650B Disc Wheel (DiscBrakes)

Jun 1, 21 23:37

Post #1 of 38 (2744 views)

Hi guys,

I am a rather small rider (5'6'' / 168cm) and own a Tri-Bike which comes with 650B wheels. Irrespective of the discussion if disc-wheels really bring about that advantage, notably @paces <45km/h, I'd like to invest into a 650B disc-brake disc-wheel.

Not surprisingly, the online-search proves to be rather difficult. Well, I found a couple of shops offering 650B Road-wheels (and one 650B disc-wheel) however, all having rim-brakes...

So my question is -> Is there a market for 650B disc-brake disc-wheels? If yes, it would be super nice if someone could post a link or reference to it.

Thanks and kind regards
Chris

Re: 650B Disc Wheel (DiscBrakes) [Chris1988] [ In reply to ]

Jun 2, 21 0:44

Post #2 of 38 (2735 views)

With the rise of gravel bikes, there are a metric crap-ton of 650-b wheels available, almost all with disc brakes. This makes me think that maybe you mean 650-c?

Tech writer/support on this here site. FIST school instructor and certified bike fitter. Formerly at Diamondback Bikes, LeMond Fitness, FSA, TiCycles, etc.
Coaching and bike fit - http://source-e.net/ Cyclocross blog - https://crosssports.net/ BJJ instruction - https://ballardbjj.com/

Re: 650B Disc Wheel (DiscBrakes) [fredly] [ In reply to ]

Jun 2, 21 1:10

Post #3 of 38 (2729 views)

fredly wrote:

With the rise of gravel bikes, there are a metric crap-ton of 650-b wheels available, almost all with disc brakes. This makes me think that maybe you mean 650-c?

Nope, it's 650B (Speedmax CFR XS-Frame) and you're right, there are numerous 650B Gravel-wheelsets out there. However, I couldn't find a 650B disc-wheel suitable for disc-brakes :)

Edit: Well, the DT Swiss Wheelset which comes with the CFR is 650B...But maybe I may also look for 650C Disc-wheels? Don't know the exact difference between B and C...

Last edited by: Chris1988: Jun 2, 21 1:14

Re: 650B Disc Wheel (DiscBrakes) [Chris1988] [ In reply to ]

Jun 2, 21 1:39

Post #4 of 38 (2719 views)

Ah, got it. I misread - sorry, it's late here.

Yeah, your options are going to be extremely limited. You might wind up having to use a cover.

Tech writer/support on this here site. FIST school instructor and certified bike fitter. Formerly at Diamondback Bikes, LeMond Fitness, FSA, TiCycles, etc.
Coaching and bike fit - http://source-e.net/ Cyclocross blog - https://crosssports.net/ BJJ instruction - https://ballardbjj.com/

Re: 650B Disc Wheel (DiscBrakes) [Chris1988] [ In reply to ]

Jun 2, 21 3:13

Post #5 of 38 (2709 views)

Chris1988 wrote:

fredly wrote:

With the rise of gravel bikes, there are a metric crap-ton of 650-b wheels available, almost all with disc brakes. This makes me think that maybe you mean 650-c?

Nope, it's 650B (Speedmax CFR XS-Frame) and you're right, there are numerous 650B Gravel-wheelsets out there. However, I couldn't find a 650B disc-wheel suitable for disc-brakes :)

Edit: Well, the DT Swiss Wheelset which comes with the CFR is 650B...But maybe I may also look for 650C Disc-wheels? Don't know the exact difference between B and C...

650B is a 584mm bead diameter while a 650C is a 571mm bead diameter so the B is 13mm taller. Yes, a 650C will work but it will drop you 6-7mm closer to the ground. Some may think it's not big deal until they skip a pedal in a turn.

It is perhaps the stupidest change ever forcing people that had 650C bikes to buy a new bike that is either 650B or 700C.

The good news is Schwalbe and Continental make good tires in that size.

Post deleted by Administrator [ In reply to ]

null-and-void

Jun 2, 21 4:39

Post #6 of 38 (2690 views)

Re: 650B Disc Wheel (DiscBrakes) [null-and-void] [ In reply to ]

Jun 2, 21 5:55

Post #7 of 38 (2673 views)

In theory, I'd imagine the same cover for rim brakes would work with disc brakes. Perhaps the only modification would be to make a slightly larger centre hole on the NDS cover to fit around the 6 bolt (or center lock) mount. ...however, in practice, I have never tried a cover on a disc brake.

null-and-void wrote:

fredly wrote:

Ah, got it. I misread - sorry, it's late here.

Yeah, your options are going to be extremely limited. You might wind up having to use a cover.

Do you know of a cover compatible with disc brake wheel? I’ve been searching and not finding any.

Post deleted by Administrator [ In reply to ]

null-and-void

Jun 2, 21 6:23

Post #8 of 38 (2660 views)

Re: 650B Disc Wheel (DiscBrakes) [null-and-void] [ In reply to ]

Jun 2, 21 9:02

Post #9 of 38 (2623 views)

Maybe try contacting Frank Renn and see if he can make a custom disc for you? He still makes them in 650c, so might be worth a shot.

No coasting in running and no crying in baseball

Re: 650B Disc Wheel (DiscBrakes) [null-and-void] [ In reply to ]

Jun 2, 21 11:55

Post #10 of 38 (2598 views)

Quote:

Do you know of a cover compatible with disc brake wheel? I’ve been searching and not finding any.

I don't know of any that you won't have to modify to fit, but looking at the disc wheels in my shop right now, I'm positive one could be made to fit on at least most of them.
You might also think about making a monokote disc. The fact that you don't need a brake track makes this a really compelling approach, I think.

.

Tech writer/support on this here site. FIST school instructor and certified bike fitter. Formerly at Diamondback Bikes, LeMond Fitness, FSA, TiCycles, etc.
Coaching and bike fit - http://source-e.net/ Cyclocross blog - https://crosssports.net/ BJJ instruction - https://ballardbjj.com/

Last edited by: fredly: Jun 2, 21 14:48

Re: 650B Disc Wheel (DiscBrakes) [Chris1988] [ In reply to ]

Jun 2, 21 13:51

Post #11 of 38 (2580 views)

Chris1988 wrote:

Is there a market for 650B disc-brake disc-wheels? If yes, it would be super nice if someone could post a link or reference to it.

As there is one frame size from one brand that requires that wheel size in Tri/TT - no.
Disc covers are dished too much to fit nicely on a disc brake wheel.
Your only option is to make your own cover - either with plastic or shrink flim.

Re: 650B Disc Wheel (DiscBrakes) [Chris1988] [ In reply to ]

Jun 2, 21 18:00

Post #12 of 38 (2556 views)

Is there any reason why you can't run 650B front and 700C rear?

The reasons for 650B are usually related to the front (toe overlap, and handling designed for 650B).

Re: 650B Disc Wheel (DiscBrakes) [mcalista] [ In reply to ]

Jun 2, 21 18:56

Post #13 of 38 (2545 views)

Trail and bottom bracket height

You would steepen the head tube and reduce the trail making the bike really twitchy.

You'd drop the front end 2cm and take chances on skipping a pedal in every turn

Re: 650B Disc Wheel (DiscBrakes) [jaretj] [ In reply to ]

Jun 2, 21 19:00

Post #14 of 38 (2543 views)

jaretj wrote:

Trail and bottom bracket height

You would steepen the head tube and reduce the trail making the bike really twitchy.

You'd drop the front end 2cm and take chances on skipping a pedal in every turn

umm, the OP's bike is already set up for 650B. Adding 700c rear would not drop the front end at all over the base configuration. And bottom bracket height would be INCREASED with 700c, leading to a REDUCED chance of pedal strike.

Last edited by: mcalista: Jun 2, 21 19:02

Re: 650B Disc Wheel (DiscBrakes) [jaretj] [ In reply to ]

Jun 2, 21 19:50

Post #15 of 38 (2526 views)

No chance of pedal strike (aside from the fact the BB would rise) when the rear tyre is jammed into the chainstay yoke and you can't move.

Re: 650B Disc Wheel (DiscBrakes) [cyclenutnz] [ In reply to ]

Jun 2, 21 20:13

Post #16 of 38 (2517 views)

cyclenutnz wrote:

No chance of pedal strike (aside from the fact the BB would rise) when the rear tyre is jammed into the chainstay yoke and you can't move.

Yep, this was the very issue in my mind, hence why I asked the question as to whether they could fit a 700c in the rear. Perhaps I should have spelt this out more explicitly.

Re: 650B Disc Wheel (DiscBrakes) [mcalista] [ In reply to ]

Jun 2, 21 20:23

Post #17 of 38 (2514 views)

The diametric difference between 650B and 700C is much greater than the tyre clearance tolerances on frames.
The only way you get multiple rim sizes is when the frame is designed to take a fatter tyre on the smaller diameter rim, which leads to the tyre diameter being similar to a narrower tyre on the larger diameter rim.
That's not the case here - Canyon have just made it difficult by being the only 650B tri bike (they did this on womens road too) without any fit advantage.

Re: 650B Disc Wheel (DiscBrakes) [cyclenutnz] [ In reply to ]

Jun 2, 21 23:33

Post #18 of 38 (2494 views)

Thanks for all the Feedback and Input guys :)

I guess I'll have to "live" with the 50mm DT Swiss 1100 Rims (which surely are High-End and performing very well, I guess)...

Never heard of that cover thing (I'm from Germany, it's not very common here)...very interesting, but I think no option for me...

Maybe I try finding someone who builds disc-wheels individually, but I fear that'll cost deeeply 4-digit...

I'll check that out and will update this, if anyone (smalle riders notably) search a 650B disc-wheel, too :)

Re: 650B Disc Wheel (DiscBrakes) [Chris1988] [ In reply to ]

Jun 3, 21 0:33

Post #19 of 38 (2489 views)

You might try to contact Poland based brand RON WHEELS RON Wheels ; in fact, these guys produce disc wheels in the shape of spoked rims covered by carbon layers; possibly they have the "flexibility" to provide a 650B version.
Another option could be to contact these guys in Spain laminarcover, bikes, wheels, idec and ask if they can provide carbon covers for your wheels

Re: 650B Disc Wheel (DiscBrakes) [mcalista] [ In reply to ]

Jun 3, 21 3:11

Post #20 of 38 (2467 views)

mcalista wrote:

jaretj wrote:

Trail and bottom bracket height

You would steepen the head tube and reduce the trail making the bike really twitchy.

You'd drop the front end 2cm and take chances on skipping a pedal in every turn

umm, the OP's bike is already set up for 650B. Adding 700c rear would not drop the front end at all over the base configuration. And bottom bracket height would be INCREASED with 700c, leading to a REDUCED chance of pedal strike.

I find it unlikely that a 650B tri bike would accept a 700C rear wheel since the 700C wheel would have a radius ~19mm larger.

If it was possible it would raise the rear and change the trail on the front end, steepening the head tube and make handling interesting. The BB height would increase like you said.

Re: 650B Disc Wheel (DiscBrakes) [jaretj] [ In reply to ]

Jun 3, 21 3:19

Post #21 of 38 (2464 views)

jaretj wrote:

mcalista wrote:

jaretj wrote:

Trail and bottom bracket height

You would steepen the head tube and reduce the trail making the bike really twitchy.

You'd drop the front end 2cm and take chances on skipping a pedal in every turn

umm, the OP's bike is already set up for 650B. Adding 700c rear would not drop the front end at all over the base configuration. And bottom bracket height would be INCREASED with 700c, leading to a REDUCED chance of pedal strike.

I find it unlikely that a 650B tri bike would accept a 700C rear wheel since the 700C wheel would have a radius ~19mm larger.

If it was possible it would raise the rear and change the trail on the front end, steepening the head tube and make handling interesting. The BB height would increase like you said.

even if it could, the bike would become useless, since different diameters on front and rear are not allowed in races

Re: 650B Disc Wheel (DiscBrakes) [jollyroger88] [ In reply to ]

Jun 3, 21 3:32

Post #22 of 38 (2460 views)

They aren't allowed in races that follow UCI rules so likely any ITU sanctioned race. I'm pretty sure USAT allows them, I'll look that up.

USAT rules 5.11g
(g) Except as otherwise determined by the race director in the interest of safety, the front wheel may be of a different diameter than the rear wheel, but the front wheel must be of spoke construction (spokes may be bladed, round, flattened, or oval) an must not be of solid construction. The rear wheel may be either spoke or solid construction. Wheel covers shall only be permitted on the rear wheel.

https://www.teamusa.org/...rt/competitive-rules

ITU 5.2 e (vi)
Both wheels must be of equal diameter

https://www.triathlon.org/...s_2020_201811253.pdf

Last edited by: jaretj: Jun 3, 21 3:43

Re: 650B Disc Wheel (DiscBrakes) [Chris1988] [ In reply to ]

Aug 30, 23 13:00

Post #23 of 38 (1762 views)

Hey Chris. Curious if you ever had any luck with this. Really frustrated that Canyon is making a triathlon bike that doesn't fit triathlon wheels. Buying a disc cover for my back wheel, but anything else you can point to that has worked for you?

Re: 650B Disc Wheel (DiscBrakes) [RMcMahon21386] [ In reply to ]

Aug 31, 23 1:14

Post #24 of 38 (1697 views)

RMcMahon21386 wrote:

Hey Chris. Curious if you ever had any luck with this. Really frustrated that Canyon is making a triathlon bike that doesn't fit triathlon wheels. Buying a disc cover for my back wheel, but anything else you can point to that has worked for you?

The smallest size of one bike model is a too small market for any manufacturer to develop a dedicated wheel model. Possibly a few women of the Movistar team could not use a disc wheel for time trial stages, as well

Re: 650B Disc Wheel (DiscBrakes) [jaretj] [ In reply to ]

Aug 31, 23 9:34

Post #25 of 38 (1652 views)

I'm old enough to remember when the best time trial specific bikes came with a 700c rear and 26"/650c front.

Dimond Bikes Superfan

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