650b x 38c Road Bike

[sparky33]

Originally Posted by R3awak3n

650bx38 gotta be very nice on the road. Just gotta make sure doesn't lower BB too much.

I know 650bx42 is awesome on the road too. About as big as 650b I would go for pavement only.

650bx42 slicks are super nice for any sort of road, and I would guess 38s would be similar. Going any bigger introduces some noticeable differences wrt turning and road-feel that diverge from what I consider ideal road manners for a bike. Definitely need to keep an eye on bb height in the design.

[sparky33]

Originally Posted by kingpin75s

Good to hear. I am considering having a bike designed around that specific size tire. The overall diameter a part of that consideration to allow for no limitations to the builder with respect to road geometry. Maybe that will matter. Maybe not, but at least not a limitation. If it can also run a 42 that would be fine, so long as it did not compromise the design to do so in any way. If it only clears a 38 but meets all of my other needs that will be ok.

Are you thinking of disc brake or rim brake?

650x38-42 and road geo is a nonissue for disc, especially with the nice 383 a-c disc fork options from Columbus and Whisky that exist. Also, the Enve Road Disc fork will fit a 38 but not a 42.
Bishop built this kind of bike with long reach rim brakes on 42s...the right builder can make it happen.

[robin3mj]

I had a Cannondale Slate for a while and with the 42mm slicks, it was a super fun road bike. The fork made it a tiny bit sluggish but the geometry was otherwise pretty tight.

[weiwentg]

Side question: what high performance 650B tires exist, preferably at least 32mm? I see that the Conti GP5K and the Schwalbe Pro One have 650B x 25 and 28mm versions, which is unfortunate because they offer 30 or 32mm 700c versions of those tires. Mainly asking for curiosity, since I've no current plans for a 650B road bike.

[sparky33]

Originally Posted by weiwentg

Side question: what high performance 650B tires exist, preferably at least 32mm? I see that the Conti GP5K and the Schwalbe Pro One have 650B x 25 and 28mm versions, which is unfortunate because they offer 30 or 32mm 700c versions of those tires. Mainly asking for curiosity, since I've no current plans for a 650B road bike.

unless you are sorting out a very small bike, 650x25-32 is missing the point of what is good about 650b. 650b goodness begins at 38mm.

Rene Herse sets the benchmark on slick 650b tires.

[kingpin75s]

Originally Posted by sparky33

Are you thinking of disc brake or rim brake?

650x38-42 and road geo is a nonissue for disc, especially with the nice 383 a-c disc fork options from Columbus and Whisky that exist. Also, the Enve Road Disc fork will fit a 38 but not a 42.
Bishop built this kind of bike with long reach rim brakes on 42s...the right builder can make it happen.

Rim Brakes
Post Mount Medium Racers
Custom Steel Fork (maybe Ti)