Tech Tuesday

Wheels

Wheeeeeeeeeels.  Help you go wheeeee!  You’re all set up with your helmet, frame, sizing and gears but don’t forget your wheels!  You might just go with your off-the-peg wheels, but you might want to think about a few things.

wooden wheels to match your bamboo frame?

Material

You mostly find your wheel rims made of aluminium, spokes can be stainless steel, but you can get carbon wheels for lightness.  You know you get what you pay for:

Keith Bontrager famously said of bicycle parts:

“Strong. Light. Cheap. Pick two.”

You pays your money and takes your choice – you could have a heavier frame and pay to upgrade to lighter wheels, that seems to make more sense than having a top of the range light frame & heavy wheels which counteract the benefit.

Size

It’s confusing.  However, generally adult road bike wheels are 700mm diameter.  There is a thought that smaller frames need smaller wheels (you can get “650”mm) to avoid your toes clipping the edge of the bike wheel as you turn a corner, but then you need different gearing to ensure you can go the same speed as everyone else.  You can see that in action on a Brompton bicycle with tiny wheel diameter but a huge great chain ring.

However, a smaller wheel is also lighter, which might suit a smaller rider.

Spokes

Just as you can vary wheel size you can vary the number of spokes.  There is all sorts of physics involved – from less resistance and lighter to better strength and you can read more (much more!) here, if you’re planning on building your own bike.

Rim depth

So, you can also spend your pennies on deep rims to reduce drag.  However, whilst that’s fine when you’re cycling forwards on the flat in a windless day, get a side wind up a hill and you may be over in seconds.  Get the feeling there’s a lot of money for old rope going on in wheel choices!?

Tyres

Road bike tyres are also an infinite discussion.  One of the worries beginners have is the narrowness and the lack of tread.  You can go for a mountain bike with fat tyres:

but the resistance of all that friction against the road might mean you can’t even move forwards -and look at the weight of it!  Skinny tyres (23mm) are light and no tread means less friction and it all means faster!  You can be reassured that bike tyres are too narrow to aquaplane at speeds below about 200mph.  However, they are vulnerable to skidding on gravel and sand on the road .  Also, you pump them up to 100PSi which means puncture-tasticness, especially if you end up hugging the kerb when a tractor overtakes you.

One option, now, is a slightly wider road tyre (25-27mm) with less pressure in it.  The theory being that it moulds over any potentially puncturing bits of gravel and where it’s wider the bit of tyre in road contact is shallower meaning the same of less overall rolling resistance.  I don’t know what the truth is, but that’s what I’ve gone because as a nervous beginner used to mountain bike tyres it makes me feel more stable!

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superhobbit

A tiny hobbit dedicated to saving the world with a decent second breakfast. Also, available to make you feel good in triathlon when you overtake her.......

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