16" Sturmey archer wheel

[MrW]

I 'think' 16 3/8 converts to 16 1.25 in 'new money'

 

[mrgumby]

20 x 1 3/8 wheel is a different diameter to 20 x 1.75

It's not as simple as converting the fraction into decimal.

I think sheldon has explained it somewhere, I'll see if i can find it,

 

[mrgumby]

Re:

Brown's Law Of Tire Sizing:
If two tires are marked with sizes that are mathematically equal,
but one is expressed as a decimal and the other as a fraction,
these two tires will not be interchangeable.

 

[mrgumby]

http://sheldonbrown.com/tire-sizing.html

 

[MrW]

16 x 1.375 is probably closer

 

[mrgumby]

I think you missed the point - i didn't make it very clearly, sorry.

According to brown's law: 16 x 1.375 is not equivalent to 16 x 1 3/8

Different diameter wheels..

Read the bit out of sheldons blog.

 

[MrW]

I have, it's like wading through treacle!

A 16" wheel must be a 16" wheel though??!!

The 1 3/8 is the width of the rim, hence my conversion...

Too much for my brain at this time of day!

 

[mrgumby]

I think thats exactly the point - a 16" (decimal) wheel is not a 16" (fractional) wheel.

Even if they are mathematically identical they will be different.

Same goes for 20 or 26" wheel.

An old 1970's 3 speed bikes with 26" wheels will not take mountain bike tyres.

And bmx wheels with 20 x 1 3/8 rims wont take 20 x 1.5 tyres.

The bead seat diameter is different.

My headhurts.