There are several threads about 650b+ and other plus size tyres/wheels and I thought it’d be useful to bring them together in one place so that people who fancy giving it a go on an existing (eg not specifically designed for b+) frame can get an idea whether it’ll work.

I’ll start then.

Singular Swift, original blue model with straight stays – the one with the least clearance as current models have more – but with the latest model of fork that will take pretty much anything up to 3.5″ comfortably.

Rims – 650b Superstar Components DS25 – 30mm external, 25mm internal width, tubeless

Tyres – WTB Trailblazer 650b 2.8″

The tyres are 63.5mm at their widest point which easily fits my frame/fork combination. The pic is of the front wheel in the back of the frame but it’s enough to show that it’ll work (I haven’t built the back wheel yet).

(650b on the front, 29er at the back)

The Banshee Prime and Phantom (FS 29ers) have enough room to run 27.5+ with the standard dropouts (and you can adjust the BB height to bring it up to 29 level) and if you put the 27.5 dropouts from the 26 frames (Spitfire/Rune/Darkside) on them you can run 29+.

TB 2.8″ on Pacenti DL31.

comes out at 64mm. PLenty of room in the back of an On-One Ti29er, and that’s with tubular stays at the BB. Plate stays should give a ton of space.

Also lots of room in a 100mm Jeff Jones fork, but I doubt that’s of much use to anyone since they’re hardly common and you cant get them any more.

Interestingly I’m pretty sure my old racing ralph 2.4″ 29er tyres came out at 64mm too.

Plenty of room in the back of my on one codeine and x-fusion trace forks, on Ryde enduro rims wrapped in trailblazers.

Unless it was to narrow the tyre down to enable it to fit a particular frame, I would be going for around 45mm rims. The more volume you can get, the better the ride.

On 52mm Hugos, the 2.8″ TB measures 72.2mm at the widest part of the casing. The tread does not project past the casing, so I’d prefer a narrower rim to enable it to wrap around more.

Bikes that fit a 52mm Hugo with a 2.8″ TB tyre:
Ragley TD-1 with reasonable clearance.

Don’t fit:
On-One Scandal
Kona SS
Avanti KISS 29er

Maybe fit:
Surly 1×1, but have to deflate to get past canti mounts (later versions may be ok)

While I don’t fundamentally disagree, epicyclo, at least one person on here has swapped from wide to narrow rims and said it didn’t make any significant difference. I figure that I’ll try it out with 30mm rims and change to a wider front if I like it as 30mm rims are available fairly cheaply.

Interested to know if anyone has tried a Solaris.

I think cotic already have.

Older gen Niner SIR.9
Cheap 30mm rims from a Orange Crush with WTB Trailblaster.
63mm (Ruler, not with a caliper).
Plenty of room. 70mm(ish).

Ran ok on mates Santa Cruz 29er HT.
(Hi-Ball ??)

Doesn’t look massively bigger than a 2.35 Dampf.
Waiting for Blunts to land again. Reckon that will be best combo, & at £65, more affordable.
Running 29+ Knard on rigid Niner front & that’s brill.

If anyone local to Staffs wants to try the 650+ your more than welcome.

I have a 27.5 wtb on a Sun Mulefut in the back of my Gryphon, loads of clearance to the frame but only about 1 or 2mm clearance to the chain in bottom gear on a 2 x 10 set up. Might patent it as a in built chain cleaning system.

Quick edit – Knard on one of those Pacenti rims in the front that fits easily in the stock forks.

I asked Cotic about rim/tyre combinations for the Solaris. Paul’s response (which I hope he won’t mind me repeating here) was:

“We have two pairs of wheels, one with KOMi25 rims and one with Scrapers, both fitted with the Trailblazer 2.8 tyres and they fit fine in the frame.”

Jossie, is that the mulefut 50? Looks like a good value option. One question on rims with holes like that – how do you tubeless them? Special rim tape?

Yes, Mulefut 50 don’t think the 80mm would fit (and they only do a 26″ version I think?).

I’ve got a tube in mine with a Surly 26″ rim tape that was left in hot water to expand a bit. Not entirely sure how you would go tubeless but it is possible, I think it’s a case of Surly rim tape next to the rim then tubeless tape over that.

Hugo with a trailblazer, like Epicyclo says is up at 72mm so it looks like it would even have enough room going by some of the pics above. The hugo/trailblazer doesn’t fit a Kinesis FF29. It is pretty much jammed in there once dropped into the dropouts so it’s 100% a no goer. Obviously it rolls with scraper rims as Kinesis sell them (and have a full page ad showing the bike with them fitted)

2015 Trance 3 works too. I’ll get some pics up soon.

If I went 27.5+ on my solaris would my reba 29 forks be OK?

I’d say yes.

I’m going to check on my other 29er but I reckon yes

Update on the Reba, yes, it’s fine. By my reckoning (because it’s hard to judge from the pics (the top pic is particularly misleading), there’s at least 7mm at each side of the tyre at the narrowest point but plenty more elsewhere. I’d happily ride it. Note though that as above, I’m using a relatively narrow rim for b+ resulting in ‘only’ 64mm width of the tyre which means if you used a fatter rim/tyre you may well struggle.

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Oh and a couple more pics of the full 650b+ build

It rides nicely – I reckon I could go lower on the pressure though but it was quite noticeable over rocky trails that it rolls over them very well and the grip on steeper climbs is fantastic (and something of a weakness for me so quite welcome)

Cheers Nemesis, the Reba looks possible then.

Time to gather the wheelbuild bits together…

Paul

On One Lurcher – not so good. It does fit but only with around 4 or 5mm clearance each side. I’d ride it if I needed to but it’s far from ideal.

Wheelbuild parts ordered.

Hubs – from DCR Wheels (I think Novatec underneath)

Spokes – Sapim D-Light

Rims – went for the WTB Scraper

Tyres – 2.8″ Vee Fatty’s, and for the first time for me, Tubeless

Will pick up the tubeless tape and valves from Superstar I think.

The Turner Sultan will be my initial build – it’s going to be a monster. XT groupset, Thomson Finishing kit, Reba forks.

Are you expecting those wheels to fit in a Reba? I reckon that might be a squeeze given that yours will probably be 10mm wider at the tyre than mine.

We shall see!

The chap on this site said “On the front, though the Scraper /Trailblazer combo was no issue. I have tried every 29er fork within my reach (FOX 32 and 34, ROCK SHOX Pike and MAGURA TS8R) and there was no problem with either of them”

http://twentynineinches.com/2014/08/22/wtb-trailblazer-27-5-x-2-8-tires-exclusive-b-review-intro/

OK, we’ll see then 🙂

Fingers crossed!

My LBS ( http://www.reveloutdoors.co.uk/ ) have a Cannondale SS running 650b+

Front is a Hugo and 2.8 WTB tyre

Rear is a Hugo and 2.25 Schwalbe RR – There is room for a 2.4 but not a 2.8.

The bike looks fantatsic!

Looking at my 29er HT frames I would be surprised is any took a Hugo and a proper 650b+ tyre.

I’m going to try a Hugo on the front and either a DL31 or a Superstar rim on the rear as am impressed with what the DS25 I have in 29er guise.

That does look good.

The rear has a euro VDUB look about it!

Seems to work well on the gnarcore trails we have in the flatlands:

With that fork they could go 29+!

26″ Hugo, Dirt Wizard, Cromoto fork. Loadsa room.

Rear is maxed out with 2.4 Conti X King on Crest.

So, which Dekerf frame is that?

1999 Generation. And though I said the rear is maxed out with 2.4 conti’s, it’s nowhere near as tight as the Thunder Burt in the front of the Peregrine. That’s bordering on the inadvisable.

All the bits are in. Wheels are going to look good I think.

I have rebuilt my old Turner Sultan in anticipation. A little nervous the tyres will fit…

From what I can see the important measurement is 71-72mm for a WTB Trailblazer on a scraper rim. Will get the gauges out tonight. So hope it fits, because of it does the Turner is going to be a monster. I can even overcome the small drop in BB height by deploying the CCDB- previously this raised the BB too much.

If not, the Solaris will be seeing the wheels. Hopefully they will fit both.

My wheels above are almost identical in diameter to the 29er ones I had on the bike previously – admittedly that’s with fairly skinny 2″ 29er tyres but then the 650b tyres I have aren’t massive either.

Interestingly I’m pretty sure my old racing ralph 2.4″ 29er tyres came out at 64mm too

But it’s not about the width of the tyre surely. The volume comes from the depth. Running wide rims can’t alter cushioning type volume much, does it?

But it’s not about the width of the tyre surely. The volume comes from the depth. Running wide rims can’t alter cushioning type volume much, does it?

Volume’s volume, though. If there’s more of it, there’s more cushioning. Area of the cross section times the diameter (pretty much). If you let the tyre spread out more by holding the beads an inch further apart (45mm internal width rather than 20mm i.w.) you’re increasing the amount of air in it,.

Doesn’t really matter what shape the cross section is, if it’s 20% bigger, that’s 20% more volume.

Interestingly, the Hugo doesn’t optimise volume, as the rim profile intrudes into the cross section, rather than adding to it.

I wonder what the internal width of the dually would need to be to equal the volume of the hugo for a given tyre.

+1 on ned – by my reckoning it’s mostly about volume. Having said that, the depth of the tyre must have some effect though since effectively it’s the travel of the tyre – if you ran a massively wide tyre that was only 1cm deep, it wouldn’t ride the same (over bumps, let’s ignore trying to go round a corner…) as a more conventional fat tyre, would it?

If I have a 29er and a set of 650 wheels is all I need a set of plus tyres to bodge a 650b+ bike?

I’ll not necessarily get the whole set of benefits but my funds are limited at the moment

It’s not about volume, its about tyre height and pressure.

a wider rim gives a squarer profile which is more stable and thus allows lower pressures. This also gives it more volume but that’s not the reason.

podge – possibly and that’s the point of this thread to list out combinations that do and don’t work. You do need relatively wide rims (25mm internal width which is usually around 30mm external width seems about as low as will work well) though for it to work properly or the tyre will just roll around the rim.

al – I get the logic but I’m not sure it’s really as simple as that.

a wider tyre (due to wider rim) will have a wider contact and therefore, shorter (front to back) which in turn means the tyre compresses less for a given load. That’s why you can then run a lower pressure without grounding out the rim by my reckoning though you’re also right in that if the tyre is taller, being narrower can allow a longer contact patch without risk of hitting the rim.

I suppose it comes down to the factors of tyre roll and bottoming out – depending on what/how you ride, one may be more important than the other.