650B for gravel is....out?
 

I've been hearing from people that 650B/road plus is apparently a "fad" that is now passing......personally I don't care if that's the case, as I quite like riding that wheel size--fits me and what I do.

But, just so I'm hep to what's current, is this really a "thing" in the bike industry?

Oh no! Now I have to get new wheels and tires! Bummer.

I know, right?! I just got my rig dialed!

Was it ever really 'in'? It became popular in some specific cases and specific bike designs, but the overwhelming % of gravel bikes I have seen over the last 8 years in print, online, and in person have had 700c wheels.
The smallest frame sizes on some models were 650b. Some niche brands designed a model around 650b.

Besides that though, it really just hasnt been a major player in wheel size for gravel. It's certainly more popular in gravel than road, but also much less popular in gravel compared to MTB.

I got a set of 650b wheels for my bike because it lets me squeeze in a bit wider tires. I think for smaller frames, they have some other advantages as well.

Assuming your frame can fit anything, if it is built around/optimized for, say 28mm x 700C, you can maintain the same handling (and same outer tire diameter) with 48mm x 650b, so it does make sense. If you put very wide tires on 700C rims, you will change the handling properties of the bike significantly.

As for the "fad", presumably because mountain bikes are now being sold primarily with 29" wheels (700C), the Big Gravel(™) conspiracy wants to follow that lead.

Yeah I have a 53 cm frame and get toe overlap with 700x50. 650x50 would probably eliminate it.

Yep, well put. 650B is for those that tend to ride in the rougher stuff, but most gravel out there is easily handled with 700c. Many bikes out there now support both wheel sized for flexibility and most of those bikes come with 700c wheels. Some folks that started into gravel opted for the 650b wheel size if they were uncertain what they will need and want the most versatility. New gravel bikes with 650b wheels never made up more than 20% of sales. Where did you hear 650b was on the outs? Bikes that support both wheel sizes have certainly become the norm.

What’s funny is that both my mountain bike and gravel bike have their chainstays built in such a way that dropping to smaller wheels adds barely any extra clearance at all.

I thought 650b in gravel was exclusively for people who wanted wider tires on a road bike or who were converting a 90’s MTB.

Agreed that is was never all that “in”. Out of the many dozens of gravel bikes I’ve taken note of in the flesh, I think I have seen 2 or 3 650b ones.

in the UK, from what I can see, many people ride on 650b because they use tyres bigger than 38c. In muddy clay, you need good clearance.
personally, I prefer riding on XC tyre (50-584 or 52-584). I tried G-One Bite and Ultrabite in "supposed to be" 45-622 (they are 42) and I found rubbish on muddy path, woodland and on tarmac, it was the worst... so my 700c have panaracer slicks which are ok, the Vittoria Barzo is the best tyre I rode so far (closely followed by Conti X King and Race King).
for me it is about the tyre width, I take whatever wheel size providing the frame can take 50-52mm tyres. I have my eyes on a Kona sutra LTD 52-622 or 60-584

Well, fads always change in the bike world. Gotta have a new shiny object.

You are correct though. In the last few years, the industry touted having wide 650b or narrower 700c rims, so you could have two sets of rims for different conditions. I think they figured out that 99% of the people just put one set of rims on and left it at that. 700c has better rollover characteristics, so these days they are just making bikes with clearance for wide 700c tires. Kinda removes the need for 650b. The big exception of course is if you have a small(ish) frame. To get the same geometry you'll need smaller rims at some point. 650 is great if you can't be riding 29'ers on your gravel rig.

IMO, there is way too much focus in cycling in on what’s “in” or “out.” Some riders/rides are better suited for 650b, some for 700c, and some even for (gasp!) 26”. Every wheel size works; find what works for you and be done with chasing others’ version of what’s best. ’

my upcoming gravel bike will have 650b wheels with 47mm tires. I am currently running 700x38 on my gravel bike and those will fit the new bike. I wanted to make it fit 700x60, but decided that requires too much design work on the back end. Hopefully people will still make tires and rims for it, I think it's a good size. There are tons of new hybrids coming out with 650b tires, so I don't think the size is going anywhere.

You will likely love it. When I built my Super Professional with 650x47 it was a game changer. Now that I have four 650b bikes, I doubt I’ll ever build another with 700c.

That said, my two 700c bikes do what they do very well. Variety can be a good thing.

Yeah, I love my Rove ST w 650Bx47, but admittedly I ride it often "like a mountain bike", and I have WTB knobby Senderos on it currently. It's a size 50 and the whole package fits me very well and handles great in the rough stuff. That said my 700cx40 bike feels "faster" on the smoother stuff.
In any event, I like both. I had just gotten the sense recently from various websites and some bike industry types that 650B for gravel/all road was falling out of favor, after its initial hype from a few years ago.

I think you are right. Falling out of favor is basically how the bike industry works. I think it may apply here, like it or not. Just look at 650b on the mountain bike side of things. They found that 700c is marginally faster, and gave up on 650b.

There are undoubtedly some fast 650b tires, but I was shocked at how much slower the 650B Gravel King SK tires are (louder too for that matter).

In the same width? I find at least for RH slicks that the 650b and 700c versions in 48mm roll about the same.

Not sure it's fading away, but I just sold my 650b gravel bike and am keeping my 700c one... I found that the 650b wheels spin up easier but were harder to maintain speed on the flats. Just my humble opinion though...

Just bought a 650b wheelset and put 2.1" (54 mm) tires on it to maximize the off-road capability and comfort of my bike. The places I ride gravel are hills with relatively steep grades, and my goals are to get a good cardio workout and some adventure - I really don't care about speed at all. My first ride on this wheelset is this weekend... I am expecting it to be fun.

When I do care about speed, such as on flats or road, I'll switch to a 700c wheelset with smaller tires.

Found a pretty interesting video which includes a couple of Hunt representatives giving their insights on their 650b wheels, and I got the impression listening to them that 650b was starting to fade away but started making a comeback (as of 2020). This is a long video (40 minutes) but I found it interesting.

Perhaps we're finally past the hype stage, so it will either settle down to a reasonable niche or disappear from new bikes.

There are enough wheelsets out there to ensure we'll have tires for a long time, albeit overpriced

I think the point is, that with many new frames you can put a 50mm tire in there on a 700c rim

For older frames, there is nothing wrong with using 650x48 - there is just going to be less of a need for this size in the future.

And ya know, its all about fashion and trends in this industry. Designed obsolescence! ;-)

Yeah I'm into randonneuring and I get excited when I see someone marketing a "randonneuring" bike, only to find it's just a frickin road bike with 650b wheels. So trendy, so meaningless.

My rando bike is a road bike with 650B. It also happens to be my gravel bike. My MTB still has 26" and it's what I'd use for anything chunky but we don't have fire roads around here so it just gets used for XC type stuff.

This. The main benefit of 650b for most people was the ability to fit wider tires than they could with 700c. This is no longer a problem with most "modern" gravel bikes.