650B is NOT 27.5"

[Overlord]

After reading all 6 pages I have come to the conclusion that a tire is a tire is a tire. They are round hold air and allow me to ride my bike.

As they say------Different strokes for different folks.

Just ride the bike and enjoy it.

 

Next time we can work on world peace.

[Agteros]

After reading all 6 pages I have come to the conclusion that a tire is a tire is a tire. They are round hold air and allow me to ride my bike.

As they say------Different strokes for different folks.

Just ride the bike and enjoy it.

 

Next time we can work on world peace.

world peace.. one wheel size at a time

[RockCoach]

I'm more concerned with the knobbly pattern of the tyre.

[morkys]

http://www.justridingalong.com/wordpress/wp-content/uploads/2012/04/wheel_size_illus1.gif

 

http://brimages.bikeboardmedia.netdna-cdn.com/wp-content/uploads/2012/06/650B-wheel-size-comparison-diagram.jpg

 

For all intents and purposes, when considering a 2.25 tire...

 

650B is 27.5"

 

26" mtb is not 26"...it's 26.5. That is why it is confusing.

 

I have been researching MTB wheel sizes for a little over a year now and I've learned quite a bit. When I first looked into the 650B MTB size I assumed it was in the middle of 26 and 29. I soon realized this was incorrect. If you look at the pics that Jacquers posted, and run the numbers you will figure it out. The discovery is not that 650B isn't 27.5"...because it is. In fact, a 650B wheel with a 2.25 tire is closest to 27.5" than either of the other wheels are to their namesake sizes. A 650B wheel and 2.25 tire is 27.496" so you may as well round it up to 27.50". Take a look at the 29'er wheel with a 2.25 tire, it's 28.976" or rounded up 28.98"...pretty close to 29" anyways. The thing nobody here has mentioned though is, look at the "26 inch" MTB wheel and tire. It is 26.496" or 26.5. So the reason that 650B is not half way in between the 26 and 29 wheel sizes is not that 650B isn't 27.5, it is, the reason 650B is not in the middle is because 26 is really 26.5. Look at the measurements in the diagrams and convert mm to inchs (2.54 cm per inch). Each diagram shows a rim with a tire of about 2.24 inches. Using a 2.25 inch tire makes sense since a 2.25 is exactly the average of the range of tires that many XC and ALL MOUNTAIN chose from, between 2.1 to 2.4. Measure your own 26, 650B or 29 wheels/tires and you'll see.

 

Over at MTBR there are many discussions about wheel sizes, with lot's of talk about 26, 650B and 29. There are so many reasons why people like one wheel size over another, but let's just say some people like the lightweight manouverability of the smaller 26 mtb wheels and bikes and others like the rollover and traction of the 29. Some people argue that 650B doesn't offer enough improvement over 26 to make it worth while. I have yet to test the wheel sizes extensively.

 

One reason why 650B became an mtb size is that bike designers were having trouble making long travel 29'ers with good geometry. 650B was thought to provide a bit more rollover advantage and traction without the problems of frame design. When I first started researching wheel sizes and discovered all the 650 wheel sizes (650 = 597 mm > 650A = 590 mm > 650B = 584 mm > 650C = 571 mm (and remember when GT invented the 700D wheel size for their hybrids? 587 mm), like another poster here, I thought 650A would have been the proper middle size at 590 mm. It is exactly in the middle of 559 mm 26" wheel and the 622 mm 29'er. That could have mde sense, but eventually, I believe the ideal wheel size could have actually been the 597 mm wheel size. It is exactly 1 inch smaller than 29'er. Perhaps that is all that would have been needed to make a smaller wheel that was another option that worked. I personally think that this wheel size should have been tested. Since it's only 1/2" bigger than 650B, thoeretically, I bet a 597 mm wheel with a 2.25 tire could fit on a 650B bike since it's not much bigger. Many 650B wheels fit on 26" bikes even though the wheels were 1 inch bigger. The difference between 584 and 597 mm is only 1 inch. It may seem like splitting hairs, but I still think it could be a workable option.

 

And the argument that a 26" wheel with a large tire is the same as a 650B is not comparing apples to apples. A 26" wheel with a tire big enough to be 27.5" is going to be alot different in ride and feel than a 650B with a 2.25 tire. One thing that you want to avoid, especially for those trying conversions, where you fit 650B wheels on a 26" mtb, is to reduce your tire size from the one you rode on your 26" bike. If you rode 2.25 on a 26" bike, you're best not to go down to a 2.0 just to make it fit. You lose out on cush and minimize the increase in rollover and traction you would have with 2.25.

 

Anyways, we've got 650B now, so I think it's worth a try. Next year I plan to compare all three wheel sizes. Arguing which is better is not necessary. Some wheels suit different terrain better than others and some people have more fun on a given wheel size. I don't believe any of the three wheel sizes of 26, 650B and 29 are bad.

 

Anyhow, just thought I'd add my two cents from the research I have done. Have fun riding whatever you have.

Edited November 27, 2012 by morkys

[Iwan Kemp]

Yes I know it's not a bit difference but everybody seems to be jumping onto the 26 for small, 650B for medium and 29 for large bikes rule and it simply aint true.

Nailed it on the head here...

[awesme]

Best 2 cent's I've seen in a while.

 

G

 

650B is 27.5"

 

26" mtb is not 26"...it's 26.5. That is why it is confusing.

 

I have been researching MTB wheel sizes for a little over a year now and I've learned quite a bit. When I first looked into the 650B MTB size I assumed it was in the middle of 26 and 29. I soon realized this was incorrect. If you look at the pics that Jacquers posted, and run the numbers you will figure it out. The discovery is not that 650B isn't 27.5"...because it is. In fact, a 650B wheel with a 2.25 tire is closest to 27.5" than either of the other wheels are to their namesake sizes. A 650B wheel and 2.25 tire is 27.496" so you may as well round it up to 27.50". Take a look at the 29'er wheel with a 2.25 tire, it's 28.976" or rounded up 28.98"...pretty close to 29" anyways. The thing nobody here has mentioned though is, look at the "26 inch" MTB wheel and tire. It is 26.496" or 26.5. So the reason that 650B is not half way in between the 26 and 29 wheel sizes is not that 650B isn't 27.5, it is, the reason 650B is not in the middle is because 26 is really 26.5. Look at the measurements in the diagrams and convert mm to inchs (2.54 cm per inch). Each diagram shows a rim with a tire of about 2.24 inches. Using a 2.25 inch tire makes sense since a 2.25 is exactly the average of the range of tires that many XC and ALL MOUNTAIN chose from, between 2.1 to 2.4. Measure your own 26, 650B or 29 wheels/tires and you'll see.

 

Over at MTBR there are many discussions about wheel sizes, with lot's of talk about 26, 650B and 29. There are so many reasons why people like one wheel size over another, but let's just say some people like the lightweight manouverability of the smaller 26 mtb wheels and bikes and others like the rollover and traction of the 29. Some people argue that 650B doesn't offer enough improvement over 26 to make it worth while. I have yet to test the wheel sizes extensively.

 

One reason why 650B became an mtb size is that bike designers were having trouble making long travel 29'ers with good geometry. 650B was thought to provide a bit more rollover advantage and traction without the problems of frame design. When I first started researching wheel sizes and discovered all the 650B wheel sizes, like another poster here, I thought 650A would have been the proper middle size at 590 mm, but eventually, I believe the ideal wheel size could have actually been the 597 mm wheel size. It is exactly 1 inch smaller than 29'er. Perhaps that is all that would have been needed to make a smaller wheel that was another option that worked. I personally think that this wheel size should have been tested. Since it's only 1/2" bigger than 650B, thoeretically, I bet a 597 mm wheel with a 2.25 tire could fit on a 650B bike since it's not much bigger. Many 650B wheels fit on 26" bikes even though the wheels were 1 inch bigger. The difference between 584 and 597 mm is only 1 inch. It may seem like splitting hairs, but I still think it could be a workable option.

 

And the argument that a 26" wheel with a large tire is the same as a 650B is not comparing apples to apples. A 26" wheel with a tire big enough to be 27.5" is going to be alot different in ride and feel than a 650B with a 2.25 tire. One thing that you want to avoid, especially for those trying conversions, where you fit 650B wheels on a 26" mtb, is to reduce your tire size from the one you rode on your 26" bike. If you rode 2.25 on a 26" bike, you're best not to go down to a 2.0 just to make it fit. You lose out on cush and minimize the increase in rollover and traction you would have with 2.25.

 

Anyways, we've got 650B now, so I think it's worth a try. Next year I plan to compare all three wheel sizes. Arguing which is better is not necessary. Some wheels suit different terrain better than others and some people have more fun on a given wheel size. I don't believe any of the three wheel sizes of 26, 650B and 29 are bad.

 

Anyhow, just thought I'd add my two cents from the research I have done. Have fun riding whatever you have.

[Eldron]

Ok ok I'll admit it.

 

I own a 650B bicycle.

 

My MonsterCross bike fitted with 29er wheels and cyclocross tyres is almost exactly the same OD as a 650B wheel/mtb tyre combo *grin*

 

Speaking of which - I'm gonna go and ride the bad boy... *bigger grin*

[(Deon)]

650A is for when B sales start to taper.

[Guest Latent Blue]

Okay so I posted this before but damnfangle man I'm tired of people referring to 650B as 27.5" or halfway between 26 and 29.

 

It aint!

 

Here's the low down:

26 diam = 559mm

650b diam = 584mm

29 diam = 622mm

 

So 650B is only 12.5mm bigger than 26" in radius. Not a lot.

29" is 31.5mm bigger. Also not a huge amount but nearly 3 times the amount of 650B.

 

Yes I know it's not a bit difference but everybody seems to be jumping onto the 26 for small, 650B for medium and 29 for large bikes rule and it simply aint true.

 

In my opinion 650A would have been a better "standard" to settle on.

 

For your enlightement eager one:

 

650[Letter]

In the French sizing system, tires are designated by a three-digit number, which may be followed by a letter. The number is the nominal outside diameter of the tire the rim was originally designed for. The absence of a letter indicated a narrow tire; "A", "B" and "C" indicated increasingly wider tires."A" was originally a tire about 30 mm wide, so the 650A rim is pretty large, 590 mm. If you add the top and bottom 30 mm tire thickness to 590, you wind up with the 650 mm tire diameter.

 

The 650C size was originally intended for a quite wide tire, about 40 mm wide. Top and bottom 40 mm tire plus the 571 mm rim size again bring you to a 650 mm outside diameter, even though the rim was smaller.

 

With time, however evolutionary processes have led to different widths of tires being applied to the rim, so the nominal 650 mm designation is now more theoretical than practical.

 

•597 mm, 650, is the same as the British 26 x 1 1/4" size used on club bicycles, and was also adopted by Schwinn for use on 3-speeds with a 1 3/8" wide tire. This size is seen less and less, as the bicycles which use it become rare.

•590 mm, 650A, also called 26 x 1 3/8", is the size used on the classic English 3-speed. There's nothing theoretically wrong with this size (other than confusion with the Schwinn size!), but the selection of tires and rims available for it is pretty scanty these days.

•571 mm, 650C, was originally a wide, balloon tire size, used on many older Schwinn cruisers. These days, however, it is mainly seen on triathlon bikes and time-trial machines. Available tires and rims are mostly very narrow, intended for competition use.

•584 mm, 650B, is the focus of this article. This size, also known as 26 x 1 1/2", is most popular in France, where it was the traditional size for loaded touring bikes and tandems, as well as general utility bikes.

The 650B size was never common in the U.S., and it went into decline even in France with the advent of the mountain bike. However, there is a dedicated group of fans of this wheel size, who have been diligently working to restore it to its former glory.

 

The situation as far as tire and rim availability has lately taken a turn for the better, and the future looks rosy for 650B.

 

Some good info... didnt know this!

[Capricorn]

 

For all intents and purposes, when considering a 2.25 tire...

 

650B is 27.5"

 

26" mtb is not 26"...it's 26.5. That is why it is confusing.

 

I have been researching MTB wheel sizes for a little over a year now and I've learned quite a bit. When I first looked into the 650B MTB size I assumed it was in the middle of 26 and 29. I soon realized this was incorrect. If you look at the pics that Jacquers posted, and run the numbers you will figure it out. The discovery is not that 650B isn't 27.5"...because it is. In fact, a 650B wheel with a 2.25 tire is closest to 27.5" than either of the other wheels are to their namesake sizes. A 650B wheel and 2.25 tire is 27.496" so you may as well round it up to 27.50". Take a look at the 29'er wheel with a 2.25 tire, it's 28.976" or rounded up 28.98"...pretty close to 29" anyways. The thing nobody here has mentioned though is, look at the "26 inch" MTB wheel and tire. It is 26.496" or 26.5. So the reason that 650B is not half way in between the 26 and 29 wheel sizes is not that 650B isn't 27.5, it is, the reason 650B is not in the middle is because 26 is really 26.5. Look at the measurements in the diagrams and convert mm to inchs (2.54 cm per inch). Each diagram shows a rim with a tire of about 2.24 inches. Using a 2.25 inch tire makes sense since a 2.25 is exactly the average of the range of tires that many XC and ALL MOUNTAIN chose from, between 2.1 to 2.4. Measure your own 26, 650B or 29 wheels/tires and you'll see.

 

Over at MTBR there are many discussions about wheel sizes, with lot's of talk about 26, 650B and 29. There are so many reasons why people like one wheel size over another, but let's just say some people like the lightweight manouverability of the smaller 26 mtb wheels and bikes and others like the rollover and traction of the 29. Some people argue that 650B doesn't offer enough improvement over 26 to make it worth while. I have yet to test the wheel sizes extensively.

 

One reason why 650B became an mtb size is that bike designers were having trouble making long travel 29'ers with good geometry. 650B was thought to provide a bit more rollover advantage and traction without the problems of frame design. When I first started researching wheel sizes and discovered all the 650 wheel sizes (650 = 597 mm > 650A = 590 mm > 650B = 584 mm > 650C = 571 mm (and remember when GT invented the 700D wheel size for their hybrids? 587 mm), like another poster here, I thought 650A would have been the proper middle size at 590 mm. It is exactly in the middle of 559 mm 26" wheel and the 622 mm 29'er. That could have mde sense, but eventually, I believe the ideal wheel size could have actually been the 597 mm wheel size. It is exactly 1 inch smaller than 29'er. Perhaps that is all that would have been needed to make a smaller wheel that was another option that worked. I personally think that this wheel size should have been tested. Since it's only 1/2" bigger than 650B, thoeretically, I bet a 597 mm wheel with a 2.25 tire could fit on a 650B bike since it's not much bigger. Many 650B wheels fit on 26" bikes even though the wheels were 1 inch bigger. The difference between 584 and 597 mm is only 1 inch. It may seem like splitting hairs, but I still think it could be a workable option.

 

And the argument that a 26" wheel with a large tire is the same as a 650B is not comparing apples to apples. A 26" wheel with a tire big enough to be 27.5" is going to be alot different in ride and feel than a 650B with a 2.25 tire. One thing that you want to avoid, especially for those trying conversions, where you fit 650B wheels on a 26" mtb, is to reduce your tire size from the one you rode on your 26" bike. If you rode 2.25 on a 26" bike, you're best not to go down to a 2.0 just to make it fit. You lose out on cush and minimize the increase in rollover and traction you would have with 2.25.

 

Anyways, we've got 650B now, so I think it's worth a try. Next year I plan to compare all three wheel sizes. Arguing which is better is not necessary. Some wheels suit different terrain better than others and some people have more fun on a given wheel size. I don't believe any of the three wheel sizes of 26, 650B and 29 are bad.

 

Anyhow, just thought I'd add my two cents from the research I have done. Have fun riding whatever you have.

 

so much better than the original ultra-emo blabbering.

[hayleyearth]

I don't know what you guys are always on about when it comes to size. ...

 

But I can let you all know my bike says 275 on it. The documentation on the Internet says it has something to do with 650b but if I measure the rim (lip to lip) it is 600mm and with the it is 700mm...

 

 

Joh no wonder it rolls so easily over everything. .. Ooh

 

[Azonic]

My opinion, 650b / 27.5" (or whatever) is way to close to a 26'er to even bother. The other night I was riding behind a bike and had to look and look and look and look and eventually had to ask if it was a 275er. It was. If its that hard to tell, its moer close to 26er. 26er for tight rides, 29er for tight rides if you can handle it and marathons. Thanks, I'll take my cheque now.

[Jokerman923]

So the question remains.............

 

Have you converted to 27,5" yet

[RABUBI]

I am converting my scott spark 30 as we speak.

 

Thing why I did it is I cannot bring myself to sell such a nice bike for a fraction of the cost due to 26" losing its value.

 

So will do the conversion and ride the bike till it breaks or get stolen

[Christie]

I am converting my scott spark 30 as we speak.

 

Thing why I did it is I cannot bring myself to sell such a nice bike for a fraction of the cost due to 26" losing its value.

 

So will do the conversion and ride the bike till it breaks or get stolen

Will it be so much better after conversion?

I know it sounds extreme, but I have done several multi stage events on 26" wheels, it can be done ;-)

[RABUBI]

Chris

Will it be so much better after conversion?

I know it sounds extreme, but I have done several multi stage events on 26" wheels, it can be done ;-)

 

Jip, it was good enough three years ago, so should still be.

 

Christie, I allready did the conversion on my hardtail and been riding it since december

 

Put the 26" wheels back last week and went for a ride. Feels funny as hell, like a bmx, can only imagine 29 change to 26.

 

But again, if it was good 3 years ago, should still be