Rule #30 // No frame-mounted pumps – so recommend me a 140psi pocket pump

So what’s wrong with running my tyres at 140psi then – I get the message – why is it worse than 120 or 100?

i only ever went past 110 once and the tube exploded,

At 100 mine are rock hard anyway

So what’s wrong with running my tyres at 140psi then – I get the message – why is it worse than 120

Just because it says you can doesn’t mean you should. 23mm tires needn’t go over 95psi – unless you’re riding track.

Read up on the 15% rule if you can deal with some rationale to tire pressure.

140psi will give a harsher and slower ride on UK roads, I’m 95Kg and fine at 100 front & rear. I can see a 120Kg rider might want a bit more but even then not 140psi.

15% rule?
<quick google>
as in 15% tyre drop*?
how the hell do you manage that without your own mechanic on stand by?

*i presume this means the rim is 15% closer to the ground when you are onboard and tyre is at correct pressure.

how the hell do you manage that without your own mechanic on stand by?

A friend and a tape measure?

A friend and a tape measure?

alright mate can you come round and measure my tyres while I’m on and off the bike? i’ll either get “no but I’ll meet you down the pub” or same response I’d get from my mrs, “bugger off”

You either need better mates, a more understanding wife or a complicated series of mirrors.

D0NK – Member

15% rule?
<quick google>
as in 15% tyre drop*?
how the hell do you manage that without your own mechanic on stand by?

Erm…you read the straighforward table that’s been produced?

Erm…you read the straighforward table that’s been produced?

didn’t find that, linky? just out of interest, I normally make do with 95/100 F/R

Plenty will do the job but do you really want 5 pumps for each psi?

Pumps are a straightforward trade-off between amount of air shifted and amount of force needed to shift it. A mini-pump that shifts enough air to do pump a MTB tyre to 40psi will be very hard work at 100+psi. A mini-pump that’s easy to use at 100psi will take forever to fill a MTB tyre.

Track pumps have a very long stroke and are easy to put a lot of force into so you can make a pump that does both jobs well.

With a mini-pump the trade-off really matters, which is why you get different pumps for high volume/low pressure (i.e. MTB) and low volume/high pressure (i.e. road)

alright mate can you come round and measure my tyres while I’m on and off the bike?

Of course you only needed to ask 😀
I shall return your bike standportable road side bike set up device at the same time

Not sure what mine are whatever the pump let me …will check with guage tonight as i can tell you all care

15% drop info here:
http://www.bikequarterly.com/images/TireDrop.pdf

calculator:
http://www.dorkypantsr.us/bike-tire-pressure-calculator.html

I think those seatpost/integrated pump combos you find on hybrids ad tourers are am awesome idea, and I don’t understand why we don’t have them in the MTB and road world.

What about the Airbone ZT-708 Carbonlife pump? It’s light, tiny (150mm long) and rated to 160psi.. not sure how true/attainable that is but it certainly has no problems getting road tyres to operating pressures… they do a slightly longer/bigger capacity version too.

Topeak Pocket Rocket DX11 works for me. It’s optimised for road bikes and has a smooth and easy action that stays that way even when the pressure is getting high. Takes many, many strokes mind, but it’ll get your tyre good and hard. Fnaaarggh fnaaargh, woot!

As others have said 140psi on the road is a waste of time – increased rolling resistance + sliding down the road on your backside in the wet. 140psi on a wooden indoor track yes but road no. 95-105psi is the sweet spot.