26 x 1.5 or 700 x 28 - which is more efficient?

[southfields andy]

Hi - I want to buy a bike for audaxes, leading up to PBP. I'm not sure whether to go for one with a 26 inch wheel or 700.  Leaving comfort, puncture-proof etc aside for the moment - I'm after the most efficient combination of weight/rolling resistance/aerodynamic - at average speeds of 13-14 mph.

I know that 26 x 1.5 rolls better than 700 x 28 - but how about aero and weight?  I'll never be a superfast rider, but even at an average speed of 13-14 mph on a ride there will be times when I'm doing 20 or more - so should aero come into it?

what do people think?

andy

[MikeT]

I'm also aiming for PBP. Last year I decided that my Orbit Exp. (brilliant bike) was the one for me. But after a few rides getting no where, I'm back on my normal 700's. Think the Orbit is great and ideal on the country lanes by me, but just get the feeling on 700's I'm actually getting further for the same effort?

[MikeT]

I'm also aiming for PBP. Last year I decided that my Orbit Exp. (brilliant bike) was the one for me. But after a few rides getting no where, I'm back on my normal 700's. Think the Orbit is great and ideal on the country lanes by me, but just get the feeling on 700's I'm actually getting further for the same effort?

[PH]

quote:Originally posted by southfields andy


  Leaving comfort, puncture-proof etc aside for the moment - I'm after the most efficient combination of weight/rolling resistance/aerodynamic - at average speeds of 13-14 mph.


andy

I don’t think you can leave comfort out of it
I have a touring bike that I run on either 25mm road tyres or 32mm touring tyres.
On a flattish 20 mile ride with the 25 mm tyres, my average speed will be 1.5 – 2 mph faster than the same run on the touring tyres.  On a 200k Audax there’s little if any difference in overall speed, but I’m far more comfortable at the end using the touring tyres.
As for whether 26” or 700c wheels are faster, there are people who would argue for both.  You’d need two bikes that were identical in all other respects, to make a fair comparison.  I doubt there would be much difference and I certainly wouldn’t choose a bike on wheel size.

[Alders]

You aint going to find a lot of flat road on the PBP to test a wheels areo properties, believe me.  Uphill tires wont make much difference, if you want to shave a bit of time off, get some tires that grip well to take advantage of the downhills and some decent lights so you can do it in the dark.
It’s a hard ride, don’t let anyone tell you otherwise, theres no substitute for training.

[MikeT]

Trying to put us off? Have to say, did an early morning ride last week, 6am, of 31/2h hours. Slept in front of the TV on and off all day and felt really tired about 7pm and suddenly realised I'd still be riding to finsh 400km! Is PBP really hilly?

[Alders]

quote:Originally posted by MikeT


 Is PBP really hilly?

Well it aint the Alps, the hils are mostly short and steep.  Its usually quoted as 10,000 meters of climbing. Found a route profile
http://www.seattlerandonneur.org/info/PBPElevationProfiles.pdf

I wouldn't want to put anyone off, its a fantastic ride, but it would be foolish not to know what you were letting yourself in for.

[rogerzilla]

I'd go for 700c.  26" tyres tend to be very heavy (S-Licks, which are among the lighter ones, are 430g), which negates any weight saving from the smaller rim, and the bigger wheels roll better on rough roads.

[Wingnut]

Sorry to disagree, but having used 26" wheels (1.5's mostly) now for the last three years for touring and club runs IMHO they are superior in comfort, puncture resistance and give a good feeling of reasurrance when things get fast in a group (25+ mph for the return leg on most Sunday spins). You just know if someone fails to call that hole in the road, your not going to be ringing the wife for a lift home and spend the rest of the week rebuilding a wheel. I have to admit to not being weight consciuos, I do not festoon the bike with every gimmik going, but I do like a saddlebag on the back with enough stuff for the relevent emergencies (Drives the other lads mad []) so the extra weight of a fatter tire is no bother, I use fairly thick tubes as well, better pinch resistance and they don't leak air easily, around 10 psi per month for the current ones.
Regards David.

[Colin]

I commute as fast on 26 x 1.75 (Mavic 721 & Continental Travel Contacts) as I did on 700c x 32 (Mavic Module 4 & Continental Top Touring) and the ride is much less disturbed by road repairs.

I had one puncture in about ten years with the 700c Top Touring. The Travel Contacts did 4400 km without a puncture, until last Wednesday (shard of stone) and this Monday (carpet tack). I had hoped for the same reliability  as Tilmann Waldthaler:
“The Continental Travel Contact is the best thing I have ever had on a bike. I have put two new tyres on the bike in Boulder Colorado and have travelled 12.000 Kilometers to from Boulder to La Paz with one puncture. To do this distance with only one puncture on route, it is a bikers dream…. I can honestly recommend the material used on the trip”. 

[rogerzilla]

26 x 1.75?  That's massive!  I suppose it depends on your style of riding.  I tend to hustle along at 18-20mph and the Nomad has to substitute for a racing bike in winter, hence the 52/42/26 chainrings.  I'm about to rebuild the hubs onto DT XR4.1 rims because narrower tyres just don't sit well on those steamroller Rhyno Lites.

[Colin]

26 x 1.75 is massive (about 44cm), but there's little choice of slimmer 26" tyres at the moment.

In France, for 700c road touring, the shops tend to not recommend anything wider than 700 x 23.

[Wingnut]

quote:Originally posted by Colin

26 x 1.75 is massive (about 44cm), but there's little choice of slimmer 26" tyres at the moment.

There is a good selection of 1.5's...The Continentals are good (using them at the mo). Prices to suit from cheapies for €10 to lightweights (relatively speaking) for 3x the price.
Regards, David.