Gravel bike wheelsize

Thinking of getting a cheap ish gravel bike to replace my venerable road bike. Ride mainly in the lakes roads and fire roads plus a little more gnarly. Should I get 650b or 700c wheels??

I bought a bike with 700s, I think the 650b option would have been a shed load more versatile and comfier. Mine was more intended for fast fire roads and poorly surfaced roads and it’s fine for that and I’ve also ridden a few bits of the South Downs and surrounding area on it. It’s the latter that has me thinking 50mm tyres on 650b would be more suited.

I couldn’t get my head round the idea that my drop bar bike would have smaller wheels than my MTB.

For my main use (bad roads and easy tracks) 700 is fine, for anything regularly rougher 650b all day long.

i’ve thought about chucking 700 wheels on my 650 (hybrid/gravel) and decided that they will probably make no difference at all apart from getting a bit more top end

How tall are you?

If you are tall enough then 700 wheels and tyres will suit you well.

If you are a shortarse like me then getting a wider tyre will mean you need a smaller wheelsize.

I haver both 700×40 and 650×47 for my VN Amazon. I’d say the 700s are slightly faster on the right terrain, the 650s are much more comfy and will handle rougher terrain better. Some of that translates into “faster” at the end of a long day when fatigue becomes an issue.

Agree it’s not really about wheel size, more tyre width and volume. My Croix de Fer was on 700 x 35 tyres and was a little faster on road and smooth stuff than my current gravel bike, a Topstone Lefty, with 650 x 47 tyres. Off road the Topstone is faster and much more comfortable, though in part down to the frame and suspension.

Just got back from a local mixed road/gravel ride on 650b wheels & Pirelli Cinturato M tyres which come up around 53mm wide on 25mm inner width rims. 20/23 psi. I’ve never wanted to swap out to 700c wheels, and when I did have the opportunity to get some lighter wheels I stuck with 650b…seem fine to me on the road.

I think for a tall rider 700c with space for big tyres is king

But the reality is space for big 650b is more common. With the benefit of 700c thin tyres being an option

Having re read your post maybe 40mm tyres

Off road on anything beyond sustrans 50mm are better for me

Mine has 700c with clearance for 50mm tyres and I love it. It’s the 650b vs 29er discussion and I’d rather have small lump rollability than switchback manoeuvrability as that fits with what a gravel bike does. The main reason people go 650b is for greater tyre width clearance on their frame rather than wheel size (in my opinion as it can’t be different to the mtb thoughts surely). If your frame fits wide tyres then choose like a mtb, if not then choose by tyre width, anyway my 2c

I’m 5’9”. I was thinking on either 40mm 700c or 46 on 650b.

700c every time for what you describe. I am meaning gravel as in the FC tracks including the 2″ + stuff they chuck down to fill the big holes. Lets say the manicured stuff that wears out badly that the FC also use on their trail parks.
If by gravel you mean easy MTB then this will be fine as well. My local FoD reds work well on 700c. If you want to ride all that you might on a MTB then 650b may work well but will not be as nice on the road. Comfy yeah but that isn’t really an issue. 700c means you can swap to road tyres.
Ideally, a set of both.

I think for a tall rider 700c with space for big tyres is king

This.

Mine takes 700x50c.

Ideally, a set of both.

Is, of course, the correct answer 😉

intheborders
This.

Mine takes 700x50c.

Mine too. But apparently it will also take 650×2.4 and the daftness of that really appeals to me

700 x 50mm for off-road unless you want lighter wheels or tighter geometry / wheelbase because of road riding considerations, scale back from there. I had 2 wheelsets on a bike like this and very soon got to the point where it was on 650 x 47 or 50mm all the time and the 700 x 28 to 40mm range wheels didn’t get used. For anything bar trad roadie riding it’s ideal but a 700 x 50 will obv be better off-road.

But apparently it will also take 650×2.4 and the daftness of that really appeals to me

I had G-One 650 x 60mms on for a while. That was enough to know where tyre volume and OD crossovers worked and what was too much, this was, on road at least. Was like riding a fat bike off-road where changes in the road surface can do odd things to the steering as the contact patch moves about vs the steering axis.

I haven’t tried 700c on my Genesis Fugio but I really like how it rides on 650×50 Pirelli Cinturato M’s. I do a good mix of XC trails, gravel and road riding.

buy a 700c that will fit 45-50mm tyres. most 650b top out at 47mm (ish) so there are no benefits against a 700c that will take the same tyre.
with no suspension you need ‘rollability’, 650b is basically there so that you can fit a larger tyre into a ‘700c’ frame.
any arguments on manoeuvrability are pretty weak as these bikes are already more manoeuvrable than their 29er MTB equivalent.
i have a Chamios Hagar on 700c wheels with 47mm tyres and its fine for all types of riding, better suited to trails though. personally for fire roads and paths etc i would go with a 40mm tyre. if you need to go bigger than 50mm then you should probably be on a MTB.

buy a 700c that will fit 45-50mm tyres. most 650b top out at 47mm (ish) so there are no benefits against a 700c that will take the same tyre.

..aside from lighter wheels and a potentially tighter geometry that may be a factor depending on what you want the bike to feel like. 650B is great for road riding that is often on on bad lanes and occasional off-road, on a bike that still feels road-like. 700 x 50 may need longer forks and wheelbase and begin to compromise that, imo not much, but it’s all on a sliding scale of use and performance influences/compromises isn’t it.

My tempest was on 700cc x 42. Brilliant mile muncher, okay on rough surfaces, not a lot of fun on anything much rougher than a degraded fire-road.

Now run 650bx47 on my Digger. It’s WAY more comfortable off road, lots more grip, more of a mini MTB and I was very happy to be running low 30s PSI this weekend after a few hours of Welsh gravel/slate/etc especially on the long descents.

It’s definitely slower on the road, but for what I want it for, I’d make the sacrifices. I did try it with my old 700cc wheels and they fitted, but I much prefer the smaller/wider tyres.

For me, once it goes beyond 700*45s capabilities, I’d rather be on my hardtail MTB.

Currently on 650×47. I wouldn’t want to go any narrower on the tyre choice for my (Peaks-y) riding. Hoping the next bike will take 700×50. I won’t want to necessarily use that all the time, but I feel I want the option to.

I haven’t tried 700c on my Genesis Fugio

You won’t. They don’t fit. I borrowed some 700×40 wheels/tyres to try in mine. Not even close to going in – fouls on the chainstay bridge mudguard boss.

..aside from lighter wheels and a potentially tighter geometry that may be a factor depending on what you want the bike to feel like.

I’ve JRA’s Monitor wheels in 700 – 1600g with a 25mm internal rim width for £400.

For me, once it goes beyond 700*45s capabilities, I’d rather be on my hardtail MTB.

This.

Ideally, a set of both.

Is, of course, the correct answer 😉

Attached permanently to two different bikes obviously. :D

I’m going to go all grumpy old bloke on this one.

Gravel bikes are like road bikes and should run 700c wheels and maybe 42mm wide tyres. They don’t need suspension, they don’t need little wheels and massive mtb tyres. They are for riding gravel trails, tow paths, poorly finished lanes and maybe along a beach once a year and perhaps some light single track occasionally.

If you want something more aggressive and appropriate off road. Use a mountain bike.

I completely understand why you’d come to that conclusion when you are old. At only 63, I reckon I’ve a few years of 650×47 enjoyment left yet.

Gravel bikes are like road bikes and should run 700c wheels and maybe 42mm wide tyres. They don’t need suspension, they don’t need little wheels and massive mtb tyres. They are for riding gravel trails, tow paths, poorly finished lanes and maybe along a beach once a year and perhaps some light single track occasionally.

If you want something more aggressive and appropriate off road. Use a mountain bike.

Well… first we’d need to agree what a gravel bike is these days : ) I agree with you mainly, seems like OP does, but for me it’s not about wheel spec, it’s ride quality and handling. Prefer it fairly road/touring bike influenced more than MTB. Wheel spec is just part of that.

If you want something more aggressive and appropriate off road. Use a mountain bike.

Without wandering completely off the OP’s point, I don’t think this statement holds. My Hardtail is a 160mm 64 degree head angle bruiser of a thing. It’d be zero fun on most of the trails / tracks I can ride from my house. So a 650b/47mm combo works perfectly for this. It may not for the OP.

Anyway what’s wrong with riding inappropriate bikes off road!

As it’s “a 90s MTB” 🙄 26″ wheels would be best

Gravel bikes are like road bikes and should run 700c wheels and maybe 42mm wide tyres. They don’t need suspension, they don’t need little wheels and massive mtb tyres. They are for riding gravel trails, tow paths, poorly finished lanes and maybe along a beach once a year and perhaps some light single track occasionally.

Either you’re trying to be funny or ironic or you don’t ride a gravel bike in the UK

They are for riding anything, sometimes quicker, sometimes slower than a road/MTB but always fun. They make tame trails good and harder trails a big adrenalin rush that a modern MTB wouldn’t even notice

Wider 650b rear wheel and tyre for comfort and a narrow 700 for aero gains on the front. ;)

Either you’re trying to be funny or ironic or you don’t ride a gravel bike in the UK

62 year old gravel bike rider here. 700×38 for me. For how I use the bike that’s absolutely spot on, and yes that’s in the UK. I’ve got mtb’s for tougher trails. Not sure what’s funny or ironic for shortcut to voice his opinion 🤷‍♂️

https://www.chainreactioncycles.com/mobile/continental-race-king-racesport-folding-tyre/rp-prod170295?gs=1&sku=sku642044&utm_source=google&utm_term=&utm_campaign=&utm_medium=base&gclid=CjwKCAjwo8-SBhAlEiwAopc9W4oVRL_RGb8QLS3MbN2aZ0rfJptNrRgDtiF-JrA_BYcv08UTqrwTOhoC2bMQAvD_BwE&gclsrc=aw.ds

Brilliant 650b summer rubber in my opinion. And without gravel in the name and unfashionable in mtb circles cheap as chips.

62 year old gravel bike rider here.

Either you’re claiming you invented gravel bikes or treat yourself to a new bike 😉

Either you’re claiming you invented gravel bikes or treat yourself to a new bike 😉

😂😂

Great discussion. I have a hardtail and a full suss. Perhaps the. 40mm 700c might be best and then I can sell my road bike.

There are lots of reasons to disagree on all this stuff

1. Personal preference
2. Where you ride
3. What else you own

I quite like the madness of riding drops off road

There is quite a lot of proper off road near me that seems fine with out suspension but quite limiting on 40mm tyres

I own a fs 29er and a gravel bike

So for me 650b with 50mm tyres works well riding from the house off road. On the same bike I use 700c with 35mm tyres from the house on road

Maybe I’d be better off on a hard tail or rigid mtb but don’t own one. Maybe next year I will and I’ll tell you all how gravel bikes are rubbish and you need a proper mtb.

Plus let’s not forget the reality. Bikes are versatile and in any ride we encounter a wide variety of terrain

I can ride my fs 29er whilst my grown up son on my gravel bike with 50mm tyres. It’s not that hard to plan a route where we are both having fun and both bikes work just fine. Just don’t tell the marketing guys

Interesting discussion as I’ve got a gravel bike on the way with 47x700c tyres, I’ve bought it as a more comfortable replacement for my current road bike but with the option to add the odd bridleway into a ride. I don’t know whether to look for a cheap set of 650b wheels for more off road focussed rides

I do own a hardtail but it’s not great for off road riding direct from my door. Ideally I’d want a short travel full sus but it would be a bit too niche for what I usually ride.

Yes – funny and ironic but yes, I also have and sometimes actually ride a gravel bike which has 700 x 40 tyres. Yes – I can and do ride singletrack on it but quite honestly an xc or downcountry bike is usually more fun and or faster/less terrifying. So I’m going to stand by my original statements.

Gravel bikes are great for tow paths, fire tracks, back lanes and bit of track and path to link those previously mentioned options. If it gets more exciting I’d be happier, more comfortable and considerably faster on a mountain bike.