Front shocks

[SatNavSaysStraightOn]

Can anyone tell me if I need to do anything with the front shocks on my 2nd hand mtb? (was thinking along the lines of servicing or oil (assume it has some - maybe not?). No wish to replace, no finances to replace and usually have them on lock out anyhow because I have become accustomed to my touring bike & my road bike not having front suspension. But in 5/6 weeks time I am going on a mtb skills weekend for girls to get some of my confidence back and want to make sure the bike is ready for it!

It is fitted with "SR Suntour SF11-XCR-DS-26-LO-SP, 80mm..." shocks and I know very little about them. Bike is a 2011 model and previous owner is a forum member.

They seem OK, though I have just 'accidentally' raised them somewhat by trying to suss out what the 'preload' knob was for ... I am getting black rings around them, though i suspect it is where they are cleaning invisible muck off themselves... and that 'big' black ring is what I have just accidentally acheived with the prelaod knob... (I have stopped fiddling with it now!).

 

[Cubist]

Hi

The forks could probably do with a bit of use to get them working again after such a time locked out. I can't really understand why the forks have suddenly elongated now you've fiddled with the preload, though I suspect they have been set on low preload, and have been locked when sagged. Hold the front brake on, unlock the fork and cycle it a few times, trying to drive the stanchions as far as you can into the lower leg. Listen out for dry scraping or crunching sounds. If they go in and return smoothly without too much noise or bounce then move on... I reckon they just need to be used.

Get a tape measure and measure the length of the stanchion between the seal and the crown while the bike is unweighted. It should measure somewhere between 80 and 90mm. If it is, then it's OK. If it's way over 100 then you may need it looking at. I estimate that black tide mark to be about 60mm from the crown.

You need to set the preload to suit your weight. Put your full riding kit, including a hydration pack if you wear one, and get on the bike. Lean on a wall or get your partner to hold you upright and stand on the pedals in an attack position. This is the stance you'll take when riding over rough ground next week. Look and see how much stanchion is now showing. You are aiming at 20mm sag at this stage. If it sags more, then increase the preload (making it stiffer) or decrease making the spring softer. It's a simple enough mechanism. You can tie a thin cable tie round the stanchion to use as a reference marker, but take it off before you ride as they can knacker your seals.

I may be wrong, but I think the damping is preset on those forks, so once you set the sag, get on and enjoy. If the fork is too bouncy you can get softer springs, but for what it's worth I'd be trying to source a decent Tora off eBay.

Let us know how you get on.

 

[SatNavSaysStraightOn]

thank you. will have a play tomorrow and let you know how it goes - looks like the weather should be great for getting out on the bikes!

 

[lpretro1]

You can easily take them apart and clean them. Not a lot else to do.