lets blow up some rims

[Charles Ramsey]

Rim makers have never explained why they make double walled
rims my theory is it allows the rim to take a higher
pressure while keeping the weight down. When I was young
and foolish I blew up a super champion model 58 rim at 170
psi. The model 58 was a common rim on tandems in the 70's
often used with a schwinn hp tire at 100 psi. The model 58
was made by squashing a tube it was replaced by the model
59 which was an extrusion so it should take a higher
pressure. It is easier to remove a tire on a single wall
rim than on a double wall rim often without tools.
Specialized published the blow off presure on their tires
in the 80's. I recomend using a long hose on your pump and
placing the rim in another room for your test. Better we
blow up some rims in the lab than have them blow up on the
road. People can then choose an appropriate rim for the
tire pressure they use. You may decide you don't need the
hassle of double wall rims.

 

[daveornee]

Originally posted by Charles Ramsey
Rim makers have never explained why they make double walled
rims my theory is it allows the rim to take a higher
pressure while keeping the weight down. When I was young
and foolish I blew up a super champion model 58 rim at 170
psi. The model 58 was a common rim on tandems in the 70's
often used with a schwinn hp tire at 100 psi. The model 58
was made by squashing a tube it was replaced by the model
59 which was an extrusion so it should take a higher
pressure. It is easier to remove a tire on a single wall
rim than on a double wall rim often without tools.
Specialized published the blow off presure on their tires
in the 80's. I recomend using a long hose on your pump and
placing the rim in another room for your test. Better we
blow up some rims in the lab than have them blow up on the
road. People can then choose an appropriate rim for the
tire pressure they use. You may decide you don't need the
hassle of double wall rims.

Cross bracing in double wall rims helps the structural integrity.
Check the dual level bridge design by the new Hong Kong Airport. It is able to handle 200 MPH typhoons. A single level bridge just was not an engineering practicality.
I think your ideas have much more danger than merrit.
Current double wall rims aren't a hassle and are an improvement over single wall rims.
However, I have a pair a single wall black Araya 26" rims that I would be happy to unload at a very reasonable price to anyone who wants easier tire mounts.

 

[Chris Zacho "Th]

o problem. I use box channel touring rims on mt tourer. And
my mountain bike never get inflated above 50 psi

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"May you have the wind at your back. And a really low gear
for the hills!"

Chris Zacho ~ "Your Friendly Neighborhood Wheelman"

Chris'Z Corner http://www.geocities.com/czcorner