29er-esque Roadies?

[WIGGUM1]

So, as a taller guy (6'3") I have noticed the recently popularized 29er Mountain bikes. I have ridden them and notice a tremendous diference. Has there been any thought to breaking convention and trying something similar with road bikes, perhaps an 800c? Anyone have any ideas as to the pros/cons to something like this?

 

[Eden]

unless you could get some brands behind you where would you get tubes or tires???

 

[alfeng]

So, as a taller guy (6'3") I have noticed the recently popularized 29er Mountain bikes. I have ridden them and notice a tremendous diference. Has there been any thought to breaking convention and trying something similar with road bikes, perhaps an 800c? Anyone have any ideas as to the pros/cons to something like this?

27" rims are generally 630-17 ERTO ...

The standard tire (27x1.25?) is approximately equivalent in circumference to a 700x30/32 tire.

The disadvantage is the lack of tire variety & sizes ...

AND, most current "road" frames cannot use tires larger than 700x25.

I know that MAVIC made 630-15 MA-40 (and, others, no doubt) rims.

Of course, 30+ years ago, 27" rims were common.

 

[gclark8]

I agree with Alf.

27"(630mm rins) and 28"(635mm rims) have been replaced by 700c (622mm rims), however I am building a bike 58cm for the over 6' rider using the 27x1 1/4 (630mm) wheels with 75psi tyres at the moment, see Classic Aussie Steel below.

Put the numbers into Sheldon Brown's Gear Calaulator, there is not that much speed difference. http://sheldonbrown.com/gears

 

[WIGGUM1]

Let me rephrase, I am talking a completely new size wheelset, where you would need a completely custom built frame to accomadate it like the 29ers in MTBs. I understand the world of cycling is not set up for a larger wheelset size, but I am thinking, if the mountain bike world is gaining momentum in the 29er catagory, which did not previously exist, perhaps cycling could benefit from the equivalent. The speed differences are things I am asking about re: clarks reply. Also power transfer and balance are considerations I would think....Thanks for your responses, this is just a thought I had given the 29ers I have seen about.

 

[mongooseboy]

Let me rephrase, I am talking a completely new size wheelset, where you would need a completely custom built frame to accomadate it like the 29ers in MTBs. I understand the world of cycling is not set up for a larger wheelset size, but I am thinking, if the mountain bike world is gaining momentum in the 29er catagory, which did not previously exist, perhaps cycling could benefit from the equivalent. The speed differences are things I am asking about re: clarks reply. Also power transfer and balance are considerations I would think....Thanks for your responses, this is just a thought I had given the 29ers I have seen about.

ok, simply put:

Road biking is european...probably aint gonna change (hasnt changed much either)

mountain biking is american...changes ALL the time, and there is a lot of room for change, as well.

if a 29" wheel for road biking would help, i think it would have probably made its way into the sport somehow. personally i dont think well see it because it would be limited to bigger frames. Maybe you should just buy a bigger frame? its been done for years and always works...

ps: 29" mountain bikes were NOT built for taller people, at least not the way they are marketed. they are built beacuse a 29" mtb tire rolls over obstacles a lot easier than does a similar 26" tire. 29ers are not new. the hippies had bigger wheels in mind back in early mountain biking, but somone (forgot who) decided 26" was enough...Now the idea has re-surfaced (back in late 90's/early 2000s if i remember right) and hit it big time.

ill keep my 26" mtb and my 700c road bike sizes. Im only 5'8 anything bigger would be, well, big....