tyre rolling resistance

[Blodwyn Pig]

Just looking at tyres, and Schwalbe Marathon Greenguard 37mm have a rolling resitance of 19.6 watts at 75psi but weigh 750 grams each!. Conti Gatorskins in 559 28mm have a RR of 19.3 watts  but at 120 psi, and only weight 250 gms each. I know that there are better tyres out there, but i can get the Contis quite cheap (£15 pair). Is it worth changing, as the RR is the same but weight significantly less, would the Conti's be significantly faster (on the track, as I wouldn't fancy riding 120psi tyres on Grunhilda on the potholed extremities of middle earth).  (Both tyres would be 559 on Streetmachine  'hilda btw.) Swapping tyres would mean 500g less per wheel, rotational weight, ie 1kg total 

Soat what point does weight overtake Rolling Resitance . Also Marathon racer has RR of 22.3 watts but a weight of 450 grams.?

[Kim]

Soat what point does weight overtake Rolling Resitance .

When you accelerate or climb a hill.

Also Marathon racer has RR of 22.3 watts but a weight of 450 grams.?

They're also fairly rubbish for punctures.  A middle-of-the-road tyre that's fairly bad at everything.


I feel compelled to point out that if you're attempting to save weight on a Streetmachine, you're probably doing it wrong.   

[Canardly]

Where on earth are you getting Gatorskins for £15 pair?

[mrcharly-YHT]

I'm an avid fan of the bicycle rolling resistance people, but personal experience suggests that a simplistic measurement of watts is far from the full story.

I have a choice of Marathon greenguard wired or vittoria hypers for my bike. RR tests say just a couple of watts between them.

In real life, they are totally different. The huge difference in weight affects not just riding uphill, but any acceleration. So going downhill - even a very short hill - the hypers are much, much faster.

I'm sure (because, physics), given a long hill of consistent gradient, that I'd reach a similar top speed on either tyre.

Real world riding consists of lots of little changes in elevation. The lighter tyres are easier for climbing, and accelerate much faster downhill. Faster overall.

[Kim]

But in the context of a BHPC track race, on some of the best quality tarmac you're likely to encounter, with little in the way of elevation change, I think the better approach is to find a tyre with significantly lower rolling resistance.  Which will undoubtedly be a light tyre anyway.

Schwalbe Pro One is probably the best currently available in 559, if you can get the bastard things to work (they don't tend to seat properly when fitted with tubes, which means you need a tubeless friendly narrow 559 rim).  I'm running a Conti Grand Prix on the back of the Baron on this basis.

[mrcharly-YHT]

I didn't know that smooth race tracks were the context.

Guess tubs won't work for downriders.

[Kim]

Guess tubs won't work for downriders.

Tubular tyres are a mystery to me, but after a brief google for 26" tyres and rims it looks like you're into the sort of unobtanium that makes tubeless look fun.

[Blodwyn Pig]

It's just that I'm a skinflint. I have a 559 'marathon greenguard', and a 559 'racer' (for the front) but a chance to buy a pair of 559 28mm Gatorskins  for £15,  got me wondering if they would be significantly faster as a 'punt' as I also have a 'spare 'set of 559 wheels that could be (race ready)    Not only would the tyres be 1 kg lighter, but the 26" rigid forks would be 1.2 kg lighter, also the Schmidt dynamo would go, as would the heavy 'Solid lights' front light.  So overnight the bike (in race mode  ) would be approaching 2.7 kg lighter. And be more aerodynamic.  I don't really want to spend squillions on fancy tyres, for the reasons of an experiment, and if I was THAT serious, then I would buy the Pelso Brevet on E-bay.

[Lightning Phil]

During a lockdown I did some back to back tests on some tyres 700 rear and 406 front.

Rear Vitoria Zaffiro 32mm and front Panaracer Pasela 37mm

Rear Schwalbe Surpreme 32mm and front Conti Contact Urban 32mm

The tests were over an hour , at a steady sub maximal heart rate , on a fairly flat bit of quiet country road, out and back as many times as possible in an hour.

The top combination was 2 km/h faster.  The Zaffiro is another cheap tyre, around £13 at Merlin Cycles.  Currently running Conti Ultra Sport III on rear, another cheap tyre and same rolling resistance as Grand Prix according the rolling resistance site.

[Kim]

Currently running Conti Ultra Sport III on rear, another cheap tyre and same rolling resistance as Grand Prix according the rolling resistance site.

But not available in 559

[Cudzoziemiec]

Where on earth are you getting Gatorskins for £15 pair?

Please let us know,

[fd3]

...on the potholed extremities of middle earth). 

Did not realise you lived in Brum.

[cycleman]

Just a quick query, if I run my conti 599iso tyres tubeless would I gain improved rolling resistance?.

[PaulM]

I'd go with the Gatorskins. I had a pair of 28-622 on a Thorn Audax and they impressed me. Also the RR results were for a 37-622 GG and are something of an anomaly. I've had 37-622 GG on a Spa Tourer, 32-559 GG on my Nazca and 40-406 GG on a Tern. None of them felt quick like the Gatorskins did.

I have a folding 32-559 Panaracer Pasela PT on the Nazca which is my favourite all-round 559 tyre. Expensive but the wired versions can probably be had for a lot less.

[woollypigs]

On my Azub six I have ridden with Schwalbe Marathon Racer and Continental Double Fighter III. The conti had a bit more grip on non tarmac stuff. The main difference I noticed for the style of cycling I do is how much air there is in the inner tube.