Easy way to lower rear shcok using Zeta spacer

[ChondaChondaChonda]

So I decided that my 31" inseam wasn't having so much fun trying to horse around my too tall LXR250. It comes with 12" of wheel travel at each end, which is probably only needed by top level supercross type riders. I don't think an old man trail plunker like myself will even notice that the travel is gone.

I wanted to write up the process as it should apply to lots of other bikes here too.

I stumbled across these lowering rings from Zeta a few weeks back:
12054

The web address is here: http://www.zeta-racing.com/sus/lowering_inner_r/lowering_r.html

There is a video at the bottom of the page that shows how to go about it. They sell a 46mm kit and a 50mm kit. These claim to lower the bike about 30mm or 1.18" each.

I started by folding the rear sub-frame up and unbolting the rear shock:
https://i.imgur.com/SkEUqiz.jpg


It's a good idea to take the pressure off the spring while the bike is still holding things for you:
https://i.imgur.com/8FYDCEd.jpg

Count the number of clicks on your adjusters and note it. Turn the adjusters counter-clockwise all the way out before you use a 19mm wrench to remove the compression plug; drain the old oil into a container.
https://i.imgur.com/ILK7JcW.jpg

When you get all the pressure off the spring these FastAce shocks use a clip that has to knocked loose by giving it a nice rap with a rubber hammer:
https://i.imgur.com/pJsNU0B.jpg

Next I put a high pressure gauge on the nitrogen bladder and see 105psi:
https://i.imgur.com/mnf6SBj.jpg

https://i.imgur.com/0mYicUj.jpg


Then let all the nitrogen out via the valve:
https://i.imgur.com/sReoRdA.jpg

Things should look like this:
https://i.imgur.com/hQagVAh.jpg

Note: I didn't get ALL the nitrogen pressure released and when I pulled the compression plug it sprayed oil all over. BE SURE to get it all released!!

Now the instructions in the Zeta kit are for the WP and Showa shocks. They tell you to use a chisel and hammer to pop the bottom cover off. The FastAce shock uses a very different seal head that is integral the the cover and threads into the shock body. There are 4 holes in the bottom cover for opening it up. I presume that there is a special tool for it, but I made one from some old stuff I had lying around:
https://i.imgur.com/VU8NgJL.jpg

https://i.imgur.com/3r9iadr.jpg


Once you have the seal threaded out you can pull the entire shaft out:

https://i.imgur.com/yRl3ZP2.jpg



The Zeta ring is held together with an o-ring. It simply pops off and the ring splits so you can position it around the shaft.
https://i.imgur.com/UZGyiUC.jpg

Clean up the shock and all parts for reassembly.
https://i.imgur.com/uKOHqHS.jpg


The shock should be reassembled by threading it back together with the Zeta spacer sitting as pictured above. Next fill it with fresh SHOCK OIL (I like kyb kc2) and it will need to be bled by pumping the shaft and holding the shock so the oil hole is upright. It takes a while, but eventually the bubbles stop coming!

I re-installed the spring. I will need to take the shock to get it re-charged with nitrogen on Monday.

This should lower the rear of the bike 1.18" or 30cm. I threw it on the bike just to see how it sat:
https://i.imgur.com/BC2DBGf.jpg

It's definitely lower! Sitting on it I can completely flat foot in my street sneakers! It will be interesting to see how this affects the bike and I will post back when I have some riding time on the set-up. :thanks:

[david3921]

Pretty nifty item. Thanks for the write up. I couldn't get my head around how adding something would make it shorter until I checked out the website. Now I'm curious if something like this could be used to lower other bikes.

[ChondaChondaChonda]

Pretty nifty item. Thanks for the write up. I couldn't get my head around how adding something would make it shorter until I checked out the website. Now I'm curious if something like this could be used to lower other bikes.

I'm sure it could be workable on most any bike out there. I've tried lowering links in the past; don't like how they changed the handling and I usually removed them. So a total waste of money.

These Zeta Low Down spacers were $28 and I can pull it out if it doesn't work like I'm hoping.

They make some other types of lowering spacers, so all you really need to know is the inside diameter of your shock. They wouldn't be too hard to roll your own on a lathe if you have access to one.

[Megadan]

Great Write up.

For those wondering how this works, it's a pretty simple idea. The spacer acts as a stop for the piston that prevents the shock from extending fully, thus reducing it's overall length. Unlike with lowering links, this will not alter the leverage on the shock itself, so the handling and ride quality will be no different. Same idea behind running a shorter length shock, but without having to spend hundreds on said new shock.

[Weldangrind]

CCC, that's the most enjoyable tutorial I've seen in awhile. The only point I'll add is that I think you meant 30mm, not cm.

[GlennR]

I miss riding shorter bikes too. I look forward to hearing about how it works for you.

Btw, it's amazing how much wrenching you do. When do you find time to ride? And, what's next for the Pitster?

[ChondaChondaChonda]

CCC, that's the most enjoyable tutorial I've seen in awhile. The only point I'll add is that I think you meant 30mm, not cm.

Good catch!!

I write these "off the cuff" so I'm bound to mess up here-n-there! :tup:

[ChondaChondaChonda]

I miss riding shorter bikes too. I look forward to hearing about how it works for you.

Btw, it's amazing how much wrenching you do. When do you find time to ride? And, what's next for the Pitster?

The poor Pitster is in a thousand pieces across the shop floor right now... well, almost. No riding with snow on the ground now so I might as well.

Next-is an aluminum dash, front turn signal and key-switch relocation, and going after any unnecessary weight. (Just finished an LHRB and brake pedal upgrade I will post in the main thread.)

The bike is such a good foundation and a pleasure to work on. 1/3KTm 1/3Honda 1/3PrettyDarnGoodChineseEngineering to marry the two together.

[Weldangrind]

I laughed out loud at the Safety Third decal. :D

[ChondaChondaChonda]

I laughed out loud at the Safety Third decal. :D

Hey, it's reflective.