Bike: canfield yelli screamy 29″ 130 revelation fork. Aimed at having single track fun rather than xc whippet. I use another bike for anything lairy. This is my forest or moderate trail centre go to bike.

Wheel set 1. Hope hubs on 38mm light bicycle carbon rims. Trax fatty 2.8 front, 2.8 wtb trailblazer rear.

Wheels set 2. Hope hubs, flow rims and 2.35 Hans damf front, 2.2 ardent rear.

Course: dudmaston xc. 3.5 Mile lap. Natural single track, sandstone/pine needle with interspersed areas of loose, wet mud at some tight bends. not particularly steep up or down, few jumps and a few man made berms. Lots of roots.

Format: 2 visits (this Sunday 29″, last 650b+). Lap 1 reasonably quick low 80% mhr, lap 2 slow 70%, Lap 3 flat out, Laps 4 and 5 mid 80% mhr.

Weather and conditions: relatively similar. Muddy bits were a bit worse today. So the 29″ had a slight disadvantage.

I fuelled the same, had the same crap preparation for both visits (up at 6, riding by 7).

My conclusion:

The 29″ is generally quicker. 3.5 Mile lap, flat out showed a 30 sec advantage to the 29″. This wasn’t as much as I thought If I’m honest. I had a minor fall on the 650b quick lap which nicked at least 10 secs.

On the climbs and flat the 29″ felt a lot faster. On the descents, and twisty switch back sections the 650b felt far more assured (although strava says I was still quicker on the 29er for those segments)

Loose mud, both were not great. 29″ squirmed more easily and bit. 650b squirmed less, but did wash out on me a couple of times.

Roots, 650b was far better.

What was interesting was that flat out the 29″ was slightly faster, but on the later Laps when I was cruising the 650b was quite a bit quicker than the 29″. (Circa 90 secs).

Although this is a pretty soft course. My backside preferred the 650b+. The 29″ front wheel turned much quicker, and felt more direct.

Although quicker pretty much everywhere, the 650b+ was far more capable on the couple of fast descents (which are not Strava segments on there own).

I was hoping on this I’d know which wheelset I’d keep/sell. Riding the 650b+ is more fun and will suit my local forest rides, so I’ll probably keep those and use the 29″ for when I do any type of endurance event.

Not really a bombshell, sorry.

Interesting. I have the same dilemma, in that I’m trying to decide which wheelset to go for(for a frame I don’t have yet). Same sort of conditions/trails/bike/etc – even have a bigger bike for lairy stuff.

Was kinda hoping you’d have a definitive answer for me 🙂

Are you racing, you know, to win stuff?

If not, get on, ride, smile, job done. IMO, the difference between any wheel size is too small to measure unless you are a world class xc racer……

I’m opting for keeping my 29er a 29er and buying a fat bike. 8)

Funny, I was going to buy a fatty but have opted for a b+ wheelset to go in my beloved Yelli Screamy.

As for speed, I reckon 29 is almost always going to be faster for a rider willing to pay the discomfort price. I’m old enough now that my back will really appreciate the softer b+ ride, and I found it a it more ‘fun’ too. Fun != fast for me.

@alex do you find that tyre a viable alternative for winter-front, given that’d we’ve pretty much concluded a Purgatory won’t fit in Revs or Pike?

Riding for fun, not to win.

I’m better at stuff pointing down than up. I ride anything from bmx to road bike.

Trax isn’t good enough for winter but nobby nic should be out soon

I think I read the 2.8 Nic ‘comes up big’ so it may not help us. We’ll see.

Bugger.

http://reviews.mtbr.com/scott-launches-27-5-plus-bikes/p7190001

“This 2.8 Nobby Nic is bigger than some existing 3.0 tires.”

“Seeing the bikes in person, we were surprised to see that their 2.8 tires that sit on 40mm rims look huge. They are about the equivalent of most manufacturer’s 3.0 tires since the tires have generous volume and there’s substantial knobs on the Schwalbe Nobby Nics. So our initial concerns about the 2.8 tires not being big enough have been appeased.”

Obviously that’s not conclusive, and there’s clearance there on some kind of Fox fork.

Also it makes no sense to me for Schwalbe to make the same tyre in both 2.8 and 2.0 unless 2.8 was intended for backwards compatibility.

alex – very useful test.

Informally Ive had much the same feeling from mine.

29er, rocket rons, swapped for DL31 rims with TB2.8″

A lot of fun, esp in the dry, great comfort form the fatter tyre.

Built up a gryphon a week a go straight on to the 650b+ (put the 29ers back in the Ti29) and whilst it was fine, it’s sloppy/leaf mulch out here at the moment, and it felt that I wasnt getting the positives from the 650b+ in these conditions. SO have just moved the 29er wheels to the gryphon, and put the 650b+ back in the ti29.

Will test the gryphon with 29ers for the first time maybe tonight.

I think the trailblazer is a very good rear tyre.

I wasn’t sold on the Trax fatty, but actually it seems it was quite good up against a meaty Hans damf

based on the tread at least, the Trax has to be better than the Trailblazer, which looks very much like a ‘designed in California’ tyre’.

You lost me when you mentione umston…
Eit.
The n the seem to hve stoppe working on my keybor. 😆
nyone recomen new keybor or me?

You need to fix your any key.

ssstu, splashed anything on your keyboard lately ?

my keybor is jizz free.
mybe i cn lube the n keys with some of it though. 😕

I was thinking maybe a large beaker of some sort for rinsing it out ?

Brilliant a quick lube up and it’s working again.
*No beaker required.*

Bike pron to the rescue.

Now, where were we?