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Lowering a Boxxer

dcrides

Chimp
Jun 24, 2005
92
0
I have a Specialized SX Trail that I use for downhill racing. The stock 66 that I have now just isn't cutting it. I also have a 07 boxxer race that I would like to run this coming season, but it has too much travel. How exactly do I lower the fork to about 180mm? I have done some research but have only determined that I need to add all travel spacers and cut the springs down accordingly. Do I need to do this for both legs of the fork? Also, where can I get these spacers- do I buy them from Rockshox or can I get something comparable at a hardware store? Any words of wisdom or advice would be appreciated. Thanks.
 

bushrider

Monkey
Jul 4, 2006
146
0
NYC
You can convert any boxxer with the internals from a boxxer ride.
It has a u-turn adjuster that adjusts between 4.25" and 7".

I have a spare u-turn kit as I converted my 05 ride to a WC Air.
Its new an unused. Send me a PM.

If you were to upgrade one leg to solo air you can reduce the travel by adding spacers above the top out bumpers on the air side.
Cavedweller on ths board runs a 7" boxxer WC.
 

davep

Turbo Monkey
Jan 7, 2005
3,276
0
seattle
In theory, you need a shorter spring, and a spacer equal to the loss in spring length. The spacer would go on the spring shaft between the top out bumper/spring and the top of the shaft. There is only one spring and thus only one spring shaft in the newer boxxers.

Here is where things get interesting (depending on the fork).

If you just hack off the spring, it will not sit on the spring perch correctly and will either bend to one side durring compression (causing noise an posible long term wear), or scratch the inside of your stanchion, or both.

You could just add the spacer and not cut the spring, but this would add preload in the amount of the spacer..not a great thing.

You could also add a spacer to the b/o bumper and then lower your crowns an equal amount (you will most likely need a stiffer spring for this method)..... but if your figures are off, or your spacer malfunctions some how, your crown will bottom into your tire....causing an instant loss of teeth.
 

bent^biker

Turbo Monkey
Feb 22, 2006
1,958
0
pdx
hold on hold on, doesn't the 66 have 180mm? why would you want to cut the boxxer down to that if it isn't working for you?
 

dcrides

Chimp
Jun 24, 2005
92
0
The 66 has 160mm. But if I were to use the U-turn kit, would it be as simple as changing out the old spring for the new kit? Would I have to make any modifications?
 

davep

Turbo Monkey
Jan 7, 2005
3,276
0
seattle
It is a spring/shaft assembly all in one. No mods needed, but it is a tiny bit more work than just a standard spring swap (you need to undo the footnut and most likely replace the bushing lube in the spring side).
 

dcrides

Chimp
Jun 24, 2005
92
0
Thanks. It sound to me like the u-turn route will be the most reliable way to lower the travel (without potential loss of teeth or destroying the fork).
 

TWeerts

Monkey
Jan 7, 2007
471
0
The Area Bay
the sticker on the frames say "no greater than 175mm fork". i have a RS Domain, which has 180 and have no problem with it. the point here is that the boxxers have the exact same axel to crown distance as the domains and boxxers. so you wouldnt need to cut the travel down in fear of damaging the frame. if you are ok with 8 inches, i wouldnt bother. mounting a boxxer w/ full travel is safe.
 

dcrides

Chimp
Jun 24, 2005
92
0
Yeah I assumed it would be ok. I like my bike pretty slack but I want it a little lower and more even with the rear.
 

DirtyMike

Turbo Fluffer
Aug 8, 2005
14,437
1,017
My own world inside my head
The 66 has 160mm.
Is there more than one 66 as far as travel options, I thought they were a 180 mm fork, I know mine is. Guess I will have to check the site myself


Edit.....Is it an 06, and what Model do you have??

Ok, research done, 05 66vf was 150, all others were minimum of 170, some adjustable down to 140, but if 07 or newer, it was 180
 

dhkid

Turbo Monkey
Mar 10, 2005
3,358
0
Malaysia
the sticker on the frames say "no greater than 175mm fork". i have a RS Domain, which has 180 and have no problem with it. the point here is that the boxxers have the exact same axel to crown distance as the domains and boxxers. so you wouldnt need to cut the travel down in fear of damaging the frame. if you are ok with 8 inches, i wouldnt bother. mounting a boxxer w/ full travel is safe.
:stupid:

the axle to crown height of a boxxer at 7inches is just around a 36 at 6 inches. not sure how it compares to a 66, but leaving it at 8inches wont be much difference from your 66.
 

dcrides

Chimp
Jun 24, 2005
92
0
The fork on the sx is a 07 66rv that is oem and comes stock.

Yeah, I'll see how the boxxer rides, but I'll probably still end up lowering it.
 

Dogboy

Turbo Monkey
Apr 12, 2004
3,208
581
Durham, NC
If it is a 2005 66 at 160mm it is actually taller than a 200mm boxxer. If so, I would just leave it as is.

edit: nevermind, just read your post about the year model.
 

TWeerts

Monkey
Jan 7, 2007
471
0
The Area Bay
:stupid:

the axle to crown height of a boxxer at 7inches is just around a 36 at 6 inches. not sure how it compares to a 66, but leaving it at 8inches wont be much difference from your 66.
thats what i was saying.

from RS site:axel to crown measurements:
Boxxer: 568mm, @203mm of travel
Domain/Totem:565mm, @180mm of travel

that looks pretty close to me!

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