Trying to look for a gravel bike for the wife. I might have a good deal on a 3 year old Kona Rove. Only question I have is it is a 650b tire, is it worth going to a 650b tire? She is ~5’5 so right on the border of it being ideal for 650b.
80% of the time this will be on a paved rail to trail or on the indoor magnetic trainer. I get the concept she might be a bit slower, but not sure if that is a big issue.
Other thoughts are finding a trainer tire, finding tubes, etc.
I think you have 650b and 650c mixed up. 650c is a smaller diameter then 700c, but generally the same range of widths. 650b is usually the same outer diameter of the tire as a 700c x 25 tire, but the widths are much larger. I have some 650b wheels for my gravel bike and they’re ~2.1" wide. I use it on the road as well and don’t see too much of a speed loss.
I wouldn’t let 650b hold you back for your wife. Same overall outside tire diameter, as explained above, but the tires will be much wider. Slower rolling but more comfortable because you run a lower pressure. See below for a more detailed explanation.
Why would he have 650B and 650C mixed up?
I think you have 650b and 650c mixed up. 650c is a smaller diameter then 700c, but generally the same range of widths. 650b is usually the same outer diameter of the tire as a 700c x 25 tire, but the widths are much larger. I have some 650b wheels for my gravel bike and they’re ~2.1" wide. I use it on the road as well and don’t see too much of a speed loss.
I’d rather think the debate here is 650b vs. 700c for the wife’s gravel bike. In the assumption she’s going to ride the same tyre width on either wheel, the 700c will be around 6% bigger
The wheel diameter of 650b is slightly smaller than 700c. This potentially allows you to run larger tires within the same frame (50mm tires on a 650b wheel works out at about the same diameter as 25mm tires on 700c wheels.
Also, some frame manufacturers use 650b with road tires for smaller frames to prevent toe overlap.
Paved rail to trail, and 5’5 are probably not the conditions where 650b is the preferred tire.
My commuter bike is built around a similar 650b x 47mm concept (that is how the OEM built on the Rove) and I really like it. Yes it is a bit slower to pedal on road than my road bike but not all that much. As soon as you move to pot-holed rough roads or anything mixed terrain the bike actually rolls better.
Tires are heavy and a 47mm tire means you have significantly a more rotating mass at the edge of the wheels than you would with a 25mm 700c setup. This makes t650b slow to accelerated but once they are up to speed they roll through thing and keep speed due to the increased momentum created by the extra mass. The same principle dominated mountain biking in terms of 26 vs 27.5 vs 29 inch wheel debate. A 2.4-2.6 inch 29er mountain bike tire is a lot of mass so onces its up to speed it wants to stay rolling. This leads people to rave about 29ers in there ability to maintain speed and roll over things. They can feel a lot slower because of the extra effort required to accelerate them but against the clock they really aren’t slower.
80% of the time this will be on a paved rail to trail or on the indoor magnetic trainer.
Why does she want a gravel bike? I’d recommend a road bike that can take wider tire. For example, the Canyon Endurance can take 33mm width tires which is plenty wide for some gravel riding.
80% of the time this will be on a paved rail to trail or on the indoor magnetic trainer.
Why does she want a gravel bike? I’d recommend a road bike that can take wider tire. For example, the Canyon Endurance can take 33mm width tires which is plenty wide for some gravel riding.
That crossed my mind as well, but when she does go on gravel with me. (kids go to school next week so soon), something with bigger tires would make more sense. She likes my specialized diverge, but of course its finding one right now.
My commuter bike is built around a similar 650b x 47mm concept (that is how the OEM built on the Rove) and I really like it. Yes it is a bit slower to pedal on road than my road bike but not all that much. As soon as you move to pot-holed rough roads or anything mixed terrain the bike actually rolls better.
Tires are heavy and a 47mm tire means you have significantly a more rotating mass at the edge of the wheels than you would with a 25mm 700c setup. This makes t650b slow to accelerated but once they are up to speed they roll through thing and keep speed due to the increased momentum created by the extra mass. The same principle dominated mountain biking in terms of 26 vs 27.5 vs 29 inch wheel debate. A 2.4-2.6 inch 29er mountain bike tire is a lot of mass so onces its up to speed it wants to stay rolling. This leads people to rave about 29ers in there ability to maintain speed and roll over things. They can feel a lot slower because of the extra effort required to accelerate them but against the clock they really aren’t slower.
Good info thanks.
This is disk brake bike, correct? the current Kona Rove is a 650b x 47mm tire bike. Could she put a set of 700c x 25mm wheels & tires on it for road riding, and use the 650b wheels for gravel? I remember when Slowman had an article about this on the main page: https://www.slowtwitch.com/Gravel/Gravel_Bikes_and_Tire_Radius_7871.html
One thing to keep in mind is ease of finding replacement parts - I’ve got 650b (w/38mm tires) on my Canyon Grail (XXS frame), and I’m having a hell of a time trying to find a replacement tire. Max clearance is 42mm, and all the 650b I’m seeing is wider. Think I’m going to have to order direct from Canyon, which means shipping from Germany.
I’m pretty sure they make the Conti Terra Speed in 650b and that is as fast as any of the other gravel tires (and I’ve read they measure small). I just wish they would make the 650b GP5000 in a 40-50mm width. I’d be all over that. Or the Speedking Racesport in a 40-50mm. That would be nice for courses that are mostly paved, but bump. That thing is super smooth, just a bit delicate.
They also make the GK Slick in a 1.5 (or 38mm) and that is pretty fast. Of course, you have to find them, these days.
To the OP, if your wife is smaller, I would not hesitate to run 650b or buy into it. If the pandemic ever ends, I would assume there will be a number of good tires becoming more available.
Also, if you are going to do 650b, make sure you have frame clearance to run at least a 50 but preferably a 55. The fast mtb tires are still faster than the fast gravel tires, for whatever reason. I love the Conti Raceking Protection as a gravel tire. I grind a bit of the center knobs off and roll. We have a lot of sand around here, though, so if you don’t need the float, that is probably overkill, but it still won’t be slower.
I get the concept she might be a bit slower, but not sure if that is a big issue.
In an otherwise like-for-like setup (i.e. compared with a 700c gravel bike on a similar style of wheels and tires) it shouldn’t really be slower at all, if we’re talking mostly pavement with some non-technical gravel thrown in. 700c doesn’t have much if any inherent performance benefit over 650b except where rollover is tangible.
Other thoughts are finding a trainer tire, finding tubes, etc.
It looks like Tacx makes a 650b trainer tire.
If 650b tubes are hard to come by, you can get away with 26ers just fine. It’s not quite to the same degree of “you probably won’t even notice it doesn’t match” as putting 700c tubes in a 27" tire, but it’s not difficult and it works fine.
One thing to keep in mind is ease of finding replacement parts - I’ve got 650b (w/38mm tires) on my Canyon Grail (XXS frame), and I’m having a hell of a time trying to find a replacement tire. Max clearance is 42mm, and all the 650b I’m seeing is wider. Think I’m going to have to order direct from Canyon, which means shipping from Germany.
Rene Herse makes some 650b tires in 42mm. You may want to check them out. They are not cheap, but they rides super supple.
Thanks for the tip!