When to consider going to the dark side of 650b?

[ridethecliche]

I know folks have talked about this a bunch but I've been thinking about it lately so wondered what the calculus is these days.

It seems that 650B was a stop gap when frame tire clearance was pretty limited to 35-38mm. Is there still much of a reason to go this route today when new frames clear 700x50+?
Outside of frames built with 650B in mind.

In my use case, I have a giant tcx advanced sx. Based on my measurements I have 55mm between the stays for 700c and 64mm between the stays where a 650B would go. Id say clearance is for 45mm and 54mm tires respectively, the latter of which is a 2.1.

What use scenarios have you found that dropping to a 650B is worth it? Honestly I'd have to test fit to see how things play out but there's more room back there than I anticipated for 650B

[whatshubdoc]

I think these days it’s when you want to run 2.1-2.3” meats.

[fourflys]

well, I'd say look around at the availability of 650b wheels/tires and see what you think the state is.. when I looked last month, out of curiosity, I sure couldn't find much..

[ridethecliche]

Originally Posted by whatshubdoc

I think these days it’s when you want to run 2.1-2.3” meats.

I would definitely need to test fit 2.1s before even thinking about it. There might be a local paceliner who could assist with that!

I had some kenda flintrudge tires I bought on the forum that were 40s and did pretty solid but I think there may have been something wrong with the casing since they were a bit lopsided and it weirded me out. Couldn't get it right even after reseting a few times.

I don't think I could go bigger than 45 width as measured. So likely limited to 42 stated width.

[nmrt]

I'm running 650b X 2.1 (Schwalbe Thunder Burt) for my gravel bike. It is slower than my 700c X 40 mm Conti Terra Speed (on my other gravel bike). But the 650b is so much more fun especially on smooth but rocky-ish singletrack. The downside is, as I mentioned earlier, it is slow, and I also get more pedal strikes. But it is so much more comfortable and the bike feels much more playful.

Apart from the Schwalbe Thunder Burt, you also have the Conti Race King (650b X 2.2) and Schwalbe G-One Bite (650b X 2.2). I am sure there are others.

If you just want to go fast, keep the 700c. But if you want flickability, agility, and more fun, try the 650b. I can promise everyone will like it. But it is worth a try.Maybe you'll be hooked.




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Originally Posted by ridethecliche

I know folks have talked about this a bunch but I've been thinking about it lately so wondered what the calculus is these days.

It seems that 650B was a stop gap when frame tire clearance was pretty limited to 35-38mm. Is there still much of a reason to go this route today when new frames clear 700x50+?
Outside of frames built with 650B in mind.

In my use case, I have a giant tcx advanced sx. Based on my measurements I have 55mm between the stays for 700c and 64mm between the stays where a 650B would go. Id say clearance is for 45mm and 54mm tires respectively, the latter of which is a 2.1.

What use scenarios have you found that dropping to a 650B is worth it? Honestly I'd have to test fit to see how things play out but there's more room back there than I anticipated for 650B

[Radius PNW]

Originally Posted by ridethecliche

I[...] wondered what the calculus is these days.
It seems that 650B was a stop gap when frame tire clearance was pretty limited to 35-38mm.

First of all -- I think it's the lighter side, not the dark side, of 650b. And, I think there's more to it than being a stopgap. That term implies it was a temporary part of an inevitable move to larger 700c. I have ridden both in 47c, and can tell you there are marked reasons to go either direction.

Originally Posted by ridethecliche

Is there still much of a reason to go this route today when new frames clear 700x50+?

Yes, and there is truly no substitute for trying it yourself.

Originally Posted by ridethecliche

In my use case, I have a giant tcx advanced sx. Based on my measurements I have 55mm between the stays for 700c and 64mm between the stays where a 650B would go. Id say clearance is for 45mm and 54mm tires respectively [...]

What is the BB drop of your bike, and crank length? Net BB height off the ground begins to come into a bit sharper focus if using 650b.

Originally Posted by ridethecliche

What use scenarios have you found that dropping to a 650B is worth it?

Superior handling for the given tire width. Better acceleration and braking. Running a 700x47+c feels like riding a freight train - all momentum. It's a real treat to actually be able to maneuver when you want to. 650b does give up flat out efficiency, so if you are riding purely gently curving roads, you may not immediately feel the handling benefits of 650b, and may appreciate the relative speed of the larger wheel. But for any small course corrections, the smaller wheel will respond much quicker. Think 'flickable'. The smaller wheel, contributing less rolling mass to the bike, spins up faster and brakes faster to me.

This is all very similar to the MTB debate of 27.5 vs 29, but in this case remember you only have the width of a drop bar to control the wheel. A heavier front wheel on 700c controlled by a narrower lever arm makes for pretty sluggish handling. All well and good if you can roll and lean your turns. If the going is at all twisty, the differences will become pronounced.

Running a 50+c tire in 650b gives a much plusher ride and more snakebite puncture protection at lower pressures than 42-45c x 700c.

I have tried both wheel sizes for larger than 45c on gravel, and for the my riding, have settled on 650b because the extra smoothness on the rocky roads means longer rides are possible in greater comfort.

[Radius PNW]

Originally Posted by fourflys

well, I'd say look around at the availability of 650b wheels/tires and see what you think the state is.. when I looked last month, out of curiosity, I sure couldn't find much..

Current market availability is no guarantee of actual desirability for particular use cases.

Talk with our resident wheel builder Old Potatoe if you need a set up.

[Hilltopperny]

My experience is that 700c is faster in most use case scenarios of a gravel bike, but 650b is more comfortable and better/faster on rough descents and most single track. There is more tire patch contacting the ground giving it a bit more stability.

I like 650b set ups for the times where speed isn't necessarily the main objective, but a 700c with 48-50mm tires do give plenty of cush and are faster in almost every way.

Sent from my Pixel 6a using Tapatalk

[Davist]

I have both, for dirt only, I think 650's are better. Trouble is most gravel here is at best 50/50. When riding with our group, it's usually not technical and they have lots of horsepower so the 700s with semi slick 43s work well. I can keep up with the thunderburts (they do roll very well) but don't seem to carry the momentum the bigger diameter wheels do. In the winter, my gravel bike is my main bike, so I've decided to keep it simple and I'm selling off the 650s (in classifieds if you're interested)

[AngryScientist]

I'm short and I think for very small frame sizes, like I ride, the frame is better proportioned to handle fat tires with 650B - that's why I went that direction.

[.RJ]

Originally Posted by ridethecliche

Is there still much of a reason to go this route today when new frames clear 700x50+?
Outside of frames built with 650B in mind.

For a frame built to clear a 700x50, then no, not really. I have one frame like this and I cant think of any way a 650b wheel size would improve things.

For a frame that was built for say, a 700x40 that would also take a 650x2.1" it can start to make a lot of sense to have a 2nd wheelset for it.

[El Chaba]

Originally Posted by AngryScientist

I'm short and I think for very small frame sizes, like I ride, the frame is better proportioned to handle fat tires with 650B - that's why I went that direction.

I agree. 650B evolved in France. As somebody who has spent WAY too much time looking at French bikes from that era, the top of the bell curve for frame size there is 2-3 cm smaller than here in the US. For tires 30-50 mm in width, that is the size that that evolved as the sweet spot.

[fourflys]

Originally Posted by Radius PNW

Current market availability is no guarantee of actual desirability for particular use cases.

maybe not, but it sure makes it a pain in the arse when looking for wheels/tires sometimes.. I have a 650b Riv BTW..

[thwart]

One other factor to keep in mind here is the effect of tire diameter on the bike’s trail number and what that does to handling.

I’ve found that on my current ‘gravel bike’ the handling is perfect for me with 650B wheels and 42 mm tires. I prefer this to 48 mm tires; not only steers better but also feels more lively. But if I’m doing mostly off-road stuff, the 48’s go on.

Going to 700c would increase trail even more and give me something further away from my customary road bike type handling.

Not to mention all of what’s been outlined above…

More info on wheel/trail issues here: https://forums.thepaceline.net/showthread.php?t=291837

[hokoman]

I have 2 wheelsets for my Mosaic. I only have the 650b on because it has a dynamo... but I didn't like the ride, so i bought an outbound headlight while in the states, so I could go back to 700.