Thiking of running some 650B wheels on my cx/gravel bike designed for 700c..bad idea?

[Wayne77]

I'm currently shopping around for some new wheels for my Trek Crockett. It has lots of clearance. I've been able to run 45mm WTB Riddler tires on 700c rims...plenty of clearance with the exception of the inside of the drive side chain stay where the outside is dimpled in for the chain ring. There is only has 2mm clearance. Anyway, I got a wild hair and thinking of replacing my damaged WTB i19 wheels with some 650B rims. No specific reason... maybe it would give me a little more clearance for even fatter tires? I've always wanted to try the smoother tread 47mm WTB Horizon. Any significant weight or handling considerations to think of? Or maybe since I'm already running 45c tires, the 650B benefits (bigger tires with the end result being similar overall diameter) are justified... That 45 mm tire I'm using on a 700c rim does result in quite a large diameter, probably a lot more rolling weight than the 35c tires I had before. Maybe going 650B with a similar tire gets me back down to something closer to 700c + regular tire overall diameter..

Thoughts?

[MaraudingWalrus]

The information on Boyd's website about their gravel 650b "road plus" wheelset talks about sizes, it's somewhere around 700xnormal road bikeish outer diameter.

I think WTB has, somewhere on their website, a list of some compatible frames for "road plus."


I did it with my bike. I think if you have room for 700x45 or so, you can probably fit the Horizons or byways. Not sure what all you'll gain, probably not a whole lot in terms of grip or comfort for offroad, if you're already riding big monster tires, but I'd guess you'd see a drop in rotational inertia...the benefits of which are hotly contested here on the forum if you do some searching.

I would see if you can try fitting a set of wheels with big old tires on em from somewhere before buying something crazy expensive to find it not fit afterwards.

[sales guy]

Here's a link to a good write up about choosing the right gear for an event. He talks about 650 vs 700 and tire choices.

http://www.velonews.com/2017/10/bike...hree-cs_450104

[ergott]

I have 650X42s. The tires weigh 350g and so do the rims plus 20g of sealant. That setup has very low weight considering how much tire I have. Another benefit is overall diameter is similar to 700X23 so the frame sits like a road bike.

I think more people on disc bikes should be open to the idea. It's faster with no loss in comfort.

PS - The Gravel Kings are excellent. Roll great at speed and grippy too. I went with them over the Gravel Kings for a bit more flat protection. They are still very light tires. These 42mm tires weigh about as much as 25mm Continental Gatorskins.

[Cornfed]

I think it's a great idea.

https://forums.thepaceline.net/showt...&highlight=m60

[ColonelJLloyd]

It depends as much on the tire as the wheel size. If you replace the Riddlers with a similar tire you won't notice a whole lot. There are 700x40-45mm tires that are lighter and more supple. Wider (say i23) and lighter rims and going tubeless (if you weren't already) will make a noticeable difference.

I had a frame built to take as big as 27.5x2.2 or 700x38. First set I built was a 1840g 650b dynamo set and I haven't had the desire to build a 700c wheelset yet. I've tried some other tires, but am enjoying SBH EL or 2.1" Liteskin Thunder Burts the most.

[weisan]

[marciero]

I've done this with two frames with great results.
Yes, handling is different, owing as much, probably more, to the lower pressure than to slight change in trail. Not better or worse, just different. I think it likely will work best with bikes that were designed for narrower tires though. I went from 700 28-30 to 48-650b 48-52mm tires (SBH and Byways tubeless). The bikes look like they were designed for it. If you are already running 45 tires the bike is going to sit a lot lower.

Recently discussed here


https://forums.thepaceline.net/showt...02#post2225402

[sparky33]

Do it.
There is something perfect about a snappy aluminum cx frame on chubby 650b tires.
I set my Zanconato cx with 650b on occasion and it’s buckets of fun. It really adds a new dimension to a great bike. I only wish the my clearance on 650x48 was a little better, but your Crockett might have plenty.

[Wayne77]

Thanks for the great thoughts here. I think I'm sold. Sparky, that Zanconato looks like boatloads of fun. Really leaning towards the custom build route at this point. I did come across this pre-order set online...not that I'm considering it but I'm curious if anyone knows about Hunt wheels. Can you tell what rim they're using here? Maybe a Pacenti or Stans branded as their own? Or maybe they make their own rims.

https://www.huntbikewheels.com/produ...order-sept-wk4

[Gartenmeister]

I did it on a Salsa Vaya. It came with something like 700x40 with tons of clearance. I swapped the steel fork for a Whiskey carbon one to save some weight and it was a bit tight on the tire. To get more clearance, cut more weight, and because it was cool at the time (2014?) I put 650b wheels (Stan's Crest) and Soma Cazaderos on it.

It's been that way for years now and has mostly been fine. As others have mentioned the handling changes somewhat. It is probably more nimble now, which is good since the Vaya is a bit of a truckish bike in factory form. The wheel/tire/tubeless setup is very light by comparison and for what it cost (not much). The bike is mostly a loaner for friends now and it does everything from road rides to gravel to light single track to really sketchy desert bushwacking. Sometimes all on the same ride. Credit to the tires here.

The one caveat is that since the Vaya was already intended for fat tires the net result of the conversion is that the bottom bracket is lower. The crank arms are 175, so they smack stuff.

[Kirk007]

Originally Posted by Wayne77

I did come across this pre-order set online...not that I'm considering it but I'm curious if anyone knows about Hunt wheels. Can you tell what rim they're using here? Maybe a Pacenti or Stans branded as their own? Or maybe they make their own rims.

https://www.huntbikewheels.com/produ...order-sept-wk4

I've been looking at those as well. On-line reviews are good and there's a few post here and on Velocipede from folks that have them. SalesGuy is familiar with them. Someone said they are Kinlin rims, taiwanese hubs with upgraded bearings. reports are they are very straight and that customer service is good. As I'm sure you say they are the stock wheels on the Mason Bokeh which looks like a cool bike.

[ColonelJLloyd]

Originally Posted by Wayne77

Thanks for the great thoughts here. I think I'm sold. Sparky, that Zanconato looks like boatloads of fun. Really leaning towards the custom build route at this point. I did come across this pre-order set online...not that I'm considering it but I'm curious if anyone knows about Hunt wheels. Can you tell what rim they're using here? Maybe a Pacenti or Stans branded as their own? Or maybe they make their own rims.

https://www.huntbikewheels.com/produ...order-sept-wk4

FWIW, I truly believe that 23-26mm internal (can go even a little wider no problem) is better for these wider tires. I'm really loving my Crest Mk3 rims. i23, 341g (confirmed actual weight) and built up really nicely. They setup tubeless so easy as well.

The Velocity Blunt SS is a nice choice as well.

[NHAero]

To get into the right ballpark, since a 700C rim is a 622mm, and 650b is 584mm, will a 650b tire that is 38mm/2 = 19mm larger than a 700c tire yield the same outside diameter on the bike? So a 650x42 is equal to a 700x23?

[ColonelJLloyd]

Yeah, that's pretty much it. There are a few other factors at play (tire drop, pneumatic trail), but that's a good guide to let you know what sort of BB height you'll end up with.