Tube size question, please

[Spaghetti Legs]

Well there have been 650a wheels for eons and 650c on the goofy looking tri bikes which use narrower tires so I think it shouldn’t be too big a challenge to find narrower tubes, even though the diameters are slightly different.

That 650 stuff is confusing.

[Mark McM]

Originally Posted by recarcar

For this case, I think it would be wise to look at the ERTRO sizing because just from a cursory search for tubes in 650b x 28mm, it looks like most tubes that come up are in the 650c (571mm) size. Just make sure that it's marked 584mm otherwise you might end up with a 650c tube.

One of the reasons I prefer the ISO/ERTRO tire size system - to avoid confusions like that. For example, there are at least 4 wheel/tire sizes that have been referfed to as 26", all with different Bead Seat Diameters and non-interchangeable.

[recarcar]

Originally Posted by Mark McM

One of the reasons I prefer the ISO/ERTRO tire size system - to avoid confusions like that. For example, there are at least 4 wheel/tire sizes that have been referfed to as 26", all with different Bead Seat Diameters and non-interchangeable.

Absolutely. Unfortunately, bad habits die hard. Not sure the bike industry is going to ever make common-sense decisions. I don't mind whatever people want to call the sizes and use them interchangeably just out of habit but going with the ISO/ERTRO standards would be extremely helpful to the uninitiated first encountering the idiosyncrasies of bicycle nomenclature.

[Mark McM]

Originally Posted by recarcar

Absolutely. Unfortunately, bad habits die hard. Not sure the bike industry is going to ever make common-sense decisions. I don't mind whatever people want to call the sizes and use them interchangeably just out of habit but going with the ISO/ERTRO standards would be extremely helpful to the uninitiated first encountering the idiosyncrasies of bicycle nomenclature.

As we've seen with shifting standards, the bicycle industry like to keep re-inventing things, whether re-invention is warranted or not. But they've also found that it can be cheaper simply to rename old inventions. This is how the 700c wheels was recycled to be come the 29" wheel, and the 650b wheel got recycled to become the 27.5" wheel.

One of my favorites is the 110mm/74mm BCD crank, which is the oldest commonly used BCD today. It came out close to 50 years ago, but keeps coming back with new names:

First it was a Touring Crank

After the mountain bike was invented, it became an MTB Crank (This name was modified to Standard Size MTB Crank when Micro MTB Cranks appeared)

Then they removed the 74mm inner BCD and called it a Compact Crank

Most recently they added back the 74mm inner BCD and removed the middle 110mm BCD middle position and called it a SubCompact Crank.

[SoCalSteve]

Turns out the bike shop recommended NOT swapping out the much wider-fatter-taller tires with 28’s. So, I’ll live with whatever it comes with for a bit while I put together a custom BTLOS 700c wheelset and run 32’s on them.

Thanks all for your wisdom, opinions and experience! Always appreciated.

Oh, I believe those 650b x 28 tires are meant for very small bikes. Live and learn!!!...