Fork parts question

B

ballisticexchris

Guest
New question. I am trying to source the Yamaha SST fork spring compressor tool. This is specific to the ES model. The service manual lists two part numbers; 90890-01573 and YM-01573. I can't seem to get either number to come up in any of the on-line parts fiches I've tried. Those numbers don't come up in a google search either. Anyone know how to order one?
Yes either from KFM-Motorrader: https://www.kfm-motorraeder.de/cms/en/genuine-spare-parts/yamaha-spare-parts?itemid=908900157300

Or PSJE engineering: http://www.psje-webshop.dk/index.php/yamaha-fork-spring-compression-tool-90890-01573-00.html

Both accept PayPal so it will convert to US currency. It's just a standard slide in tool for compressing springs. You still need the bolts and bottom plate.

This is the specific Yamaha tool:
fork-spring-compression-tool_medium908900157300-01_d2c6.jpg

I would recommend the Race Tech one instead. This is universal and complete. It requires just a socket and impact tool to use

This one is a few bucks more and foot operated:

I do my dirt bikes by hand.
 

WJBertrand

Ventura Highway
Joined
Jun 20, 2015
Messages
4,591
Location
Ventura, CA
Thanks ballisticexchris, Those Race Teach ones won't work. I've got the Motion Pro one which interacts with the spacer above the spring in the same way The problem is that the ES fork spacer/collar does not have the holes to receive the two bolts from either of those tools. The special ES tool fits above and pulls down on a flange built into the spacer, so no bolts are needed. The service manual just shows pulling it down and holding with ratchet straps once it's slid into place on the collar / spacer
 
Last edited:
B

ballisticexchris

Guest
I was thinking then you could weld a nuts to some flat bars and then use it over the rod like the special tool. As long as what you have works then it's all good. A long time ago I used to service my own suspension. Anymore it takes so many specialty/custom fabricated tools I just send it in.

I have never worked on sport bike forks before. Those springs look super stiff.
 

WJBertrand

Ventura Highway
Joined
Jun 20, 2015
Messages
4,591
Location
Ventura, CA
I could make something I suppose, they want ~$78 bucks for the tool!


Sent from my iPhone using Tapatalk Pro
 

RCinNC

Well-Known Member
Joined
Aug 30, 2014
Messages
2,939
Location
North Carolina
I pulled out my service manual to see how the fork disassembly differs for the ES model, and I'm a little perplexed about the proccess. The tool apparently fits on a lip on the collar, and then you push the tool down to compress the spring, and then you undo the locknut so the fork cap can be removed. This sounds like a two man job; by yourself, how do you manually compress the spring with the tool (which seems like it takes two hands) and then remove the fork cap? With the non-ES, the manual makes it clear that you need to secure the compression tool with something like ratchet straps, but the section on the ES fork doesn't say anything about that.

In any event, the tool seems fairly straightforward to make, as long as you know the outer diameter of the collar. If you know that measurement, the rest of the dimensions should be fairly easy to estimate based on the photo of the tool. I think $78 is a little outrageous for what the tool is.
 

WJBertrand

Ventura Highway
Joined
Jun 20, 2015
Messages
4,591
Location
Ventura, CA
I used ratchet straps the same way for the ES to do it by myself. I used the non-ES compressor tool I have, just placing the pointy bolts into the coils. Doing that the tool would slide over to one side, binding things up a bit. It worked but made the job fiddlier than necessary.


Sent from my iPhone using Tapatalk Pro
 

RCinNC

Well-Known Member
Joined
Aug 30, 2014
Messages
2,939
Location
North Carolina
I was messing around on Inkscape trying to come up with a homemade spring compressor tool that would be very easy and quick to make, and would work with the existing collar in the ES fork. I don't know the diameter of the collar so I couldn't give measurements, but I think the components for this could be made from 1/4" thick by 1" or 1 1/2" aluminum bar stock. The hardest part about this would be drilling the hole in the bar stock where it fits around the collar; the hole is probably over an inch, so unless you have a really big drill bit, you'd have to cut the hole out with a saw. I've used just a regular coping saw with a coarse wood blade to cut shapes from 1/4" aluminum.

The two larger pieces fit around the collar, and trap the collar in the center. The two smaller pieces then bolt the larger pieces together, locking the two large pieces around the collar. The holes for the ratchet straps go through both the smaller pieces and the larger pieces. Just clamp the two pieces around the collar, bolt them together, then compress the spring with the ratchet strap. There wont be any risk of the tool slipping off the collar while you're compressing the spring, and it should hold everything steady while you're working.spring compressor.jpg
 

WJBertrand

Ventura Highway
Joined
Jun 20, 2015
Messages
4,591
Location
Ventura, CA
Thanks, that would work. I have similar thoughts. I've got some aluminum sheet 1/4" sitting around and I was thinking to make the tool about as wide as you show for the assembled tool from one piece. Then just make the center hole open to one side, like more of a slot. That way I could just slip it on the way the OEM tool works without having to assemble anything. I could drill an initial hole as large as possible, then grind out the rest of the shape. I would include a couple of small outboard holes to receive the ratchet strap hooks. Wish I knew what the diameter of that spacer is above the collar feature though. Didn't think to measure it whilst I had it all apart.
 

RCinNC

Well-Known Member
Joined
Aug 30, 2014
Messages
2,939
Location
North Carolina
I thought about doing is as an open ended slot, but I know how finicky it can be sometimes when trying to adjust ratchet straps. I can imagine the tool slipping off the collar while trying to take the slack out of the straps; not really dangerous, but just frustrating. With the two piece unit, you can bolt it in place so it'll stay where you put it while getting the straps set.
 
B

ballisticexchris

Guest
Holy crap!! These street bike forks look to be a real pain to compress. I have always been able to service dirt bike forks by hand with no compression tool.
 

WJBertrand

Ventura Highway
Joined
Jun 20, 2015
Messages
4,591
Location
Ventura, CA
It could be done by hand with a second person. The hard part is holding the spring down whilst you loosen the jam nut that holds the cap to the damper rod. It’s not that much force really.


Sent from my iPhone using Tapatalk Pro
 

rodeoclone

Active Member
Joined
May 13, 2019
Messages
53
Location
SE-Iowa
Reviving an old thread. Im looking at sources for the ES specific fork compression tool, referenced earlier and my question is has anyone heard of www.cmsnl.com before? Are they a legit shop? Looks like I can get the FORK SPRING COMPRESSION TOOL for about $76.
Here’s a suggestion for you that I did. I went to a machine shop with the plastic piece from the fork, that the tool fits around and had them stamp a hole in a scrap piece of iron that they had. They then used a hand grinder to open up the hole and clean it up. I think the stamp was 1.25 inch. Length and width of the bar was approx 1.75 X 12 in. I think the iron was 3/8” perhaps. I took them 15 minutes, most of which was setting up the press. I used it once a month ago and had a second pair of hands so I didn’t need holes for straps but certainly could be added. It worked perfectly. IMG_2325.jpeg
 
Top