9.00-16 U.S. versus British wheels

Originally posted by Mike Kelly
Yes, its common practice here for restorers to have their CMP rims turned down 1/4" in diameter to accommodate the U.S. spec 900x 16's , it doesn't seem to cause any structural harm to the rim . I have never heard of a rim collapsing .

It's a odd fact that the post WW2 Dunlop T24 RF tyres were made to the U.S .specs . The Ferret alloy rims are slightly smaller in the bead diameter than the wartime steel version .

Mike

Like Pete I'd be wary of turning rims down even a whisker.

As far as we can deduce the 5 deg "English" bead angle allows for a tyre to become loose immediately it is broken away from the rim flange making removal more easy assuming that the well is also set at 5 deg.

US and Canadian tyres seem to have a 0 deg bead angle and so need encouraging all the way off.

Run-flats are another matter, here the sudden loosening is a definite disadvantage and the rim needs to be a 0 deg angle to keep the tyre in place with the spreader. Also by its very nature, field replacement is less of an issue.

You'll also notice that Ferret T24s have a rim type designation on the tyre wall, doesn't it say something like "for H section rims" or something like it ?

R.