Bicycle Mechanics - 27" wheel -> 29"

Can I switch my 27" wheels to 29" wheels? Or will most frames for 27" wheels not work with 29"?

I assume I would have to change/adjust my brakes.

Can I switch my 27" wheels to 29" wheels? Or will most frames for 27" wheels not work with 29"?

I assume I would have to change/adjust my brakes.

Well here's where it gets wierd. You see. a 27" wheel rim is larger than a 29" rim. 29" is what they call a 700c when it's fitted with wide tall tires.
The 27" rim is 630mm bead seat dia. the 29r is 622.
If you have 4mm downward travel available on your brakes, it will likely work. It's done all the time.

Diametrally speaking you can easily put 29er wheels into a 27" frame because the 29ers are 622mm and the 27s are 630mm.

However, the rim width may present a problem. It would likely fit in the frame but if it is a wider rim, it is possible it would be unsafe to use with a tire which was narrow enough to fit the frame. You don't want to put too narrow of a tire on a wide rim. I know a recommended limit for my 27mm wide Rhynolites is around 1.4.

You could probably fit hybrid tires into a 27" frame no problem, because the 27" bikes I have seen usually come with plenty of clearance around a 32mm tire and can run 35 or 37mm cyclocross knobbies (27x1-3/8) no problem. However, it would be wise to check how much clearance you had in the frame, fork, and under the brakes.

sorry by 29" I meant 700c... which looks like it should work fine... sweet.

The brakes should have enough adjustment just by moving the pads down because a lot of bikes came with 27" training wheels and 700c tubulars which were called 27 but were the same size as 700.

29" or "29er" is the colloquial name for 700c/622mm mountain bike equipment.

29" or "29er" is the colloquial name for 700c/622mm mountain bike equipment.
my bad

29" or 29er is just marketing hype invented by some guy trying to re-invent the 700c large tire/wheel market for themselves just to get 15 minutes of fame and a billion in the bank and some bike "culture" wannabes to call him "dude!"

=8-)

???why shouldn't 700c mountain components have their own name?

Diametrally speaking you can easily put 29er wheels into a 27" frame because the 29ers are 622mm and the 27s are 630mm.

However, the rim width may present a problem. It would likely fit in the frame but if it is a wider rim, it is possible it would be unsafe to use with a tire which was narrow enough to fit the frame. You don't want to put too narrow of a tire on a wide rim. I know a recommended limit for my 27mm wide Rhynolites is around 1.4.

You could probably fit hybrid tires into a 27" frame no problem, because the 27" bikes I have seen usually come with plenty of clearance around a 32mm tire and can run 35 or 37mm cyclocross knobbies (27x1-3/8) no problem. However, it would be wise to check how much clearance you had in the frame, fork, and under the brakes.

It's also possible that the 29er tire is so much bigger than the 27 inch tire that the overall diameter of the 29er is significantly more than the 27 inch. It that case radial fork and brake bridge clearance is an issue, especially with fenders.

29" or 29er is just marketing hype invented by some guy trying to re-invent the 700c large tire/wheel market for themselves just to get 15 minutes of fame and a billion in the bank and some bike "culture" wannabes to call him "dude!"

=8-)

I think we've discussed this before a bit, and I really get the impression your shop doesn't have many mountain bike customers(?). If it really bothers you that some mountain bike tires are called, say, 29 x 2.2 instead of, say, 700 x 56c, that's your business and you're entitled to your opinion. But I remember you saying customers will come in and ask for a 29er tire and then you will, exasperated with their cluelessness, show them something in 700 x 32c or whatever. And sure enough, it will turn out that they didn't need a 29er mountain bike tire after all, they needed a hybrid tire.

What the heck is going on out there in San Jose? Do you not have any 29er mountain bikes? Have you not noticed the huge numbers of these bikes being produced by nearly every major bike brand? Have you ever seen or ridden one? Whatever the heck you want to call them, the wheels (with the inflated mountain bike tires installed) are indeed huge compared to anything else commonly available.

And throughout their history, mountain bikes, being an American invention, have always had their frame sizes referred to in inches, not centimeters, and their tire sizes referred to in inches as well (26 x 2.1" as an example). To me, it makes sense to refer to a true mountain bike tire (not a hybrid tire!) in inches. I have a good point of reference when I think of, say, a 26 x 2.2 mtb tire, and if the same tire is available in 29 x 2.2, I'll know, without any conversion necessary, how wide that tire will be on the larger diameter rim.

And btw, the guy who "invented" 29ers, defined as mountain bikes designed for big fat tires mounted on 700c rims, is neither famous nor rich. Not by a long shot. He does, however, despise Gary Fisher.

And btw, the guy who "invented" 29ers, defined as mountain bikes designed for big fat tires mounted on 700c rims, is neither famous nor rich. Not by a long shot. He does, however, despise Gary Fisher.
Very often the person who actually invents a product or comes up with a new concept is not the one that benefits in fame or finances from it but the guy who produces and markets it does.

"Gatorade" was developed by a man at the University of FL and sold millions and millions of dollars worth. However, the inventor made nearly nothing from his invention for decades until enough publicity finally shamed the producer (Stokely Van Camp, IIRC) into rewarding him a bit.

I think we've discussed this before a bit, and I really get the impression your shop doesn't have many mountain bike customers(?). If it really bothers you that some mountain bike tires are called, say, 29 x 2.2 instead of, say, 700 x 56c, that's your business and you're entitled to your opinion. But I remember you saying customers will come in and ask for a 29er tire and then you will, exasperated with their cluelessness, show them something in 700 x 32c or whatever. And sure enough, it will turn out that they didn't need a 29er mountain bike tire after all, they needed a hybrid tire.

What the heck is going on out there in San Jose? Do you not have any 29er mountain bikes? Have you not noticed the huge numbers of these bikes being produced by nearly every major bike brand? Have you ever seen or ridden one? Whatever the heck you want to call them, the wheels (with the inflated mountain bike tires installed) are indeed huge compared to anything else commonly available.

And throughout their history, mountain bikes, being an American invention, have always had their frame sizes referred to in inches, not centimeters, and their tire sizes referred to in inches as well (26 x 2.1" as an example). To me, it makes sense to refer to a true mountain bike tire (not a hybrid tire!) in inches. I have a good point of reference when I think of, say, a 26 x 2.2 mtb tire, and if the same tire is available in 29 x 2.2, I'll know, without any conversion necessary, how wide that tire will be on the larger diameter rim.

And btw, the guy who "invented" 29ers, defined as mountain bikes designed for big fat tires mounted on 700c rims, is neither famous nor rich. Not by a long shot. He does, however, despise Gary Fisher.


Here' the problem in a nutshell:

There's enough confusion already in the bicycle tire market already with the multitude of tire sizes available...why add more especially considering that the "new" reference isn't for a new tire but rather nothing more than a marketing rehash and hype?

I'm not the only person shaking his head...the several shops I visit...all in private shake their heads as well.

It's frustrating and time consuming enough already to have a customer walk in without his bike or wheel or tire and the following ensues:

Customer: I need a tire for my mountain bike...
Shop: Does it have 24" wheels or 26" wheels?
Customer: Um...I don't know...it's a mountain bike.
Shop: (Points to two different bike on the racks...)
Customer: Oh..that one...(points to an MTB bike with 26" wheels...)
Shop: Okay...26 by 1.5, 26 x 1.95 or 26 x 2.125?
Customer: Um...not sure...
Shop: (Grabs a 1.5, a 1.95 and a 2.125....)
Customer: Oh...that one right there look pretty close...(points to the 1.95).


Now let's do a take two with the above dialog as a customer walks in claiming he has a 29er and needs a tire...and of course doesn't have the bike, wheel or tire with him:

Customer: I need a tire for my 29er...
Shop: Does it say "29" on the side of the tire?
Customer: Um...I don't know...I'm pretty sure it's a 29er...my friends say I have a 29er.
Shop: (Points to several different 700c tires up on the the racks...)
Shop: How fat does the tire look...does it look like any of these...
Customer: Oh..that one...(points to a 700 x 45c tire...)
Shop: (Hands the customer the 700 x 45c tire...)
Customer: Um...this says 700 x 45c...I need a 29" tire...
Shop: Don't mean to talk down to you or offend you in anyway - 29er tires are 700c tires...
Customer: Oh...well my friend was telling me that I have to buy a 29" tire...
Shop: Yeah...well basically all a 29er is is a hybrid-mountain bike with really fat 700c tires.
Customer: (Thinks for a minute...) So...I really don't have a 29er then?
Shop: Technically...yes...but a lot of folks now are calling hybrid-mountain bikes 29er's anyway.
Customer: So are you sure this is the right tire?

...and so it goes...for the next 5 minutes the shop has to reassure the customer several times over that the tire will work just fine...and even if it doesn't...bring it and the bike right back and they'll take care of things...

...and then 15 minutes later another person walks in needing a tire...


Poor customer just trying to navigate the worldly maze of different tire specs and trying to trust his local LBS has been victimized not because a fundamental bike design change has occurred - but rather because some moron out there realizing that their "new" hybrid would just be another hybrid in a mature an stable hybrid market needed to establish a "category" of his own in order for it to get the "NEW AND DIIFFERENT" label hype and marketing that would make it stand out.


Don't get me wrong...from a shop perspective...products are products...sales are sales...I'm going to sell the customer what he wants - hopefully I have it.


My point really is...I feel sorry for the customer who once again has to adapt...not because of some fundamental design or frame size change - but for nothing more than marketing and hype. I see it as jerking the customer around.


As a side note...I'm a teacher as well. One thing drives us teachers nuts is for someone to call a seminar to teach us a new and innovative method...only for us to realize 5 minutes in that it is nothing more than "A" that was rehashed as "B" a decade ago and is now presented as "C" and we are all expected to embrace it along with all of its "new" labels and an adopt it - NEVER MIND THAT "B" WAS BANNED Xn YEARS AGO and "B" WAS ADOPTED AFTER "A" WAS BANNED A DECADE BEFORE.

Waste of time and energy for the consumer...waste of time, money and energy for teachers...waste of money as in, "I need to hit the bar for a stiff drink!!!".

=8-)

lol i tell all my friends to call me before they buy anything for their bikes.
I think everyone who bikes needs a bike mechanic friend, to wade through the craziness and to tell them what they do and dont need replaced...regardless of what the shop says. :P

Funny how if you buy a car tire you better be damn specific, but for a bicycle so many people assume they're all the same?

You walk into a big car tire house (we have Mavis) and tell them the year and model of your car and you are set.

You can do the same thing with bikepedia in a bike shop. There is no need for 20 questions. You don't even need the year in most cases. Just who made it and the model. If a customer does not know that, interrogation under the sodium lights is not going to help.

Here' the problem in a nutshell:
.....Waste of time and energy for the consumer...waste of time, money and energy for teachers...waste of money as in, "I need to hit the bar for a stiff drink!!!".

=8-)
Dude, that wasn't a nutshell, it's a novel. You just don't like 29ers :)

Shop: Yeah...well basically all a 29er is is a hybrid-mountain bike with really fat 700c tires.

Is this really what you think? Have you ever seen a 29er mountain bike? Ridden one?

You walk into a big car tire house (we have Mavis) and tell them the year and model of your car and you are set.

You can do the same thing with bikepedia in a bike shop. There is no need for 20 questions. You don't even need the year in most cases. Just who made it and the model. If a customer does not know that, interrogation under the sodium lights is not going to help.

I agree. Most people with a 29'er know they have a 29'er. Chances are, the bike itself has "29'er" or "twentyniner" splashed all over the frame. The owner didn't accidentally purchase a 29'er bike. They either read about them, had friends who convinced them to get one, or had a bike shop salesman convince them, giving them the whole pitch concerning the advantages.
Let the customer ask the questions. If it's clear the customer doesn't know what size he needs, a red flag should go off. Have him bring in the bike. Once he has the bike in the shop, there's every chance you'll be able to sell him something along with the tire.
The bike makers, tire makers, and customers have adopted the 29'er term. It's useless to trying to turn back the clock, or hold out on speaking the language because you have a problem with the terminology.

And btw, the guy who "invented" 29ers, defined as mountain bikes designed for big fat tires mounted on 700c rims, is neither famous nor rich. Not by a long shot. He does, however, despise Gary Fisher.

Now, I recall seeing an early prototype mountain bike from the 50's, developed independently of the re-pack hill crowd. It was built around an old ten speed frame, with cantilever brakes brazed on, and fat 700c tires. Does that make it a 29er?

I can't for the life of me remember the guys name, but he called it a 'woodsie'

29'rs have quite the following and they have their +/-... but they are simply a wider 622 rim with a wider deeper tyre that is designed for off road riding.

A purpose built bike is going to have additional clearance to accommodate the rim / tyre whereas a bike designed to run 622 hybrid wheels / tyres may not have enough clearance and most 700c road bikes are quite limited as to the tyre sizes they can use depending on their configuration.

Full on racing bikes may be limited to a 25 or a 28 while touring bikes and cross bikes can usually handle a 32 or 35 and still have room for fenders... my hybrid can handle massive tyres as it has some insane clearances and anything smaller than a 700:35 looks like it is too small for the bike.

Funny how if you buy a car tire you better be damn specific, but for a bicycle so many people assume they're all the same?
People needing new tires for their cars almost always have the car with them and the dealer can go out and see exactly what size is on it. Customers very rarely come in just for tires without the car they are to go on.

Bike tire customers often come into the LBS sans bike.

Now, I recall seeing an early prototype mountain bike from the 50's, developed independently of the re-pack hill crowd. It was built around an old ten speed frame, with cantilever brakes brazed on, and fat 700c tires. Does that make it a 29er?

I can't for the life of me remember the guys name, but he called it a 'woodsie'

Keep in mind, as mountain bikes came into being, they were all cobbled together from bikes that weren't "mountain bikes." As for your question, "does that make it a 29er?" I would say, at that time (the 1950's), call it whatever you want. "Woodsie" sounds as good as anything to me. See my above post for why I think it makes sense to call a 29" tire a 29" tire now.

Most people with a 29'er know they have a 29'er.

Exactly. That's what baffles me about mr rabbit's postings on the subject. He keeps referring to these customers that have hybrids and yet ask for 29" tires, and then he has to explain that they simply need a hybrid tire. Okay, fine, I could see that happening occasionally. But this seems to be his only experience regarding 29" tires. I've asked him in two different threads whether his shop carries 29er mountain bikes. I've asked him if mountain bikers with 29ers ever come into his shop, not hybrid riders thinking they have 29ers, but actual mountain bikers who do have 29ers. They need tires sometimes. No response, other than to repeat the stories of the mistaken hybrid riders. And then comes the text I highlighted in post #17.

If you're gonna go off on 29ers, that's fine if you know what you're talking about. I think it's preferable if you've actually ridden one off road a bit. Experience off road with a 26"bike, and experience off road with a 29"bike. If you prefer the 26"bike, that's cool; 29ers aren't for everybody-

I have to say that the ride you get on a larger diameter tyre can be very nice... my old roadster runs English oversized 28's which have a 635mm rim and some fairly high volume tyres... it devours bumps.

People needing new tires for their cars almost always have the car with them and the dealer can go out and see exactly what size is on it. Customers very rarely come in just for tires without the car they are to go on.

Bike tire customers often come into the LBS sans bike.

I shop them hard, always have to go look. Then I always know what I want with bike tires, too, so my experiences don't matter much. I have sold bike tires to clueless people, though...amazing how little some know about what they ride.

There are so many tyre and rim sizes out there it can be a little confusing... I deal with a lot of vintage bicycles at my shop and at the co-op and am one of the few people that can replace just about any size of tyre since we stock some pretty obscure sizes.

Just because a tyre says 26 does not mean any 26 inch tyre will fit... there are probably more variations here than with any other rim size.

lol i tell all my friends to call me before they buy anything for their bikes.
I think everyone who bikes needs a bike mechanic friend, to wade through the craziness and to tell them what they do and dont need replaced...regardless of what the shop says. :P

I've watched customers walk into local shops with a knowledgeable friend in tow...yes it does help alot.

=8-)

Dude, that wasn't a nutshell, it's a novel. You just don't like 29ers :)

My problem is with the label...not the bike...which after all is just a mountain-hybrid with very fat 700c tires.

=8-)

There are so many tyre and rim sizes out there it can be a little confusing... I deal with a lot of vintage bicycles at my shop and at the co-op and am one of the few people that can replace just about any size of tyre since we stock some pretty obscure sizes.

Just because a tyre says 26 does not mean any 26 inch tyre will fit... there are probably more variations here than with any other rim size.

You are absolutely right...classic Schwinn 26' stuff is an example...and it's not unusual for someone to walk in with a modern tire and an original Schwinn rim wondering why the two just don't work - the shop that I hang out at alot happening to have a vintage Schwinn expert as the owner is able to straighten things out really quick.

My point basically is: Do we really need to add more of the above to the equation? I mean...enough already!!!

=8-)

Exactly. That's what baffles me about mr rabbit's postings on the subject. He keeps referring to these customers that have hybrids and yet ask for 29" tires, and then he has to explain that they simply need a hybrid tire. Okay, fine, I could see that happening occasionally. But this seems to be his only experience regarding 29" tires. I've asked him in two different threads whether his shop carries 29er mountain bikes. I've asked him if mountain bikers with 29ers ever come into his shop, not hybrid riders thinking they have 29ers, but actual mountain bikers who do have 29ers. They need tires sometimes. No response, other than to repeat the stories of the mistaken hybrid riders. And then comes the text I highlighted in post #17.

If you're gonna go off on 29ers, that's fine if you know what you're talking about. I think it's preferable if you've actually ridden one off road a bit. Experience off road with a 26"bike, and experience off road with a 29"bike. If you prefer the 26"bike, that's cool; 29ers aren't for everybody-


(I'm in San Jose, CA dude...not the Gobi desert...so clue in a little...in terms of what I see, work on and ride...)

Here's the problem...a lot of folks hopping on the 29er bike purchase bandwagon - don't know their tires are 700c unless they ignore the HUGE WHITE LABEL and read the fine black label that most of us know exists...

And then you have the opposite...folks who own a mountain-hybrid without the 29er label getting told by others that they are riding or fixing up a 29er...

...and so the misinformation and confusion starts...


=8-)

I shop them hard, always have to go look. Then I always know what I want with bike tires, too, so my experiences don't matter much. I have sold bike tires to clueless people, though...amazing how little some know about what they ride.


That is very true...as most just want to ride...not get a Ph.D in cycling specifications...yet the day comes when they have to get something themselves...sans bike quite often...and start the locate and purchase quiz with no reference.

=8-)

(I'm in San Jose, CA dude...not the Gobi desert...

I don't know anything about the Gobi desert, but I do know about 29" wheeled mountain bikes. And you still haven't answered my questions about whether you sell 29er mountain bikes (not "mountain hybrids" as you keep calling them), sell actual 29" mountain bike tires (not wide hybrid tires), or have ridden a 29" mountain bike off road. Because you certainly do have some strong opinions about 29ers. I do too, but then again, I own one and ride it. I also sell them, the tires for them, and am thankful for the business they bring to my shop.

I don't know anything about the Gobi desert, but I do know about 29" wheeled mountain bikes. And you still haven't answered my questions about whether you sell 29er mountain bikes (not "mountain hybrids" as you keep calling them), sell actual 29" mountain bike tires (not wide hybrid tires), or have ridden a 29" mountain bike off road. Because you certainly do have some strong opinions about 29ers. I do too, but then again, I own one and ride it. I also sell them, the tires for them, and am thankful for the business they bring to my shop.

Are you new here...cause this is the first time I've seen you in a Bicycle Mechanics thread...and did you really read my posts? Did you? Cause you are raising rebuttals that suggest you read too fast...

...I'm a wheelsmith - 2000+ wheels since 1984...sell online and distribute thru shops...and import as well from Taiwan myself. Did 10 years in shops as a general mechanic and wheelsmith...and now get to watch what I've described above via regular visits to a shop. I'm not someone at home quarterbacking with a cycling magazine as a short yardage pass reference...

Clear now?


Multiple Choice Test of Whether You've Read My Post:


1. MrRabbit hates the 29er label because:

a. He hates the bike.
b. He hates the label.
c. He hates the tire.
d. He hate the introduction of a new size that really isn't new.
e. "b" and "d"


2. MrRabbit's real concern is:

a. Greedy capitalist shop owners who are happy to part the customer with their money.
b. Greedy capitalist promoters doing what promoters do best.
c. A new source of confusion for customers who just ride - as a result of a rehash - not a fundamental req.
d. Greedy capitalist advertisers killing trees for a new product that really isn't new.
e. "a", "b" and "d"


Go back and read my posts...


=8-)

My problem is with the label...not the bike...which after all is just a mountain-hybrid with very fat 700c tires.

=8-)

I think the problem is that you are mislabeling the bike as a mountain-hybrid. You're creating the same confusion you're railing against. You do understand that a 29er is a straight up mountain bike, not in any way a hybrid, don't you? I've never seen a manufacturer label their bike a "29er" intending it to be used for anything other than off-road specific intentions. If they market a bike intending it for city use, or commuter use, they may label the bike as a hybrid, comfort, or commuter, or even a "cross", but never as a 29'er. As such, the label actually helps clear up confusion by specifying both the bikes tire size and intended use. Hell, I don't own one and have never even sold one, but I managed to wrap my brain around the concept.

My problem is with the label...not the bike...which after all is just a mountain-hybrid with very fat 700c tires.

=8-)

mrabbit, you've got a problem, perhaps several issues....you and your friends have driven everyone off of the mountain bike sub-forum with hatorade posts, now you're roaming around BF looking for fights. Sheesh, who reads those pedantic rambles, much less, who has time to write them?

Look at yourself, you've turned into a one-man forum wrecking crew. Please go back under your rock on the MTB sub-forum....

I have to say that the ride you get on a larger diameter tyre can be very nice... my old roadster runs English oversized 28's which have a 635mm rim and some fairly high volume tyres... it devours bumps.

I've got an older English bike that devours bumps. An Alex Moulton.

tcs

you've got a problem, perhaps several issues....

I see one guy writing, attacking a marketing approach.

I see another guy writing, attacking another poster.

tcs

People needing new tires for their cars almost always have the car with them and the dealer can go out and see exactly what size is on it. Customers very rarely come in just for tires without the car they are to go on.

People who complain about bike tire sizes are the same people who think car tires are some mysterious thing as well. Car tires have a lot in common with bike tires in terms of the myriad of options most of which are not correct for a given vehicle. For instance, there are many different widths of tire available for 14" wheels.As you go up in wheel diameter, the width options become even greater. However, you need to pay attention the sidewall aspect ratio because even though you might think you can easily mount a wider/narrower tire to a rim, there is usually a diameter change to go along with it. Car speedometers can't be manually adjusted to accommodate this change either. Among those width options, you have different speed ratings (S thru Z and sometimes beyond). You have also have M&S tires and strictly "summer" tires. There's the ever confusing tread wear rating that's manufacturer specific (you can't compare a 300 tread wear rated tire from one manufacturer to another). Then there are the multitude of tread pattern options depending on whether you want performance or comfort.

As to knowing the model of vehicle and thus knowing what tire size it needs, that's BS. A Honda Civic has about 8 different versions for every model year, using anything from a 14" wheel to a 17" wheel. More knowledgeable customers will want a specific tire width depending on whether they are going for dry performance or grip in snow. They might also have aftermarket wheels that use a far different tire than stock. Those wheels could even different widths front to rear (my Porsche has 7" front and 8" rear rim widths and uses two different tire sizes).

In conclusion, quit yer *****in'!

I've got an older English bike that devours bumps. An Alex Moulton.

tcs

Having ridden a Moulton I agree... their ride is fabulous but that is not due to their tyres but rather, because of their brilliant suspension that compensates for the very small wheels. Without that the Moulton would suffer from a very harsh ride.

I see one guy writing, attacking a marketing approach.

I see another guy writing, attacking another poster.

tcs
Right, but the poster being "attacked" has earned the enmity. This is not an isolated case.

mrabbit, you've got a problem, perhaps several issues....you and your friends have driven everyone off of the mountain bike sub-forum with hatorade posts, now you're roaming around BF looking for fights. Sheesh, who reads those pedantic rambles, much less, who has time to write them?

Look at yourself, you've turned into a one-man forum wrecking crew. Please go back under your rock on the MTB sub-forum....


Mountain Bike sub-forum...? Where's that?

=8-)

First let me say, no, I'm not new here. Second, I'm not going to discuss "29ers" anymore with someone who's issue with it relates to a political agenda. They have other forums for that. So I'm done with that. But since this is a mechanics' forum, and speaking from a mechanics' perspective, maybe these pics will shed some light on what 29er tires actually are and if they make a real difference, whether they're just a hybrid tire, etc. As for what you call them, they're called 29ers. They just are. I've already explained why I think that makes sense IN THE WORLD OF MOUNTAIN BIKING. They're not for everybody. But they do make a bike ride differently off road. Look at the pics, particularly the one comparing a 29" tire and a 26"tire, and imagine the tires rolling over rocks, roots, logs, etc. It's fairly easy to see, from a mechanical perspective, what the difference will be. There is some downside to the big tires. Choice is good.

Also, maybe this will help the OP a bit in seeing what these tire sizes are really like.

In this first pic, I got the biggest 700c hybrid tire I have in the shop, a 700 x 37c, and used it for comparison. The 29er tire is from my own bike, it's 29 x 2.2. If you want to call it a 700 x 56c, that's fine with me. You'll be the only one, though.


http://i414.photobucket.com/albums/pp226/wellbiked/002.jpg

700 x 37c hybrid tire next to the 29 x 2.2:

http://i414.photobucket.com/albums/pp226/wellbiked/003.jpg

And here's the one that's most important in the world of mountain biking. Again, there are advantages and disadvantages to each. But they ARE very different when it comes to riding them off road. Maybe they should have called 29ers "Big-Ass Mountain Bike Tires." Because that's what they are-

http://i414.photobucket.com/albums/pp226/wellbiked/005.jpg

First let me say, no, I'm not new here. Second, I'm not going to discuss "29ers" anymore with someone who's issue with it relates to a political agenda. They have other forums for that. So I'm done with that. But since this is a mechanics' forum, and speaking from a mechanics' perspective, maybe these pics will shed some light on what 29er tires actually are and if they make a real difference, whether they're just a hybrid tire, etc. As for what you call them, they're called 29ers. They just are. I've already explained why I think that makes sense IN THE WORLD OF MOUNTAIN BIKING. They're not for everybody. But they do make a bike ride differently off road. Look at the pics, particularly the one comparing a 29" tire and a 26"tire, and imagine the tires rolling over rocks, roots, logs, etc. It's fairly easy to see, from a mechanical perspective, what the difference will be. There is some downside to the big tires. Choice is good.

Also, maybe this will help the OP a bit in seeing what these tires sizes are really like.

In this first pic, I got the biggest 700c hybrid tire I have in the shop, a 700 x 37c, and used it for comparison. The 29er tire is from my own bike, it's 29 x 2.2. If you want to call it a 700 x 56c, that's fine with me. You'll be the only one, though.


700 x 37c hybrid tire next to the 29 x 2.2:


And here's the one that's most important in the world of mountain biking. Again, there are advantages and disadvantages to each. But they ARE very different when it comes to riding them off road. Maybe they should have called 29ers "Big-Ass Mountain Bike Tires." Because that's what they are-



However you feel about 29ers or 700C or hybrid or mountain bike tires, you have to admit that tire sizing is a confusing mismash. mrrabbit has a point on tire sizing and the confusion of introducing a new size that is really just the old size repackaged.

Car tires aren't sized like bicycle tires and are at least somewhat less confusing. Unlike car tires, bicycle tires are sized to the outside diameter of the tire. That leads to lots of confusion. A 700C or even a 29er tire fits on a 622mm rim. That's a 24.4" rim. Add a 1.125" tire and the size is 26.6". Add a 2.2" tire, like yours and the size really isn't 29"...it's 28.8". Sure you can round up but why be so precise on the tire diameter...2.2"...and then fudge the size by rounding?:rolleyes: To make a true "29er" the tire would have to be 2.3":rolleyes: Or, if you want to be hyperprecise about it, you'd have to measure the knobs so that you could have an accurate height measurement.

And it gets even worse when you go to other sizes. Looking at Sheldon Brown's article on tire sizing (http://www.sheldonbrown.com/tire-sizing.html), you can get a feel for just how silly bicycle tire sizing is. For "26 inch" tires you can range in rim size from 559mm (22") to 599mm (23.6") and still have the tire called a 26". For 24" tires the range is from 507mm (20") to 547mm (21.5").

A far better system...and much less confusing...would be to go by rim size like automobiles do. Calling a tire that fits a 622mm rim...or 24.4" if you insist on the 'Merican system:rolleyes:...by a different name doesn't make it a different size. It still fits the same rim.

A far better system...and much less confusing...would be to go by rim size like automobiles do.

As I pointed out, the automobile tire sizing system has it's own little quirk with specifying "aspect ratio" as opposed to the simpler to understand and equate "outside diameter." Given tire diameter's importance for speedometer accuracy, you'd think they'd want to make that dimension clear to buyers. There's also the issue of mixing millimeter dimensions for the width and inch dimensions for the rim diameter in the tire size.

Car tire sizing can be a bit confusing, but very few people buy tires and then take them home to mount them. You almost always have professional help to find the right one. That's not true with bike tires.

@ well biked - I see what you're saying about naming tires based on what they're used for. But what do you call a 700x35 knobby tire? It's made for a 'hybrid' bike, but is not well suited for riding on pavement, much better for trails. Should there be another size for "dirt tires for hybrid bikes"? Seems more confusing to me. I say, have the size be an accurate statement of what it will fit on. 29=700 so call them one thing. I know there are issues of clearance for different widths, but that's true of almost all bikes as well. Should a 700x28 road tire be called something different becuase it might not fit in a frame designed for super narrow racing tires?

The fact that there are at least three different "26" sizes is bad enough. I hate that fractional sizes are different than decimal. Anyone who has studied any math should be annoyed that 1 3/4 does not equal 1.75. Most of the odd ball 26's were caused by Schwinn trying to force a new standard on everyone else a la Betamax. It didn't work out too well in either case.

I think the number should refer to the rim size. Where in 29 er's it refers to the standard tire size. I mean you don't use a 29" rim. That is my opinion. 29X2.2 is weird since both numbers refer to the size of the tire, and none of them refer to the size of rim. So really it needs to be something like 622/29X2.2? But the second part is just redundant.

However you feel about 29ers or 700C or hybrid or mountain bike tires, you have to admit that tire sizing is a confusing mismash. mrrabbit has a point on tire sizing and the confusion of introducing a new size that is really just the old size repackaged.

I completely understand that. But again, within the world of mountain biking, it actually does make sense. 26 vs. 29. Simple. As already stated in the thread, most people with 29ers realize they have a 29er. I think there are some marginal "mountain hybrids" that probably use something like a 700 x 45c tire and have them labeled as 29ers. I admit, that's especially confusing. But those aren't real mountain bikes, and it's not like they're among the most common hybrids out there.

[QUOTE=DLM;10295454]But what do you call a 700x35 knobby tire? QUOTE]

If it really is a knobby tire, and its 700 x 35c, it's probably considered a cyclocross tire. Not that they're only good for cyclocross, but most people know what a cyclocross tire is, especially someone looking for a knobby tire in 700 x 35c.

Car tire sizing can be a bit confusing, but very few people buy tires and then take them home to mount them. You almost always have professional help to find the right one. That's not true with bike tires.

@ well biked - I see what you're saying about naming tires based on what they're used for. But what do you call a 700x35 knobby tire? It's made for a 'hybrid' bike, but is not well suited for riding on pavement, much better for trails. Should there be another size for "dirt tires for hybrid bikes"? Seems more confusing to me. I say, have the size be an accurate statement of what it will fit on. 29=700 so call them one thing. I know there are issues of clearance for different widths, but that's true of almost all bikes as well. Should a 700x28 road tire be called something different becuase it might not fit in a frame designed for super narrow racing tires?

The fact that there are at least three different "26" sizes is bad enough. I hate that fractional sizes are different than decimal. Anyone who has studied any math should be annoyed that 1 3/4 does not equal 1.75. Most of the odd ball 26's were caused by Schwinn trying to force a new standard on everyone else a la Betamax. It didn't work out too well in either case.

If you count decimal and fractional and French sizes, there are 12 sizes that "fit":rolleyes: within the 26" category. 'Tis a dumb way to size anything.

I completely understand that. But again, within the world of mountain biking, it actually does make sense. 26 vs. 29. Simple. As already stated in the thread, most people with 29ers realize they have a 29er. I think there are some marginal "mountain hybrids" that probably use something like a 700 x 45c tire and have them labeled as 29ers. I admit, that's especially confusing. But those aren't real mountain bikes, and it's not like they're among the most common hybrids out there.

I don't know how long you've been mountain biking so please don't take this the wrong way. There was a time when mountain bike tires were really rather narrow in an attempt to make the bikes faster. Some race tires were as narrow as 1.5" and still as knobby as a 2.125" tire. The intended use should indicate whether a tire is a 'mountain bike tire' or not. Would a 26x1.95 tire not be a mountain bike tire because it's narrower than the 'usual' mountain bike tire? It's a 49mm tire which is only slightly wider than a 45.

Same with bikes. There are some bikes that I might not consider to be real mountain bikes but other people are perfectly happy with them.

Let's also not forget that chico1st original question was whether or not he could convert a 27" wheel to a 29" wheel. That, in itself, speaks volumes about the confusion that is tire and wheel sizing. 30 years ago, 27" wheels might have been referred to as a 28" wheel.