Tedious wheel size (again) but simply which size is best for techy rocky downhill sections such as the Beast in Ladybower?? I keep reading that 26 is best for downhill but this seem contrary to the idea that bigger wheels roll better over rocks etc.

26″ wheels are best for DH but not because of the wheel size – its because of the suspension travel. You physically struggle to get much more than 140/150mm suspension travel with a 29er, and if you’re serious about DH, especially knarly rock gardens then suspension travel is what you need and these guys are running around 200 mm of suspension travel.

So large wheels do roll over bumps better – it reduces the angle of incidence, but when it gets proper knarly it is suspension travel you want.

Suspension travel can be a problem, some times

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There’s also an unsprung weight issue – a larger wheel of equal strength, stiffness and cost will be heavier.

^ that higher unsprung weight is moving less though as it’s settling less into the depressions between rocks ..

ie, it all evens out somehow and comes down to riding style, preferences, suspension travel / bike type etc.

So therefore if my wheels never really leave the ground and I spend all my time riding in the peaks or lakes then a 29er might me the best option for me? I’m 5’11 btw.

This would be faster uphill and possibly faster downhill as i’m just not that rad to jump over stuff, but rather roll it.

I personally think you’d be better off with a 29er for that sort of XC duties. I used to have a 29er XC hard tail and it just munched up the miles, it was so efficient. More like riding a road bike in terms of the way it covered ground.

We have a fair bit of rocky tech up here in Aberdeenshire. Not that I’m any good at it. I still walk down stuff that I’m sure many folk on here would take in their stride. But I’ve given this question a fair bit of thought. I’ve tried various 26″ and 29er options out and the basic conclusion is that wheel size is only one part of the equation and not actually that important a part. Some, some bikes are better suited to rocky tech stuff than others and some of those have larger wheels, but others don’t. It also depends a lot on your riding style too of course.

I’ve ended up with the venerable old 26″ Five as I find that gives me more confidence on rocky sections than anything else I’ve ridden. But a different rider with a different style may come to a different conclusion.

I also have a 29er HT (FF29), which is great for munching the miles. I don’t find it anywhere near as good as the Five on steep rocky stuff, but that’s hardly a fair comparison.

A few things that I’ve observed:

1. Having a big wheel out in front of you can be quite reassuring and it does roll over stuff well. However, a slacker head angle and extra suspension travel have a similar effect in terms of rolling over rocks. So, if your 29er has 20mm less travel and a 2 degree steeper head angle it may not actually roll over bigger rocks any better.

2. Once you reach the point where you can’t just roll over the rock then the smaller wheel is easier to move around. The same is true with steps. If you need to shoot the front wheel out a bit to stop it digging in then that seems easier with the smaller wheel.

But, as I say, it’s not really the wheel that is the deciding factor, it’s the bike as a whole.