So is it 26 or 27.5"

[brocklanders023]

Re:

To be fair I was pretty hammered when I offered the short response although I stand by it. I'm certainly not offended and agree choice and opinion are a good thing but if the opinion offered is clearly wrong to be surprised if it gets questioned

From memory I demo'd a Trek Fuel, Santa Cruz Superlight, Giant Reign, Marin Wolf Ridge and some Scott or other when I got the 2010, a Santa Cruz Tall Boy LT, 650b Orange 5RS, a full suss Niner, Specialized Camber and another Trek when I got the 5 29. Didn't bother with the Segment as it was spur of the moment for a good deal. I've obviously tried mates bikes over the years too so think I've tried a fair few different systems. To be honest some of the quirks that people don't like about single pivot are the reason I stick with them. I prefer the bike to be talking to you rather that just flattening everything out.

 

[ultrazenith]

I have to say those single pivot Oranges look good to me, and it's nice to see Orange ar still going strong when so many other brands from back in the day have gone bust (e.g. Raleigh).

If I remember back in the 90s, I sort of lusted after Orange bikes but they always seemed slightly over priced to me, compared to bikes at the same level from other brands. Yes, they were well specced and looked very clean, but the frame and components were all far-east mass produced stuff just like the other big brands, so I never felt it would be worth paying a premium for an Orange. Orange were always a bit slow to modernise their bikes, although perhaps this is just in a superficial sense, because I remember they were the last serious brand to abandon 1" head tubes and threaded steerers.

Nonetheless, I'd gladly have a top of the range Orange XC FS bike, not least because round my way it'd be very exotic.

Getting back to 26 vs 650b, I would like to know whether having a larger diameter is more important for the front or rear wheel. It's a lot easier to get a wider tyre on the front, so in theory you could have something like a bomber Z2 with 70 mm travel up front, with a 26x2.5" tyre squeezed in there (virtually the same as 650bx2.0" diameter). Someone correct me if I'm wrong, but the front wheel should then roll as well as a 650b, or maybe slightly better given the width.

I have a hunch that it's the front wheel that's more important to be fast-rolling, for the same reason that adding front suspension gives a much bigger speed boost than adding rear suspension - if the front wheel can get through the rough stuff, the rear wheel follows.

Anyway, I'm planning to test this by building up a spare frame with 26x2.35 and comparing strava times against the same bike with 26x1.8. The outer diameter difference should be about as large as the difference between 26 and 650b, so if makes a big difference, my strava times will show it.

 

[ultrazenith]

On the topic of wheel size speed comparisons, this guy (Clint Gibbs) has done an interesting 26 vs 29 test, and concludes his 29er FS is around 1-4% faster than his 26 FS Anthem. That's just the raw numbers, without correcting for heart rate etc. It's just one guy, testing two bikes, but I find it more trustworthy than GMBN's covert marketing videos:
https://www.youtube.com/watch?v=T1WA-4ASr0g
(This tallies with the only attempt to do a scientific test, that I know of, which found a similarly small difference in XC speed between 26 and 29, around 5% if I recall correctlly).

Looking at values for tyre rolling resistance (RR), it looks like tyre choice (and going tubeless) probably has a bigger impact on speed than wheel size.
https://www.bicyclerollingresistance.com/mtb-reviews
https://www.bicyclerollingresistance.co ... utyl-tubes

In my case, I output something like 150 W on a typical climb. Differences in RR between tyres can be 5 W or even more, and going tubeless can reduce RR by about 5 W (depending on pressure etc.). Putting this in context of speed, if I got faster rolling tyres I might reduce the RR by 5 W per wheel (10 W for 2 wheels, corresponding to a 7% speed increase), and by going tubeless I might reduce the RR by a further 5 W per wheel (another 10 W), in total I might trim 20 W off RR like this, giving me a 13% increase in speed on pedalling sections (climbs and flats, where most of the time is spent anyway).

To be honest, I now suspect the reason we retrobikers report huge speed increases (I've read of XC speed increases of up to 30% from some people, which I don't doubt) is because when we move on from our retrobikes and buy a decent 29er (or 650b), the larger wheel helps slightly, but it's the other technological improvements that give the real speed boost: better, faster rolling tyres, tubeless, excellent suspension design - things like that.

Compared to buying an entire new bike just for the bigger wheels, fitting a set of fast rolling tubeless tyres is pretty cheap (about 100 gbp?) and should give a proportionally bigger increase in XC speed. Other improvements, like bigger wheels, top flight FS, carbon everything etc., will probably get you another 5-10% if you do them all and are willing to spend a few grand.

But I might be completely wrong...

 

[cce]

Looking at values for trye rolling resistance (RR), it looks like tyre choice (and going tubeless) probably has a bigger impact on speed than wheel size.
https://www.bicyclerollingresistance.com/mtb-reviews
https://www.bicyclerollingresistance.co ... utyl-tubes

a lot of people are missing this part.

There's a world of difference between my same-size Schwalbe Racing ralph (noodly XC tyre) and Hans Dampf (all mountain tyre). Bigger tyres are generally more heavily treaded, with stickier compounds

 

[tintin40]

I know this i wished i'd recommended a 26er from crc.co.uk and not a 27.5 :facepalm: As they have a good choice of 26er for his needs. But no i said go for a 27.5 Lucky his wife took no notice and bought a 26er I have removed the sales man's mind control hat. 26er's rule.

 

[cce]

buying a brand new 26er is batshit mental, and i say that as someone who is cheerfully cpaitalising on 26er worthlessness

 

[ultrazenith]

buying a brand new 26er is batshit mental, and i say that as someone who is cheerfully cpaitalising on 26er worthlessness

I hope to find myself a 26er Giant Anthem in my size one of these days.

 

[brocklanders023]

Re:

I couldn't really tell you which is fastest between my 650b ht and 29" fs. Strava suggests they're similar but I've never really done back to back testing and have no plans to start!

They certainly feel different though and lead me to ride in different ways and pick different lines. As I've mentioned before, the 29er feels like a puppy straining at the leash, always trying to pull you along where as the 650b likes you to make the choices for yourself but rewards when you do. It's easier to chuck about for sure.

As for 26", my last modern one was far slower than my current bikes. It's hard to compare though as it had noodly suspension, narrow-ish tyres and geometry that I'm not used to. I'd imagine a modern 26" wouldn't be too far off the pace.

 

[tintin40]

buying a brand new 26er is batshit mental, and i say that as someone who is cheerfully cpaitalising on 26er worthlessness

true the 26er's on offer are not to a high standard. But if you don't need a top level machine. Then not a problem But if like me a bike snob then this would be a top quality buy

https://www.dulight.fr/en/47-26er

 

[cce]

buying a brand new 26er is batshit mental, and i say that as someone who is cheerfully cpaitalising on 26er worthlessness

true the 26er's on offer are not to a high standard. But if you don't need a top level machine. Then not a problem But if like me a bike snob then this would be a top quality buy

https://www.dulight.fr/en/47-26er

decent forks are getting harder to find, and the best new tyres aren't coming out in 26 though. You'd be mad to buy it over the 650B version