Am considering two bikes - one has 650c tires (because of the small frame size), the other 700c. Any disadvantage having 650c tires?

700C.

650C: Hard to find spares, tires, tubes. Harsh ride. Tri-Geeks only. If you are less than 5 feet tall though, it may help the geometry on a small frame.

Flatting more than once on a group ride, almost never anyone able to help you with a tube.

Hmmm......650c = Tri-Geeks only? So one of your justifications for riding 700c is that you get to look like everone else. To that I say 700c = Lemming Award.

Its not that hard to find 650c tubes/tires. In fact, it might be beneficial as it encourages you to do a little better planning. Its not that hard to pack 2 tubes. I always take an extra tire to any triathlon/race in case something goes wrong before the start. Don't pack it during the race, just keep it with your gear. Its a tire that I like and want to use. My buddy trusts that 700c tires are easier to find in shops. Well, he blew out a tire before our last race and had to settle for something he would not ordinarily buy at a premium price.

What's your reason for using 650c?

When I purchased my bike, I wasn't specifically looking for a bike with 650c wheels. I just happened to find a good deal on one. Since then I've sat back and listened to alot of the pros and cons of both wheel sizes and I feel content riding on the 650's.

Some of the arguements I've heard for both sides:
700's have more rotational momentum. - 650's spin up faster.
700's ride softer. - 650's don't flex as much when you are really driving.
650's have less rolling resistance because the angle coming in contact with the ground is more acute.
650's have less wind resistance. Shorter wheel = less surface area. This is why TT'ers were using a 700c on the back, and a 650c on the front for a while. (It is illegal now. Must have same size tires on front and back.)

I think its silly to say go 700c because it is easier to find tubes/tires. Yes, it is, but how often do you wait until a tire blows to replace it? And how often is an LBS there when it happens? If you are lucky enough to be near an LBS, you will be at the mercy of their stock on hand at their price. Better to buy your spares ahead of time when you can get exactly what you want for a respectable price.

I ride solo alot. I enjoy company some of the time, but I also appreciate the time when it is just me and my bike going at my pace. I have learned to not depend on others for tubes and tires. Would you expect somebody to carry your water bottle for you?

In all honesty, I would not have even chimed in here if Spunout hadn't used the term "Tri-Geek." Why not just say Tri-athlete? It is true that the trend a few years back was for multi-sport athletes to use the 650c because they were thought to be more efficient and better suited to the geometry of a tri-bike. But to put it frankly, I have only been into cycling for the past 5 months and before that I thought anybody on a bike wearing spandex was a "geek." I have learned the fault of my ways and relish the opportunity to wear spandex now. If you go through life putting people into the category of "geek," you deserve no better than to be put into that category by someone else.

I wouldn't pass up a good deal on a bike sporting 650c wheels just because I'm afraid of looking like a tri-athlete. Encouraging, exercising, or tolerating such a mindset only adds one more barrier to entry in a sport that already has enough. Roadbikers cry for community support, yet a handful of them can really make a mockery of the entire institution. In my opinion, anybody that invests time and money into cycling, with the intent to improve their self and the knowledge of the risk involved, doesn't deserve to be labled a "geek" by anyone.

Holy rant! Time to put on my sleeveless jersey and ankle socks and hit the road.

I was curious because I ride MTB. Since the introduction of 29" wheels it's become obvious they offer quite an advantage on smoother terrain over 26" wheels. Therefore it sounded odd to me that smaller road wheels would have an advantage aside from the aero aspect.

I was curious because I ride MTB. Since the introduction of 29" wheels it's become obvious they offer quite an advantage on smoother terrain over 26" wheels. Therefore it sounded odd to me that smaller road wheels would have an advantage aside from the aero aspect.

Well, for one thing, there is a bigger difference between 26" (559 mm dia. rim) and 29" (622 mm dia. rim) MTB wheels than between 650c (571 mm dia. rim) and 700c (622 mm dia.rim) road wheels.

But more to the point, just as it is difficult to build a 29"er bike for a smaller rider, it can be difficult to build a 700c bike for a smaller rider. Generally speaking, 700c wheels are preferable for medium to large riders (for a variety of reasons), but 650c may be preferable for smaller riders for geometry reasons. As far as potential performance advantages, it is interesting to note that professional racers have occasionally experimented with 650c wheels, but except for smaller women, pro racers have always returned to 700c wheels (both sizes are perfectly legal under UCI rules).

Interesting topic for me since I will be looking at a bike with 650c tires later today. This will be for my son (15 years old) and I am a bit hesitant because of availablitlty of tires and tubes for this size. But since I am riding a mtn bike converted to a pseudo-road bike, would my mtn bike tube work with his 650c wheels? My tire size is 26 x 1.125.
As for the original poster, if the mtn tubes will work, then you may only be inconvienced in the tire selection in the lbs. But you will still be hard pressed for a tube or tire from somebody on the road.

No, ATB tubes are 559mm diameter, 650c tubes are 597mm diam, so they absolutely won't work.

As for nobody having a 650c tube-you can always use a 700c tube and fold it over. It will work well enough to get you home.

When I purchased my bike, I wasn't specifically looking for a bike with 650c wheels. I just happened to find a good deal on one. Since then I've sat back and listened to alot of the pros and cons of both wheel sizes and I feel content riding on the 650's.

Some of the arguements I've heard for both sides:
700's have more rotational momentum. - 650's spin up faster.
700's ride softer. - 650's don't flex as much when you are really driving.
650's have less rolling resistance because the angle coming in contact with the ground is more acute.
650's have less wind resistance. Shorter wheel = less surface area. This is why TT'ers were using a 700c on the back, and a 650c on the front for a while. (It is illegal now. Must have same size tires on front and back.)

I think its silly to say go 700c because it is easier to find tubes/tires. Yes, it is, but how often do you wait until a tire blows to replace it? And how often is an LBS there when it happens? If you are lucky enough to be near an LBS, you will be at the mercy of their stock on hand at their price. Better to buy your spares ahead of time when you can get exactly what you want for a respectable price.

I ride solo alot. I enjoy company some of the time, but I also appreciate the time when it is just me and my bike going at my pace. I have learned to not depend on others for tubes and tires. Would you expect somebody to carry your water bottle for you?

In all honesty, I would not have even chimed in here if Spunout hadn't used the term "Tri-Geek." Why not just say Tri-athlete? It is true that the trend a few years back was for multi-sport athletes to use the 650c because they were thought to be more efficient and better suited to the geometry of a tri-bike. But to put it frankly, I have only been into cycling for the past 5 months and before that I thought anybody on a bike wearing spandex was a "geek." I have learned the fault of my ways and relish the opportunity to wear spandex now. If you go through life putting people into the category of "geek," you deserve no better than to be put into that category by someone else.

I wouldn't pass up a good deal on a bike sporting 650c wheels just because I'm afraid of looking like a tri-athlete. Encouraging, exercising, or tolerating such a mindset only adds one more barrier to entry in a sport that already has enough. Roadbikers cry for community support, yet a handful of them can really make a mockery of the entire institution. In my opinion, anybody that invests time and money into cycling, with the intent to improve their self and the knowledge of the risk involved, doesn't deserve to be labled a "geek" by anyone.

Holy rant! Time to put on my sleeveless jersey and ankle socks and hit the road.

Cervelo's posted research for their reason for dropping 650 in all but smallest sizes: http://www.cervelo.com/tech/qa/Q-A168.html

Apologize for the Tri-geek comment. Change that to multi-sport geeks ;-)

If it came down to a choice that isn't required solely because of an extremely small frame, go 700. I seem to be supported here on that.

Geek -
1. A person regarded as foolish, inept, or clumsy.
2. A person who is single-minded or accomplished in scientific or technical pursuits but is felt to be socially inept.
3. A carnival performer whose show consists of bizarre acts, such as biting the head off a live chicken.

Athlete -
1. A person possessing the natural or acquired traits, such as strength, agility, and endurance, that are necessary for physical exercise or sports, especially those performed in competitive contexts such as triathlons, but not road bike races.

I'm not quite sure how a three-sport competition can be described as single-minded, but I sure have seen lots of tri-athletes bite the heads off chickens. ;-)

700C.

650C: Hard to find spares, tires, tubes. Harsh ride. Tri-Geeks only. If you are less than 5 feet tall though, it may help the geometry on a small frame.


And proud of it. I do not like 650's due to the fact that you just can't find good deals on tires, tubes, spokes and wheels... You got to go 55/48 or larger on the front rings and if you are taller than 5'8, your bike just looks strange...

If there is an argument for 650, it is for just the reason you stated, small frame sizes.

I have logged a zillion of miles on 650 and 700. I can't really tell the difference in harshness, stiffness or anything. What I hated about the 650's was the really long head tube that accompanied my 55 or 56 cm frames.

Now, if you want to put a 650 front and a 700 rear funnybike under me, now that is a different story...

Hey, any of you roadies want to go swim back and forth in the pool about 60 times with me at lunch today??

Hey, any of you roadies want to go swim back and forth in the pool about 60 times with me at lunch today??

Geeze, can't make it. Just booked a massage!

No, ATB tubes are 559mm diameter, 650c tubes are 597mm diam, so they absolutely won't work.

As for nobody having a 650c tube-you can always use a 700c tube and fold it over. It will work well enough to get you home.
You can stretch the tube to make up the diameter (circumference) difference, but the valve is probably a different type so you are screwed with the MTB tube.

Back to the original premis, there is no availability problem with 650 tires and tubes. www.biketiresdirect.com (http://www.biketiresdirect.com), yeah, yeah, or one of the great sponsors here. yes you will be hard pressed to get a tube from someone on the road, but so what, you always bring a tube don't you? As far as getting a tire from someone on the road, that's not going to happen in this country, regardless of size.

If you mean the LBS does not have them available, well the LBS rarely has what you need, "Dude I can order it, if you want". Of course it is at a 50% premium when they do have it. LBS guys are nice guys, but they do get under my skin sometimes.

Most standard to higher-end MTB stuff is presta valve.

No, ATB tubes are 559mm diameter, 650c tubes are 597mm diam, so they absolutely won't work.

As for nobody having a 650c tube-you can always use a 700c tube and fold it over. It will work well enough to get you home.
the diff is 559 vs 571, which is pretty minimal so the tubes can be swapped. it's not 559 vs 597(?) as you stated.

nmnmnm