performance on Monday and I'm waiting on them to arrive. Now I have an idea as to what to look forward to in regards to installing these. Thanks everyone!

Maybe I'll start a post with pics as I go through this.

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