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Discussion Starter · #1 ·
Hi, can anyone please help explain to me the best way to find the ideal pressure for 2.6" tires? I've read conflicting opinions on how to go about it.

I'm running 17/19 psi f/r on i30 rims and I weigh 84kgs ~180lbs. I'm getting a fair amount of bounce out of the rear. Some say increase pressure others say reduce, both agreeing on 1psi at a time. So which is it?
 

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Depends on the terrain and speed you are running at. Higher speeds and rockier terrains need more pressure. You can reduce until you get rim hits in the rockiest part of your ride.
I'd take a gauge and small pump out on your trails and experiment.
Many 2.6 tires would allow lower pressures if you had a wider rim, say 40mm for some terrains and medium speeds . . . less than downhill.
Bontrager XR tires, for example, have a more rounded profile and higher volume design meant for wider rims. 30mm works for their 2.35 or 2.2 XR2 tires. The 120tpi sidewalls wrinkle instead of fold when you lower the pressure. This can give you a bigger footprint and more traction. At the right pressure they don't bounce.
As you get into heavier sidewall tires you won't get as much from the sidewall. Lower pressure won't help as much.
 

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Discussion Starter · #3 ·
I am actually running bonti xr5/xr4. It's the low speed technical climbs where bouncing over rocks and roots is painfull.

So you're saying lowering the pressure should help eliminate the bounce? When you say low pressure, how low is low?
 

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Lower the pressure until you get rim hits or squirm in cornering. I'd drop 2 to start.
I'd add 'or you start getting rim strikes.' At 170 lb, I'm running 14/16 f/r with 2.4 tires on i29mm rims. This will rarely give me squirm during fast flat corning on hard high-traction surfaces and I can, on rare occasion, feel a rear rim strike if I ride clumsily over a sharp edge. With their rarity, I find it an acceptable trade-off for the improved ride and traction, particularly when climbing.

Basically, you need to experiment and find what works best for your riding in different conditions. You do need an good gauge that will adequately indicate these pressures. I use an 0-30 psi Meiser Accug-Gage.
 

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Yeah, I agree, start with low pressure - what you would normally consider too low - and add as/if needed. Find what works for you. The pressure you are running seems in line with what I run. I started at a pressure where, sitting on the bike, the corner knobs are touching the ground. That ended up being too low for me, so I ended up adding air. I'm 160lbs ready to ride, and I "ride light" so 16-17psi rear and about 13psi front works for me where I ride. When I go to Moab, I add a couple of psi front and back on both my 29x2.6/2.5 F/R and 29x2.35 F/R.

I also advocate using an accurate gauge, but for consistency, I'd at least use the same gauge.
 

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As an experiment or accident I ran 11psi in the front on a 30mm wheel using an XR2 2.2 on trail in Phoenix. The traction from the bigger footprint was noticeably better for the granite dust areas in changing directions cornering. But it had to be really babied over the rocky sections because of lots of rims hits otherwise. Had to be a one time loop.
 

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I have 2.6 XR5 on 30mm and 35mm. 30mm is on the narrow side; you're not going to get optimal performance. But I have never experienced "bounce"; maybe your rear suspension could use some tuning.
 

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Discussion Starter · #13 ·
I have 2.6 XR5 on 30mm and 35mm. 30mm is on the narrow side; you're not going to get optimal performance. But I have never experienced "bounce"; maybe your rear suspension could use some tuning.
This is on a hardtail, only air to tune. Like I said the 2.6 Maxxis didn't seem to bounce that much but were a little draggy.

Would you suggest a tire swap to something else given I have i30 rims?
 

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Discussion Starter · #14 ·
Thanks for all the feedback, I have a Topeak digital gauge which I use to set pressures. I normally inflation slight beyond where I think I need to be then use the gauge to bleed off some air to get the pressure I want.

So from what I'm hearing, basically higher pressure increases bounce lower reduces it. What does it mean if you cannot eliminate bounce without rim strikes? I have been thinking about using rimpact inserts but tyre roll might still be a problem.
 

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IMO, use the lowest pressure where you don't get strikes or squirm for the riding you're doing. That's the best you'll do. Find that pressure and see if you have any "bounce" problems.
 

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I am Walt
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I’m 180 lbs, and ran XR2 2.6’s on my SS on 29mm ID rims at 16 PSI front and 19-20 PSI rear, with no rim strikes. I carefully measure the pressures before every ride with a very good analog gauge.

I believe most people run way higher pressures than they should, or need to.


Sent from my iPad using Tapatalk
 

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Wow, you guys are getting away with much lower than I can. However, there are many factors to consider when talking about tire pressure. Tire brand and flavor, size, rim width, tubes or tubeless, riding style, terrain, full sus or hardtail, rider weight, and don't forget the fact that everyone's gauge is not calibrated under the same roof. IMO this is important because I've found on the larger tire sizes that 1/2psi can make a noticeable difference.
I can only tell you what I've found to work well for my 185lb self on my 2.6 27.5 i35 tubeless Minion DHF/DHR2 exo setup on my hardtail. That is 20psi front (but feel I could go lower safely) and 24psi rear.
Not very "bouncy" and pretty amazing cornering. Though I think I can better it by dropping the front pressure a little. It's a never ending experiment.
Hope this helps.
 

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Discussion Starter · #19 ·
Wow, you guys are getting away with much lower than I can. However, there are many factors to consider when talking about tire pressure. Tire brand and flavor, size, rim width, tubes or tubeless, riding style, terrain, full sus or hardtail, rider weight, and don't forget the fact that everyone's gauge is not calibrated under the same roof. IMO this is important because I've found on the larger tire sizes that 1/2psi can make a noticeable difference.
I can only tell you what I've found to work well for my 185lb self on my 2.6 27.5 i35 tubeless Minion DHF/DHR2 exo setup on my hardtail. That is 20psi front (but feel I could go lower safely) and 24psi rear.
Not very "bouncy" and pretty amazing cornering. Though I think I can better it by dropping the front pressure a little. It's a never ending experiment.
Hope this helps.
I was running similar pressures on my dhf (20/22) and I didn't have any bounce.
 
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