February 16, 2011
Jon tweaks the carbon machine with a custom tuned Fox shock. Will it be harder, better, faster, stronger?
From: Hotlines UK
Tested: 8 Months
In my last few Long Termer posts I’ve been playing with the stock setup of the Ghost AMR Lector as a bit of an experiment to see a couple of things, firstly, how much a trail bike is capable of and secondly, how much the ‘feel’ of a bike can be changed with a few bits of re-speccing. Starting off as a very capable bike that was light enough to be ridden on long distances, I’ve been playing about with a few things. First up the cockpit got beefed up with those rather wide 780mm Syncros FR31 bars and a matching and extremely neat 45mm Syncros FRIC stem. Soon after I decided that the full potential for thrashing the downhills could be reached by sticking on a slightly longer set of Fox 32 forks, going for 140mm of travel instead of the standard 120mm.If you followed the previous blog HERE, I’ve been very pleased with what’s happened.
A slightly slacker head angle, a bit more travel and the Ghost started to feel much happier on trails where the convention said the bike should start feeling out of it’s depth. Thanks to that carbon fibre front triangle and the full XT build the weight was still perfectly acceptable for all day riding but the bits that I prefer (downwards facing) were made more fun thanks to the greater level of control and greater stability . It’s a theme a few of the new-skool riders in the office keep coming back to, but changing relatively narrow bars and a longish stem for wide bars and a short stem doesn’t really seem to affect the ‘working space’ available on a bike thanks to the lost cockpit length being compensated by the wider stance such a setup pushes you into. Somewhat counter-intuitively, I think it also forces you to place more weight over the front while you’re doing stood up descending.
Anyway, I digress. I’d started to wonder about offset bushings, something I’d seen on Nico Vouilloz’ bike from Matt’s video report at Eurobike HERE, so I rang a man who’d know, the ever helpful Chris Porter of Mojo Suspension. I’d also been wondering about running a harder compression tune on the Fox RP23 shock after test riding the shorter travel sibling of the AMR, the Ghost RT. On that bike, designed for XC and marathon racing, the shock used harder compression and rebound tunes and the sprightly feel that resulted was something I was eager to experiment with on the plusher AMR. I was aware that changing this would involve a trade off with small bump performance for a bit more feedback and control when things got a bit rougher but the standard AMR has such a very plush feeling I was confident a harder tune wouldn’t ruin climbing traction or make the bike get looser on small trail chatter.
Well, having a chat with Chris was enlightening. The harder shock tune would be no problem and at the same time a harder Pro Pedal tune would be used. As for offset bushings, I was a bit wide of the mark. It’d be very expensive to do one off bushings and there’s limited scope for movement anyway – especially when the shock uses needle roller bearings, which the Ghost does. All was not lost though – Mojo have had plenty of experience in getting the results I wanted, they just go about it a different way. By using a shorter shock body the overall length of the shock can be changed without losing travel but lowering BB and knocking back the head angle a touch.
So, my new, harder tune shock came through the post and on it went. On the first night riding mission the Ghost felt remarkably different. More aggressive, more responsive to pumping and pushing. More purposeful. The dropped BB and slacker head angle that resulted wasn’t as noticeable straight away but it did come into it’s own. On the first techy descent of the evening a rather poor line choice took me off into the rough and directly into a harsh compression on a rather steep section. In my mind I’d already gone over the bars – it was a compression that’d have made me wince on a big, slack bike – but the rejigged Ghost responded to panicked last minute lurching and to my surprise sucked it up without fuss. From then on I started noticing more subtle but important changes. Rocky sections felt much better when attacked at speed, my worries about pinch flats thanks to the hard shock tune disappearing as the bike tended to skip of the tops rather than getting bogged down in dips. Again, it’s a feel that could be construed as either fast and agile or somewhat skippy or nervous depending on your disposition. I was loving it though – and still do. The bike is more willing to pop through bits and although it’s lost a portion of the ‘magic carpet’ ride I liked so much of the original bike, it’s a compromise I’m happy I’ve made.
So, I think I’ve started to answer my own questions. You can ride a trail bike hard, but with a bit of tweaking, even very well set up suspension and standard geometry can be matched to suit a rider’s taste perfectly. I’m pointedly not using the word improved – I’m pretty sure some people would absolutely hate the feel of the bike now – but that’s the magic of the many custom tuning and tweaking options available to anyone nowadays. You can take something good and tweak it to your preference. It’s probably an important thing to remind yourself that bike setup shouldn’t stop at setting the shock and tyre pressures – you can go much further.
Now we move onto cost. If you’d like your Fox shock shortened or a new tune putting on it then send it over to Mojo Suspension. They’ve got a famously rapid turnaround time so you can probably have it back in time for the weekend if you play your cards right. Here’s the price breakdown for the work I had done to the Fox RP23 found on the Ghost:
£89 for the service (including new bushings)
£30 for the custom tune work
£30 for the shorter body tube at retail
Mojo have had success lowering the BB by reducing shock length on some Treks, Orange Alpine and most DH bikes.
More info is available at their website: www.mojo.co.uk
As Chris points out:
“All this work is ‘to order’… If you don’t like the result it’s a paid job to put it back! Think carefully!”
Big thanks to Chris at Mojo Suspension for help and advice. So what’s next for the Ghost? Well, the SRAM X9 groupset has arrived and it’s going to go on for a 2×10 setup for a properly aggressive trail/enduro bike. I’d also questioned Chris at Mojo about low volume shock bodies but he suggested an easier way to do that – more on that next time…