26" 'fast' tyre recommendations?

[mercalia]

Maybe my Marathons go so well as they were about 3 years old stored away before I used them and now 5+ years old and barely worn, only the rear losing the top central very thin groove.

[Brucey]

in this context 'squirm' refers to the behaviour of upstanding regions of the tread. Yes it can affect grip, but it needn't do this greatly whilst still creating additional drag. You can see how this happens by considering the way hysteresis works in rubber. This curve



shows roughly how rubber behaves under load. (Real rubbers vary a lot, but the curve will be of the same general form)
The energy absorbed by the rubber is in proportion to the area enclosed by the hysteresis curve. You can see that if you apply a small load, the area within the curve is small. However, over a certain load/extension, the energy absorbed per unit volume of rubber becomes disproportionately large.

So if you have a thin tread without grooves in it, you will be straining the least volume of rubber the least amount. By contrast if you have a thick tread with lots of grooves in it, the upstands 'squirm' and you will be straining a lot more rubber to a far greater extent, and this absorbs a load more energy.

The devil is in the detail; rubber compounds vary and the exact shape of the tread blocks (in the same rubber) makes all the difference, both in terms of Crr and any loss of grip through squirm.

I'd expect the Crr of RPs to get better and better as the tread wears off; the carcass is known good and its just the tread rubber that is letting the side down Crr-wise. It might even be worth shaving them when they are new.

I think that the relatively good Crr of the Schwalbe greenguard tyres is due to the highly elastic (non-hysteretic) nature of the rubber underlying the tread. Even though it is thick, it sees little strain (no grooves) and its elastic nature means it absorbs little energy. Generally you can't use that kind of rubber in the tread itself because it will wear too rapidly, but some racing tyres are built with tread rubber that is highly elastic and the high wear rate is acceptable if you have a 'one race' tyre.

cheers

[reohn2]

Brucey
I can't disagree with any of that,but I'm a practical man,who deals in the reality of daily life andI do agree that RP's aren't as fast as Hypers and aren't as comfortable.
I was trying to clarify the term 'squirm' which to my mind is slimy,wriggly,wormlike.
The only tyre I would describe as squirmy were a pair of Conti Top Touring 2000's that gave the impression of a slow puncture in the wet,they squirmed so much

It might even be worth shaving them when they are new.

Or buying Hypers

[reohn2]

Maybe my Marathons go so well as they were about 3 years old stored away before I used them and now 5+ years old and barely worn, only the rear losing the top central very thin groove.

I/we(on the tandem) rode Marathons for years HS308's and 368's and thought the world of them,don't fix what ain't broke and all that.
But when 368's wore down quickly on the back of the tandem,I began to look out side the box,which lead me to where I am now.
Please don't think I'm behind condescending.But knowing what I now know a Schwalbe Marathon wouldn't get anywhere near any of my bikes these days.
Marathons are a reliable go anywhere bombproof tyre but they're sllloooowwww and uncomfortable compared with either Randonneur Pros and even better,Voyager Hypers,
Give 'em try,as Tony the Tiger used to say they're GRRREATTT!

[Brucey]

It might even be worth shaving them when they are new.

Or buying Hypers

but can you get them in a 559 fitment?

BTW 'squirm' (as I have described it) is the term normally used for that behaviour by people who design, manufacture, test, and sell tyres.

cheers

[niggle]

It might even be worth shaving them when they are new.

Or buying Hypers

but can you get them in a 559 fitment?

cheers

Nope but you can get Vittoria Rubino Pro Slicks in 26x1.5" and they are the next best thing to Hypers IMO, certainly they are not as thick and heavy as the Randonnueur Pros are described as being. They are folders with a 120tpi casing: http://www.wiggle.co.uk/vittoria-rubino ... GBP&dest=1

I have used Conti Sport Contacts in 26x1.6" and they are not bad but not as good as the Rubino Pro Slicks.

Previous threads:

viewtopic.php?f=18&t=93813&hilit=rubino

viewtopic.php?f=5&t=93847&hilit=rubino

[reohn2]

but can you get them in a 559 fitment?

Oops! forgot we were talking 559

BTW 'squirm' (as I have described it) is the term normally used for that behaviour by people who design, manufacture, test, and sell tyres.

cheers

I'm sorry for carrying on with this but I didn't want people thinking RP's were a bad tyre because they were 'squirmy' in a wiggly fashion.

[mercalia]

Maybe my Marathons go so well as they were about 3 years old stored away before I used them and now 5+ years old and barely worn, only the rear losing the top central very thin groove.

I/we(on the tandem) rode Marathons for years HS308's and 368's and thought the world of them,don't fix what ain't broke and all that.
But when 368's wore down quickly on the back of the tandem,I began to look out side the box,which lead me to where I am now.
Please don't think I'm behind condescending.But knowing what I now know a Schwalbe Marathon wouldn't get anywhere near any of my bikes these days.
Marathons are a reliable go anywhere bombproof tyre but they're sllloooowwww and uncomfortable compared with either Randonneur Pros and even better,Voyager Hypers,
Give 'em try,as Tony the Tiger used to say they're GRRREATTT!

The Brucey chart put the Marathons near the top of the list only bettered by the hypers? My 368's so far lasted 2500+ miles the rear just showing a bit of wear so dont know why you think they wear easily, how many miles do u expect? I dont find them uncomfortable( 1.75" x 559) & your slooooow is out of proportion to the percentage comparision - should be one less "o"....atleast. Shame u cant get 1.75" pros I might get a pair if they were cheap. Who the **** is Tony the tiger?

[reohn2]

The Brucey chart put the Marathons near the top of the list only bettered by the hypers? My 368's so far lasted 2500+ miles the rear just showing a bit of wear so dont know why you think they wear easily, how many miles do u expect?

I never rated them as a fast tyre,wear rates were 2,500miles on the rear of the tandem max.Solo 4,500miles

I dont find them uncomfortable( 1.75" x 559)

Only rode them in 32's and 37's,so your's will be more comfy

Who the **** is Tony the tiger?

I'm showing my age:- https://en.wikipedia.org/wiki/Tony_the_Tiger

[Bmblbzzz]

Put a tiger on your rim!

[fast but dim]

Well, the Vittoria Randonneur pro's are on... eventually Folding tyres are a right pain to fit.

Initial impressions are good. The bike ( a Dawes Sardar picked up from a wanted ad) rolls well: surprisingly well for a 26" wheel bike: certainly not like an MTB

Any pointers for tyres pressures for an all up weight of just over 100kg with 1.5" tyres? I've put 50 front, 60 rear. I know I could google it, but I know how much you all love discussing rubber.

[Brucey]

at ~37-38mm width, kg = psi is about right on bad surfaces.

So 45kg front load ,55kg rear means 45psi front 55psi rear pressure is a good place to start.

If the road surface is good, you can go up a bit from there, but a little extra speed will cost you a fair wadge of comfort...

cheers

[reohn2]

For 40mm actual size IMO Brucey's about right.
But a bit low for 37mm actual size I run mine with a 98kg load 40%front 60%rear distribution @45psi f 65psi rear.

[niggle]

Bit late now but the Rubino Pro Slick 26x1.5" I mentioned previously is 39mm on a 15mm rim, weighs 420g, with 150tpi carcass and totally slick. I would think it is even quicker and more comfortable than the Randonneur Pro...

[markjohnobrien]

I've bought some randonneur pro also for my Dawes One Down (earlier version of Sardar) and will fit on Friday as the Schwalbe Marathon XR are bombproof, never had a puncture, but not very comfortable.