"650B - Finally a reason to exist?"

[dwt]

Interesting blog opinion:

Vintage One: 20 years of Mtn Bike passion and counting.: 650B - Finally a reason to exist?

[ljsmith]

I have never like this idea that 650b is basically a compromise allowing for longer travel big wheeled bikes. Basically its saying 650b is not as good as 29, but since you can't fit 29er wheels on a long travel frame I guess 650b is good for something. It just gets tiring when people speak like 29ers are the best at ALL things and there is no reason not to ride one unless you cannot actually fit the wheels in the type of frame you want. I personally believe there is a place for every wheel size, even 26! It all depends on your riding style and your local terrain.

[dwt]

Originally Posted by ljsmith

I have never like this idea that 650b is basically a compromise allowing for longer travel big wheeled bikes. Basically its saying 650b is not as good as 29, but since you can't fit 29er wheels on a long travel frame I guess 650b is good for something. It just gets tiring when people speak like 29ers are the best at ALL things and there is no reason not to ride one unless you cannot actually fit the wheels in the type of frame you want. I personally believe there is a place for every wheel size, even 26! It all depends on your riding style and your local terrain.

That's "glass half empty" spin." An other way of putting it is that as the terrain and style move from "XC" to "AM" the benfeits of the 29 platform start to get outweighed by the burdens:

As one frame builder put it:

Why 650B? It makes a lot of sense on a lot of fronts. But why 650B instead of 29 inch or 26 inch wheels? Here’s my take.

Twenty-nine inch wheels are a hoot to ride. And at 6’3” tall, the big wheels make my bike look very proportional. But, there are some problems that need to be overcome because of the big wheels. When designing a bicycle frame, I start with a general concept of what I want my seat angle, head angle, effective top tube length, and bottom bracket height to be. Then starting with the bottom bracket, I lay in my seat tube. The seat tube/bottom bracket relationship is crucial to the rider’s position on the bike because the position of your butt and feet is what gets the pedals rotating. You can’t fool with that relationship beyond a small variance.

With the bottom bracket and seat tube in place, I figure out what my bottom bracket drop (bottom bracket height) will be. Then creating a horizontal line above the bottom bracket that represents my drop, I draw a circle with the center being the center of the bottom bracket and the radius representing the chainstay length that I want. Where that circle intersects the horizontal line of the bb drop, that is where the rear axle of the wheel will be located. Then from this spot, I draw in the diameter of the rear wheel.

Oops, those 29” wheels don’t fit. I’ve either got to increase the seat angle or lengthen the chainstays. Altering the seat angle is not an option, in my opinion. So, here comes the first concession to designing around 29” wheels – lengthening the chainstays. Lengthening the stays isn’t actually a bad thing. It’s what helps a bike climb steeps. Getting the rear wheel back further helps to keep the front end of the bike down when climbing. But because the big tire also takes up space that is also occupied by the front derailleur, the stays have to get pushed back even further.

So, I lengthen the chainstay so the rear wheel clears the seat tube and the front derailleur. Then with the top tube, head tube, down tube, front wheel in place along with the fork and fork offset, I fine tune the head angle to get a decent amount of trail which aids in the stability of the bikes steering. All is good until I get to the smaller sizes and realized that toe overlap is a possibility.

On the smaller sizes, you have to push the front end out to where the wheel and toe doesn’t overlap. You do this by also increasing the seat angle and reducing the head angle to also try to preserve the riders’ position. What you end up with is a “small” sized frame that has virtually the same front center as the “medium” sized frame.

Okay, that didn’t seem too hard. But this is a hardtail. When you throw in suspension, the design takes on a whole new variable. Now, you’ve got that big ole rear wheel moving in an arc around a pivot. Seat tube angles just got ridiculously steep. Some are over 74 degrees. Talk about being over the front of the bike!

So, here’s where 650B wheels come in. This mid-sized wheel “almost” fits into existing 26” wheel frames. Minor tweaking is all that is needed to fine tune a suspension frame for 650B wheels instead of a complete overhaul that is required of 29” wheels. A full-suspension bike can be designed with bigger (than 26”) wheels without having to make many concessions to accommodate the wheels.

But why 650B wheels and not 26 or 29? I don’t think that’s the question. There’s no reason why all can’t co-exist. After all, road bikes are available in 700C and 650C wheel sizes. BMX bikes are available in 12”, 16”, 18”, 20” and 24” tire sizes. All of those tire sizes (700C, 650C, 26", 24", 20", ... and even 650B) are also available in a huge variety of widths. And further, cranks and stems are available in a wide range of lengths that allow riders to tailor their fit on the bike. So why not wheel sizes?

Black Mountain Cycles: 650B...

[MMcG]

Too bad that Mike Varley never followed through with his 650b mtb frames. I guess he had to follow where the market would be best suited for solid sales and thus went for a road bike frame and a CX bike frame for his first two Black Mountain Cycles frames. With that said - both his road and CX frames are mighty mighty nice frames!

With that said - it would have been cool to have a 650b mtb frame option from the likes of Mr. Varley.

[mtroy]

Originally Posted by ljsmith

I have never like this idea that 650b is basically a compromise allowing for longer travel big wheeled bikes. Basically its saying 650b is not as good as 29, but since you can't fit 29er wheels on a long travel frame I guess 650b is good for something. It just gets tiring when people speak like 29ers are the best at ALL things and there is no reason not to ride one unless you cannot actually fit the wheels in the type of frame you want. I personally believe there is a place for every wheel size, even 26! It all depends on your riding style and your local terrain.

You may be tired of people saying it, but I am not one of them. Re-read the blog post...maybe I was not clear enough.

Even if the 29" wheel fit perfectly in that over 120mm spot, I am not convinced it would be best. But, that is a silly point, since, in point of fact, it does not fit there without all kinds of compromises.

2013 will be interesting, if I am right. If not, well, there ya go.

[dwt]

Originally Posted by mtroy

You may be tired of people saying it, but I am not one of them. Re-read the blog post...maybe I was not clear enough.

Even if the 29" wheel fit perfectly in that over 120mm spot, I am not convinced it would be best. But, that is a silly point, since, in point of fact, it does not fit there without all kinds of compromises.

2013 will be interesting, if I am right. If not, well, there ya go.

I agree. More than one poster in the AM forum is waiting for a big wheel bike to podium in a gravity event such as megavalanche before even thinking about one. My guess is that a Lunch Box or a 650b version thereof would be excellent in an enduro.

[ljsmith]

Originally Posted by mtroy

You may be tired of people saying it, but I am not one of them. Re-read the blog post...maybe I was not clear enough.

Even if the 29" wheel fit perfectly in that over 120mm spot, I am not convinced it would be best. But, that is a silly point, since, in point of fact, it does not fit there without all kinds of compromises.

2013 will be interesting, if I am right. If not, well, there ya go.

I re-read what it said. Basically there is nothing in the blog about the merits of the actual ride characteristics of the 650b wheel itself. It basically says that people want long travel 29ers but the wheels don't fit well, so 650b fits the bill.

[mtroy]

Originally Posted by ljsmith

I re-read what it said. Basically there is nothing in the blog about the merits of the actual ride characteristics of the 650b wheel itself. It basically says that people want long travel 29ers but the wheels don't fit well, so 650b fits the bill.

True, I do not speak to the merits other than size and fitment. But I am not really stating that it is only fitment that rules out 29" wheels as well. I am a skeptic that it is the best place for 29ers...bigger travel. I guess that was more to the point of my rebuttal, but not the point of my blog.

So, your point is valid to that regard.

Carry on.

[Walt]

That Black Mountain guy does not IMO know what he's talking about (to be fair, it looks to me like they only ever did one frame, a CX/monstercross kind of thing). Curved, kinked, offset, or interrupted seat tubes are used for all kinds of bikes with all sizes of wheels, and it's actually really easy to get the saddle where you want it with just a tiny bit of creativity, while leaving room for whatever size of wheel you want. Hell, I've done hardtail 29ers with <16" chainstays... though of course that means I could do a 26er with <14.5" ones, I guess.

I just built a 6" travel 29er with a shorter wheelbase than an equivalently sized SC Nomad (and I've been doing stuff like that since 2005). If I can do it in my garage, you can bet that big companies can do it if they want to. If you can't conceive of building a frame with anything but a straight line seat tube connecting the BB and saddle, then yes, you're pretty much screwed.

Just to be clear, I love 650b wheels, I build 650b bikes, but I just don't like seeing uninformed framebuilding info passed on as gospel. Long travel 29ers have very few tires, rims, or forks available, basically. Those are the obstacles to doing FS bikes similar to what's available in 26", not geometry or wheel size constraints. 650b may very well find a niche in the gravity market, and I'd love to see that happen, but it won't be because it's impossible to build 29ers that do the same job.

-Walt

Originally Posted by dwt

That's "glass half empty" spin." An other way of putting it is that as the terrain and style move from "XC" to "AM" the benfeits of the 29 platform start to get outweighed by the burdens:

As one frame builder put it:

[dwt]

Originally Posted by Walt

650b may very well find a niche in the gravity market, and I'd love to see that happen, but it won't be because it's impossible to build 29ers that do the same job.t

You can see how the mechanically challenged among us get confused by the info that's out here. The "29'er not good for long travel" meme has been in circulation a while.

You and Lenz disprove the folklore with actual functioning realities. I also appreciate your explanations of this stuff in this forum and others

Nonetheless, I can't help but wonder: if Lenz calls his 4" version of 650b "Revelation", what will he call the 6" version: "Paradise?"

[Walt]

Having Devin doing a 650b frame is the best news in the 650b world this year. I could care less about Jamis, I could care less about stuffing 650b wheels into 26" frames - Devin will do 650b and FS right, and the bike will kick ass.

Then 3 or 4 years from now, lots of other companies will do something similar, and we'll all have 3 good mountain bike wheel size choices without having to make sacrifices on parts availability or travel or geometry. Hopefully.

I do not understand how Devin picks the names of his bikes ("Revelation" is fine, "Lunchbox"? That's the name of my sister-in-law's morbidly obese cat...) but that's not much of a criticism!

_Walt

Originally Posted by dwt

You can see how the mechanically challenged among us get confused by the info that's out here. The "29'er not good for long travel" meme has been in circulation a while.

You and Lenz disprove the folklore with actual functioning realities. I also appreciate your explanations of this stuff in this forum and others

Nonetheless, I can't help but wonder: if Lenz calls his 4" version of 650b "Revelation", what will he call the 6" version: "Paradise?"

[dwt]

Originally Posted by Walt

Having Devin doing a 650b frame is the best news in the 650b world this year. I could care less about Jamis, I could care less about stuffing 650b wheels into 26" frames - Devin will do 650b and FS right, and the bike will kick ass

I agree. Here's a frambuilder who produced 29'ers with 5, 6, and 7" of travel, when most of the folklore buzz was "that not possible." With that accomplishment under his belt, he goes ahead and produces a 650b, which is not only bold in itself, but pretty much competing with his other products. Showing that he is more about the mechanical possibilities of bicycles than just crass sales or riding the 29'er wave.

I do not understand how Devin picks the names of his bikes ("Revelation" is fine, "Lunchbox"? That's the name of my sister-in-law's morbidly obese cat...) but that's not much of a criticism!

Here's where "lunchbox" came from:

Interbike 2011: Havin’ A Hot Dog With Devin Lenz | Twenty Nine Inches

Still think that his 6" 650 b will be called "Paradise" or "Heaven" or "Perfection."

[MMcG]

I can't help but wonder if Mr. Lenz didn't decide to change up the Revelation to 650b wheels more because he wasn't selling many in 26er guise than anything else.

Do you think that's the case - or do you think he see's true merit in the wheel size? It would be great to hear from him or someone affiliated with him on the subject of 650b and the merits of the wheel size for Full Suspension applications.

[laffeaux]

Originally Posted by Walt

That Black Mountain guy does not IMO know what he's talking about (to be fair, it looks to me like they only ever did one frame, a CX/monstercross kind of thing).

I believe that he's talking in terms of frames that will be produced in larger number production runs, not about one-off custom frames. Mike (at Black Mountain) designed quite a few bikes at Haro before going out on his own.

[laffeaux]

Originally Posted by dwt

Interesting blog opinion:

Vintage One: 20 years of Mtn Bike passion and counting.: 650B - Finally a reason to exist?

I like the conclusion: "New motto: Ride the biggest wheel that works for you."

Every frame, every wheel, and every tire is a compromise. Nothing can be perfect for every rider under every condition on every trail. Giving builders and riders more choices will only make things better (unless you have to stock all of the new items that are being made).

The answer is: "there is no right answer." Ride what works for you. And keep an open mind.

[Guitar Ted]

Originally Posted by Walt

Having Devin doing a 650b frame is the best news in the 650b world this year. I could care less about Jamis, I could care less about stuffing 650b wheels into 26" frames - Devin will do 650b and FS right, and the bike will kick ass.

I agree, and I would love to try his version of one.

Then 3 or 4 years from now, lots of other companies will do something similar, and we'll all have 3 good mountain bike wheel size choices without having to make sacrifices on parts availability or travel or geometry. Hopefully.

_Walt

You won't have to wait 3 or 4 years if what we're hearing is true. I've no doubt it is.

[Walt]

The folks at Lenz, Canfield, and Kona have proven that you can do a mass-production 29er with short (shorter than the average 26er, anyway) chainstays in various configurations, so Mike's claims are demonstrably false, even if we assume he's talking only about production bikes. That is the point I was trying to make.

-Walt

Originally Posted by laffeaux

I believe that he's talking in terms of frames that will be produced in larger number production runs, not about one-off custom frames. Mike (at Black Mountain) designed quite a few bikes at Haro before going out on his own.

[Malibu412]

I can't wait 'til Copperfield stops by and takes a dump in this thread.

[colker1]

Originally Posted by Walt

That Black Mountain guy does not IMO know what he's talking about (to be fair, it looks to me like they only ever did one frame, a CX/monstercross kind of thing). Curved, kinked, offset, or interrupted seat tubes are used for all kinds of bikes with all sizes of wheels, and it's actually really easy to get the saddle where you want it with just a tiny bit of creativity, while leaving room for whatever size of wheel you want. Hell, I've done hardtail 29ers with <16" chainstays... though of course that means I could do a 26er with <14.5" ones, I guess.

I just built a 6" travel 29er with a shorter wheelbase than an equivalently sized SC Nomad (and I've been doing stuff like that since 2005). If I can do it in my garage, you can bet that big companies can do it if they want to. If you can't conceive of building a frame with anything but a straight line seat tube connecting the BB and saddle, then yes, you're pretty much screwed.

Just to be clear, I love 650b wheels, I build 650b bikes, but I just don't like seeing uninformed framebuilding info passed on as gospel. Long travel 29ers have very few tires, rims, or forks available, basically. Those are the obstacles to doing FS bikes similar to what's available in 26", not geometry or wheel size constraints. 650b may very well find a niche in the gravity market, and I'd love to see that happen, but it won't be because it's impossible to build 29ers that do the same job.

-Walt

The Black Mountain Guy helped design Haro's Mary.. he has more experience w/ the wheel than just his own bike like.
"I just don't like seeing uninformed framebuilding info passed on as gospel."
I know.. bad internet day.