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TBLS
05-17-2015, 12:59 PM
Have a Deda Magic 31.7 bar and 130 stem...want to try a shorter stem. Can I use a 31.8 stem of another brand or should I try to find a shorter (110 or 120) Deda 31.7 stem?

Think'in should stay with 31.7 but thought I would ask
eBAUMANN
05-17-2015, 01:11 PM
It's basically the same thing ;)
A 31.8 stem/bar plays nice with anything 31.7.
11.4
05-17-2015, 01:28 PM
The difference between those sizes is a matter of who tried to patent what. Deda tried to lock the market by patenting a size. Everyone else just went to a tenth of a millimeter different. Italian business strategy at its best.

None of them are within a tenth of being perfectly round anyway. They are interchangeable.
Mark McM
05-18-2015, 09:51 AM
These two handlebar diameters are exactly the same. The true dimension standard is 1.25", which is exactly 31.75 mm (1" = 25.4 mm exactly). Some manufacturers choose to round the number up to 31.8 mm, and some round it down to 31.7 mm, but the reality is that they are really the same size.
noshaver
05-19-2015, 01:40 PM
Isn't there a collar you could use to make up the slack? Should be much is any at all.
staggerwing
05-19-2015, 01:47 PM
To put it in real world perspective, if not rounding error as surmised, the difference in diameter would be about the thickness of a single sheet of 20# copier paper.

Those parts aren't even made to that tolerance level. No shim required.
thirdgenbird
05-19-2015, 05:06 PM
To put it in real world perspective, if not rounding error as surmised, the difference in diameter would be about the thickness of a single sheet of 20# copier paper.

Those parts aren't even made to that tolerance level. No shim required.

Yeah, the difference is about 20#. A full shim would need to be half that thickness :)
Rebel_Biker
05-19-2015, 05:27 PM
The difference between those sizes is a matter of who tried to patent what. Deda tried to lock the market by patenting a size. Everyone else just went to a tenth of a millimeter different. Italian business strategy at its best.

None of them are within a tenth of being perfectly round anyway. They are interchangeable.

Well said.


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