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Higher or lower pressures contribute more to dented rims?

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Just wondering, never tested it, and I dent mine on all the rocks here. Not sure if "dent" is the correct term, but the flare out from hitting rocks with force.

 

Mike

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Lower pressure leaves more factor for dents as you call it.

Higher pressure calls for cracks.

If you have a low pressure and you take a jump or hit a rock then even though you have more width scientifically the pressure gradient which means pressure pushing up X width can not withstand which in turn will cause damage to a rim.

Now higher pressure will take the impact as well as a lower pressure bit in a different way.

You can hit jumps rocks etc but over time the hydrostatic pressure no longer takes affect it is noe more of a velocity factor. Pressure X force = ?

The more pressure applied over time means the more stress fracture. The same as a frame etc. . Although these factors may apply don't go for it. ....

A median pressure around 13 to 10 are a good area but you need to figure for your conditions.

May better advice come to you from what my knowledge has

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Lower pressure leaves more factor for dents as you call it.

Higher pressure calls for cracks.

If you have a low pressure and you take a jump or hit a rock then even though you have more width scientifically the pressure gradient which means pressure pushing up X width can not withstand which in turn will cause damage to a rim.

Now higher pressure will take the impact as well as a lower pressure bit in a different way.

You can hit jumps rocks etc but over time the hydrostatic pressure no longer takes affect it is noe more of a velocity factor. Pressure X force = ?

The more pressure applied over time means the more stress fracture. The same as a frame etc. . Although these factors may apply don't go for it. ....

A median pressure around 13 to 10 are a good area but you need to figure for your conditions.

May better advice come to you from what my knowledge has

Not sure I quite understand all that. I'm running about 20# which is high, but I'm dual sporting. You are saying if I air down, I will have greater "dent" issues?

Thanks, Mike

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Not sure I quite understand all that. I'm running about 20# which is high, but I'm dual sporting. You are saying if I air down, I will have greater "dent" issues?

Thanks, Mike

 

It depends on your riding style and what/where you ride. I run very low pressures (7-9psi front/5 rear) and have no problem with denting my rims. For some people those pressures would be disasterous for their situation.

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Not sure I quite understand all that. I'm running about 20# which is high, but I'm dual sporting. You are saying if I air down, I will have greater "dent" issues?

Thanks, Mike

How heavy are you and your bike? That may be the deciding factor.
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It depends on your riding style and what/where you ride. I run very low pressures (7-9psi front/5 rear) and have no problem with denting my rims. For some people those pressures would be disasterous for their situation.

Do you get Pinch flats ?

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Not sure I quite understand all that. I'm running about 20# which is high, but I'm dual sporting. You are saying if I air down, I will have greater "dent" issues?

Thanks, Mike

Maybe not.

I run 10-14 F 8-12R

Tires need to flex and absorb some shock. This will depend on how fast you ride, as to how much pressure you should run and will vary greatly from tire brand to tire brand. Rims can crack with too much pressure.

Granted at approximately 50 psi you could get a rim explosion!

With that said, metal fatigues, so constantly running rocks, will eventually bend and buckle rims.

I'm no engineer but I'm sure someone else will be along with the full metallurgy and rolling resistance 101 course!

To explain the physics equation in this situation.

Then you will probably just down pressure the tires and all will be well. Unless they're tubeless.

Lmbo

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It depends on your riding style and what/where you ride. I run very low pressures (7-9psi front/5 rear) and have no problem with denting my rims. For some people those pressures would be disasterous for their situation.

 

 

How heavy are you and your bike? That may be the deciding factor.

 

 

Maybe not.

I run 10-14 F 8-12R

Tires need to flex and absorb some shock. This will depend on how fast you ride, as to how much pressure you should run and will vary greatly from tire brand to tire brand. Rims can crack with too much pressure.

Granted at approximately 50 psi you could get a rim explosion!

With that said, metal fatigues, so constantly running rocks, will eventually bend and buckle rims.

I'm no engineer but I'm sure someone else will be along with the full metallurgy and rolling resistance 101 course!

To explain the physics equation in this situation.

Then you will probably just down pressure the tires and all will be well. Unless they're tubeless.

Lmbo

 

It's a '07 KLR 650, probably 375# ? wet, I'm 180#. I'm really getting into dual sporting Arizona. In searching new areas I might do 75 miles of slab, 75 off road, 75 slab again. Thus the high pressures. Most of the off road consists of rocks, I ride quickly but nothing like a race speed. I can air up and down as surfaces change, the rim denting figures into whether I should. I run D606's or MT21's.

 

Thanks, Mike

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It's a '07 KLR 650, probably 375# ? wet, I'm 180#. I'm really getting into dual sporting Arizona. In searching new areas I might do 75 miles of slab, 75 off road, 75 slab again. Thus the high pressures. Most of the off road consists of rocks, I ride quickly but nothing like a race speed. I can air up and down as surfaces change, the rim denting figures into whether I should. I run D606's or MT21's.

 

Thanks, Mike

Is soon as I heard dual sporting I thought it might be something like a big bike at the root cause. I'm not knocking the KLR, they are a good bike for what they were intended to do. Which is not rock bashing- way too heavy for the regular-strength wheels they come with. I'm sure that eventually you'll need to buy some heavyweight aftermarket wheels.

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Is soon as I heard dual sporting I thought it might be something like a big bike at the root cause. I'm not knocking the KLR, they are a good bike for what they were intended to do. Which is not rock bashing- way too heavy for the regular-strength wheels they come with. I'm sure that eventually you'll need to buy some heavyweight aftermarket wheels.

Yes, I've been thinking wheels also, or a KTM 690. Actually the KLR does surprisingly well, compared to my prior WR450 and DRZ400 except on the long rocky down hills. I have RaceTech suspension F&R. They shut down most of the single track here and I was drifting towards DS anyway, a lot of Arizona to explore. I ran across the KLR and since I had 1 before I thought I knew what to expect, guess I'm riding more aggressively.

So consensus is bike, wheels, terrain, and riding style are the biggest factors? PSI, not so much?

Thanks, Mike

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psi is very important, if you are denting your rims you are esentially bottoming it out and rocks or whatever so hard you are one are flaring or bending the rim. Flat spots are generally the result of lack of rim strength and proper inflation. 

Edited by Wild Alaskan

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Do you get Pinch flats ?

 

I run heavy Maxxis tires (SI front/IT rear) and Tubliss so pinch flats are a thing of the past for me. The Tubliss lets me run those pressures while also protecting the rim. BTW, I'm a mid-pack B-rider if that helps anyone.

Edited by SS109
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psi is very important, if you are denting your rims you are esentially bottoming it out and rocks or whatever so hard you are one are flaring or bending the rim. Flat spots are generally the result of lack of rim strength and proper inflation.

So, back to my original question, what is the proper inflation? Higher or lower?

I know the rims are cheap, it's a KLR.

Mike

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as everyone has said higher means less rim damage I run 13psi in the front and have only bent one rim slightly, and it was a hell of a hit on a square edge rock!

OK, good to go with my current setup. My rock riding is constant hits. Used to live in Alaska, mostly Palmer and Kodiak. Alaska is a big state, but I've never seen rocks like those in northern Arizona.

Mike

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BTW, I'm a mid-pack B-rider if that helps anyone.

Nope, not really!

Unless you are mid pack b class rock riding!

Lmbo

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the one i bent my rim on was actually during the dessert 100 race in odessa WA.  Also did a few cringe worthy frame checks! haha

 

Many of the old farts will tell you not to run any less than 20psi for that race, entirely for flat prevention, with the benefit of less rim damage. Fast guys with mouses or tubliss come back with hammered rims.

 

 

The tire is extra suspension. The softer it is, the easier it is to bottom out. The carcass is supposed to support the rim and distribute the load evenly. With too low pressure for the terrain, the rim hits the ground and takes that same load at a point, causing dents and flats. Off road guys often switch out the 19" for an 18" rim to gain more sidewall for the same reason.

 

As for what pressure to run, IMO if you see more than 5mm of clean rim or scuffing you should consider upping the pressure.

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