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View Full Version : We've finally done it - The Switch 700c<> 650B


rain dogs
06-03-2020, 03:28 PM
The switch being: swapping wheelsets between gravel/all road bikes.

Quick backstory: Wife and I bought matchy matchy Niner gravel bikes (different colors). We have 3 wheelsets - 700x32 slick, 700x35 light knobs, 650bx45 slick for now. All have the same 11/34 cassette.

Wife has been riding the 650bx45 for a while now and I finally got around to putting some spacers behind the discs of the lighter wheelset to make a "road" option. And this past weekend we finally swapped em and saw how the biggest change for each of us felt.

Takeaways:

1. Totally sold on the one versatile frame, multi-wheelsets.
2. The swap took no effort... nothing, 5 minutes tops... if that (once the initial one-time set, rotors were spaced etc.) no brake.rub, no ghost shifting, nothing. worked perfect.
3. The handling change is really noticeable for the first half hour then not. The whole "a bike is designed for 1 size 700 OR 650B" is totally overblown. Maybe if you went from 700x25 to 650B x 2,1 or something.
4. There is NO WAY that 650B or much wider tires roll faster than or even close to 700c (irrespective of what the wider/lower gurus say). Not even close. I was suddenly pedaling non-stop like I was on a fixed gear and all I heard all day long behind me was bzzzzzzzzzzzz.... pedal pedal... bzzzzzzzzz. It would be mentally heavy to do a big brevet on the 650B if my wife was behind me buzzing away the whole time reminding me how much more I'm working than if I had chosen 700c x 32. Every descent she just rolled on past me unless I pedaled. Same 55 psi btw
5. Opens my mind to options for when we go bikepacking and me being her "team car".... I can just roll with the less suitable wheel option for the given the terrain and profile - give her the best wheelset option for the riding we'd do that day.

It's super nerdy, but it's pretty cool. Previous most similar bikes we had were a couple of CAAD's.... max tires 25c. Switching wheelsets was never a thought. Why would you? This is pretty cool/nerdy for us/her. One day she could be riding 700x30 road.... the next day 650bx45 singletrack, and we don't even have to be home to make the change. :cool: I'm just gonna have to be working to keep up now!

XXtwindad
06-03-2020, 03:41 PM
Really informative Lawrence. I was always hesitant on the 650b front, especially regarding rotational speed. Knobbies for the dirt might work where that's less of an issue. Thanks for posting.

TheseGoTo11
06-03-2020, 03:49 PM
Nicely documented observations. FWIW, this is pretty much consistent with my own experience running 650b and multiple 700c wheels.

robt57
06-03-2020, 04:09 PM
"The whole "a bike is designed for 1 size 700 OR 650B" is totally overblown. "

Unless you are dealing with a geometry to the edge of.. What I mean by that is one bike I have with a 8CM BB drop even with 170mm cranks does not handle non huge 650b tires on the wheels near as well a bike with 67-70mm BB drop which 175mm cranks plays better.

In fact I just filed and sanded the crank arm curb grind on the 8CM bike last week after I forgot and popped on the 650b wheels with too small tires and went for a ride...

weisan
06-03-2020, 04:11 PM
Yuuup!

Here's my gravel ti bike going through tire metamorphosis

700X32 <> 700X44 <> 650bx48

http://alicehui.com/bike/Plug/ezgif-3-d0aad8c095.gif

unterhausen
06-03-2020, 04:16 PM
which 650b tires are you using?

brucehappy
06-03-2020, 04:55 PM
Also interested in the tires on the 650b, and was this tubeless or tubes with 55psi?

Toeclips
06-03-2020, 10:41 PM
I'm 60 years old half blind and on muscle relaxers, I thought that bike was breathing
Pretty cool

a1k
06-03-2020, 11:31 PM
Huh, interesting. Would also be curious which 700x30 and 650x45 you are using.

I'm currently riding similar 700x32 and 650bx42 bikes, and it's NOT my experience that the former is somehow way faster. So far, I'm faster on sustained climbs on the 650b bike and about the same on other terrain.

In my case the 700x32 are compass and the 650bx42 are gravelking slicks. I attribute the difference to lighter weight and springier frame of the 650b bike.

2000m2
06-03-2020, 11:37 PM
Cool info, thanks for sharing

CNY rider
06-04-2020, 05:13 AM
I'm 60 years old half blind and on muscle relaxers, I thought that bike was breathing
Pretty cool

Flexing its muscles.

R3awak3n
06-04-2020, 05:49 AM
also curious on tires.

Just because you tell me you have WTB byways and no wonder you feel like you are loosing too much speed, those things suck.

there are some decently fast 650b tires but I agree that to me, on pavement 700c feels faster. I always say, maybe its just how it feels, less volume means it feels less soupy. Also think that 42mm 650b is about as wide as I would get if there is a lot of pavement miles, i think 42mm is the sweet spot for fast road and some gravel.

ColonelJLloyd
06-04-2020, 08:01 AM
also curious on tires.

Just because you tell me you have WTB byways and no wonder you feel like you are loosing too much speed, those things suck.

there are some decently fast 650b tires but I agree that to me, on pavement 700c feels faster. I always say, maybe its just how it feels, less volume means it feels less soupy. Also think that 42mm 650b is about as wide as I would get if there is a lot of pavement miles, i think 42mm is the sweet spot for fast road and some gravel.

Agree with all this.

On the same bike I think I roll better/faster on pavement while using Bon Jon ELs versus Switchback Hill ELs. But, it's not a stark difference by any means. Those WTB 47-584 tires are not in the same league.

R3awak3n
06-04-2020, 08:11 AM
Agree with all this.

On the same bike I think I roll better/faster on pavement while using Bon Jon ELs versus Switchback Hill ELs. But, it's not a stark difference by any means. Those WTB 47-584 tires are not in the same league.

absolutely. Rene Herse and even panaracer GK feel great in 650Bxbigger volume but I just got some Bon Jons myself and they rip on pavement.

AngryScientist
06-04-2020, 08:23 AM
i wanted to like 650B a lot more than i do, but i have yet to do any real off-road miles on the 650 set-up.

i'm thinking within the next few weeks i'll get the opportunity to see if i feel any better off pavement with the fatter smaller diameter wheels.

25c tires are still king for pavement in my book.

pbarry
06-04-2020, 08:28 AM
JMO, but the OP is running the the 700c tires a bit low, and the 650b tires on the high side. Also, are you accounting for weight differences between riders? Seems like the perfect excuse to buy more wheels. ;)

rain dogs
06-04-2020, 08:44 AM
Panaracer Gravel Kings in the 32 and 45's... I guess the 45's are officially sized as 1,75"... but they measure 45mm

Gravel King SK' in the 35 with little knobs

In all cases tubeless so, the max pressure is 400kpa (about 58psi)... I did inflated them the same for the 'test' conditions/control.... just to eliminate tire pressure variance from the confusion.

Wheels are Stan's ZTR Arch (the lighter set), Fulcrum racing 6, and Fulcrum Rapid Red 5 650B - all fairly low/mid range, trip serviceable wheels. Really happy with the Rapid Red's.

a1k
06-04-2020, 11:36 AM
I thought the GKs come in 28 and 32, but not 30 -- do you know which you have? (Curious is 28s run big or if 32s run small. Or maybe i'm wrong and they do sell 30 now).

rain dogs
06-04-2020, 01:02 PM
I thought the GKs come in 28 and 32, but not 30 -- do you know which you have? (Curious is 28s run big or if 32s run small. Or maybe i'm wrong and they do sell 30 now).

Yes, you're correct. They are 32. Don't know why I kept typing 30. Fixed