"Self-preservation, and a desire to pedal out yonder, restricts my bike choice to less than 6 inches of travel; enough to have fun downhill but not enough to encourage a huck fest."
My bike is kitted out with a Fox RP23 rear air shock, fairly common on many trail bikes. Out of curiosity I wanted to try a coil shock. For this I picked up the phone and a day later I was in possession of a Fox DHX RC2.
Familiar with the performance and settings of my air shock, I was eager to swap it for its coiled counterpart and go for a ride in the Port Hills. Broadly speaking, coils have a linear force vs travel relationship throughout their stroke, air shocks generally take a bit to get going at the start and bottom out much quicker at the end of their stroke. This makes airs very good for climbing but somewhat limited when you get a little gnarly.
As for the test, well with no room to spare I managed to squeeze a coil shock into my frame. Firstly, it looked bad-ass and I instantly noticed an increase in steeze points as well as weight. Never mind figures, picking the bike up and putting it on my shoulder, it no longer felt like a light trail bike.
Pedalling on the road was much smoother, albeit it squeakier, then climbing the hills, boom, dreaded pedal-bob. Fitted with the air shock I just didn't get pedal-bob. A few laps on ‘Brake Free’ to set the rebound and I was off down Sesame St to ‘Rad to the Power of Sick’. It’s a fast and flowing track littered with jumps and drop offs. It’s a little too tight for downhillers, so aggressive trail riders seem to be the best suited to this trail.
Back to the shocks, landings on jumps and drop offs just felt plusher and when riding roots and rutted terrain I found that you can ride much faster, yet still controlled with the coil. When pedalling on flowing trail there wasn’t much between them but if I were to give a gold star to one over the other it would go to the air.
I was really starting to like the coil for aggressive riding but could see that it would be a limitation on longer cross country rides. My bike was designed for an air and as much fun as I was having I had to swap back as it was just too big for my frame and was starting to damage it. Now my judgments are for laymen like myself. If you’re looking at replacing a rear shock on your bike, I’d encourage you try out a few, but for quick reference here are my rules of thumb.
- XC: Go air, lighter and less bob.
- Trail: Go air, newer air shocks like RP23’s and CTD are in their element here.
- Freeride: Go Coil, if you like big drops you’ll be happy to have that end stroke performance.
- DH: Go Coil, high speed on burly terrain you’ll have much more control.
- All Mountain: Hmmmmm, if you do more technical descents than climbs go coil, if it’s pretty even or vice versa go air.