I’m looking at 20er frames and the geometry thereof. Most seem to have a BB drop of between 60mm and 65mm. I’ve worked out that there might be some advantages to be had from a lower drop – something like 35mm-40mm. The only frame I’ve yet found that falls into this bracket is the Charge Cooker Ti.

So – any feedback from Cooker Ti owners or suggestions for suitable alternatives would be welcome.

Also – any comments generally on the pros and cons of higher BBs?

Pros – less pedal strikes.

Cons – you’re further from the ground and more likely to fall off

What and why have you worked out higher is better?

A 20er, when did I miss out on this development? I know you’re only wee but surely you can manage something a bit bigger.

They transform the trail I head.

I have a rigid steel Charge Cooker 29er, the geometry is spot on for woodland singletrack trails, it corners really well and is surprisingly agile through the twisty/techy stuff for a rigid clown bike. I imagine the Ti version would be superb.

STW is linking up nicely tonight

😆

What trail do you head?

We’re pretty certain the Cooker’s fun loving character comes from its higher BB. With 29ers the BB drop (BB distance below the axle centre-line) can be as much as 60mm and still give ample pedal clearance. But this excessive drop could be the reason why some big wheelers feel almost too stable and unwieldy. Not something that can be said of the Cooker.

From here – http://www.mbr.co.uk/news/tested-charge-cooker-hi-review/

Oh, blow it…

Fewer pedal strikes is a minor pro but it’s got more to do with luggage carrying…..

Geoff Apps makes some interesting points on higher bbs and moving a bike around at lower speeds on techy terrain.

Good to know it’s not a completely goofy idea.

Not a goofy idea at all.

Contrary to much of the so called expert opinion in the cycling trade, tall top heavy objects actually fall over more slowly than shorter ones. This is not just opinion as it’s down to the laws of physics. There is even a branch of physics called “inverted pendulum theory” that explains why this is so.

http://en.wikipedia.org/wiki/Inverted_pendulum

The physics works for all top heavy object balanced objects, including bicycles. Apparently, The taller an object the slower it falls and so the easier it is to keep balanced.

You can experience this when riding a Penny Farthing. Which though very tall and top heavy is also remarkably easy to balance. Especially so when moving forwards at very low speeds.

Contrary review here:
http://www.bikeradar.com/mtb/gear/category/bikes/mountain-bikes/product/review-charge-bikes-cooker-hi-12-46025/

Bike and wheel weights provide plenty of momentum to carry you through rough sections in a way that 26in bikes just can’t, and the tall bottom bracket means there’s rarely a need to stop pedalling either. The long stem, broad bar and long back end maintain stability at high speeds too despite the steep head angle, and on open trails – smooth or rutted and rocky – the Charge absolutely ?ies.

Those same attributes make it less at home in tight, techy, slow speed situations though. The long stem and tall bottom bracket height give a tendency to tip over if you run out of rolling speed

So if the actual physics (rather than some daft bike journo’s review) tell us that tall top heavy objects are easier to balance, that surely means that us titchy riders on our 16 inch bikes are actually much better riders than the tall fellas that ride huge 21 inch gates.. 😀

Yes, the further away the centre of gravity is away from the ground contact points, the less skills are required to balance the bike.

It’s very similar to the physics of why larger wheels require more energy to rotate them.

Also heavier weights require more energy in order to move them a certain distance.