[Closed] 26" wheels in a 650b frame...instant *death?

Imagine a Hummer with Ford Focus wheels on, it'll be like that.

No really, i've not tried but i'm sure it'll be fine, not optimised but fine.

I actually think in the not-too-distant-future that frames will be manufactured so that the geo can be optimised for either 26" or 27.5" using offset bearing-chips or whatever...Could be wrong.

Just run it on 26" 2.4 conti rubber queens ;o)

Crossed my mind to fit 26" wheels with 2.4 Ardents on a Bronson with my 36's upfront 😀 can't be far off a 27.5"

as above put big tyres on them for the '650B without having to change rims' experience.

Your bottom bracket would be just under half an inch lower than if you have the same tyre/wheel combo in 650b. And your fork offset would be a little off compared to a 650 specific fork.

So yes, fiery explosive death, guaranteed.

A low volume 650b tyre is the same size as a high volume 26" tyre.

Make sure you have something big like the Rubber Queen or Ardents as mentioned and it probably won't be that different from someone running more conservative 650b tyres.

the difference would be so small i doubt anyone would notice if you didn't tell them

I was about to ask the same question and foumd this. OP did you try it..or has anyone?

I once fitted my road wheels to my 26" Zaskar, not only did it look ridiculous with 23c wheels it would have been instant death on the first hill, becasue at that time I didn't have disc shod 700c wheels, now that I do, hm...

Just put enormous 650B logos on the wheels and tyres, like the manufacturers do- only way most folks can tell the difference anyway.

Ha northwind..good tip.

Might just venture over to stif and have a chat.

You'd buy a frame to bring the trail to life then kill the trail with old fashioned wheels? Madness..

I had an enduro race recently on really steep muddy trails so fitted some old 26" wheels with 2.5 wetscreams to my 650b frame n forks, bike rode fine and even had added mud clearence.....ended up with 2nd in category and 9th overall.......did about 20 miles on them that day with no issues at all.

Thinking of this myself...good way to allow me to 'future proof' my bike. Aside the drop in the BB height can't really see too many problems.

I was wondering also, even if I got some new 650b wheels and forks for the new 650b frame, whether to keep my my 26" AM/DH forks and wheels and fit them to the 650b frame for trips abroad where you know wheels will get dinged and forks scuffed up.

I know somebody who ran 26" wheels with mud tyres as there was a dearth of suitable rubber in the larger size. Worked perfectly well as was required.

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So how much difference is there between a 26 and a 27.5 frame? I just got a Nukeproof mega and CRC has a table with the geo of both frames and there does not seem to be much difference. Would it be possible to machine different dropouts so you get about the same geo?

Mega 26
Frame Sizes 43cm (17")
TT Effective 590
Head Angle 66
Head Tube 115
Seat Tube Angle 72
Wheelbase 1168.88
Chainstay 440
BB Height +9.6
Reach 415

Mega 275
Frame Sizes 43cm (17")
TT Effective 596
Head Angle 66
Head Tube 110
Seat Tube Angle 73
Wheelbase 1175
Chainstay 445
BB Height -3
Reach 418

If you machined some dropouts where the axle was a bit higher up and pushed a bit further back how much difference is there going to be? The BB height is also going to be affected by how much sag you run.

Not that I really really want 27.5 wheels as I already have a big wheeled Titus Fireline and although it is a lovely bike and great for trail duties it is not as fun/manoeuvrable on drops/jumps and really steep stuff which I what I bought the Nukeproof for.

i was thinking about this earlier, because i really fancy this:-

http://www.chainreactioncycles.com/commencal-el-camino-650b-disc-frame-only-2014/rp-prod109238

i have a exotic 29er fork already but 26" wheels.

what do you reckon?

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The BB drop is the critical thing. The Banshee Spitfire is very low slung, 4mm BB drop unsagged, adjustable +/-6mm via the dropouts, so with the droputs in the neutral position and 26" wheels it's 336mm (13.25") BB height and with 650B wheels it's 346mm (13.65") BB height.

I wouldn't go putting 650B wheels on a 26" bike unless it's very low as a 26" because half the benefit of the bigger wheel is increased BB drop without a BB height so low you're always pedal striking. If you just take a balanced and normal BB height 26" bike and give it 650B wheels it's like putting a footballer in platform soles and thinking it'll make him better at everything, not just reaching headers.

With a full-sus you could just run more sag with the 650B wheels to get the BB down to a good height but how well that work depends on the suspension characteristics - quite a lot of modern bikes are designed to work around a certain sag for good pedalling and pumping without needing tons of low speed compression damping on the shock.

but aren't they talking about doing vice-versa, 26" wheels in a 650b frame..? Would they still achieve good performance with 26" wheels in a 650b frame, bearing in mind the geometry mentioned above?

[img] [/img]

A Bronson with 26" wheels!
Doesn't look like a death machine to me!

I've realised that my next frame will have to be a 650b frame and I don't really want to shell out for new wheels and forks and pondered the OP's question, which led to this bit of research on B/B heights.

Nomad with 26" wheels and 160mm Pikes = 355mm B/B (my current bike)
Bronson with 650b wheels and 150mm 650b Pike (same length as 26" 160 Pike) = 346mm B/B
Bronson with 26" wheels, 160mm 26" Pike = 336mm B/B, which puts the B/B height at the same height as a Santa Cruz 5010 and 6mm higher than a Nukeproof TR275!
The angles would remain the same, but with a nice low B/B height.
I reckon it'd be a right laugh to ride!

Surely it would be about the same as running a 2.1 tyre on a 26er.
i.e you'll lose about 10mm bottom bracket height.
Bet you don't notice.

[i]Bet you don't notice.[/i]

WHHHAAATTT??? you mean there's no difference? Crazy talk

Surely it would be about the same as running a 2.1 tyre on a 26er.
i.e you'll lose about 10mm bottom bracket height.
Bet you don't notice.

I notice how much lower my Soul sits with its winter tyres (Baron 2.3 & XR-Mud 2.0) than with its summer tyres (Rubber Queen 2.2).

People seem to think the difference is about this much:

[img] [/img]

When in reality it's actually about this much:

[img] [/img]

It'll be fine. as many people have already said the like for like difference is pretty much bang on 12mm radially 559 Vs 584mm for the Rims...

but going for a bigger 26" tyre will reduce the difference: A 650b wheel using a 2.2" tyre comes out about 695mm OD (~27.4") a 26" using a 2.5" tyre would out 686mm OD (~27")

It will look, feel and corner like this.

[img] [/img]