The shock of your life

9 comments
By Jake Ireland in the Forest of Dean, UK | Wednesday, Jan 25, 2012 10.50am

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So, you’ve bought a new mountain bike and it’s got the latest rear shock on it, with all kinds of letters and numbers after its name, and an RRP that would make you wince if you had to buy it aftermarket. That means your bike is going to work perfectly, right?

Wrong. What most people don’t realise is that the shock probably has a broad tune inside it that's designed to suit a wide range of riders, of different sizes, weights and riding styles. Almost a jack of all trades in shock absorber form. And like a jack of all trades, it may be master of none.

Companies like RockShox and Fox Racing Shox now offer a range of base shock tunes, which are designed to extract maximum performance from particular suspension designs and models of bike. Custom valving for a more specific feel is sometimes available too, depending on the shock. 

But a bike company's idea of how a bike should feel may not match up to your own preferences. On the shop floor, a linear suspension curve feels plush, and plenty of low-speed compression damping gives a bob-free test ride. But out on the trail, more aggressive riders are likely to regularly bottom-out, and excess compression damping can choke the suspension and give a rough ride over smaller bumps.

If your new bike isn't giving you the ride you'd like, don't go straight out and spend a massive amount on component upgrades or a new shock – you could achieve a lot more by getting your existing damper tuned up. Custom tuning generally costs around £150 and it's one of the best ways of increasing your bike’s performance without spending a serious amount on something new and shiny. I've had some of my best rides on bikes with cheap shocks that have been tuned to the application (ie. the type of riding) and to myself as a rider.

Shimmy Shimmy Ya

I'm part of Mountain Biking UK's product testing Wrecking Crew and we've spent a lot of time with SRAM over the past year, working with our trail bikes and the new RockShox Monarch Plus shock to get the exact performance we were after. I first had a Monarch Plus bolted into my Devinci Dixon long-term test bike back in June while out in Les Gets, France. Since then I've worked with Torben and Danny, RockShox's elite suspension fettlers for Europe, to achieve the perfect tune for my downhill-orientated riding style.

The rockshox monarch plus rt3 bolted to jake's devinci dixon: the rockshox monarch plus rt3 bolted to jake's devinci dixon

Jake has swapped the Fox RP23 shock that came with his Devinci Dixon for a RockShox Monarch Plus RT3 that's now been tuned to suit his aggressive riding style

What I wanted was a shock that gives loads of support throughout its stroke, so the bike doesn't wallow or blow through its travel, but one that'll still deliver full travel when needed. Essentially, I wanted a coil shock feeling, but with a more progressive leverage curve.

Basic tuning of the Monarch Plus is done by altering the internal shim stacks. These piles of thin shims – basically, washers – sit either side of the main piston and determine the rebound and compression characteristics of the shock. By altering the size of the shims, oil is made to flow through the shock in a different way and this either slows down or speeds up its movement as it's compressed (when the wheels hit a bump) and then re-extends.

We decided to stick with the stock rebound damping and concentrate on adjusting the compression stack to extract maximum performance from my Monarch Plus. We also made the air chamber of the shock smaller, to create more ramp-up towards the end of the travel. It's possible to tune the Monarch Plus's internal floating piston arrangement too, using different air pressures, but this wasn’t something we needed to change for the Dixon.

The shim stack is laid out, with the rebound and compression shims on different sides of the piston head :

The Monarch Plus shim stacks laid out, with the rebound and compression shims on either side of the piston head 

So, could we notice the changes we'd made? Undoubtedly. Although the tune that we had done for our super-hard riding wouldn’t be perfect for everyone, it's massively improved the bike’s handling over some serious terrain.

When sending your shock off to be tuned, be sure to let the tuners know your weight, riding style and what kind of trails you ride, as well as the bike the shock is going on. Chances are, it’ll be some of the best money you’ll spend in terms of bang-for-your-buck ride improvement. 

Check out our image gallery to see the SRAM shock tuning team in action.

You can follow BikeRadar on Twitter at twitter.com/bikeradar and on Facebook at facebook.com/BikeRadar.

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User Comments

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  • **sigh**....having the experts from rock shox with you must be nice, but what about ordinary joes struggling with psi, rebound, compression, low speed compression, sag....just doing the settings is a minefield of potential unimprovements.

    Suspension stuff seems to be a black art, everyone has conflicting advice. Then if you send it off to a tuner and say "I'm average weight, average skills & I ride a bit of everything"....what are they gonna do?!

  • likewoah, if you're of average weight, with average skills and ride a bit of everything you're probably best off sticking with the standard tune and learning how to tweak your suspension settings instead. Hopefully the articles below may be of help:

    Workshop articles

    http://www.bikeradar.com/gear/article/video-workshop-how-to-set-up-a-suspension-fork-32460/

    http://www.bikeradar.com/gear/article/workshop-setting-up-your-rear-suspension-18195/

    Buyer's Guides

    http://www.bikeradar.com/gear/article/buyers-guide-to-mountain-bike-suspension-part-1-28367/

    http://www.bikeradar.com/gear/article/buyers-guide-to-mountain-bike-suspension-part-2-28438/

    http://www.bikeradar.com/gear/article/buyers-guide-to-mountain-bike-suspension-part-3-28498/

  • @Likewoah

    .

    My advice, next time your shock needs a service, get in touch with TFtuned.

    Provided you answer their questions honestly (bike, weight, preferred riding style, how you like the shock etc) they will valve it up for you and provide a base setting.

    .

    It takes a huge amount of the guesswork out when the shock comes back with "Fill to Xpsi, rebound is set Yclicks from closed, compression is set Z clicks from Open,"

    Best of all, should you tweek too much and muck up your setting, you can just go back to the base on the form knowing it will always be about right.

  • "Provided you answer their questions honestly (bike, weight, preferred riding style, how you like the shock etc)"

    I know my bike and weight but I have no idea on how to describe my "style" or how I would like my shock. I just get on and ride my bike!!

  • Thanks for the helpful replies james & crash- been studying those workshop guides and they are pretty logical. I'm still not quite sure how I'd know when I've got my suspension just right. I can see you basically have to adjust each setting in isolation, just a little bit, and test each setup....maybe that's where I get bored and just go ride :)

    Trailpuppet makes a good point though - many of us are not WC DH racers who know what their 'style' is...

    If your style is 'DH-orientated' James then how would your bike feel for a XC racer who tried it out? I'm guessing the suspension would still basically work!

  • Hey guys

    D'you think we'd benefit from doing a basic shock setting up write up or video? I know that it's something we take for granted really with the amount of riding we're doing.

    @trailpuppet, it would simply be a case of writing that down on the sheet then, and the tuners would work it out for you. Even if it's a case that you tell them you're running XXXpsi, and not bottoming out/bottoming out too much, and with knowing you're weight as well they could make an educated guess as to what to do.

    Yes @likewoah, you're right, even if an XC racer got onto the Devinci, the suspension would still totally work for them, even if it was a case of simply adjusting the main air can pressure to suit their weight.

    Bang on though with the adjusting settings in isolation. With the huge amount of testing we do, adjusting settings in isolation is the only way to get to the optimum setup - although I do tend to get to a base setting first before I start isolating settings to change. You don't have to get bored though, change a click of something every time you ride and you'll soon feel the difference - no need to keep stopping and repeating trail if you don't want to!

  • I try adjusting stuff on the fly sometimes Jake - sometimes it feels better, sometimes worse, sometimes errr...no different.

    The trouble is I can't remember where I had it set before, so I end up a bit lost. & I'm meant to be an engineer! You guys rty so many bikes, how do you manage to keep track, do you write it all down?

    I think what I'd like to see is someone explaining what happens when you get it all WRONG. Like a video that shows a bit of trail and how it slows you down, lose grip etc. if your suspension is not optimized. No idea how you show this on a video as I guess it's quite subtle. But something clearer than just a rider saying "this feels sorted"....

  • i have just sent my RP23 to mojo for a custom tune, the shock feels fine jumping & small bump control but tends to 'wallow' in medium low speed compression.

    Doing the research as written here i have discovered that the shock was set for 12.5 stone rider & thats never gonna work for me (15).

    The current 'tune' is made clearly & obviously unsuitable by the Kashima coating on the shaft, due to the reduction in stiction there is a little too much interplay at 20% & 30% sag & didn't feel right.

    So i called Mojo, very helpful, only gonna cost around £60 & considering i was about to spend £400 on a Cane Creek double barrel im chuffed (if it works!)

    Cheers Bikeradar!

  • i have just sent my RP23 to mojo for a custom tune, the shock feels fine jumping & small bump control but tends to 'wallow' in medium low speed compression.

    Doing the research as written here i have discovered that the shock was set for 12.5 stone rider & thats never gonna work for me (15).

    The current 'tune' is made clearly & obviously unsuitable by the Kashima coating on the shaft, due to the reduction in stiction there is a little too much interplay at 20% & 30% sag & didn't feel right.

    So i called Mojo, very helpful, only gonna cost around £60 & considering i was about to spend £400 on a Cane Creek double barrel im chuffed (if it works!)

    Cheers Bikeradar!

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