Taller forks

I’m currently running a pair of 2006 Floats on my Cotic Soul hardtail as 130mm is the maximum recommended fork travel. However, the Pace RC40/41s that are often shown gracing the front ends of show bikes, etc, have quite long crown to axle lengths for their travel — 510mm. I want to run a set of Pikes (preferably the Dual Airs), and their axle crown length is 518mm I believe. Can I use the negative air pressure to reduce it to 510mm without affecting the ride and tunability? If not, it looks
like a set of U-turns!
Hope you can help.
Chris Anderson, South Wales

With the Pike Dual Air system, increasing the negative pressure will reduce the axle to crown height and the travel, although you will find yourself blowing through the mid-stroke too easily. If you can’t live with the additional weight of the U-turns the better solution would be to install the travel reducers/spacers that are available for the RockShox Pikes. Changing the effective ride height of the Pikes or any other fork to fall in line with the manufacturer’s recommendations is a wise move, not so as to conform to their idea of ‘good’ handling but because issues on warranty can be avoided. Ride quality is a very subjective thing, so even if you think a frame handles better with longer forks fitted the real question should be: does the frame’s design allow for the extra stresses that will be placed upon it by the fitment of longer travel forks? Is it safe? Were do I stand with warranty should the frame fail?
I spoke to Cy at Cotic to check on the recommendations for the Soul frame. He confirmed that 130mm is the maximum recommended fork travel and his concerns about fitting a longer fork relate to the long-term effects of the additional stresses that the frame will inevitably have to
cope with. Cotic, like most other manufacturers, can only warranty a specific design against failures that occur from manufacturing defects or faulty materials, not against crash damage or damage caused by fitment of inappropriate components.

Shocking set-up

I’m after a little bit of advice on suspension set-up. I have a Manitou 3-Way Swinger on my Giant VT2 2004. It seems I’ve been using the shock while incorrectly set up. I’m a near 14-stone rider and ride mostly up and down around the Peak District area. I always thought that I had a good bike until recently when I had a go on my mate’s new Scott Ransom 40. I thought that he had bought a heavy freeride bike, but it handles so much better than mine. The front end is so much more positive, which I understand is due to his better forks and wider tyres.
What I didn’t expect was that this ‘heavy freeride’ would outperform my XC bike on the climbs! So I checked my shock against the settings in the manual and it’s all set up completely wrong (my doing I’m afraid).
I just wanted to know if you had any starting points for the settings — particularly the rebound dial? Any advice would be greatly appreciated.
Dale Swain, email

It’s no surprise that your friend’s new Scott Ransom outperforms your four-year-old Giant VT2 on the descents as demand for more downhill-capable all-mountain bikes has moved things forward considerably over the last few seasons. Like you I am surprised that you feel the Ransom climbs better than the VT, as many still view the VT as one of the best climbing mid-travel bikes. Your guess about the poorly set up shock being to blame is likely to be correct, as you are not the first person we’ve seen struggle to get the Swinger
3-Way set up correctly.
Set-up sequence should be: check that all pivots and bearings are moving freely; next pressurise the SPV chamber to just over the recommended minimum of 50psi; now inflate the main chamber and set the correct sag, which should be 25-30 per cent of the available travel (tip: if your shock is missing its
O-ring travel marker, use a small zip-tie around the shaft to act as a marker BUT remove it when you’ve finished); finally set the rebound so that when you push down hard on the saddle with your hands the return is still quick, but does not kick your hands off the seat.
The aim with rebound adjustment is to have the shock recovering quickly from being compressed by one bump so that it is ready for the next. Too much (slow) rebound damping and the shock ‘packs down’ when hitting closely-spaced bumps; too little (fast) rebound damping and the ‘kickback’ throws you over the handlebars on the next jump! At both extremes grip is severely compromised.
I feel it is impossible to get the optimum setting in the workshop, as rider style, terrain type and shock/frame combo can greatly affect the final settings. This is particularly relevant to the SPV feature on the Swinger which, depending on pressure, can make the shock feel very lively or firm, independent of what the main air chamber pressure and rebound settings are.
Spending a little time out on the trail with the shock pump, tweaking the settings, will pay dividends.

Chain jump

Here’s a problem that’s been puzzling me, my mates and several bike shops over the past few weeks. I recently replaced the SRAM cassette and chain on my DMR Trailstar with new SRAM items. I didn’t replace the chainrings because they looked in good nick. As soon as I started riding the chain started slipping on the middle chainring. So I replaced that with a new one. But still the same problem.
The chain lifts off at the bottom of the middle chainring when putting the power down, causing the chain to slip before catching again. It only does this on the middle ring, though. I’ve tried another SRAM chain and a Shimano chain, two middle rings, another SRAM cassette and SRAM and Shimano rear derailleurs but still the same problem.
The chainrings and crank are all inline and the front derailleur is a new Shimano Hone. Any ideas?
Ade, email

Your email really is a teaser and is more reminiscent of a wind-up email I’d get from a certain (mbr bike test editor) Mr. Muldoon, ie, at first glance it seems like a simple problem, but the more you look into it the less obvious the answer becomes! By systematically changing out all the drivetrain components (which of course were new?) you’ve already tried the obvious and the not so obvious solutions, leaving me scratching my head as to what the answer could be.
The whole issue of slipping chain combined with the chain lifting of the front chaining is a textbook example of worn components, and I’m still convinced, despite the changing of all
components, that one of them is still to blame, as opposed to it being a frame related issue. The best way to check at this point would be to swap the whole drivetrain onto another bike and see what happens. “When you have eliminated the impossible whatever remains, however improbable, must be the truth” — Sherlock Holmes.

Shock tactics

Good job on the mag — I always look forward to the great features. Here is a technical question: I have a Claud Butler Shamen and I’d like to upgrade the rear shock and include one with a lockout facility. Any guidance as to what I should go for?
Mike McLeister, email

The Claud Butler Shamen with its 3in, 4in and 5in travel settings is aimed at covering the XC to all-mountain riding categories. With the standard shock fitted to the bike being a very basic coil-over unit we would suggest you look at upgrading to a good quality air shock. Both Marzocchi and Fox produce excellent shocks in the appropriate fitting for your bike.
The Marzocchi Roco 3PL at £299 has adjustable rebound, compression, an air spring and, of course, features the all-important lockout lever. Fox’s RP23, again at £299, offers very similar features in terms of rebound and air spring adjustment, but the compression/ProPedal adjustment works a little differently from a traditional lockout lever. The ProPedal lever when switched on does not lock out shock movement but increases the low-speed compression to minimise pedal/rider-induced shock movement, while still allowing the shock to move under impacts. The compression adjuster below the ProPedal lever provides three levels of tune for the ProPedal.
The quick and wide range of adjustment that air shocks provide — simply by inflating with a suspension pump — means they are particularly suited to bikes that offer adjustable travel settings, where the change in leverage ratio also alters the spring rate.
Which one to choose? Both shocks are quality items that will be lighter, more adjustable and generally perform better than the standard fit item. Also the back-up from both UK distributors is very good. So which colour do you like best: Marzocchi Red or Fox Blue?