thehammerdog

never had the chance to ride a 650 gravel bike but seems very jeep like to have a off road 650 wheel big juicy tire bike for dirt but on the road?
I am currently leaning towards as means to go gravel road and full dirt trail riding.
thoughts?
Marin has one for $1200.

chaadster

Don’t forget that high-volume goes a long way towards obviating the need for aggressive tread. I run 650b x 48 file tread, and for gravel roads, it’s fine. In trail riding conditions, you may want some tread blocks, but it’s always about picking the right tire for conditions, less so the right wheel size.

I find that setup, with the plush Herse tires, rolls tarmac pretty nicely, but does give up real speed to 700x23c or 25c rubber. Granted, the 650b bike is 30lbs compared to my 16lbs road bike, so it’s not apples to apple comparison, but I wouldn’t call the 650b Jeep like in any case. Rather, it’s a smooth, comfortable road bike for reeling off painless miles.

For your use, if volume doesn’t get it for your trails, there’s always the second wheelset play, where you keep some knobbies ready to go. Spinergy have a nice, 1555g, $800 650b wheelset which would, if my experience on their 700c gravel wheelset is any guide, be great for either the trail set or the road wheel set.

ChrisCrash

I have two bikes with 650b. One drop bar with 47mm WTB byways, and a flat bar with gravel kings, 650x48. These are pretty much what I ride all the time, and I have some other good bikes - carbon racer, steel drop bar, dual sus MTB. They're all collecting dust. Because like they say.. Once you go Phat, you'll never go back.
The only caveat - 650 may change your handling and bb height a bit. On my road bike the handling got a bit quicker but I love the cushy ride of the 47mm wtb's which I just set up tubeless. And I've got to be a little careful to watch out for pedal strike on my flat bar. But, do it a couple of times and you'll remember not to pedal and lean at the same time. Not a big deal. And none of this will be an issue if you get a bike specifically designed for 650.
And.. if you go with a decent wheel set your bike does not have to weigh a ton. And if it does, so what.

ThermionicScott 

What do you mean by "viable"? I've come back from every gravel ride I've done on 650B, to the best of my knowledge. Ditto for the gravel rides on 700C or 26".

A big footprint helps on big, loose gravel, which again is possible with many wheel sizes. I'm flirting with the idea of putting 52mm tires on my 26"-wheeled bike, which could easily make it the best bike in my quiver for gravel. Currently it's on 42s.

mstateglfr 

Yes it's viable.

Rolla

I have a 700 x 43 gravel bike and a 650b x 47 “all-road” bike. I vastly prefer the 650b; the acceleration, traction, and comfort are all superior, at least where I ride.

Cyclist0108

I've been riding gravel for several years with 700c x 38mm tires, and just recently acquired a 650b wheelset, and the improvement in handling, as well as the ability to use a bit wider set of tires, has been transformative.

Now I am wondering if I should put 650b wheels on for on-road riding.

Ideally, your 650b wheels with fat tires should have about the same outside diameter as the 700c x 25mm or whatever tires your bike was designed for. That way you get the benefits of a wide tire without altering the geometry and handling of your bike.

In my case, the tires I can fit give me a smaller outer diameter, and do change the handling of the bike as a consequence, but off-pavement, it handles better.

My wife was really happy that I bought a third wheelset. Not.

Cyclist0108

One what?

A bike?

My 650b wheelset ran me more than that.

thehammerdog

yes.
an actual bicycle

chaadster

I suppose it depends primarily on your system weight, and a bit on internal rim width. I’m a 245lbs clyde on a 30lbs bike, and with my 650x48 tires at max pressure of 55psi, I find the tires to mushy for sporty road riding. They just don’t jump or carve like a narrow HP tire, and they definitely don’t cut crisply. I’d be terrified to dive a corner on those things, and simply don’t like the overall feel on the road for aggressive road riding. I’m also on comparatively narrow 19mm IW rims, so the bulbous shape and supple Herse sidewalls provide a lot of Jello-like slip when pressing the tires into a lean. It’s acceptable on gravel where you need and want compliance, but not on tarmac, IMO.

shelbyfv

This. "Gravel" here is dirt roads that may even be graded once a year. No comparison to the rocky stuff I see in other areas. Even so, there are washouts, accumulations of loose dirt, creek crossings, etc. For someone of my limited skills, even 42mm is marginal. I had much more confidence riding the 2.2 inch mtb tires. I'd certainly consider 650b if it enabled a wider tire.

thehammerdog

the marin nicascio is very affordable with 650 wheels.

mstateglfr 

Many brands have spec'd 650b wheels on their gravel/adv bikes for a handful of years now. Its often the smallest 2 or 3 sizes, but others have models designed around 650b. That wouldnt happen in 650b was not a viable wheel size.

revcp 

You'd be surprised what you can get for the cost of a set of overpriced wheels.

shelbyfv

And then there is this....https://www.bikeforums.net/general-c...-11-5-0-a.html

ThermionicScott 

Oh, dear...

thehammerdog

i am tallish so it is not that. The large tires seem slow to me on tarmac but should be great on dirt roads...i have a cross bike already but they are limited...

unterhausen

I hope 650b will remain viable, because my new gravel bike is going to have them. Although it will also fit 700c x 40mm tires, which is probably big enough. I had originally aimed for being able to fit 700c X 2.25" mtb tires, but that just seems like too much tire for gravel. The thing that made me stop worrying about the continued viability of 650b is the number of hybrids I have seen with that size tire. Giant went all 650b on their mtb for a while, but they have backed away from that.

you can get an entire bike for the price of the pedals on my gravel bike, but that doesn't surprise me much. I'm building a set of 650b wheels that would probably cost over $1000 retail, but I could have easily spent more than that if I hadn't gotten a cheaper dynohub and a Hope rear hub instead of going to higher priced options. Barring accident, I'm sure they will last me quite some time. Long enough that everyone involved is going to forget how much they cost.

msu2001la

I'm confused about what is being asked.

In the context of gravel riding, 650b is generally a solution to fit wider/higher volume tires than would otherwise not fit with 700c wheels. If your frame has limited clearance for wider tires, switching to 650b size can (sometimes*) solve this and allow much wider tires to be used. Generally speaking, the idea is that the 650b wheel with a larger tire would have the same overall diameter as the 700c wheel with a narrower tire.

*This isn't always true due to chain stay shapes, so on some frames the 650b size doesn't actually allow you to fit anything wider than you could fit on a 700c wheel - so these frames would be deemed "incompatible" with 650b.

Marin says the Nicasio (with a 1x drivetrain) will fit up to 40mm in 700c size, or 47mm in 650b size. If you want to run larger than 40mm tires, 650b is your solution on this bike.

Bikes like this with two wheelsets offer a lot of range. You can run something like a 700x35 for faster road riding and smooth gravel and swap to a 650x47 for really rough stuff.

mstateglfr 

not the only one because of course they are viable- its well documented.