rock shox reba sl question

kev2b3

hi all
i am a complete beginner to mtb. i have just recently bought a fantastic second hand bike . the guy i bought it off advised me to increase the air pressure in the forks due to me being a heavy set person. i have looked over the forks and the table on the side of the forks recommend 160 psi. the question may sound daft to you but is it the case that all i have to do is buy a pump for the forks and just pump them up. second daft question one side of the forks is the valve for the pump the other side is a dampner,what is a dampner. third and last dull question,like i said there is a valve on one side of the forks. so how does the air get around to the otherside of the forks when bieng pumped up.

nicklouse

buy a pump and there is only an air spring on one side.

PS, www.sram.com and download a manual.

and you will see a valve on the top and botton of the left leg.

djamiej

How do,

I'm also a bit of a newbie to all this, I've got a pair of Reba's as well. What's written below's been said a bit more succinct by Nicklouse but for what it's worth...

The dual air means that you can pump them from the top and the bottom of the fork (you want to be matching similar air pressure on top and bottom here), but it is only on the same side side. You were right, the other side's totally for damping and rebound. No air pressure there, or at least that you pump into it.

If you can get hold of a pump, have a play, and yeah, it really is that easy. I'm proper brain-dead but I can work a shock pump.

You've prob sussed this but damping is the speed that the fork bounces back/extends after it soaks a bump. You can adjust this with the rebound adjuster at the bottom of the fork. The manual says that you want to be setting it to be pretty responsive. But not to the point where it's skitty and you're getting kick-back. I don't go out often enough to get a feel for it, so I've set mine at about 3/4 towards the rabbit symbol. But I'm no pro and others could prob give you better advice here.

And just to say nice one, I've only had mine a few months, and after my last forks I'm over the moon. Have a good'un chief.

pdid

Hi

Generally, the figures for air pressure in the manual are too high. Set both to the manual setting minus 10 psi and go from there. If you are not within the 15-25% recommended sag, then you either need to increase or decrease pressure.

For rebound go as far as possible to the tortoise then turn between 2 and 5 full turns towards the hare. I currently use 2.5.

I am 5 10 weigh approx 78kgs, i have positive and negative set around the 105psi mark, however i am not completely comfortable yet and still feel some adjustment is needed, but they feel alot better than when they were at 120psi.

HTH Phil

milkywhite

you want to be matching similar air pressure on top and bottom here

Not exactly true. SRAM/Rockshox recommend matching the + and - air as a starting point, but negative air is more of a preference IMO.

More negative air = more sensitive fork. Less "effort" to make the fork compress. Conversely, less negative air = more rigid fork.

I run mine quite close to the positive air pressure as I like to feel the fork working, and soaking up small bumps. All down to personal preference.

broachboy

Hi forum people

I'd just like to thank kev2b3 for asking this question well done chap. I have just brought a pair of Reba SLs and was just about to ask the question, when I noticed you'd done it for me.

Thanks dude

BOYDIE

As regards to the air pressure,set your positive spring (top) to your weight as per the manual plus minus 10psi,tie a zip tie round one of the fork stanchions and move it down till it hits the fork seal and then sit on your bike get of and measure the distance the zip tie has moved.If your forks are 100mm like mine you would want around 20mm of sag,this is so the forks will move in and out of holes and over bumps better.Always set your forks up for sag, not "recomended pressure" as getting the sag right will make your forks perform better.

As for the negitive spring try and match it as close to your positive side,but more air will mean better small bump tracking,less will make the fork ride a little harder.As for the rebound setting this is a personel thing some like it slow some fast,I run mine as fast as possible with out it kicking back.Remember you need more damping the higher the spring rate "air pressure" is.

Most XC riders run there damping fast as that type of riding means the fork is taking frequent hits quickly,so they want the fork to rebound faster ready for the next hit.Where freeriders/dirt jumpers like a slower rebound setting as they typically take bigger single hits,fast rebound could make the bike kick back to fast and knock the rider of the bike.

Hope this helps.

Sorry for any spelling,I cant be bothered checking :P

uristamonov

Hi Guys

I am after a pair of SL's and have also heard a lot about sag etc - when you say

"sit on your bike get of and measure the distance the zip tie has moved"

Do you mean with feet on the ground, feet on pedals leaning against the wall with your body etc?

Many thanks for any assistance

Uri

(p.s - looking at these: http://www.merlincycles.co.uk/?fn=produ ... egoryId=18 )

nicklouse

normal riding position.

feet on the pedals etc..

uristamonov

ok cool, many thanks

just got to sell my old bike, build up my new one and i'll be sorted!

Uri