Have we done 750d wheels yet? Pick ANOTHER wheelsize and be a dick about it

Nope.

My "gravel" bike has 29 wheels and 50c tires. Same diameter

Those are possibly a bit lighter, but I'll stick to being able to find tires, tubes and rims most places.

And certainly not buying a bike that you might not get parts for

In my mind there's no doubt that bikes should, in theory, adapt according to rider size. For instance there's no way that anyone can argue that an Small or Medium version of a given bike will handle and behave in the same way as an XL if they both have the same length chainstays. The fact that so few brands spec different length chainstays on their bikes is a cost factor, no more no less.

As it is with frames, so too with wheels. As a 6'4" rider, the days of being perched at dizzying heights above a 26" wheeled bike are thankfully no more. But even XL road bikes make the 700c wheels seem small by proportion.

I guess what I'm trying to say is that in an ideal world, the wheel size should be proportionate to the frame size, so for XL (and above) riders, 650D probably makes sense.

Am I about to rush out and buy a bike with that wheel size though? Probably not. The cost and inconvenience would outweigh the benefits as I see it, but if costs and availability of spares, tyres etc were broadly the same as for 700/29" then I'd be all over them

In my mind there’s no doubt that bikes should, in theory, adapt according to rider size. For instance there’s no way that anyone can argue that an Small or Medium version of a given bike will handle and behave in the same way as an XL if they both have the same length chainstays. The fact that so few brands spec different length chainstays on their bikes is a cost factor, no more no less.

That depends I guess on what you think the limitation is. Is a small too long, or an XL too short?

Some brands solve it by steepening the seat angle on larger bikes to keep the riders COG (via the saddle position) consistently ahead of the rear wheel.

For gravel bikes I don't think it makes any sense, the handling is already dominated by the short front end and the weight pitched over it, no one want's a longer chainstay relative to that.

But even XL road bikes make the 700c wheels seem small by proportion.

The road is just as rough though.  There's no advantage to giving tall people big wheels because there's nothing to smooth out so there's no logical need to make wheels bigger.  Most experimentation has been with making wheels smaller as it massively cut's their drag, hence 650C, 650b, 26" and even more extremes like the Moultons  with 20" wheels.

Maybe there'll be another revolution with geometry, 29ers didn't really take off until bikes got long enough to make them fit without compromises

750d sounds like a BMW model. Oh wait, it is!

Little to no interest in this. Would like to see more effort being put into 36ers and stop wasting time with kids wheels like this.

Little to no interest in this. Would like to see more effort being put into 36ers and stop wasting time with kids wheels like this.

Or 750D is to 36" what 650b is to 29ers.  A halfway house for those that didn't want to make the leap. But that implies 36" has already hit it's peak popularity.

Pinkbike had it right in their review IMO.  750D with a 40mm tyre is basically the same diameter as a 29x2.4.  So why would you not just fit a fast rolling 2.4?

It's such a small change as to be almost completely pointless. But if 650b vs 29er taught us anything it's that it's much easier to market a smaller and less pointy change because it's less scary and easier for manufacturers to adapt to. What we want, apparently, is something shiny and different and novel seeming but that we can only tell is different because it's written on the side in big letters. Oh and if it already exists, rebrand it with a misleading new name while you're at it.

But especially gravel seems to be clearly trendign towards fast large tyres anyway to do the exact same job, or at least has been so far. So the gap isn't just small, it's probably closing. Which is probably ideal for the pointless change marketeers because in a couple of years they can switch to 803A or 675C ("so you can get the benefits of a bigger tyre without the drawbacks of a bigger overall wheel/tyre package!")

As gravel continues to converge towards Just Being An XC Bike we're going to get more and more of this I think.

Nope.

For smaller people you tend to get toe clip overlap on bikes with drop bars why make it worse?

Wasn’t 700D an old GT MTB size?

in an ideal world, the wheel size should be proportionate to the frame size

I'd say wheel OD and tyre size is about your weight, speed and the terrain far more than your height - taller riders simply have more choice in wheel size. Rear axle from the ground / wheel radius also influences handling and not always better to go bigger, hence mullet bikes. With you on proportional rear end lengths in an ideal world though.

750D with a 40mm tyre is basically the same diameter as a 29×2.4.  So why would you not just fit a fast rolling 2.4?

Or smaller, a 58mm tyre on 750d (660mm BSD) should be the same as a 40mm on 700c. Agreed, why not use a larger tyre - if you're tall enough to want rims that big you're probably heavy enough to justify the volume of a 55-60mm tyre. Efficient rolling is about OD for roll-over on bigger bumps and tyre volume for small high frequency bumps, but it's 2 parts of the same thing. Gravel is mainly the small high frequency stuff which is why 650b x 50mm tyres can be so good until it gets chunky lumpy, and then you want to increase the OD and keep tyre the volume, or increase that too. Wanting the larger OD rim but not the tyre volume is pretty niche. A 660mm BSD rim with a 2.4" tyre would be pretty niche too.

I thought the reason for piloting this was that it meant a bike could run 29er wheels on rough terrain and 750d with the thinner tyres on the road or less rough off road. Whilst keeping roughly the same outside diameter and bottom bracket height

like 700c 28mm tyres is the same diameter as 650b 47mm.

I’m really tall and I’d love a 36 inch wheel bike. But only for the LOLs,  they are staggeringly heavy

Would be a good size for touring bikes where stability is all.

I’m really tall and I’d love a 36 inch wheel bike. But only for the LOLs,  they are staggeringly heavy

Would help if the only half decent tyre wasn't over 1400g from a company that's never cared much about weight