Rock Shox Mag 21 - anyone still remember how to use this fork ?

Hi,
As a little retro-restoration project I'm working on a rather
neglected but very beautiful Klein Pulse '96. Anyway, the Rock Shox
Mag 21 forks are completely unfamiliar to me. I remember the name,
but have no idea what to do with them. Inflate them ? How ? Change
the oil ? What's inside ? I don't want to disassemble them without
at least some idea of what I'm getting into.
Rock Shox don't support their older products. Does anyone have a user
or service manual online, or any advice ?
Thanks,
Doug.

"Doug Baillie" wrote in message
om...
Hi,
As a little retro-restoration project I'm working on a rather
neglected but very beautiful Klein Pulse '96. Anyway, the Rock Shox
Mag 21 forks are completely unfamiliar to me. I remember the name,
but have no idea what to do with them. Inflate them ? How ? Change
the oil ? What's inside ? I don't want to disassemble them without
at least some idea of what I'm getting into.
Rock Shox don't support their older products. Does anyone have a user
or service manual online, or any advice ?
Thanks,
Doug.

The Mag21 was an air-sprung fork. It required air pressure in the region of
80-100psi in each leg if I recall correctly. There is a damping mechanism
of some kind as well as I remember fiddling with the adjustments on my
boss's Mag21Ti. The big problem with them was that the seal held in the
air-pressure as well as the oil, so if a seal blew, you're fork is flat.
Nice light fork though..good for big hits, while it lasted. I have no
manuals..sorry!

Good luck,

Scott..

"Doug Baillie" skrev i melding
om...
Hi,
As a little retro-restoration project I'm working on a rather
neglected but very beautiful Klein Pulse '96. Anyway, the Rock Shox
Mag 21 forks are completely unfamiliar to me. I remember the name,
but have no idea what to do with them. Inflate them ? How ? Change
the oil ? What's inside ? I don't want to disassemble them without
at least some idea of what I'm getting into.
Rock Shox don't support their older products. Does anyone have a user
or service manual online, or any advice ?

Hi!
The mag 21 was everybodys dream in the early 90's before the Judy came
around.
It was air sprung and oil damped with externally adjustable damping. I still
have part of a pump and the green is from 35 to 45 lb/in2 or 2,5 - 3,5
kg/cm2. The pump use a basketball needle to inflate the fork and this seal
is a weak point. Presumably some parts form the SID can be used om Mags but
I am not shure about that.

The Mag 21 was a light weight racing fork that was less presice in the
steering than the competing Manitou 2 and 3. Properly adjusted it did cope
with medium and large hits quite well

I sold my Mag 10 that was essentially the same fork but with steel
stanchions rather than alu as in the Mag 10 two years ago and it is still
working great on a Bontrager somewhere in Norway

You can try to post this question on www.angryasian.com and maybe somebody
can help

Good Luck
Lars Birger Nielsen

"S. Anderson" wrote:

The Mag21 was an air-sprung fork. It required air pressure in the region of
80-100psi in each leg if I recall correctly.

I've still got one on my old bike, circa 1992. I believe something in
the range of 40-50 psi in each leg is what RockShox recommended. I run
around 50-55 psi for a somewhat firmer feel.

Dean

the mag21 is air sprung and oil damped.

the knobs on top of the legs adjust compression damping only.

spring rate is adjustable by changing the air pressure in each leg.
80-120psi as previously stated will blow the seals in a heartbeat...30-50psi
is more like it. inflate/deflate with a standard ball needle, *greased* and
inserted through the hole in the center of the damping knobs. yes, these
seals are fragile, and virtually impossible to find replacements for these
days. also, there isn't much air volume in the legs, so if you use a floor
pump go *slowly* .

rebound damping can be adjusted only by changing the oil weight...10wt was
oem i believe...5wt or even 3wt, especially in conjunction with higher air
pressure and a low compression damping setting was 'the hot setup' and
resulted in a much more supple ride. to change the oil, deflate the legs by
inserting a loose needle (ie: not attached to a pump) in the fill port, then
loosen the bolts in the crown that clamp the legs in place and unscrew the
(long winded) top caps of each leg. dump the old oil out and
refill...*don't quote me on this*, but i believe the correct oil volume is
~2cm from the top of the leg, about as deep as the top caps extend into the
leg.

i just sold my mag21, but rode the crap out of it for a long time. it was a
great fork in its day, and while a bit fragile, very reliable if properly
maintained. i had mine totally rebuilt by rock shox a couple times, and
replaced the top air seals a couple times more myself. if yours doesn't
have boots over the stanchions, get some. also, keep an eye on ebay for a
rebuilt kit, which includes pretty much everything you'll need to keep it up
(including instructions)...except for the top air seals.

fwiw,

dookie

"Doug Baillie" wrote in message
om...
Hi,
As a little retro-restoration project I'm working on a rather
neglected but very beautiful Klein Pulse '96. Anyway, the Rock Shox
Mag 21 forks are completely unfamiliar to me. I remember the name,
but have no idea what to do with them. Inflate them ? How ? Change
the oil ? What's inside ? I don't want to disassemble them without
at least some idea of what I'm getting into.
Rock Shox don't support their older products. Does anyone have a user
or service manual online, or any advice ?
Thanks,
Doug.

Doug Baillie wrote:

Hi,
As a little retro-restoration project I'm working on a rather
neglected but very beautiful Klein Pulse '96. Anyway, the Rock Shox
Mag 21 forks are completely unfamiliar to me. I remember the name,
but have no idea what to do with them. Inflate them ? How ? Change
the oil ? What's inside ? I don't want to disassemble them without
at least some idea of what I'm getting into.
Rock Shox don't support their older products. Does anyone have a user
or service manual online, or any advice ?
Thanks,
Doug.

Try http://www.math.chalmers.se/~olahe/B...ont/rsmag.html

"dookie" wrote in message
. com...

the mag21 is air sprung and oil damped.

the knobs on top of the legs adjust compression damping only.

Not really. It's actually a blow-off valve, to adjust the lock-out threshold.
Tightening it will lock the fork except on the biggest hits. People were
concerned that fork movement would absorb too much pedaling energy, thus the
adjustable lock-out. Bontrager modified the forks that came with his bikes to
eliminate this feature, and they worked very well.

spring rate is adjustable by changing the air pressure in each leg.
80-120psi as previously stated will blow the seals in a heartbeat...30-50psi
is more like it. inflate/deflate with a standard ball needle, *greased* and
inserted through the hole in the center of the damping knobs. yes, these
seals are fragile, and virtually impossible to find replacements for these
days. also, there isn't much air volume in the legs, so if you use a floor
pump go *slowly* .

rebound damping can be adjusted only by changing the oil weight...10wt was
oem i believe...5wt or even 3wt, especially in conjunction with higher air
pressure and a low compression damping setting was 'the hot setup' and
resulted in a much more supple ride. to change the oil, deflate the legs by
inserting a loose needle (ie: not attached to a pump) in the fill port, then
loosen the bolts in the crown that clamp the legs in place and unscrew the
(long winded) top caps of each leg. dump the old oil out and
refill...*don't quote me on this*, but i believe the correct oil volume is
~2cm from the top of the leg, about as deep as the top caps extend into the
leg.

i just sold my mag21, but rode the crap out of it for a long time. it was a
great fork in its day, and while a bit fragile, very reliable if properly
maintained. i had mine totally rebuilt by rock shox a couple times, and
replaced the top air seals a couple times more myself. if yours doesn't
have boots over the stanchions, get some. also, keep an eye on ebay for a
rebuilt kit, which includes pretty much everything you'll need to keep it up
(including instructions)...except for the top air seals.

I don't think they were fragile at all. In fact, they were more durable and
reliable than anything else, until very recently. However, most forks since the
mid-90 outperform the Mag, which by modern standards is too flexy and doesn't
have enough travel.

Matt O.

Does anyone have a user
or service manual online, or any advice ?

Doug, I often see original service manuals and related tools for the Mag 21 on eBay. This
weekend I saw a brand new, never used Mag 21 SL (Titanium, very light!) listed on eBay.

eBay is an incredible place to find odd and rare things like this.

Just a thought.... You probably already know this but I figured it wouldn't hurt to
mention it anyway.

Does anyone have a user
or service manual online, or any advice ?

Doug, I often see original service manuals and related tools for the Mag 21 on eBay. This
weekend I saw a brand new, never used Mag 21 SL (Titanium, very light!) listed on eBay.

eBay is an incredible place to find odd and rare things like this.

Just a thought.... You probably already know this but I figured it wouldn't hurt to
mention it anyway.