So one thing led to another and I put a 650b rear wheel on my FS 29er.

Didn’t know exactly what to expect but I’ve found surprisingly few drawbacks and a lot of improvements – particularly in the fun dept.

Have a read…
http://unduro.co.uk/mtb/behold-the-frankenthumper-aka-project-279/

Antyone else done this?

I’m tempted. The mud clearance on my Whyte t129 is horrific.
I can just squeeze a 2.2 MK in there for summer.

My best buddy has done this with his stooge, albeit slightly differently. He’s running 29+ at the front, and fat-but-not-full-650b+ (mild paunch?!) on the rear! He’s using a 25mm rim on the rear with wtb breakout 2.5, and soon a trailblazer. He loves it, and it adds fun to an already shortish rear end.

^^ That must be slack.
My stooge is 29er+ front and 29er rear and the front is kicked out a fair bit.
Would love to try that though.
Wheels are just too expensive to buy just to ‘have a go’.

650b wheels and big tyres are in increasing sight on 29ers. If I remember correctly there is only 20mm difference on the radius between 650b and 29 depending on tyres

It is pretty slack, but the rigid fork isn’t too long (it’s not the stooge one anyway), which helps a little bit. I fancy playing araound with the idea on my parkwood, but agree that wheels are too expensive just for experimentation, especially in true plus size widths.

Just read your review. Very interesting indeed. To get 20mm more travel could you stick a longer stroke shock in as the smaller rear is less likely to clash with the frame?

I have no idea TBH but it’s an intriguing idea.

The frame takes a 190×50 and I do have a spare 215×63 shock at the moment that I could use to test the clearance – though it’s a coil and the wrong tune.

I’m considering permanently changing the front wheel on my 29er for a b+ one – the rear is too tight for b+ but it’s fine on the front.

I’m getting increasingly sold on b+ the more I ride my other 29er with b+ wheels front and back (and as I set more PRs on climbs with them)

I’ll still probably try B-plus at some point, but this has opened my eyes to a few flaws with my bike’s geo TBH.

What size tyre have you got in there right now?

2.35 hans dampf, fair bit bigger volume than the 29er maxxis tyre I had before

Liteville have been pushing this for years…

Have a read about why they think it makes sense. I run the 26 rear-650b front and love it for the Gnarr

http://www.liteville.de/t/25_579.html

😉
[url=https://flic.kr/p/wRvnCd]IMAG0124[/url] by pten2106, on Flickr

Damn, out-niched already.

Ah yes. Done that on the NS Eccentric – 650b rear, 29er front. Waay to stiff at the back for the front flex. I guess different forks would help but still it rode like a bag of nails so I moved on…

Would be interested in this experiment as a fellow Thumper owner.

Had considered trying a 200×57 which wouldn’t affect the static geometry too much, especially if paired with offset shock bushings. I think I’d get away with it in 29 flavour, but suspect the 216×63 might be pushing it too far without a 650b rear though.

I’ll report back here when I get a chance to do it, might not be til after the weekend now.

It’d steepen up the geometry again and raise the BB as well as adding more travel I guess?

If you get a 200 x 57 shock and some offset bushes it’ll shorten the shock to roughly 190 so you’ll be exactly where you are now geo wise.

That was my thoughts, reckon it would boost travel to about 148mm from 130. Thumper was great in the alps this year, but I did notice a difference going from a Mega with CCDB coil last time to the Thumper with CCDB inline this time, in that I did feel more beat up by the end of the day.

Either that or I’m getting too old!!!

Looks like Foes had the same idea…
http://www.vitalmtb.com/videos/member/Foes-Mixed-Wheel-275-29-Best-of-Both-Wheels,29835/timberlinecycles,33865

I can see the point of mixing wheel sizes when designing a new bike as it allows for shorter chainstays, which are apparently better. Not sure I necessarily agree with that, but the market does, which is all that matters. But sticking a smaller back wheel in an existing 29er just gives a bit more mud clearance, a slacker head angle and a lower BB right? So it might work if those things were an issue, but it could just as easily mess up the handling of a bike that suited you well. Interesting thread though.

In this case it’s made the bike more aggressive, more fun and more confidence inspiring.

It’s faster in some situations, it feels faster in quite a few – and it’s slower in some circumstances too obvs.

Suits me though, don’t think I’ll put the 29in back wheel in again.

I’m really starting to hanker after a 650b+ hardtail, not sure how much of the shed I’d have to sell to clear a space for it though! Replacement for the fatty or replacement for the El-mariachi?

I was keen but the more I looked into it the more doubts I had about B+ being right for my riding at the moment – mainly due to limited tyre choice.

However there is now a bargain 200×57 shock on its way to me to fit to the bike featured above.

I’m really getting sucked into this now.

Oh well that was an anticlimax – the shock doesn’t physically fit – eye-to-eye is too long.

🙁

That’s why you need the offset bush, it shortens the eye to eye

There is a thumper in the classifieds, it’s taking a lot of will power to not buy it and follow in your footsteps

Ah right I had it in my head that offset bushings went in the other way around for some reason. I’ve just checked up and I see what you mean.

I do have a spare set in the van, will check if they’re the right size later.

Where are you based podge? You should have a go on mine before splashing out if poss.

I’m in Sheffield, the one in the classifieds is I think over priced but I can’t really justify a new frame as my hardtail covers 95% of my riding. Not that it stops me from looking and wanting something else

Righto, yeah it’s a bit steep and the Hope headset is nice but I have an angle adjust one to make mine a degree slacker.

I’m across the Pennines north of Manc – come for a ride at Rivi if you ever get over this way?

I don’t get over that way much but if I do I might have to take you up on that. Thanks

I’ve been keeping an eye out for a cheap shock too, glad you got one and will be interested to hear the verdict!

thepodge: I’ve got a medium Codeine frame for sale in the classifieds and I’m in Sheffield too! Be much better to be the first to 279 a Codeine 😉

Just window shopping at the moment thanks, as above my hardtail is doing me just fine for now. Plus while I like the Codeine I’d never be happy riding a bike from those robbing shitters at On One

Thv3 – have you already popped a 650b rear wheel in?

I have a 2014 650b Nicolai Helius with a 29er wheel up front and I love it, but then I also own a Jones and a 69er and am clearly not to be trusted.

Foes are going to be doing this off the shelf

http://m.pinkbike.com/news/foes-mixer-breaking-the-rules-again-interbike-2015.html

Nope, not got a compatible 650b rear to try yet.

Hoping it would work with a 29″ rear, I’m planning to build up a set of light bicycle carbon wheels at some point soon and would like to know my options before I decide on rim size.

Cheers podge. I posted the Foes vid on the last page but its good to see PB’s take on it – I’ll look forward to their review.

thv3 – Putting the longer shock in has raised the BB again – I don’t think it would work with a 29er rear wheel from that POV alone.

You’re also welcome to try mine if you’re near NW England.

Cheers, give me a shout if you’re up Innerleithen/Glentress direction, would be interested to try it.

Has it raised the BB with the 200×57 shock and the offset bushings? Thought they may cancel out some of that extra length?