Marathon Plus Rolling Resistance?

Manc33
Manc33 Posts: 2,157
edited May 2013 in Road beginners
These Schwalbe Marathon Plus tyres say they go up to 115 psi on the tyre, I have had them that high (lol at the grip), but I am sure I found a graph/chart a while back that said the lowest rolling resistance happens when the tyre is at something like 80 psi for these tyres. I just don't know how that can be true, but then I am not a physics buff. :roll: Marathon Plus isn't the same as a normal tyre because of the strip it has inside.

Could that be true? You'd get less rolling resistance @ 80 psi than you will on 115 psi? It doesn't seem possible but I am sure thats what the chart said. I will try to find the graph... just thought if anyone knows people here will know this like the back of their hand. I weigh about average (165 lbs) and I am not carrying panniers or anything, just a rucksack with waterproof clothes so the only real weight being added apart from me is 2 water bottles.

Comments

  • dodgy
    dodgy Posts: 2,890
    Over inflated tyres (for the road conditions) results in a the bike skipping into the air every time it hits a bump. This costs energy as the bike is being launched into the air (maybe only a tiny bit, but it's happening). A tyre that is able to deform around small imperfections will mean less energy is being wasted.

    If the road is perfect (such roads do probably exist, but I haven't found them), then a tyre inflated to 115 and well beyond will probably be faster.

    Hope this helps.

    By the way, your autosig is bolleaux.
  • Manc33
    Manc33 Posts: 2,157
    I have noticed that on bumps when they are @ 115 psi having to pedal a bit more after a bump.

    I don't even know what to set them at. :roll:

    Gonna pump them to 115 psi and do my usual 20 mile run and see what the time is. Then I might put them down to 80 psi and do the same run the next day.
  • lawrences
    lawrences Posts: 1,011
    How very scientific...
  • Sprool
    Sprool Posts: 1,022
    its to do with hysteresis and elastic recovery of the rubber plus some friction between inner tube and tyre wall. Defornation of the tyre and tube soaks up energy which is felt as rolling resistance. Over-inflation makes tyre walls too rigid and may well increase rolling resistance, though you'd probably need calibrated instruments and a wind-free day on a very smooth road to notice much real difference.
    80 psi will give you a more comfortable ride though it sounds to me like not enough pressure. It depends on your weight and the tyre size.
    105 - 100 psi for 23's = about 95 psi for 25's to optimise rolling resistance for a 80kg rider. Theres a technical website and a chart somewhere that goes into a lot of detail about this but to be honest its nice out there and I'm off for a ride ;)
  • Manc33
    Manc33 Posts: 2,157
    I pumped them up today, they were on about 70 PSI lol. :oops:

    Yesterday @ 70 PSI:
    Distance: 19.99 miles
    Average speed: 12.6 MPH
    Time: 1 hr 34 mins 48 secs
    Max Speed: 35.8 MPH

    Today @ 115 PSI:
    Distance: 19.99 miles
    Average speed: 12.8 MPH
    Time: 1 hr 33 mins 21 secs
    Max Speed: 36.8 MPH

    I agree this isn't very scientific because of the wind and my own fatigue, but it seems quite a negligible difference considering one is 70 PSI and one is 115 PSI.

    12.8 MPH might be absolutely pitiful to most here on a road bike @ 115 PSI but for me it is a personal best over the above distance, 20 miles. :mrgreen:

    Saw a bunch of cyclists at the top of a hill today, I guess they had just rode up it and were getting a rest, there were about 8 or 10 of them and I thought hmmmm, I could stop and chat, ask them if I can join the club etc but hell, they are stopped there, no thanks! I cycle to get fitter, who knows why they are cycling. :roll: To some people it is just a day out I guess.

    Mind you my mate is like that when he says stuff like "I don't know why you bother having a bike computer" but he doesn't seem to grasp that constantly beating your own times and KNOWING you are is a motivational thing, you know for definite you're getting fitter and can see exactly what rate, how would I know I am getting fitter if I didn't keep track of it! I know, ignore such people. :lol:
  • rolf_f
    rolf_f Posts: 16,015
    This is how much rolling resistance a Marathon Plus has.
    0_edinburgh_transport_steam_roller_1960s.jpg

    Be nice to yourself and get a set of tyres that don't have concrete sidewalls. Marathon Plus will stink in terms of feel whatever pressure you run them at - no amount of puncture fear is worth ruining your ride running these things. It just isn't worth it. Eg try Schwalbe Durano - plenty of puncture resistance and they actually feel nice.
    Faster than a tent.......
  • exlaser
    exlaser Posts: 264
    first of i must say i hate punctures so i do use marathon plus on my commuter bike but i would not think of using them on my better bikes. if i were the op i would think about about using durano plus or conti four seasons.
    Van Nicholas Ventus
    Rose Xeon RS
  • Manc33
    Manc33 Posts: 2,157
    Nah I can't go back to punctures again. I tell you what, if I ever get one single puncture on the Plusses, I will go back to normal ones again.
  • declan1
    declan1 Posts: 2,470
    Manc33 wrote:
    Nah I can't go back to punctures again. I tell you what, if I ever get one single puncture on the Plusses, I will go back to normal ones again.

    Well, put a load of tacks on your driveway and ride over them. Tada - puncture! :lol:

    Road - Dolan Preffisio
    MTB - On-One Inbred

    I have no idea what's going on here.
  • rolf_f
    rolf_f Posts: 16,015
    declan1 wrote:
    Manc33 wrote:
    Nah I can't go back to punctures again. I tell you what, if I ever get one single puncture on the Plusses, I will go back to normal ones again.

    Well, put a load of tacks on your driveway and ride over them. Tada - puncture! :lol:

    This is good advice - you'll thank Declan in the long run if you do this! You might as well get a normal tyre and fill it with cement - you won't get any punctures and it will still feel better than a Marathon Plus!
    exlaser wrote:
    first of i must say i hate punctures so i do use marathon plus on my commuter bike but i would not think of using them on my better bikes. if i were the op i would think about about using durano plus or conti four seasons.

    No, no, no, no! Anything from Schwalbe with a 'plus' on is to be avoided. They are for terrified little rabbit types who panic when the 'p' word is mentioned! The standard Durano still has loads of puncture guard and weighs stacks less than the Plus. I use the lighter still Durano S for winter commuting and they are fine. Normally I manage about 2500 miles between punctures and those are usually my fault.
    Faster than a tent.......
  • roger_merriman
    roger_merriman Posts: 6,165
    marthon pluses have rather hefty side walls so you can reduce the pressures somewhat, used to run the 25mm on the last bike at around 70 psi (i''m 13 and half) too high and they are just wooden.

    They aren't that slow, but they do feel fairly dull so if it's your best bike i'd find others.

    I use various training tyres while it's fairly uncommon to get a puncture, with all the gravel etc they get cut up quite quickly.

    This said my wifes bikes over last 10 years on Marathon pluses, 20,000 miles no penetrative punctures. Had ones from ill fitted tyres and so on, but nothing got though the tyres.
  • cougie
    cougie Posts: 22,512
    They are absolutely bomb proof tyres. I've used them on my cross bike for adventure races - nasty terrain and not one flat.

    Now summer is here get a set of conti gp4000s. Brilliant tyres. Run them no higher than about 95 psi and you'll be flying.