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roadwork
Hi all
Posting this stuff for a friend of mine, because I myself am not sure and the cat has really dodgy internet in Thailand.

"I was reading an old thread about tire pressure and some people said they run 60-75, one person even said 110psi. My tires only go up to 65 psi max as stated on the sidewall, but is this just a safety precaution or can they go up higher?

Also, I have 2.3" in the front and 2.1" in the back with my current bike. A long time ago when I rode BMX bikes (a really long time ago), all of our bikes had 1.75" tires on them or 1.95" front and 1.75" rear, but they were all knobbies.

Do any of you riders use a 2.1" front/1.95" rear combo, or even 1.95" front and rear? If so, how does it feel? If I run smaller tires like that, will the rims run a bigger risk of warping? In the old days the rims weren't double walled like these suckers I have now and we were doing the same basic tricks and didn't have any problems. I know the amount of surface contact will decrease, that's obvious, but do you foresee any other side effects of "going skinny"?

Thanks a lot and Happy belated New Year"

Okay, that's the email he sent me
Let me know what y'all think.

jumpinjim
I run 1.95's front and rear, and keep them at the sidewall rating 65 psi.
roadwork
QUOTE (jumpinjim @ Jan 10 2011, 08:58 AM) *
I run 1.95's front and rear, and keep them at the sidewall rating 65 psi.


Any problems with them feeling unstable or anything?
BS
Sidewall ratings are just a recomendation. I've run 90 pounds in a Comp III that was rated for only 35. It's like the tag on your matress. You really can remove that thing. The cops won't stop you.

On the skinny tire thing, I run a 2.125 front and 1.75 rear Maxxis Holy Roller in a concrete park with 80 psi front and 90 psi rear. You may notice a little bit of difference but it won't be a big deal. Bike riding is about the rider not about the bike or the tires. They can hold you back a little bit but they can't make you good.

The important thing to remember is to keep a lot of pressure in your rear tire. The biggest problem in riding the skatepark is hanging up your rear wheel on coping. That is what destroys wheels. If you run a lot of pressure it'll keep you from destroying your rear wheel. If you run low pressure the impact will go straight to the rim instead of getting absorbed by the tire.
roadwork
Thanks. Still not sure if the psi should be cranked up more than the rating on the sidewalls, though. They're just cheap Salt tires that came stock with the bike. I think they should be replaced with some Duo Stunners, which are hard to get in SmileyLand. And, my buddy uses the bike for 99% street.

Thanks for the responses.
BS
Like I said, I routinely ran 90 pounds in a Comp III rated for 35 pounds. Their sidewalls were notoriously fragile and every once in awhile you tear one. If they're rated for 65 you can rest assured that they'll hold 90 easy.

Something you have to remember is that guys were riding street on skinny Comp III's as recently as the 90's. Sure, big fat tires are popular now but lots of amazing street moves went down on skinny knobby tires not very long ago. Pump 'em up and run what you've got. Upgrade later when you wear the current ones out.
Greyryder
As far as stability at low pressure goes, because I ride on mountain bike trails, I run Max Daddies at about 15 to 20 PSI, with no unstable feeling. (1.85 rear, 2.25 front) Never felt like they were going to roll over in the corners. Once, my rear tire got low enough, to make the back of the bike feel kind of weird. Not sure how low it was, that day. I wouldn't run them that low on pavement, , just because of how much it would feel like you're dragging something.

I don't how much difference you'll really notice between 60psi, and 90 psi. Large volume tires like our bikes use will always give a little, under our weights. That's where the drag comes from. The higher pressures just help avoid pinch flats, and rim damage, when you don't quite make it over the curb or coping.
BS
QUOTE (Greyryder @ Jan 10 2011, 06:26 PM) *
I don't how much difference you'll really notice between 60psi, and 90 psi.

...just help avoid pinch flats, and rim damage

This is what I was referring to. I notice a huge difference between 60 and 90 and primarily in the area of pinch flats. I'll flat at 60 but not so much at 90.

Have to admit I race at lower pressures (70 or 80) but always pump up the back to 90 when I get to the skatpark. It makes a huge difference.

On your 20 psi are you referring to tubeless mtb tires? That environment and technology is very different than a street/skatepark environment where 100 psi plus is the norm.
Greyryder
QUOTE (BS @ Jan 12 2011, 06:59 PM) *
This is what I was referring to. I notice a huge difference between 60 and 90 and primarily in the area of pinch flats. I'll flat at 60 but not so much at 90.

Have to admit I race at lower pressures (70 or 80) but always pump up the back to 90 when I get to the skatpark. It makes a huge difference.

On your 20 psi are you referring to tubeless mtb tires? That environment and technology is very different than a street/skatepark environment where 100 psi plus is the norm.


Nope. Not running tubeless. Not sure I'd even want try doing that, with my BMX. (I don't own a mountain bike) I just haven't noticed any weird unstable feeling in my tires, until I get the pressure really low. I personally don't notice much difference in feel over about 45 to 50 PSI, but so far both of my bikes have knobby tires. The inherent resistance of the knobbies might be keeping me from feeling a difference. I don't ride at parks, and don't do any kind of riding that's very risky of pinch flats, so I can't comment on that. I was just commenting on stability.
BUB
I really like the Odyssey Path K-lyte 1.85 in the back and Ody Aitken 2.1 in front I've been running for the past 2 years or so (and still have some life left in them). Skinny in back is faster and lighter; fatter in back is a little more shock absorbing and seems easier to manual (though you'll eventually adjust to it). I'd get the new Ody white tires with the tanwalls, but they only come in the regular heavier compound and I really like having that kevlar tire in back.

What everybody said about tire pressure is true - you can pretty much fill them over the psi limit without any problem. In fact, I think running anything less than 80-85 for ramp riding is kinda pushing it - if you case with tire softer than that, you can really flatten your rim, or get a flat.

BS
QUOTE (Greyryder @ Jan 12 2011, 06:51 PM) *
(I don't own a mountain bike)

Sorry, I thought you were talking about an mtb but you just said "mtb trails". Man, if I ran 20 psi in my Holy Rollers I would be riding on rim. I'm never under 70.
woodybmx86
I easily notice a huge difference between 60 and 90. I run mine religiously at 70-80, cheap tires or not. any lower, I notice... 85 and higher, feels like riding without a tire... well not quite. I wiedh around 230 lbs. If i run 50, when I tail tap I bottom out.
Your SALT tires will easily take it. shoot, the cheapest tires there ever were, Poverty's, took it. And they sucked badly. hahah
jesboogie
I am a park dog so I run 90# in 1.90 tires Fit Kevlar Tires. Less rolling resistance = more air time. I weigh $175 more or less. JD
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