It’s on a 40mm rim and the shoulders appear to be quite steep. I think it would maybe work better on a wider rim (hugo etc) to slacken the shoulder angles. It might self steer less.

Not too many tyres out there to play with, I want to try the maxxis offering.

Out of interest what pressures have people tried? I’m 11st 3 and have used 16 psi front and 20 rear, but I might up the front to try and reduce the self steer.

Ive not been out this week to have more of a play with pressures, only a rip round the garden. It’s amazing how nimble the bike feels for tight turning.

I’m more like 17st and running 15-18psi front and 20-25 rear.

Cheers nemesis.

I’ve had a play tonight and I found the self steer was being triggered at about 11psi, above that it was ok. The shape of the tyre appears to have changed shape a little, maybe stretched and the effects seem to be less

Nemesis, you running tubeless with those rims and pressures? Currently have same set up but with tubes (although haven’t ridden yet due to broken shoulder blade 😥 ).

Forget my last ^^^^^^^^. Stupid question!!!! 🙄

No stupid questions 🙂 (yes, tubeless)

[url=https://flic.kr/p/xosNFY]image[/url] by niksnr, on Flickr

Charge Cooker (steel), Manitou Tower fork, SS DS25 rims and WTB TB’s 2.8. First time tubeless. Was worried when the rim was leaking air on the seam on first inflation but seems to be holding well now I’ve added sealant and done the usual shaking like a madman! There’s loads of clearance on rear but wouldn’t want any wider rim on front as Tower is not so generous.

Mine leaked a bit at the seam on the first ride too. It’s been fine since though. Your charge looks good though. It’s amazing actually how normal it looks and how skinny standard 29er wheels look.

I went out on standard 29er wheels today to compare – did the same route as at the weekend. According to Strava there’s basically no difference in speed on the flat/climbs (and again, this is borne out by several rides) – certainly not enough that you’d notice (I did set a PR by 2 seconds over the PR I set at the weekend on a 7 minute climb today) unless you’re a serious racer.

I really noticed the difference DH though – It’s the first time I’ve ridden an mtb without b+ wheels for at least a month and it felt really quite sketchy on the front even though I was riding my much more capable bike (lighter, dropper and front sus).

It’s made me think that I might actually change my front 29er wheel for a b+ one permanently

That reads as if you had two different bikes, not the same with 2 different wheels. How much was the wheels and how much the bike do you think?

Yeah, two different bikes so it’s far from scientific but the point is that the more capable bike which I rode today (lighter, front sus, 29er wheels, dropper) was only fractionally quicker on the climb and markedly worse on the DH.

I’ve also ridden both bikes with 29er and b+ wheels and again, don’t notice any difference on the climbs/flat.

Again, not scientific but for me, showing (along with many other rides) that b+ wheels don’t seem to be inherently slower on the non technical stuff despite perception that big tyres will be slow. Again, I think that a lot of it comes from big tyres having always been FR/AM/Enduro/DH focussed and built as such – tougher sidewalls, big knobbly treads, etc whereas b+ tyres are scaled up trail/XC tyres rather than DH style.

The real point being though, if you’re a similar pace to your riding mates on 29er wheels you’ll probably be much the same on climbs/etc if you switch to b+ ones, unlike say a proper fat bike which IME is noticeably slower on climbs.

My bike isn’t slow I am, I was / am looking at b+ stuff for a bit of confidence at the front and cushioning at the rear so knowing that there is little performance difference gives me even less excuses to not buy stuff

I’m much the same. The point is that b+ isn’t making me any slower on the bits that I’m worst on (the climbs). If I got a fat bike, I’d be getting left way behind on the climbs compared to other riders I ride with which would piss me (and them, probably) off.

Right then, the Spec Purg 3″ is too much for pikes on 45mm rims. Too much rubbing. So what 2.8 options apart from trailblazer are out there with decent amount of grip?

My Chubby Solaris.

[url=https://flic.kr/p/wNhopk]IMG_20150808_155042[/url] by Paul Stanley, on Flickr

[url=https://flic.kr/p/w8Uvqk]IMG_20150808_155007[/url] by Paul Stanley, on Flickr

More fun than a bag of ferrets.

Spec Purgatory on 45mm Scraper rims comes at pretty much spot on 80mm edge to edge. Hope that helps those who asked above

Variflex – I have Panaracer Fat B, 3.5 on 45mm rim which fit in Revs with a few mm either side. Grip seems better than the WTB TB, but side walls are light and I’ve not managed to seal them tubeless (not really tried properly yet). They stretch a few mm after inflation. Much rounder profile than the TB on wide rim, so nicer steering.

Where can you get Spec b+ tyres?

Thanks boxelder, also looking at Trax Fatty 2.8.

Spec b+ from any Spec dealer. My LBS got it for me. Circa £45.
Mine may well be for sale later this week if the Trax Fatty works. Will be up for £29 posted. Only done 2 rides.

I may take/swap that if it fits. I think the weight of the trax put me off.

Have we confirmed a normal on one parkwood takes 650b+? Seem to recall a picture on their facebook page or on here but might have dreamt it?

By my understanding any 29er will take 650b+, it depends more on the width of the rim you want to use… the wider you go the less likely it is to work

Not all will take it. If you can get a 2.4 rear tyre on a 29″ you have a good chance, but it really depends on how the chainstay is formed. The on one lurcher for example doesn’t have the clearance.

Vee trax fatty is a far better front tyre than the wtb. I’ll keep mine until I can get a maxxis offering.

I’ve lowered by bars a touch and that coupled to the lower bb and extra grip has resulted in some awesome tight handling characteristics.

By my understanding any 29er will take 650b+

No chance on a Scandal.

Yeah, I should keep my mouth shut. I just measured my honzo and I’ve got 68mm max at the chainstay. Not going to get much b+ in there.

I did wonder about a 650 rim and something like a 2.5 tyre but I’d imagine the diameter wouldn’t be big enough

Another ride today and I’m sold on this set up.

The vee Trax front appears to have stretched and isn’t self steering anywhere near as much.

I had an absolute blast on it today and ride the natural wyre trails like a hooligan (or it certainly felt that way).

Doesn’t appear to be any slower climbing or on the flat too, over the 29″ set up.

Significantly reduced chatter on the rear, stupid amounts of grip and the lower cog makes for nice handling. I’m sold

Tootallpaul, your Solaris looks great, exactly what I’m in the process of doing, just waiting for my rims. How much clearance do you get on that front mech?

OK, got mine all sorted now too.

Front: 45mm Velocity Dually with 3.4″ Panaracer FatBnimble = 70mm wide, giving just 3-4mm at either side in RS Revs.

Rear: 30 Easton Arc rim with WTB TBlazer = 64mm wide, giving 8mm clearance to the chainstays and 11mm to the seatstays on an XL Solaris.

How much clearance do you get on that front mech?

No front mech issues on 2×10, but I wasn’t expecting any as the mech never shifts ‘inboard’ of the chainstay. I’ve no doubt the FatBnimble/Dually combo would easily fit on the back too.
With 180mm cranks, there’s 138mm clearance to the floor and the BB clears the ground by 310mm.

First ride in the morning.

For comparison, I’ve measured the widest 29er tyres I run:
2.4″ Hans Dampf on Flow EX = 59mm
2.4″ Geax Goma on Alex XC rim (25mm) = 59mm

The B+ wheels are, as expected smaller radius by around 15mm – can’t be arsed measuring as it won’t affect folk wanting to know if B+ combinations work.

Looking forward to the Nobby Nics coming through. Would like to run the Spec Purg etc, but they aren’t going to fit those forks.

Front: 45mm Velocity Dually with 3.4″ Panaracer FatBnimble = 70mm wide

That seems quite narrow for being marked as a 3.4″ 😕
The Trailblazer 2.8 on Scraper comes out at 71mm.
I know the Scraper’s wider than the Velocity but only a few mm.

That seems quite narrow for being marked as a 3.4″

Sorry, typo – it’s marked as 3.5″…….. Glad it’s no wider, or it wouldn’t fit. the Panaracer is a light tyre (~800gms) with thin sidewalls – haven’t managed to seal it tubeless, though haven’t tried too hard, as it’s so ‘puny’.
I bought it instead of another TBlazer, as I didn’t like the squared profile of the TB – especially on a wider rim on the front. The FBN is a much nicer, round shape with side knobs, err, on the side.

The WTB went tubeless no problem on both rims.

Sorry, typo – it’s marked as 3.5″

That’s even worse.
How can they call it a 3.5 when it comes up smaller than a 2.8?
Most odd.

I didn’t like the squared profile of the TB

I’d not want to use one on the front either.

I could try my scraper/trax fatty 2.8 combo in a Rev for you to see if it fits?

It’s definitely wider than the TB (which I was running on the Dually at the front) and the tread covers all 71mm, unlike the TB, on which the tread isn’t as wide as the carcass, even on the 30mm rim.

FatBnimble = 70mm

It’s definitely wider than the TB(which I was running on the Dually at the front)

I’m a bit confused here as the TB comes up at 71mm. 😕
So the TB should have measured around 69/70mm on the Dualy

I’m a bit confused here as the TB comes up at 71mm.

Mebbe yours does, but on a 30mm rim, mine measures 64mm. The seatstay ‘gap’ is 75mm, so much wider wouldn’t be great.

Could you measure the TB mounted on a Dually for me please?
I’m looking for a bit more clearance for another frame and my TB/scraper setup it a little too tight to fit in there.

No, sorry stu – it’s set up tubeless and would mean removing and refitting both tyres. It stands to reason that it was wider than it’s current 64mm, but was certainly narrower than the Panaracer at 70mm. I’d say 66mm.

I’m tempted to pick up the 650B wheelset pack from Cotic (they offer it for 6 months 0% too btw).

1. Do we think the i29 rim with the 2.8 tyre will fit in most 29er frames?
I’ve got a Whyte t129 SCR and mud clearance is very poor with a 29” 2.2 conti- worth the risk?

2. Whats the height difference between 650b+ and a 29” wheel with 2.4 tyre? If the 650b+ dosen’t fit in the back I’d still like to run one on the front and put the rear on the Stooge.

Check your minimum clearance, I was planning to go b+ but most tyres on reasonable size rims seem to be around the 65-75mm wide mark. I didn’t have that much room.

1. Do we think the i29 rim with the 2.8 tyre will fit in most 29er frames?

Most? probably not IMO. You’ll need to do some measurements to check but you really need a frame with chain/seatstays with decent 29er clearance (so 2.4″ tyres ish, probably) that don’t narrow in after the point where 29er tyres fit – that’s going to rule out quite a lot of frames.

2. Whats the height difference between 650b+ and a 29” wheel with 2.4 tyre?

Depends on the 2.4″ tyre but I’m going to estimate around 1-2cm difference. It’s about 7mm on my 29er but my tyres aren’t as big as 2.4

The 2.8 trax fatty has a width of approx 74mm on my 38mm rims. It doesn’t leave much room to the bulges on the revelation forks (side to side clearance) . I’ve had no contact but I would not dare go wider. Lots of room elsewhere.

The wtb on the rear also comes up surprising wide, circa 70mm when I did a quick measure. I thought it was going to be less.