I’ve been diligently hauling my Commencal Normal Disc 2008 mountain bike the 8ish miles back and forth to work for the past six months or so now. Though it’s not my much missed Diamondback Ascent ’92, the Normal is a fine and capable steed, more so since I acquired it at a bargain half price (from Real Cycles, Carryduff). But, given that it’s home is the tarmac of the Antrim and Shore roads I’d felt for some time that the large 2.1″ off road tyres and suspension forks were surplus to requirements and extra weight and drag that I didn’t need on my regular 500ft grind up the side of Cave Hill.
And so a project was born: fit rigid forks and slicks to the Normal to convert it to a more suitable “urban commute” configuration.
After much research (thank you, as ever, t’internet), I chose the following as replacements for the heavy Suntour XCR-100 LO suspension forks and chunky Kenda Karma tyres that came fitted as standard to the Commencal.
Forks: F8 Rigid Forks, by Orange Mountain Bikes
|A number of factors pointed me towards these Orange Mountain Bikes F8 Rigid Forks.
Tyres: Ultra Gatorskin, by Continental
|Continental Ultra Gatorskin tyres are described as “the ultimate wire bead training & racing tyre where puncture protection is priority”. I think there”s not much more frustrating than trying to make your way to work only to be stopped by an errant fragment of someone’s discarded beer bottle lying in the road, so armored, puncture resistant tyres are my ideal choice for cycle commuting. There are tyres that are lighter than the Ultra Gatorskins, but with less protection. There are also heavier tyres that are all but impregnable. I chose the
Ultra Gatorskins as I felt they struck the right balance between speed and strength.
After printing out some likely looking fork fitting instructions, I took myself off to the garage “workshop” for an evening and set about my Commencal’s front end with spanners, hammers and other entirely unsuitable tools. I’ve performed quite a bit of DIY bike butchery in the past but I was still a little bit daunted by this project as, according to the instructions, there were a couple of tricky parts and stages where it could all go horribly wrong and leave me with no bike, a set of ruined forks and a lot of explaining to do.
I’ve made more photos available in the excitingly entitled Picasa web album “Fitting Orange F8 rigid forks and Continental Ultra Gatorskin slick tyres“.
As you can see from the pictures, however, changing forks would appear to be within my capabilities after all. I managed to save myself a (proper) bike mechanic charge, not wreck my work bike and have a bit of manly fun with tools, bearings and grease in the process.
After that, changing tyres to the Ultra Gatorskin slicks was child’s play!
The results are in
I’ve now been on a number of commute runs with the new machine. There’s not much difference in the handling of the bike, if anything it’s a touch more nimble and responsive at cornering and filtering through traffic. The ride position and geometry have also hardly changed.
The ride itself, however, is very different. The combination of rigid forks, slim tyres running at high pressure (95psi) and a stiff aluminium mountain bike frame gives a fairly hard ride with every vibration and bump being transmitted from the road surface. I never realised before this just how bad and uneven the roads are along my commute route; come on Northern Ireland Roads Service, sort it out, these are supposed to be A-roads, darnit! I find myself taking a more careful line around gratings and uneven parts of the surface and I’ve had a couple of bone jarring impacts with hidden potholes that I didn’t see. It’s not unbearable though and I’m quickly getting used to the new dynamics, though I expect they’d be tiring on longer rides.
As you’d expect, the slick tyres offer much less rolling resistance than the chunky off-road models that were fitted before. Combined with a guess-timated weight reduction of 1.1Kg (from 14.5Kg), I feel the bike is easily 2-3mph faster with the same rider power input. Given my previous “cruising” speed of 15-16mph this would seem to be a significant efficiency improvement of over 12%. I’ve heard it said that the gain in going to a full on road bike is 25-30%, so for an investment of £80 and a few hours hammering I’ve got myself half a roadie’s worth of extra performance. I’m very pleased with this result! The tyres also grip well in the wet and give confidence while travelling at speed or going into corners, and this confidence is increasing all the time as I get used to the new handling characteristics. No punctures yet either, touch wood.
And the looks? Well, let’s just say I now refer to it as the “Mutant Freak Bike”.
But it’s quick!