Just been getting ready for a bit of a bike ride tomorrow... Mainly sorting wheels for tyre pressure and/or trueness to eradicate brake rub, and adjusting v-brake return spring tension, and refitting a mirror, and changing a saddle...
Anyway, that's 2x 700c wheels true and up to pressure ~80psi,
2x 26" wheels true and up to pressure ~35psi
2x 20" wheels up to pressure ~40psi
2x 12" wheels up to pressure ~25psi
My commuter, wife's MTB, little girls Islabike Rothan and the Burley Bee for the baby/picnic. Now, what tubes shall I take... Or just a repair kit and eat when we puncture :-)
You'll have arms of steel after all that pumping!
ReplyDeletewow, all of those pressures seem so low :)
ReplyDeleteThe joys of a proper track pump make it fairly painless, my 3 year old can get the first 15psi on her own if she needs to! Although she is in bed so I was fettling the bikes solo.
ReplyDeleteNo, the real challenge is getting a pump onto the presta valve in a 12" wheel, talk about snug! The "Lezyne micro floor drive HVG" has just enough flex to squeeze in though thankfully.
Tom Ligman the 700c are fairly large volume "come on a hybrid" type tyre, at their max pressure. The 26" are at a suitable comfort, slow ride pressure. The trailer wants a little give so little Lily doesn't shake to pieces and our 3 year old is feather light so really doesn't need much. It's ask for a rammed gravel trail so huge pressures aren't going to gain anything really.
ReplyDeleteYou probably don't want to know what I run on my full suspension bike with tubeless tyres though ;-)
35 psi in a 26" tire?! Are you running tubeless or something?
ReplyDeleteFS tubeless should be ~ 20-24 psi. :)
ReplyDeleteDave Bartel they are only 2.1" but they come up reasonably large, my wife however doesn't and yea, the 2.3" Big Earl Wet on the front of my FS gets to about 20 before it gets a top up :-)
ReplyDeleteMust confess, I was thinking tubeless 29er pressures. I'm amazed you can ride a 26er that low even tubeless.
ReplyDeleteTom Ligman and Dave Bartel I can't find the original study but this has much of the relevant detail http://www.mtbonline.co.za/info/mtb-tyre-rolling-resistance.htm Now get off road and drop some pressure! ;-)
ReplyDeleteChris Auton I was offroad on my MTB yesterday @ 30 psi with tubes. ;)
ReplyDeleteThat study overlooks rider weight :)
ReplyDeleteTom Ligman I might get a bit of a sweat on whilst riding but I don't think my weight changes enough to alter pressures mid ride ;-) but yes, the whole line might slide up and down going from Clydesdale to whippet, but I like it when my logic and science meet and don't clash to badly :-)
ReplyDeleteDave Bartel , as Tom Ligman points out, meaningless data without rider and bike weight! Much like the original post actually... :-)
ReplyDeleteAnd I am actually quite excited about riding any bike, any distance as it has been to long, and our 3 year old is really getting the hang of her balance bike. She keeps telling us she will need a bike with pedals soon. We think she really needs to learn how to use the brakes properly first.
I'm not sure I'd say "meaningless" just that it's not particularly easy to apply. "Pinch flat" or "snake bite" or whatever you want to call them are a sad fact of life for every weight class if you run underinflated, it's just that underinflated for me at 200+ is different from my friend Matt at 290 and my friend Bob at 125... so they need to do more research! I'd gladly offer to be a paid research subject for that testing...
ReplyDelete150km uphill, a third of it on grass? Would do it for money, sure, but not for fun :-) within the limits of exploding tyres and pinch flats or dinged rims, and not forgetting tyre sidewall stiffness I think the general principal should hold.
ReplyDeleteHowever a road bike on super smooth tarmac with stratospheric (OK, bad choice of superlative add the pursue is lower up there, but you know what I mean) will always be a joy I am sure.
Chris Auton If I ever find myself in an area where I get to ride a road bike on actual smooth tarmac, I'll let you know. Our roads have more in common with a cyclocross course.
ReplyDeleteStill sounds kind of fun... but I think the most striking thing about that study is that it doesn't seem to matter much what pressure you run... I want a new study for the info I'm after, I think...
ReplyDeleteI got to ride my beater bike on smooth tarmac last night... i kept thinking about how much I wished I'd brought the roadie, even if it was completely inappropriate for the style of riding going on :)
ReplyDeleteMy front tyre on my 29er was on about 15 psi because I couldn't be bothered to pump it up. Bottomed it off a few drops...
ReplyDeleteYou see, Chris McGovern , it's behaviour like that, that gives low pressures a bad name! Now if you haven't done it already go and put another 6 psi in there right this minute!
ReplyDeleteQuite enjoyed the pootle today, caught the sun, got covered in dust and wished I was running 10psi less in my tyres #rattlingteeth
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