Weights and tyre pressures...

[Spinney]

I'm hoping someone can save me a bit of time, rather than me having to trawl through various manufacturers websites....
This is for a worksheet I'm writing for 11 year olds on pressure.

Can anyone give me a mass/weight for a road bike* and a mountain bike, including pedals etc, and also some idea of the total mass/weight of a fully loaded touring bike (think front and rear panniers). I'll add the weight of the rider myself.

And also a typical tyre pressure for these?
I'm thinking something like 80 -90 for the tourer. What's typical for a road bike? 100?
And is a mountain bike tyre normally inflated to a much lower pressure?


(I'm not talking TdF machines here - say a £1000 example of each, so we're not talking fully carbon or anything).

I just like to make sure I'm providing realistic figures when giving the little blighters some sums to do!

Cheers!

 

[MontyVeda]

do we get paid for helping with your lesson plans?

 

[Cubist]

OK, my road bike weighs 9kg with pedals, and has 23mm tyres with a max recommended pressure of 120psi. I run them nearer 100.

My full suss MTB weighs 13.2kg with pedals, has 26x 2.4 tyres, run tubeless at 22 and 28 psi on Stans Flow rims. The tallish sidewalls are Snakeskin (kevlar thread reinforced) and the low pressures are designed to allow the tyre to spread to give a greater contact patch for increased grip on rocky trails and hardpack. There is an obvious drag payback on tarmac. Running them tubeless means a reduced chance of pinchflats. The tyres are different compounds front and rear, with a stickier compound front where you need the most grip (less likely to recover from a front tyre washout) and a harder compound rear for improved wear.

My hardtail MTB weighs 11kg with pedals, and is shod with 26x 2.25 Snakeskin tyres on Stans Arch Ex rims. Again tubeless, but this bike tends to run at slightly higher pressures, 25 and 30psi on Stans Arch Ex rims , sacrificing a little bit of grip for reduced drag. This bike spends more time on hardpack and less time on rocky steps and rocks. Both tyres are the same "pacestar" compound.

Max recommended tyre pressures for a MTB tyre on Stans tubeless rims is 40psi. With that sort of pressure you'd fly, but ping off every pebble on the trail.

My lad runs his 11.5 kg hardtail MTB on the same tubeless tyres, 26x 2.25, but on heavier DT Swiss EX500 rims . He is far less subtle, and tends to straightline a lot of stuff, and has managed to pinchflat a tubeless tyre at 28psi by clouting a square edged step at full pelt. He runs his at 28 and 35 psi.



Daughter runs her 13.5kg hardtail MTB with narrower 2.1 tyres, 17mm rims, tubed at 30 and 35. Far less aggressive as a rider she picks better lines and is less likely to smash edges or ride on the edge of grip.

That help?

 

[Rob3rt]

About 9kg for a £1000 road bike? Tyre pressure anywhere between 90 psi and 140 psi. Lets call it 110 psi?

 

[Spinney]

That help?

Brilliant - thanks! Info about the different compounds on the MTB will come in useful too!

 

[Spinney]

do we get paid for helping with your lesson plans?

All you get is a

 

[tmesis]

Don't forget to add the weight of the rider's toolkit/tubes/pump etc. and any drinks they're carrying.

 

[Spinney]

Thanks all - worksheet done!