Suntour Fork Set Up

[akb]

I have SR Suntour XCR forks as standard on the Rockhopper and wish to set them up properly to ensure that the travel suits my riding weight and style. How is best to do this? The Suntour manual shows how to measure the ammount of travel required using 2 cable ties, but I am not sure what to adjust after this. Any help appreciated.

 

[Drago]

How heavy are you? These forks are hopelessly under sprung for anyone North of 12 stone and you'll never set the static sag properly.

 

[akb]

No idea how heavy I am, I just go by the location of the cable-ties after I have sat on the bike as instructed by the Suntour manual. What is the next stage in adjustment after measuring the fork movement with the cable-ties? There is a an adjustment on one of the forks which clicks when turned, but I have idea what that does and how it effects the sag characteristics.

 

[akb]

Anyone?

 

[Cubist]

The clicking button is spring preload. Wound all the way to the negative the fork should be easier to compress. Wind it towards teh positive and you make the spring stiffer initially.

So, cable tie at the ready, measure the amount of sag you have when you stand up on the pedals dressed in your normal riding gear. Do this next to a wall for support, or get someone to lean against. Don't bounce on the pedals and give a false reading. The optimum is around 20-25% of the travel, so on a 100mm fork you are looking for the cable tie (which you push down to the seal to start with) should have been pushed 20-25mm up the fork stanchion. Increase or decrease the preload in order to get somewhere near that optimum.

This now means that the spring is set somewhere near where you need to have it given your bodyweight, but terrain and riding style may make you look for different settings.

Does your fork have adjustable rebound damping?

 

[akb]

Thanks Cubist. I don't think so; spec from website

Fork: SR Suntour XCR (SF11-XCR-DS-26-LO-SP), magnesium lower, 30mm steel stanchions, 1-1/8" alloy steerer, hyd. damping with Specialized Spike Valve and alloy LO cartridge, XS/S: 80mm, M-XXL: 100mm travel

They have 100mm travel.

 

[Drago]

And no damping adjustment, and the preload adjuster is more like a switch - nothing, or everything (but still not much)

I've tried finding heavier springs with no joy, but a local DIY shop came up trumps with steel conduit, and about 1/2" chopped off to make a spacer to sit atop the spring and give it some preload, albeit at the expense of a slight loss of travel. I got 2 dozen sets of these bleeders to keep on song, so I only did the M and L framed bikes most likely to get heavier riders.

Unless you're quite light you'll never set the sag properly. The adjuster does not much more than bugger all, making the instructions more a work of theoretical physics than a useful tool.

 

[Motozulu]

I've got XCM's - they are a heavy fork but they get me around the Cannock red routes ok. Seriously I would'nt worry about it too much - I played and played with em at first but as Drago says, it seems more like a 'one size damping fits all' but unless you are thinking of flying down a black route you'll be ok, just look to upgrade in the future. I've never bottomed mine out and tbh the worst thing about them is the heavy front end you get. Having said all that my next bike will have Reba's on it so I'll be in a position to judge better then.

 

[Drago]

On the plus side they're plenty stiff.

 

[Cubist]

...... and for less than £100 you can upgrade to a Tora.......

 

[Drago]

But who wants to spend £100 upgrading a Rockhopper?

 

[akb]

Who said anything about upgrading?! I have no problems with the XCM forks with the current usage of locals trails and the off-road winter commuter.

 

[Motozulu]

If you're happy with them great - but there is'nt a lot of adjustment on mine (think mine are next one down to yours?) but like I said they do the job. I just want something lighter for the climbs is all.

 

[Cubist]

But who wants to spend £100 upgrading a Rockhopper?

A hundred quid? You can get a whole bike for that.... etc etc etc