Benji argues that weight does matter (but not much).
The following column will hopefully unite the warring tribes in mountain biking. From the weeniest of weight watchers, to the whatever-est of funtime trail riders, everyone should be able to get behind the following words.
Essentially, I think – no, I know – that bike weight matters. I also believe – and know – that it doesn’t matter very much. Certainly not significantly for most riders out there. If you get your kicks by being one second faster up a climb than Your Mate and/or Some Random On Strava, then saving weight on your bike is worth it.
The current best* science about the whole subject of the effect of weight when mountain biking is from a Kiwi professor called Paul Macdermid. His article ‘Weight: Does It Matter?’ roughly speaking states that a bike that weighs 20% heavier will be 3% slower uphill. So by my rubbish maths, this means a climb that takes a 13.5kg bike 30 minutes to ascend will take a 16kg bike 31 minutes. Now then, being one minute faster up a decent drag will absolutely make some rider’s day. But for some people, it won’t even register.
So in a stopwatch-centric lifestyle, lighter bikes win on climbs. And because gravity is a bastard, this means that light bikes go faster around a whole Sunday ride route in less time than heavier bikes. All skills being equal, riders of heavier bikes never recoup that minute back on descents. Sorry. Cross-country races, like road races, are won on the climbs. It’s just how it is.
But.
You knew there was a ‘but’ coming, didn’t you? But the thing is, most people mountain bike for the feeling of mountain biking. Not the stopwatching. As soon as you introduce some sort of metric into your hobby, you’ve lost. You’ve turned it into a competitive sport. It’s become about Other People rather than You. You’ve lost the whole point of why you do the hobby in the first place. There are people who don’t know if they’ve enjoyed their bike ride until they wait for Strava to upload their activity and tell them.
I know an awful lot of people who have given up cycling because they could no longer meet the metric.
Don’t get me wrong. I love mountain bike racing. Watching it that is. Following it. I have no problem with stopwatches in racing. But racing is not riding. Racing metrics should not be applied to riding.
Anyhow. I’ve gone off-point. Back to weighting.
The important question should not be ‘how many seconds does X kilograms slow you down by?’ The question should be ‘how does weight affect how a bike feels?’ And again, I think I can unite the clans a bit here. A light bike feels thrilling from 0mph to about 6mph. Stomp and GO! Woo! Thing is, once above jogging pace, not only does it not feel as thrilling, I’d actually go as far to say that it feels worse than a heavier bike. Much like small wheels, a light bike gets up to speed quicker sure, but it also loses speed depressingly quicker as well. Maintaining speed is massively more important than the initial achieving of speed.
But.
(Another but…) I’m also aware that a lot of mountain biking takes place in a psychological realm. That initial 0–6mph thrill goes a long way to making you feel happier on the ensuing upslope slog. In a physics sense the light bike is making a negligible difference, but, because you feel better, the climb feels better/easier.
So, my sagely advice is, if you have a light bike, try to ignore the science. Just stick with the feeling that it’s better. Ignorance is bliss. And if you do have a heavier bike, take solace in the science and know that your bike isn’t really making it significantly harder. It’s all in your head.
With my Tech Editor hat on, I should probably advise you on where it makes most sense to save weight on a mountain bike. So here goes.
You already know the answer, kind of. Save weight on your wheels. But (that’s the 12th ‘but’ so far by the way) don’t save weight on your tyres. Light tyres are rubbish. Splash the cash on a lighter wheelset – and cassette/chain/mech – instead. Your bike will feel and perform better.
Or don’t. It doesn’t really matter. Just go ride your bike on nice trails and remember why you started riding in the first place.
