Personal psi / tyre pressure choices

Hence the expression `boneshaker'......

23mm tyres @ 100psi front and 110psi rear. Memory has retained something about the lower front to help absorb road buzz and lumpy bits of tarmaccadam.

Lower front may also be because much there is much less weight on the front. Unless you are riding a TT bike or something.

That is a good point. Most of the time the back will be taking the majority of the weight...

I make an analogy with downhill skiers; they want to keep their skis on the snow as much as they can because that is quicker. Similarly if your tyres are rock hard you're going to spend longer in the air as you bounce over surface defects. And recommended tyre pressures are recommended for what: perfectly smooth roads? cobbles? wet weather?
But try telling that to a young courier with a bad attitude and a Joe Blow and all you'll get is a packet of Werther's Originals thrown in your face.

No traction when you are flying is there? It is all a balance but no pressures can account for all the road conditions you will face. Rock hard tyres are great on the track of a velodrome but a bit rubbish on Borough High Street.

I've let mine down by about 10psi now its winter and there is more water and wet leaves about, and I'm cycling in the dark more so it's harder to spot cracks and potholes.

I slightly increase my psi as proper winter approaches, as the psi is reduced by the colder weather/roads,
because cold causes gas (air in tyres) to contract, and heat causes expansion.

On a really hot day (hardly ever happens in this country), I actually will let a little air out of fully pumped tyres.

The heat of the road/weather will ensure the expected gas expansion.

EDIT:
I should add the proviso, that I have to keep my tyres at near maximum psi, as I'm a heavy guy, and I try to avoid pinch-flats.

I keep a pressure gauge permanently attached to each of my tube valves so that I can monitor tyre pressures in real time. Reading them takes some practise, but my fixie wheelie/skid skillz are dope.
I find it takes alot of the guesswork out of calculating leakage rates and the impact of environmental factors; this allows me to concentrate on my trackstanding.

Running a vittoria tub at around 145psi on the rear. It exploded yesterday in quite spectacular fashion. I think I hit a stone in the road.

Running a vittoria tub at around 145psi on the rear. It exploded yesterday in quite spectacular fashion. I think I hit a stone in the road.

And.......there's an app for that.

;)

I just read that the old vintage rims (not clincher I think) like weinmann used to make only pump up to max 80-90psi. Is it true? What are the disadvantages with that? Anyone help!!!! I've got to make the choice of either lacing up a vintage 27 1 1/4 rim on some track hubs or buying modern wheels with double walls.

well, they're clincher since the 'not clincher' one are tubular, of which the tyres are tubular (inner tube already in it) glued onto the rims, the clincher are named because the tyres 'hook' onto both side of the rims.

older rims are sometime not as strong as modern rims, and rims do have a limit on how high you can go, e.g. Mavic Open Pro recommend not to pump the tyres anymore than 140psi with a 23c tyres.

the disadvantage of your rims is that (if it is indeed correct) you can't exactly use those modern skinny tyres like a 23c (depending on which one, some are fine at 100psi).

The best thing you can do is get thicker tyres (the thicker the tyres, the less psi.), says, a 28c which sometime require only 85psi, especially touring tyres.

I just read that the old vintage rims (not clincher I think) like weinmann used to make only pump up to max 80-90psi. Is it true? What are the disadvantages with that? Anyone help!!!! I've got to make the choice of either lacing up a vintage 27 1 1/4 rim on some track hubs or buying modern wheels with double walls.

they are clinchers in a sense but are what might be referred to as non-hooked, i.e. they are straight sided rims.

as was said, the rim has no psi spec associated with it, this is determined by the tyre. With the old non-hooked 27 x 1 1/4 wienmanns, when I got up to 90psi (which was the maximum specified on my 32-630 schwalbe marathons) I noticed in a couple of minutes that I could see a bulge appearing somewhere around the sidewall, and the tyre climbing off one side of the rim, and the inner tube starting to bulge out. If it happens when you're riding then you are in trouble obviously....

I run them at 60psi and have had no problem (although I've only been on them a week!) could probably go a little higher but don't want to risk a blowout mid-ride.

Don't know where you're based, but I had Arup Sen build the fixed hub onto my old Weinmann rims out Ealing way, great job and great service.

I did it as part of trying to restore my conversion back to something like it's original state now that I have an OTP fixed getaround. Nice to have the old one set up as a relaxed slow comfy bike to potter about town on, particular now the weather is good, 27" rims (make me feel much higher up despite it only being mm difference), north road bars for upright position, brooks b17 narrow (really uncomfortable at the moment, still breaking it in, wish I'd gone for the wider one or something with springs).

90psi front and rear
Michelin world tour 32's

120/100 on vittoria zaffiro pro's (thin walled kevlar jobbies)

if you google "15% tire drop" you will find an interesting techy article on optimising your tyre pressure for your weight in order to achieve this magic percentage deflection .

I Pump them up until they "sing".

if you google "15% tire drop" you will find an interesting techy article on optimising your tyre pressure for your weight in order to achieve this magic percentage deflection .

http://www.vintagebicyclepress.com/images/TireDrop.pdf

this? it happens to correlate with what i find comfortable to ride.
cool.

Only just discovered this thread.

Pseudo-science crown winner without a doubt. Utterly epic.

" I slightly increase my psi as proper winter approaches".

Magic.

200psi, accept no substitute.

you mean 20psi?

I discovered I've been running on 10psi for a month, whoop!

No, I mean 200psi.

ha!

you mean 20psi?

I discovered I've been running on 10psi for a month, whoop!

Wow, that's worse than me, i'd been running 20psi for almost a year on my cruiser.

Pump the fuckers up until they sing with each pedal stroke !!!