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I am looking at a new road bike that has some gravel pretensions. It comes with 650b wheels which really puts me off for my mainly road use. Do people find 650b ok for the road and are there enough tarmac oriented tyres available?
I have a Slate with a 650b wheelset, I'd say tyres make Far more difference than wheel size. Something like a Panaracer Gravelking or the Pirelli Cinturato Gravel H is still quick. Its not 'Road Bike' quick, but I don't feel that 700c or 650b is going to change that appreciably.
keep the 650b wheels with gravel orientated tyres on it, for diversions or extra comfort (panaracer gravelkings are awesome) and get a sexy set of 700c with ultra fast tyres for when you want to go full bore...
I've got 650b x 42 on my road bike - it's fine for me - it's not the bike or tyres that make me slow!
Very comfy and fast rolling even at low psi (30-40)
I don't find my 650b x 47 Byway shod Warroad holds me back much, certainly not on crappy Suffolk rural roads.
I am tempted to try out some 42s however.
I switched from 700x28 to 650x42 (gravel king slicks) on my audaxy type bike, didn't make my average speed slower - although it wasn't that high to begin with... I do notice I'm much more comfortable, especially my hands at the end of a long ride.
Sound advice STW, I think I'll take the plunge
I don’t think it’s any slower if the tyre is bigger the profile is usually larger so you should get approximately the same distance for each pedal revolution with the same gear ratio. I will measure the profile of my 650b gravel tyre against my road bike tyre. 25mm deeper is what I’m hoping for as it doubles up for the outside diameter.
My 650b Trig does not feel any slower on road than my old 700c 4 corners.
I've got 2 sets of wheels - 700c with 38mm slicks on, and 650b which I had some WTB Byway 47s on. The Byways didn't feel noticeably slower when up to speed, but I always felt they were a bit more work to spin up. My 700c wheels are nicer though (Mavic Allroad SLs vs Aksiums) so hard to make a direct comparison.
Depends on the riding you want to do and the roads you'll be doing it on I suppose. I do really like the grip and the volume on the Byways.
IME it depends on tyre width. 700x30 is about the same diameter as 650x47, but drop your 650 to 30mm and you'll lower your gearing and lower the BB by ~17mm, possibly increasing pedal strikes
I went from 650x47 Byways to 650x42 and haven't noticed a practical difference on or off-road (commute/gravel)
Used to have a 650c road bike for my son. Was a perfect scaled down bike, but the size was unusual and the bike was stolen.
These are all the road tyres you will need, so it's fine to proceed.
https://www.continental-tires.com/bicycle/tires/race-tires/grand-prix-5000
I have 3 wheelsets for my Amazon.
650x47 Teravail Rutlands (recently replaced Byways)
700x40 Nanos
700x28 Conti 4Seasons (or sometimes Marathons)
The speed difference is noticeable as you work from top to bottom of that list. For any given ride I'll weigh up distance, surface and likely duration and then choose the appropriate wheels.
Yes unless after KOMs or racing.
The longer I'm out for the more inclined I am to take the 650B bike, road or mixed surfaces. 650 x 42 is great on average UK road and lane surfaces. 650 x 50 G-Ones are fast but I do like a narrower tyre on tarmac, more of an cornering edge feel than a sideways roll. 2.3 G-Ones were too big for sure. I still like my 700C bikes a lot but it gets a bit much on long rides and I don't think they're as efficient overall on the sort of lanes I'd rather be on. 650Bs feel like the ideal OD and volume for general road riding and they're great for the off-road bits (and you might find yourself short-cutting and linking roads more with the bigger tyres).