Confessions from the fuckwits

beeb

beeb

Dr. Beebenson, PhD HA, ST, Offset (hons)
Yeah, I went through that phase for a while too. Go too low and the tyre squirm becomes a big issue...

If you really want to smash rocks though, maybe look at tyre inserts? Slightly lower tyre pressure for better suppleness, sidewall support (assuming cushcore or similar), more rim protection. I CBF'd with the extra weight, but it does seem to work well.
 
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Petero

Likes Dirt
Yeah I'll admit to this too. Thinking lowest tyre pressure possible without rim damage = better / moar grip.

Now I just go by feel, a pressure gauge is overrated. Soft enough to allow some conformance to the surface of and limit any bouncing off small trail chatter, anything more is what suspension is for.

Realistically though I've found (obviously) lowest pressure being better only applies to certain surfaces, and even then the tyre squirm and drag is most often not worth the extra grip in those circumstances (basically in hero dirt anyway).
IMO with peagravel, or other loose over hard, where traction is hard to find - running a super low pressure is actually detrimental as you get a floating effect (think aquaplaning) on the top surface and no bite into the surface below. This is the same and more noticeable with larger volume tyres.

(hero dirt is anything not peagravel in WA)

EDIT: Will also admit that my ability is limited by skill far more than the bike or any component or setting.
 
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DMan

DMan

shawly the least hangeriest guy on rotorburn
Spike-X said:
I've been such a fool...

For the last 3-4 years, I've been running super low tyre pressures on my bikes. My thinking had been lower pressure = more rubber on the ground = better grip, but turns out there's more to it than that. I'd gone so low that my tyres were squishing really badly in corners, leading to slower speeds and lack of control.

When I rode the Sight on Tuesday, with the new rear rim and tougher casing tyre, I increased the pressure, and it made a hell of a difference. Went from 22F/25R to 24F/35R. The 35 was probably too much, because now it feels really harsh over rocks, and even started bouncing off them at one point. Next ride I'll go down to 32 and see how it goes. But it was much quicker and more precise through corners, and didn't feel like I was sacrificing grip, which I was worried about.

Then yesterday I tried the same on the LaPierre 29er, going from 23F/26R to 26F/30R. Again, a big difference in cornering. Turns out the bike had been understeering the whole time, because I was oversteering at first, until I got used to it.

So for this whole time, I thought my sucktitude through corners was the result of being fat and unskilled, when really, it's simply because I was a fuckwit. I feel a right tit.
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Don't be so hard on yourself man! It could also be that you are fat and unskilled as well?
 
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Paulie_AU

Likes Dirt
Spike-X said:
I've been such a fool...

For the last 3-4 years, I've been running super low tyre pressures on my bikes. My thinking had been lower pressure = more rubber on the ground = better grip, but turns out there's more to it than that. I'd gone so low that my tyres were squishing really badly in corners, leading to slower speeds and lack of control.

When I rode the Sight on Tuesday, with the new rear rim and tougher casing tyre, I increased the pressure, and it made a hell of a difference. Went from 22F/25R to 24F/35R. The 35 was probably too much, because now it feels really harsh over rocks, and even started bouncing off them at one point. Next ride I'll go down to 32 and see how it goes. But it was much quicker and more precise through corners, and didn't feel like I was sacrificing grip, which I was worried about.

Then yesterday I tried the same on the LaPierre 29er, going from 23F/26R to 26F/30R. Again, a big difference in cornering. Turns out the bike had been understeering the whole time, because I was oversteering at first, until I got used to it.

So for this whole time, I thought my sucktitude through corners was the result of being fat and unskilled, when really, it's simply because I was a fuckwit. I feel a right tit.
Click to expand...
How heavy are you for those pressures to cause understeer? At 80kg I race with 23F/26R on 2.5 tyres and apart from on super duper grip fast berms never feel squirm. I do run a DD rear casing though.
 
Ultra Lord

Ultra Lord

Hurts. Requires Money. And is nerdy.
Anyone go through the stage of pressure north of 50? Belting around on a old Kona cowan, anything less was pinch flat central and obviously higher pressures = leas rolling resistance so who cares if your bouncing off marble sized rocks. My shins hated me for all the slipped pedals I had.

Even now I run front 27F/30oddR. Tried lower and ripped front tyre off rims a few times and smashed rear rims. Still bonk the odd rear if I mess up (there was one section in derby, every bloody time resulted in a new ding and a burped rear tyre. @hifiandmtb to the trailside rescue with the oneup pump :D)
 
Isaakk

Isaakk

Likes Bikes and Dirt
Just a small one. Bought a new SS cog for the dirt jumper but didn't have time to install so left it in the padded envelope, sitting on my desk. Went to install it today but couldn't find it?

Just realised I binned it thinking it was rubbish. Rubbish already been collected. F-wit.
 
moorey

moorey

call me Mia
Isaakk said:
Just a small one. Bought a new SS cog for the dirt jumper but didn't have time to install so left it in the padded envelope, sitting on my desk. Went to install it today but couldn't find it?

Just realised I binned it thinking it was rubbish. Rubbish already been collected. F-wit.
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What size? Might have one you can have
 
moorey

moorey

call me Mia
Isaakk said:
16t, would be very much appreciated if you do.

I recall thinking as I sat it on the desk that it looks empty & thought "nah, I'll remember". Apparently not haha.
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One 16. New. Not a wide base one though, so it’s no good for alloy freehub body. Fine for steel. Yours if any good.
366578
 
rowdyflat

rowdyflat

chez le médecin
Suspected I would end up here but was proud of my effort changing rear axle size boasted on LTIL tested it , my wife rode it for 2 hrs , then yesterday it started to occasionally spin ,pawls didnt engage , locking nuts now not tight enough!!!!
 
Cardy George

Cardy George

Piercing rural members since 1981
Ultra Lord said:
Anyone go through the stage of pressure north of 50? Belting around on a old Kona cowan, anything less was pinch flat central and obviously higher pressures = leas rolling resistance so who cares if your bouncing off marble sized rocks. My shins hated me for all the slipped pedals I had.

Even now I run front 27F/30oddR. Tried lower and ripped front tyre off rims a few times and smashed rear rims. Still bonk the odd rear if I mess up (there was one section in derby, every bloody time resulted in a new ding and a burped rear tyre. @hifiandmtb to the trailside rescue with the oneup pump :D)
Click to expand...
Never gone to 50, but I go 35r for the commuting runs because of the stupid amount of weight I carry. I'm genuinely concerned about cracking another carbon frame. Maybe I should buy a duallie.
 
silentbutdeadly

silentbutdeadly

has some good things to say
Ultra Lord said:
Anyone go through the stage of pressure north of 50? Belting around on a old Kona cowan, anything less was pinch flat central and obviously higher pressures = leas rolling resistance so who cares if your bouncing off marble sized rocks. My shins hated me for all the slipped pedals I had.
Click to expand...
A bloke on an enduro bike with 2.8" wide tried it in an effort to be competitive in a race around Coomie. As I recall, we were in a train about a third of the way around the first lap when it sounded like someone had just let fly with a shotgun in our direction. Nearly had a couple of lads diving for cover.

Old Mate's rear tyre blew off the rim with the cornering effort on an over inflated tyre... apparently he'd lifted it to 60 PSI!
 
Isaakk

Isaakk

Likes Bikes and Dirt
moorey said:
One 16. New. Not a wide base one though, so it’s no good for alloy freehub body. Fine for steel. Yours if any good.
Click to expand...
Ahh, yeah it's a DT alloy freehub so might be best to get another kit. Live and learn I guess. Thanks anyway :)
 
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