How does wheel size relate to frame size?

Just wondering, given all the debate regarding different wheel sizes, how does the size of the wheel relate to the size of the frame? It seems to me that an XS frame will sit and behave differently with 26″ wheels than an XL will. Is there an argument for saying that larger frames should have proportionally larger wheels in order to create the same riding position and feel for the rider? If not, how do frame designers/manufacturers design around this?

Apologies for my ignorance on this. As a rider very much on the XL end of the spectrum I see very small frames with wheels that look proportionally like 29″ do on an XL frame and it does make me wonder..

29″ wheels definitely look more normal on my bikes, 6’6″ and ride 21-23″ frames.

Even though the saddle is in orbit, everything is sort of in proportion. The bars are lower now, it’s using a 70mm 0 rise stem and low riser bars, those were a temp measure.

Both XL 😀


If you’re tall, they fit and handle better IMO…

Thanks guys. Love the bikes Khani. Ride an XL 2011 Flux myself at the moment but am eagerly awaiting the XL Burner frames that are due sometime soon.

It does seem to me that the 29″ wheels look more in proportion with larger frames. Question is though is there a tangible difference in how they ride? Would bike designers ideally spec 24″ on XS frames, 26″ on Medium frames, 27.5 on L and XL frames and 29″ on XXL in order to guarantee the same ride/handling characteristics, or do all sized bikes of the same model handle and ride the same with the same wheels regardless of how they sit?

for a tall person to get the 29r ride, you need 32″ wheels.

It seems to me that an XS frame will sit and behave differently with 26″ wheels than an XL will. Is there an argument for saying that larger frames should have proportionally larger wheels in order to create the same riding position and feel for the rider? If not, how do frame designers/manufacturers design around this?

Bigger bikes will ride differently in some ways as the front/wheelbase gets longer, but they’re more similar if you keep the wheels the same size and the differences aren’t reduced by changing the wheels, quite the opposite imo.
Wheelbase, frame angles and wheel size ‘feel’ are one thing. Rider size is another. Seems logical to make big frame bikes with 29″ and smalls with 26″ but it’s not so simple, a 26″ bike will always ride differently to a 29″. Compared to a small 26″, a bigger bike with a 29″ wheel is a very different bike, more so than a larger framed 26″. The ‘wheel size proportional to frame size’ idea is old but the logic doesn’t stack up for me. Small riders may struggle on a 29er, big riders may not like 26″ as much, but that’s a different point. What that says is that the bike needs to be different in many ways for extremes of height – not that you can make ‘the same bike’ with differing wheels. It won’t be ‘the same bike’, it’ll have different pros and cons that skew the design intentions (if there really are any).

All that really matters is your mass and how it’s balanced/centred over the wheels – geometry affects how you are centred over and interact with the wheels and also the feedback you get from them, the wheels themselves help influence the bikes ride feel. Get that package right and you have a great bike regardless of wheel size.
(edit to add, 650B is closer to either main wheel size so may be more of a fine-tune either way, that may work better, but 26-29 seems to pronounced to be able to ignore the differences in feel)

for a tall person to get the 29r ride, you need 32″ wheels.

Very droll! 🙂

Perhaps I’m being a bit vague. My query isn’t about how different wheel sizes relate to different size riders, it’s about how different frame sizes relate to the same size wheels. In other words, is ride/handling very different for an XS frame with 26″ wheels than it is for an XL with 26″ wheels?

I thought about this today as well.

For the same frame design around whatever wheel size, one of those sizes will be the sweet spot, there is no way the riding experience for someone on an XS frame & someone on an XL frame is the same.

It would make more sense to not just have wheel size dictacte but to scale things like 26″ for XS & S, 27.5 for M & 29 on the L & XL.

What that says is that the bike needs to be different in many ways for extremes of height – not that you can make ‘the same bike’ with differing wheels. It won’t be ‘the same bike’, it’ll have different pros and cons that skew the design intentions (if there really are any).

I think its one we will never know the answer too, but I am certain that even the same frame in different sizes gives a different riding experience, its just impossible to quantify.

In other words, is ride/handling very different for an XS frame with 26″ wheels than it is for an XL with 26″ wheels?

Definately, but how to measure it?

is ride/handling very different for an XS frame with 26″ wheels than it is for an XL with 26″ wheels?

Hard to find testers who can ride both equally in order to say! )
Many brands used to vary road frame geometry as frame sizes changed to keep the wheelbase consistent and the rider in the middle of the wheels (in theory at least), but that can have a different set of flaws.

I think its one we will never know the answer to

We seem to agree that 26″ and 29″ tend to ride quite differently though and that’s where my scepticism of ‘scaled wheels and frames’ comes from.
Yeti make the XS ’29er’ in 650B, that’s probably not a bad compromise, but taking the idea further is just like offering 3 different models in limited sizes.

Larger frames tend to just get larger in the front-centre, not in chainstay length. 29ers usually have longer chainstays so the fore-aft position of the BB is more likely to be optimal in larger sizes, whilst an XL 26″ could be very rear wheel heavy, front wheel light without deliberate weight shifts.

Many brands used to vary road frame geometry as frame sizes changed to keep the wheelbase consistent and the rider in the middle of the wheels (in theory at least), but that can have a different set of flaws.

But it would make more sense than current. In my mind at least!

29ers usually have longer chainstays so the fore-aft position of the BB is more likely to be optimal in larger sizes, whilst an XL 26″ could be very rear wheel heavy, front wheel light without deliberate weight shifts.

This is true. But so many riders of L-XL 29ers still want 425-430mm chainstays, same as a 26″.. Colnago and some others have longer stays on larger road bikes and it’s a good thing.

jameso, of Tour divide fame, good ride chap, I enjoyed following the race.

No supporting evidence but….

Frame designers design around a medium frame, 17″ – 18″. That’s what they sell most of. If you happen to be at the freak end of sizes, XS or XL, (I’m a freak too) then you get compromised bike geometry.

Some of the above XL 26″ bikes, the seat position is too much over the rear wheel. Makers keep the chain stays the same length, the seat angle the same, regardless of where it will position the rider. Laziness. Every mainstream bike comes with the same length crank arms. 5′ or 6’6″, apparently your legs are the same length.

The only option would be to have a frame custom made to get the sweet geometry of classic bikes but altered to suit our freak sizes. Then you have to find a designer and tester with the same body shape as you to get it spot on.

Or just compromise with what is available. IMO anyone over 6′ should be on a sorted 29er. 5’4″ and below on a 24″. I ride 26″ bikes because its what has been available and what I’m used to. If I could find a 29er designed for my size and shaped to hoon about on, I’d be on one.

Designers are just making 29ers with the average sized rider in mind and pro level XC. There’s a few exceptions, but not many.

My view exactly, wheel size should just go up with frame size. All bikes should look like a medium but just be bigger smaller chain stays, top tubes and wheels as required.

As a very short person who has ridden good 26″ and 29″ wheel frames, people need to get out of their heads the silly idea that wheel and frame sizes should correlate. The benefits of each wheel size are the same irrespective of rider size. Ie reduced rolling resistance, greater roll over etc.
Obviously there is a point where big wheels don’t fit into a small frame, but it’s a lot smaller than you guys seem to think. I think the limitation is really measured at the head tube hight. For a given suspension hight your stuck at your minimum bar hight and if your head tube and there fore bars are too high your not going to keep the front down. From my experience, with a short head tube, a 5′ person can fit on 80mm 29er hardtail. And seat and bars nearly level. That’s my wife. 5’3″ 100mm the same. But if you go for more travel handle bars will be too high.

There does come a point where the extra work required to change the direction of travel of a larger wheeled bike is no longer compensated by the improved rolling efficiency, and that tipping point will be sooner for both shorter and lighter riders. I suspect the lower your own CoG and the shorter your limbs for your height, and the lower your height, and the less perfect your timing/technique the more this will be exacerbated.

It’ll be interesting to see what inroads larger wheels make into enduro and DH racing and if smaller riders end up on smaller wheels (but marketing requirements may prohibit truly honest decision making).

I don’t think anyone said they “should correlate” did they? It just often works out with less compromises on bigger frames. The most notable thing would be the centre of gravity differences between the two, after years of riding bikes miles over the axles, just shifting it up an inch made me feel a lot more stable.

I’d also assume a taller rider would have an easier time chucking a 29er about, due to being further from the axles.