140mm discs

Giraffoto

I recently asked (in this thread) about fitting 140mm discs instead of 160mm at the back: over the weekend I fitted a Shimano front 160mm PM-IS adapter at the back, and replaced my 160mm disc with a 140mm item to try the whole thing out. This is for anyone else who's thought about this . . .

First thing to report - it's very easy to set up.

Second thing - by my scribbled calculations, the smaller disc provides 12.5% less braking torque than a 160mm one. In practise, this means that it needs more of a squeeze to slow down and is quite hard to lock up. It's especially hard to lock up instantly, which was pretty easy with the 160mm. Since the plan is to use it on a bike for a much smaller rider (8-10 years old) this is just what I wanted: it should provide plenty of braking, without wearing the tyres out

thekickingmule

If I were 8-10 years old and found that my brakes didn't lock when slamming the brakes on, I'd be fixing them so they did. That's one of the great things about being 8-10, you can pull a skid and let your parents worry about the tyres!

Giraffoto

They can be locked, but he now has the option of finesse (thus becoming the first 8-10 year old ever to demonstrate it). The important thing is that there's something between no brakes and locked.

paulbox

thekickingmule wrote:

If I were 8-10 years old and found that my brakes didn't lock when slamming the brakes on, I'd be fixing them so they did. That's one of the great things about being 8-10, you can pull a skid and let your parents worry about the tyres!

Well said!

Skids are for kids and nobody should be taking that fun away...