Doing the C2C this summer with Gti Junior and some kids from his school and don’t want to use the precious roadie so have revived the neglected old Global Ti mountain bike with rigid carbon eXotic fork and fitted some Specialized fatboy tyres in 1.25″ size. Trouble is, they look ridiculous in the frame and especially in the very spacious forks.

As an experiment I fitted the 700 wheels from the crosser and they look excellent, they fill the space for the wheels with about 5mm clearance at the bridges and the bike rides nicely with only tiny adjustment needed to the brake calipers. However GtiJ is using the crosser for C2C.

How much would it cost to buy some reasonable 650b wheels and slicks? It’s for tarmac use only so they don’t need to be super-butch.

Since you know 700c works, would that not make more sense? Many more wheels and tyres to choose from.

They were a tight fit, any muck on the tyres would hit the chainstay bridges. Mind you that was with a 28mm tyre.

Leave the MTB treads on or get some 2″ semi slicks. That way you can do the off road bits if you fancy (and the gravel sections are more comfortable) and you’ll prob still be faster than a load of kids.

I can confirm this is a very bad look…
[url=https://flic.kr/p/akHLU7]Road Ready[/url] by theflatboy, on Flickr

and it was not a pleasant ride to Brighton, either!

26×2.0 or 2.35 Schwalbe Big Apples can be had pretty cheap. Or you could not worry what the tyres look like, cheaper still.

and it was not a pleasant ride to Brighton, either!

the echos of the derisive laughter still haunt you today, I expect 😉

Get some fat slicks like big apples

partly the laughter, partly the stupidity of thinking it was a good idea and partly my lack of fitness at the time… 😆

Isn’t 1.25″ closer to 32mm? In which case, 700c with 25 or 28mm would give more clearance.

Yes. Anybody want to lend me some crosser 700s with 140mm discs for a week?

Sorry, you did say further down that the cross tyres were 28mm. Think the sun must have got to me.

I can confirm this is a very bad look…

Strangely I quite like that!

Wasn’t it good fun launching the bike off speed humps and the like at max velocity?

I tried some continental city slicks on my 26″ giant mtb rims (yukon hardtail), it was a truly horrendous experience, came off big time once, that was the end of those tyres.

I ran some 2″ Schwalbe Kojaks on an mtb for a while.

they were brilliant once you got them rolling.

nd, yep that bit was massively fun – the brakes were incredible as well, 185mm rotors with those tyres on tarmac… 😀

What about rebuilding my existing Hope hubs with a 650b rim? I reckon I could even do that myself if somebody could sort me out with the right spokes.

26×2″ Kojaks look about right in my opinion. Much more cost effective than new wheels!

The main problem with very narrow tyres on MTB rims is that the profile of the tyre is stretched accross the wide rim. This makes the tyre feel a lot stiffer as there’s no give in the sidewalls. A similar size tyre in a narrow road rim would feel much better.

If I were you I’d get some 2″ semi slicks – I have Halo Twin Rail tyres which are very nice – as they’ll be comfy, fast enough and look a little more in proportion.

billytinkle, what mudguard is that on the second picture (silver bike)?

I guess the other question is which 650b road tyres would you want to use? AFAIK there aren’t many options. Grand Bois Hetre are lovely though…

Hmmmm yes, got the tryout ride for C2C this Sunday so I’ll see how the bike rides over 30 hilly miles on those Fatboys. On a Ti frame with carbon fork the lack of flexibility might not show up.

Where can you buy those Grand Bois Hetres? They look interesting.

billytinkle, what mudguard is that on the second picture (silver bike)?

It’s a cut down SKS Bluemel on the back (does naff all to protect your back, but stops the front mech from getting caked in crap), I use it in conjunction with a quick release Topeak Defender when it’s wet.