Schwalbe air plus

[ourclarioncall]

Anyone tried em ? 70% thicker , holds air in better/longer

https://www.ebay.co.uk/itm/Schwalbe-Sv-13AP-Air-Plus-Bicycle-Hose-26-40-62-559-/393228643493?_trksid=p2349624.m46890.l49286

[PH]

I wouldn't find it any advantage.  I check tyre pressures regularly, air loss from the tube is just one reason, so even if I knew there would be none, I'd still check.  I like Schwalbe lightweight tubes, I can't feel the weight difference, but I'll accept the tested advantage, they may lose a little more air, but it's never been an issue, they don't seem to puncture any more often and the spare packs smaller.  They also come in a size that I can use on several bikes. They've been on offer at SJS for a while, so I probably have enough stock to last a few years (Though I don't get through many).

[JohnR]

It's about a month since I last adjusted the pressure in my inner tubes (one is a Schwalbe extra-light and the other the normal type) and I don't feel that they are in need of more air yet. However, air loss is less noticeable with high volume 50mm tyres and at 30 psi the leaks won't gush air as quickly as with much higher pressures. I feel I'm likely to lose more air in using a pressure gauge to check the pressures than will leak through the rubber in a month. A dose of Doc Blue might also be helping and is probably more use than much thicker (and heavier) rubber inner tubes. I also believe that thicker tubes also increase tyre stiffness and worsen the ride quality but have yet to find tubeless tyres that will happily seal on my rims without needing a bigger air tank than the one I bought. The bike came with Schwalbe G-One Speed tyres fitted by SJS but I took them off in the autumn as I wanted more grip for the winter and I failed to get the replacements to seal despite much huffing, puffing and cursing. And if one can't succeed at home then there's minimal chance of succeeding while touring.

[PH]

It's about a month since I last adjusted the pressure in my inner tubes

I'm a little surprised by that.  My daily ride gets the pressures checked weekly and usually requires a couple of PSI. I probably don't need to do it that often, but it's the sort of routine that saves it getting too low and with a decent pump is quick enough.  My least used bike might go a few weeks between rides and will always need topping up.  The change to extralight tubes hasn't altered this in any significant way.  I use the SKS digital gauge, the loss of air in using it is minimal as long as you're careful.  It's easy to check, I've done so and it took a few uses before it registered one PSI less, I've forgotten how many, at least five.

[Matt2matt2002]

Let's discuss pressures.
More in the rear?

[JohnR]

It's about a month since I last adjusted the pressure in my inner tubes

I'm a little surprised by that.  My daily ride gets the pressures checked weekly and usually requires a couple of PSI.

As I noted, I wonder if the Doc Blue sealant does reduce seepage through the tubes as well as reducing the risk of puncture problems plus losing a few PSI on a fat tyre is less noticeable. I checked today and suspect that the back tyre has lost a few PSI but it doesn't look or feel soft when on the bike. I'm planning to do a tyre swap in the next week and won't fiddle before them. Yesterday I bought a pair of Marathon Almotions for £31.99 each https://www.wiggle.co.uk/schwalbe-marathon-almotion-road-tyre . I think they were the last of old stock as the new ones are fatter https://www.wiggle.co.uk/schwalbe-marathon-almotion-evo-tyre but at the price I felt they were worth trying. I've also got some 42mm Marathon Supremes waiting to be tested. Whichever tyre does the better job of smoothing rough road surfaces will stay on the bike for the summer.

[ourclarioncall]

Let's discuss pressures.
More in the rear?

Good question

[JohnR]

Let's discuss pressures.
More in the rear?

Good question

And my answer is yes as the majority of the weight is on the back tyre.

[Danneaux]

In my case, it comes down to about 60% of my weight on the rear, 40% in the front on most of my unladen bikes when I am in my preferred riding position with a 45° back angle and slightly bent elbows for shock absorption. Tire pressure varies accordingly. See:
http://thorncyclesforum.co.uk/index.php?topic=3798.msg37707#msg37707

There's a lot of rich information in the archives about tire pressure and even F/R variations; just do a search for "pressure" (no quotes).

Best,

Dan.

[ourclarioncall]

Andre

So , just to clarify , you recommended keeping both front and back at the same pressure as it is safer and gives better handling ?


I think I remember you saying your in Ireland? Where about? I had my honeymoon in Ireland many years ago and I remember the roads being pretty bad at the time

[Andre Jute]

So , just to clarify , you recommended keeping both front and back at the same pressure as it is safer and gives better handling ?

So as not to hijack your thread, which is on a different subject, I've opened another thread to discuss differential inflation regimes, at:
How to tune a bike's roadholding & handling to be sharper
http://thorncyclesforum.co.uk/index.php?topic=14168.0

I just forgot to remove my post here, and have now done so. I'll answer your question there.

I think I remember you saying your in Ireland? Where about? I had my honeymoon in Ireland many years ago and I remember the roads being pretty bad at the time.

I'm in West Cork, in the countryside, not too far from Cork City.

[PH]

Play around with it, find what you like, just please don't be telling others they're wrong! 
It's at most 50% science and the rest a mixture of fashion and personal preference, so what?
I like to have a wider tyre at the back than the front, I currently have on my 700c bikes - 28/32, 32/35, 35/40, 2"/2.15", though none of them actually measure what they say.  If you start with the idea that the rear tyre has a different job to do than the front, why would you not choose each on their own criteria?  The size differential also covers the pressure differences, using the 15% drop formulas those sizes are about the same pressure on a 45/55 to 40/60 weight distribution, though you have to be aware that that distribution is fluid.

[Andre Jute]

It's at most 50% science and the rest a mixture of fashion and personal preference...

I know any number of tyre engineers who will be highly flattered at your assessment of their "scientific" grip on their black art.

[PH]

It's at most 50% science and the rest a mixture of fashion and personal preference...

I know any number of tyre engineers who will be highly flattered at your assessment of their "scientific" grip on their black art.

I wish this discussion hadn't been split across two threads, and also that you'd speak plainly, is the above intended as sarcasm? I haven't in any way disputed the science, just pointed out that it isn't all there is to the tyres we choose, as you seem to have said in the other thread, so where are we?
How about this one - You pump your tyres up really hard and go out for a ride and the bike feels faster, probably due to the direct feedback from the road surface due to less cushioning.  it feels faster, so you're inclined to push harder, you get home and there you have it, the computer tells you that with harder tyres you are faster 2+2=5
I've fallen for that myself, believing one bike was faster than another and having the data to demonstrate it - until I got a HR monitor and could see I was putting 15% more effort in for a 5% gain...
Or maybe the scientists could tell us why the tan wall tyres that Panaracer have struggled to sell for the last twenty years are now so sought after.  Or why the thirty year old science about contact patch shape and size has just been rediscovered?
Just to be clear - I know the tyres I like, better than I know the reasons why I like them.  That's fine, as is someone telling me they like their 25mm, 130psi tyres.  If they didn't entirely like them, I might suggest they try something else, but I'm not going to tell them they're wrong because the science says so. 

[Andre Jute]

I wish this discussion hadn't been split across two threads, and also that you'd speak plainly, is the above intended as sarcasm?

This forum is a mine of good information but the problem is mining it. I'm starting to have some sympathy with the thread subject purity police, so I'm trying to do my bit to open new subjects in their own threads rather than in the other-subject threads that suggest the new subject. Apologies if in this case it caused an upset.

No sarcasm. I was merely pointing out that many tyre engineers agree with you, that we don't know everything yet.

My article in the other thread isn't so much about the 15% drop at the rim; it is about using your pump to tune the handling of your bike at the sort of speeds that some of us now attain only on downhills.