# SR Suntour XCM - Newbie question



## Sootchucker (May 19, 2014)

Hi all. Totally newbie here. I've decided to get fit (as I'm overweight) and have purchased a nearly brand new Mongoose Tyax Comp (26" Wheels) at a steal of a price. I think it's a 2012 or 2013 model year.

I know it's not a top drawer bike, but it will do me to start with. As a total newbie to suspension forks I do have a couple of questions if I may.

My bike comes with SR Suntour XCM front forks (they have no V2 / V3 numbers on the side), and at the top of each tube are two dials. Looking down from the the seat position, the one on the left has a + and - dial and turns relatively freely by about 3 turns. The one on the right also with a + and - also turns about 3 turns but is very stiff and difficult on the fingers to adjust.

The first question is what are these for, and I guess how should they be adjusted for my weight ( I suppose it's all to do with adjusting the relative tension on the springs) ?

The second question came from the friend of mine, who was expecting one of the dials to act as a "lock out" meaning the forks would lock with no suspension travel (or minimal) whilst riding on smooth surfaces such as roads. However, try as we might, no matter what positions we set both of these knobs, the forks still move. Does that mean these forks don't have a lock out feature ? If not can this be added - is it worthwhile to have, or is it better to go with a new set of forks ?

Many thanks in anticipation.


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## Frantic (Apr 24, 2014)

I have the XCM and it looks like the one in the pic.On one side is the preload knob which I havent messed with yet and the other is the lockout mechanism(blue knob) which you turn on one side to fully lock and the other to fully open. Is this what you have?


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## Sootchucker (May 19, 2014)

Thanks for the quick response. The black knob on the far side of your photo is what I have on both sides (see image below) albeit with a yellow plastic indicator though the middle which goes up and down as you screw or unscrew the knob.

Apologies for the dust, the bike was stored for 6 months and I haven't had time to clean it yet 

shox


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## AndrwSwitch (Nov 8, 2007)

Another likely adjustment is a rebound damper.

Try the knobs in their extreme positions and see if you can feel a difference. The preload should make the fork stiffer. That'll reduce sag, and also cause it to use less travel on the trail. It's useful if you find you bottom out, and can mitigate issues like brake dive and pedal bob.

The rebound damper damps rebound.  If your fork kicks after a hit, like rolling off a curb or over a root, try more damping.

Fair warning, the knobs on your fork may not work, or may not have the adjustment range you need.


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## eb1888 (Jan 27, 2012)

There are several models of that fork you can look at on Suntour's site. You can download an exploded view for a better idea of what's going on. Call Nick at Suntour for more info.


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## cobba (Apr 5, 2007)

It's a preload adjuster for the coil spring. Some of the cheaper Suntour forks have coil springs in both legs, they have nothing in the way of rebound adjustment, compression adjustment or lockout, the only adjustment that they have is preload.


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## SRvancouver13 (Aug 25, 2011)

Hi. 

Cobba is correct. That is a MY2008-2009 fork. The preload adjusters should be turned simultaneously for correct SAG adjustments. There is no rebound adjustment on this level of SR Suntour fork. 

Cheers. Nick


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