Rampant Inflation

Lezyne offers a digital pump gauge retrofit that I couldn’t resist. For $35 US one can pry out the old and thread in the new. The primary benefit for me was reading a digital scale rather than a needle on a gauge, way down there. Yes, I’m old. The new gauge reads out in single digits. The old needle gauge reads out depending on one’s eyesight and ability to see where the needle stops relative to the 2 psi marks. Houston, we have improvement.

The new Lezyne gauge also goes to 300 psi (20.6 bar)! FFS, who cares? This is a bike pump, who needs the 150 psi to 300 psi pressure? The Park and Silca both go up to 220 psi (15.2 bar) which is still 100 psi more than even track racers use. I dare a pump manufacturer to make a road pump that goes from 50 psi to 150 psi. Frank could use it as it still goes up to 150 psi and everyone else might have much more accuracy from the dial. I kid Frank.

The Lezyne digital gauge also claims a maximum 3% error which I assume means plus or minus 1.5 psi at 100 psi. Everything and I mean everything has an error associated with it and I appreciate knowing this error. Nothing is absolute, not even death. I’m not dead yet. The real question is what happens when one hooks all three of these pumps to one manifold. The Silca and the Lezyne were only off by 2 psi but I would not have been surprised to to see them off by 10. The Park and Leyzne were spot on which is reassuring because the Park gauge looks to be a very professional piece of work. Anything is accurate until one has two or more of them for comparison.

Yes, I know this last paragraph will be ignored and I should move it to the top. Should you care more about tire inflation? Yes, you should. Since not one person clicked on this link in my post about chains (yes I’m watching all of you, Google analytics knows everything), the take home message was this: Aero wheels do make a real difference in speed and tire pressure is the biggest (only?) influence on perceived “vertical compliance”/ride stiffness/road feel/comfort. With 25mm tires, one can experiment with lower pressure and not flirt too much with pinch flats. It’s just air; a very cheap way to dial in your ride.

 

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88 Replies to “Rampant Inflation”

  1. Balderdash.  I have run the exact set of wheels and tires at the exact same pressures on a 2000 Lemond Chambery (alumninium) and a 2000 Lemond Zurich (Reynolds 853).  There is no way I would mistake the ride of the Chambery for the Zurich unless I were too drunk to ride my bicycle–theoretically of course–I have never not been able to ride my bicycle.

  2. @SamV Haha, that shows my reading comprehension skills need serious work – I’ve always used the pressures for total weight, not per wheel! No wonder they seemed too high for me!

  3. @Barracuda

    @Teocalli

    @SamV

    You are just going to have to put Heavy Water in your Bidons.


    My Bidon has the answer for you !

    I suspect some politicians have that written on their head somewhere (just with “bullshit” instead of “lead”).

  4. $35USD? I don’t even want to think of what that would be in CAD.

    Anyhoo, here’s my recently built up track bike. I realise that I need a less-yellow saddle, but it was cheap.

  5. @rfreese888

    I roll 110 psi on my 25mm Conti 4 seasons, have an old school gauge on my Topeak pump.

    Does anyone else have to bleed the tube a bit before pumping? Otherwise the gauge red lines and air is caught between pump and stem?

    Yes but if I forget then I just push down on the pump and the air pressure forces the valve.

  6. Tyres and pressure.

    I had some wheels made up on Pacenti SL23 rims by Wheelworks. These rims are wider than “normal’, same concept as the HED wheels. They sent out a chart with suggested pressures with this preamble:

    “The wide-rim concept of the rims used in your wheelset is designed to increase ride comfort and traction.

    Critical to achieving these riding qualities is correct tyre pressure. The wider rim opens the tyre’s casing up increasing air volume inside the tyre. This increased volume allows the tyre can be run at a lower pressure without having an effect on rolling resistance or pinch-flat ability.

    The lower tyre pressure and wider, rounder tyre improves the wheel’s traction and road-feel, especially when rolling into corners.”

    According to the chart I should run 70psi rear and 65psi front. I’m 63kg and running Conti 25mm. I use these pressures and I have never had a pinch flat. Magic carpet ride.

  7. @rfreese888

    I roll 110 psi on my 25mm Conti 4 seasons, have an old school gauge on my Topeak pump.

    Does anyone else have to bleed the tube a bit before pumping? Otherwise the gauge red lines and air is caught between pump and stem?

    I found running my Conti 4 Seasons at 110 meant the would be more susceptible to splitting quicker. I run mine at 100psi and I’m a chunky 17 stone super clyde who rarely gets a snakebite puncture… (I’ve fucking kinxed myself there for tonights commute haven’t I? Offers up a sacrificial inner tube to the tyre Gods).

  8. @geoffrey

    Tyres and pressure.

    According to the chart I should run 70psi rear and 65psi front. I’m 63kg and running Conti 25mm. I use these pressures and I have never had a pinch flat. Magic carpet ride.

    Yep, magic carpet riding with w/wider rim beds and higher volume/lower pressures indeed. I also believe in the aero benefits of the more continuous sidewall to rim profile and for no reason other than what I experience coasting down hills in groups. In my mind it is a concept proven.

    I will say this however, and that is that I still enjoy running 23c’s at higher pressures on the more narrow Dura Ace wheel sets. It’s definitely not the same ride and kinda changes the character of the bike after I’ve grown a bit complacent with the ride/handling on HED+ wheels with larger volume tires. I’m guessing that maybe it’s some gyroscopic kinda thing going on.

    I’ve gone all the way up to 30c tires but at that size it feels to me that the tires are creating more work to get on down the road. Did I read that some teams were racing 30c at PR (?) and if so, I can’t imagine racing on this size tire. Though I’ve been riding these on an I9 wheel set built up for CX and not the HEDs. So maybe its as much the wheels as the tires.

  9. Nice work Gianni, glad you included a Slowtwitch link.  The tech guys there have been educating me for years. The forum can be a jungle though.

    I’m also on the “bleed the valve first” bus.

    23 or 25mm Vittoria Corsa EVO CX at 110psi at the moment.  Down from 120.

    Speaking of pumps; does anyone here own a Silca Super Pista yet?

  10. I’ve run mid to high 90’s on the 25mm GP4000s, have moved from DA C-24s on to HED Ardennes with the new bike.

    Can definitely feel the difference in rim width with the wheels in the hand, not sure I’ve noticed much difference in wheel performance specifically, cos there’s so many things about this bike that are better.

  11. Great write-up. I, too, have both pumps. The Silca is beat-to-hell but still works as good as the day I bought it. The Lezyne is faster and easier to read, so the Silca only comes out once in a while. Tire pressure is such a subjective thing. I’ve run 100/105 for ages on my road bike, often dropping into the 90s. The origin of my approach was reading how the great Cyrille Guimard advised lower psi as the way to go. Guimard went toe-to-toe with Merckx back in the day. So I figured he knew what he was doing. Maybe I’ll jinx myself here, but in addition to smoothing out the ride, lower psi seemed to cut down on flats, too.

  12. I’ve got a Zefal Husky that is nearing 28 years old.  Took some thought to think back to when I bought it.  The presta adapter died long ago, and I’ve been using brass adapters ever since.  Other than that, it’s been a champ.  I’ve been lusting after a new digital Lezyne, but can’t justify it.  Need to think of a reason to have two pumps.  Maybe one permanently indoors for sessions on the rollers…

  13. Interesting thread – so this winter I put some 28c Specialized Armadillos on my Dogma. Now spring is here and I really don’t want to take them off!  Here are some reasons why 1) Riding them at 95psi or so is a truly wonderful ride 2) have not flatted since 3) I regularly add a few gravel stretches to my ride giving me a bunch more options for loops and some more variety!   Note – I weigh in somewhere around 80-82kg

  14. I’ve got a couple of decent pumps (Silca and SKS) but what used to drive me nuts was the chuck/valve interaction, so I sorted that out with this awesome Hirama pump head. If like me you ever get frustrated by poor clamping/valve security from your pump find one of these bad boys – you will not regret it.

  15. @PeakInTwoYears

    Check out the info on November bikes site. They have a really interesting blog on wheels in which they discuss aerodynamics, tyre pressure, stiffness and so on. The Pacenti rim gets a few mentions along with their carbon rims.

  16. @Ron

    @PT

    Nice floorboards by the way.

    Yes, we should have paid Gianni that compliment far earlier in this discussion.

    How quickly we forget our manners.

    Is it also possible that they are in fact, the boards of a velodrome? Or is Gianni just making a very subtle pun? Or am I over-thinking it horribly?

  17. @Oli

    I’ve got a couple of decent pumps (Silca and SKS) but what used to drive me nuts was the chuck/valve interaction, so I sorted that out with this awesome Hirama pump head. If like me you ever get frustrated by poor clamping/valve security from your pump find one of these bad boys – you will not regret it.

    Mmmm, chuck porn. I second @Oli‘s Hirame reverence.

  18. @Oli

    I’ve got a couple of decent pumps (Silca and SKS) but what used to drive me nuts was the chuck/valve interaction, so I sorted that out with this awesome Hirama pump head. If like me you ever get frustrated by poor clamping/valve security from your pump find one of these bad boys – you will not regret it.

    I love the Lezyne connecter but with all the valve extenders I use they do wear out (the threads wear out due to not going on squarely enough).

    I am going on a fucking mission to find one of those, that looks beyond fantastic.

  19. @frank

    @Oli

    I’ve got a couple of decent pumps (Silca and SKS) but what used to drive me nuts was the chuck/valve interaction, so I sorted that out with this awesome Hirama pump head. If like me you ever get frustrated by poor clamping/valve security from your pump find one of these bad boys – you will not regret it.

    I love the Lezyne connecter but with all the valve extenders I use they do wear out (the threads wear out due to not going on squarely enough).

    I am going on a fucking mission to find one of those, that looks beyond fantastic.

    It’s beautiful and it’s a Kuwahara so it’s the next best thing to having ET blow your tyres up but is it £74 worth of beautiful, alien inflation?

  20. Contador spoke at the finish, calling it a very difficult day and saying he suffered a lot on the opening four hours of today’s monster stage.

    He has gone down and then back up in the odds today.

  21. @Peter

    I’ve got a Zefal Husky that is nearing 28 years old.  Took some thought to think back to when I bought it.  The presta adapter died long ago, and I’ve been using brass adapters ever since.  Other than that, it’s been a champ.  I’ve been lusting after a new digital Lezyne, but can’t justify it.  Need to think of a reason to have two pumps.  Maybe one permanently indoors for sessions on the rollers…

    In situations such as this I ask myself whether I need a good reason or just a reason. If it’s the latter then one to inflate front wheels and one to inflate rear wheels would be my starting point.

  22. @frank

    @Oli

    I’ve got a couple of decent pumps (Silca and SKS) but what used to drive me nuts was the chuck/valve interaction, so I sorted that out with this awesome Hirama pump head. If like me you ever get frustrated by poor clamping/valve security from your pump find one of these bad boys – you will not regret it.

    I love the Lezyne connecter but with all the valve extenders I use they do wear out (the threads wear out due to not going on squarely enough).

    I am going on a fucking mission to find one of those, that looks beyond fantastic.

    Or one of these:

  23. @snowgeek

    “A man with one watch knows what time it is…

    … a man with two watches is never sure.”

    – Some Smart Guy

    Unless they both read the same time. Great quote all the same

  24. @rfreese888

    I roll 110 psi on my 25mm Conti 4 seasons, have an old school gauge on my Topeak pump.

    Does anyone else have to bleed the tube a bit before pumping? Otherwise the gauge red lines and air is caught between pump and stem?

    Yep and it fucks me right off!

  25. Apologies up front because there is some great debate and persuasive argument here and my theory isn’t at all scientific. I put in around 110 psi rear and 100 front on Conti 4 seasons & Ksyrium SL’s. Im 79 kilos. More than the gauge I rely on visible tyre splay once I’m riding.  In my mind, which admittedly can be a lonely place, that splay equals greater friction to overcome and wasted effort. Psychologically, if I see that splay I convince myself that’s why I sucked on the last climb. So I get the pump out of my jersey pocket…

  26. @tessar

    @frank

    @Oli

    I’ve got a couple of decent pumps (Silca and SKS) but what used to drive me nuts was the chuck/valve interaction, so I sorted that out with this awesome Hirama pump head. If like me you ever get frustrated by poor clamping/valve security from your pump find one of these bad boys – you will not regret it.

    I love the Lezyne connecter but with all the valve extenders I use they do wear out (the threads wear out due to not going on squarely enough).

    I am going on a fucking mission to find one of those, that looks beyond fantastic.

    Or one of these:

    Now you’ve gone and done it !  I dont need one of these, but I WANT one of these, and I shall have one.

  27. @Oli

    I’ve got a couple of decent pumps (Silca and SKS) but what used to drive me nuts was the chuck/valve interaction, so I sorted that out with this awesome Hirama pump head. If like me you ever get frustrated by poor clamping/valve security from your pump find one of these bad boys – you will not regret it.

    You are such a little bitch. I never knew I needed one because I never knew it existed! And now I have bought one because I can’t live another day without one.

    Except I have to wait until some time between May 22 and May 28. Which seems impossible.

  28. @Oli

    I’ve got a couple of decent pumps (Silca and SKS) but what used to drive me nuts was the chuck/valve interaction, so I sorted that out with this awesome Hirama pump head. If like me you ever get frustrated by poor clamping/valve security from your pump find one of these bad boys – you will not regret it.

    I have to admit, this thing is a pleasure. I even just love how it feels etc. Such a great piece of equipment, which is not shocking since it costs as much as most pumps.

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