The answers to all your technical questions, plus how to get the right chain length and our blu er’s guide to tubeless sealant
Your questions answered
I’ve put off buying a new bike for two years due to the rapidly-changing technology and trends, but can’t wait any longer. Fortunately, in the intervening time my budget has risen to £4,000. Presently, I have a 2010 BMC Trailfox and an old Orange hardtail, but I want one bike to cover everything. The new breed of long-travel 29ers which also accept 650b+ wheels have caught my attention. Any suggestions? Chris Bamber, via email
Building a bike that can be switched between wheel sizes without being compromised in some way is a big ask, but there are some that can do this really well. One of the first was the 135mm-travel Santa Cruz Hightower, which uses a small flip-chip to keep its geometry the same whether you’re running 29x2.3in or 27.5x2.8in tyres. Santa Cruz now offer the 150mm Hightower LT too. Both are only available with carbon frames, so aren’t cheap. The £3,999 full builds come with a RockShox Revelation fork, which is OK but no match for the Pike, and SRAM NX Eagle 12-speed gearing, which we’ve had good experiences with.
Scott’s Genius also lets you adjust its geometry to suit different wheel sizes. The twin-ring 930 model costs £3,899 but, if you like the look of this bike, we’d recommend pushing your budget to £4,099 to get the Genius 920, which has a 1x drivetrain and carbon front triangle.
Our pick would be the Whyte S-150C RS though. It doesn’t offer any geometry adjustment, so fitting 650b+ wheels and tyres does drop the bottom bracket pretty low. But at £3,850 it’s cheaper than the others here, and comes with a better spec too. That includes a RockShox Pike fork, SRAM GX Eagle gearing (a step up from NX) and some great rubber from Maxxis. It comes with 29in hoops as standard but, for an extra £599, Whyte will provide a spare set of 650b wheels, Maxxis Rekon+ tyres, sealant and disc rotors, making it easy to go 650b+.
Penny-farthing effect
I’ve been following Russell’s progress with his Specialized Turbo Levo long-termer with great interest, as I ride a 2018 Specialized Kenevo. I was particularly interested in Guy’s advice that he should try a 29in wheel up front and 650b+ on the rear. This sounds like an excellent solution to the problems I’ve encountered. My Kenovo has a different fork to the Levo – a 2018 RockShox Lyrik. Will a 29x2.4in wheel/ tyre fit in it?
Chris Jones, via email
This is something Seb tried while testing the Kenevo for our biketest on page 94. Unfortunately, it uses the 650b version of the Lyrik, not the 29er variant. While this has plenty of room for a 27.5x2.8in tyre, it doesn’t have quite enough for a 29in wheel with wide rubber on. Sorry to be the bearers of bad news, Chris!
This sucks!
I still run two chainrings. Lately, I’ve had a number of transmission problems, including shifting issues and the chain derailing and getting wrapped around the rings. Any ideas what’s causing this? Clive Winston, via email
Sounds like a bad case of chain suck. Start by checking the rings for wear or damage – if the teeth are starting to look like shark fins, they could be hooking the chain and not disengaging when they should. The chain could also be stretched. Before forking out money on new parts, give the drivetrain a degrease and relube, as a sticky, gritty and gunked-up chain is another possible cause.