Author Topic: Suggested MTB air pressures by GEAX (full suspension vs front suspension  (Read 1044 times)

jim-ratliff

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OK, I'm convinced.   ::)
« Last Edit: August 17, 2011, 06:49:38 am by jim-ratliff »
"If you're gonna play the game boy, ya gotta learn to play it right."

jim-ratliff

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lighter faster rolling tires are not faster on trail

http://www.leelikesbikes.com/are-freeride-tires-faster-than-xc-race-tires.html

----  when speed, especially speed through corners, is the criteria. (i.e. Racers)

My experience on that same course probably would not be the same, because I'm not going to be pushing the limits of traction in the corners.

"If you're gonna play the game boy, ya gotta learn to play it right."

Svend

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Hey Josh,

Nice review on the Geax Saguaros.  Thanks for finding that, as I've been looking at replacements for my Bontragers for a while, and that one looks like a winner.  As I mentioned, my wife has Geax Arrojo on her bike, and loves them.  They make great tires, and I'm pleased to see a good one of theirs in 29er size.  Might be a great choice for my rig, and for my wife's when the Arrojos wear out.

As for our ongoing pressure debate, I think you are somewhat missing my point.  I have said all along that for single track riding, we all prefer to run our tires at lower pressures than for the hard pack flat trails -- ie. at 30 to 35 psi, even on my bike.  This does not seem overly high to me.  That is about as low as I am comfortable going with tubes, for fear of pinch flats or denting our rims.  For a rider of my weight (220 lbs), 35 psi with tubes is kind of pushing the limit, don't you think?  And yet, I have not had a pinch flat so far. 

So.....it seems that you and I actually agree on something. 

Coincidentally, our pressures happen to agree quite closely with Geax, at least for the lighter girls, but I don't recall you saying that 30 psi was WAY too high, at least for a tubed tire.  Perhaps the Geax tables are not "utter b***sh**" after all, as you so eloquently put it.  So....perhaps we agree on that too?

Believe me, if I could go lower, I would.  But other than on my bike, which is TLR, I am just not willing to go tubeless, meaning that I don't want to go through the hassle of converting non-TLR rims and tires to tubeless, for reasons I've already stated.  I don't think anyone is doubting your assertions that tubeless is better.  I'm sure you are right.  You are a far more experienced rider than we are, and I do believe you.  But you have different demands of your gear, and are willing to put extra time and effort into getting better performance, but I am not.  We are all recreational riders, not professionals or serious racers, and therefore have different expectations of our gear, and limits to the time and money we spend.

Speaking of which.....
a real rider riding a Geax tire......

Not sure what you mean by a "real rider"? What is your definition of real rider? Does that include only racers? Elite mtn. bikers? Am I a "real rider" in your eyes? I hope we have some mutual respect here....with emphasis on mutual.

Regards,
S

bushwacka

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I actually do respect you guys, but would you respect you even more if you tried something before discounting it and did not just say its too tough or to much hassle with out first ever trying any of my methods.

He is a real rider because he is someone who has figured out what pressure and what tires will work best for him. What you guys are doing is like arguing whether a 78mm or 82mm ski is better in powder, when the real answer is neither.

I just hate arguing quantifiable facts about physics.  Its like arguing whether the sky is blue or not, or whether gravity holds us to the earth. The scary thing is we know much more about why the sky is blue, or the rolling resistance/grip of tire than we know about gravity. I do not speak opinions ever.

If I did not respect you guys Id be telling you to run 1.8 at 60 psi because that is the faster way to ride!  ;D


jim-ratliff

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lighter faster rolling tires are not faster on trail

http://www.leelikesbikes.com/are-freeride-tires-faster-than-xc-race-tires.html

This was a pretty good link, and my compliments to Lee's bikes for putting together such an instrumented and objective test. It just doesn't prove your assertion.  On the three mile flat putting out 100W, the cross country was 38 seconds faster.  On the 2 mile 10% climb the XC tire was 19 seconds faster.  On the trail, the lighter faster rolling tire was faster.  On any section that included curves and demanded traction, the freeride tire killed the XC tire. And they clearly say that in their analysis.

My conclusion.  Freeride (wider, low pressure) tires don't roll faster, but what they surrender is more than made up by additional traction for those riders that can take advantage of the traction.  Not my opinion, facts proved in the test. And it certainly highlights why real racers use wider, lower pressure tires.
And, even for me, I'm feeling like we've talked this to death.
« Last Edit: August 17, 2011, 07:18:10 am by jim-ratliff »
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Svend

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Hey -- thanks Josh.  Good of you to clarify that.  And sorry if I took you on on that one.  I wasn't sure where you were coming from with the "real rider" comment, and just wanted to make sure that you were on the up-n-up.  We have had some people here on this forum who have behaved in a very disrespectful and condescending way to others because we didn't seem to fit their elitist ideals.  So thanks for sorting that out.  I appreciate that.

As for tubeless vs. tubed, high pressure vs. low -- I think we've flogged this one enough.  Please don't get the impression that I am criticizing what you have to say.  I said the following last night.....
As for our ongoing pressure debate, I think you are somewhat missing my point.  I have said all along that for single track riding, we all prefer to run our tires at lower pressures than for the hard pack flat trails -- ie. at 30 to 35 psi, even on my bike.  This does not seem overly high to me.  That is about as low as I am comfortable going with tubes, for fear of pinch flats or denting our rims.  For a rider of my weight (220 lbs), 35 psi with tubes is kind of pushing the limit, don't you think?  And yet, I have not had a pinch flat so far. 

Believe me, if I could go lower, I would.  But other than on my bike, which is TLR, I am just not willing to go tubeless, meaning that I don't want to go through the hassle of converting non-TLR rims and tires to tubeless, for reasons I've already stated.  I don't think anyone is doubting your assertions that tubeless is better.  I'm sure you are right.  You are a far more experienced rider than we are, and I do believe you.  But you have different demands of your gear, and are willing to put extra time and effort into getting better performance, but I am not.  We are all recreational riders, not professionals or serious racers, and therefore have different expectations of our gear, and limits to the time and money we spend.

.....which indicates pretty clearly that I actually agree with you, and would like to try tubeless for my bike.  But that I have other reasons for not going tubeless on the other bikes (ie. I don't own an air compressor, etc.....) that have nothing to do with dismissing your advice or disrespecting what you have to say. 

We do like a good argument around here at times, but no one should take these lively discussions personally.  Sometimes we take a contrary position just to flush out more detail, when the original assertion looked a bit sketchy.  Then we all agree in the end....or not.  But that's OK, ain't it?  This tire pressure debate was great fodder to kill some time until we can argue about ski stuff once the autumn comes.  Speaking of which, what's wrong with using an 82mm ski in powder?

(just kidding..... ;D)

Cheers,
Svend
« Last Edit: August 17, 2011, 07:24:43 am by Svend »