I’m going to be doing the Corrieyairack challenge (mountain bike the whole way) in July. They have changed the route this year, so it is now a 14 mile off-road section (over the Corrieyairack pass) followed by 38 lumpy miles on tarmac to finish at Badaguish. The deal is that you can change wheels or tyres at the changeover, but not bikes.

I’m only doing it for a bit of fun, but still, I might as well take the best bike for the job. Currently my choices are:

1. My trusty Giant Trance full suss. This will obviously cope with the off-road section just fine and I have a spare set of wheels, so can put on narrow slicks for the road section. But, even with road tyres it’s not the fastest road bike in the world ! and switching wheels seems to involve a bit of fiddling to stop the Avid brakes from rubbing.

2. Buried at the back of the shed is a 20 year old Specialized Rockhopper. Fully rigid, steel, 7 speed, bar-ends and cantilever brakes. There are a few old wheels knocking about too, so I might be able to get two working sets so that I can switch from nobblies to slicks at the changeover. I reckon that this will be a fair bit faster on the (long) road section and it takes less faffing with brakes to switch the wheels. But I have no idea how touch the descent is so have no idea how much could be ridden by a talentless mincer on a rigid (and steep) bike. I don’t mind walking the odd section as I reckon I’ll gain a fair bit of time back on the road, but if I’m going to be walking for miles I might as well take the Trance.

The path has mostly been smoothed out but there are enormous water-bar/steps that you will have to negotiate going East. I managed the descent last year on a Ti hardtail with panniers etc….

I used to do it on a road bike when I was a lad with 32mm road tyres.

The Rockhopper is more than up to the job.

The descent is a minor part of the ride time wise, even if it takes you twice as long on that bit, it isn’t significant.

hardtail all the way, some wheels with slicks on at the change over point, good luck and enjoy! 🙂

Thanks. Unfortunately a hardtail is not an option; it’s full suss or fully rigid. It sounds as though the Rockhopper may be the way to go. If nothing else I won’t feel obliged to try and jump those water bars as I would on the trance. So I should save a fair bit of time in puncture repairs 🙂

and switching wheels seems to involve a bit of fiddling to stop the Avid brakes from rubbing.

get some rotor shims from Syntace so that you can shim the rotors to match on both sets of wheels – then no fiddling required

so can put on narrow slicks for the road section

don’t go narrow – stick with something like Big Apples so that you maintain the diameter of the wheel. The might be heavier but so long as they’re up to pressure they’ll roll just as well if not better than a narrow tyre. MTBs have a lower gearing than road bikes as it is, sticking a narrow tyre on reduces the diameter of the wheel and lowers the gearing even more so on flat /downhill sections you’ll just keep running out of gears. The alternative is to stick 700c wheel with disk hubs on, that gives approx the same dia with a narrow tyre on and preserves you’re gearing.

Thanks for the tips folks, but it turns out that a hardtail is an option after all 🙂

I tried the options I have and hated them both. Even with narrow slicks at 80 psi the Trance was really slow on the road and even with fat nobblies at 30 psi the Rockhopper was scary on anything rocky. OK, the Rockhopper would have worked, but I’ve been thinking of building up a 29er hardtail for a while now and this was too good an excuse to miss. So, I’ve just ordered the bits for a Kinesis FF29 build 🙂

29er is definitely the weapon of choice for it. I rode it from Laggan to Fort Augustus on Sunday and it was fine. The big wheels really helped the horrible drainage channels, but perhaps rigid wasn’t the best choice for my arms…

And how do you think those drainage “steps” would be heading East?

Thanks.

Obviously I didn’t really buy a new bike for one event (it was just a convenient excuse) but the potential advantages of the bigger wheel in negotiating those drainage ditches was a factor. Mind you, as I said above, it would probably be quicker to walk them rather than try my rubbish hopping technique and spend the next ten minutes fixing the puncture. I managed to put a lovely big hole in a tubeless tyre “practicing” on some drainage ditches up on Bennachie the other week.

Mostly rideable heading East I reckon. Just slow down and roll through them.

Ah, so not so deep that you have to jump them then. Things are looking up 🙂

We’ll see. I was walking down that way a few weeks back and some of them required a substantial step “up” rather than across.