Author Topic: Rim size for beaded edge tyres  (Read 8631 times)

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Offline Ian

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Rim size for beaded edge tyres
« on: 11 Nov 2004 at 02:35 »
I am getting to the stage of building the wheels for my 1926 OC600. The standard tyre size for this machine is a 26*3" beaded edge. I have some rims here that are supposedly the right size but they look quite small to me - significantly smaller diameter than the wheels for the TS which has 26*2.5. Can anyone help me with the correct dimensions for the rim for the 26*3 ? and also how to measure it ?

Offline graeme

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beaded edge rims
« Reply #1 on: 11 Nov 2004 at 03:42 »
Ian,
26x3 BE rims are a smaller diameter than 26x2.5. About the equivalent of 19" compared to 21". They are also wider than the 2.5 rims. Good luck in getting tyres - I think the VMCC here have sold the last of the Japanese 26x3 tyres and they aren't making any more. Alan Lowe sounded out the Thai firm who are making the 26x2.5 tyres the club is selling, and they would make 26x3 tyres - as long as we ordered 1000 of them! You can still get Dunlop 26x3 tyres - at a price - but with the power the OC will put out they are probably a better bet in any case. We have found that our OB is rapidly wearing out the Japanese tyre, so will undoubtedly be purchasing a Dunlop tyre ourselves.
Cheers, Graeme

Offline Doug

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Rim size for beaded edge tyres
« Reply #2 on: 11 Nov 2004 at 14:21 »
Ian,

Rim size for the 26x3 beaded edge tires on my 1928 Douglas are 2.375” wide over the outside of the rim, and Ø20” to the well of the rim (no drop center!)  

I installed a set of Cheng Shin tires some twelve years ago on my 1928 Douglas 600 side valve.  I found the rumors that one needed to warm the tire in the sun to make them pliable enough to stretch over the rims to be very much true.  At first I tried to install them on the original rims, but had difficulty getting them to stay on.  One blew the tire off overnight and the other cut loose under my very nose whilst I was leaning over to inflate it.  I then purchased new rims.  Not sure what the problem was, if the clench on the old rims was a little more open than the new, or if the new square edge on the replacement rims bit in to the hard tire better.  Glad to hear Graeme that the Chinese rubber at least stays on long enough to wear out.  I never put the machine on the road and had my doubts!  

Had a quick look for 26x3 tires.  Not finding the Cheng Shin, pity as the tread looked period and the logo was not obtrusive (the tendency to blow inner tubes to shreds not withstanding.)

A few places to initially check:  www.coker.com have a Coker 26x3.  Two with a round button tread that probably are not suitable ($126US); one of which is pure white ($206US), definitely not suitable for a Douglas!  The third ($141US) is listed as for a Simplex (Servi-Cycle) that has a tread pattern that you might like on the OB, and is reminiscent of the Cheng Shin.  Also: www.universaltire.com , www.longstonetyres.co.uk , and www.classictyres.com  (Lambrook Tyres) all have the Ensign 26x3, probably the Chinese copy of the Dunlop 26x3.  (Universal Tire, Ensign $135US)  (Longstone Tyres, Dunlop, £156GB)  Both these have the same “twin stud” tread, or what I call the ‘twin-block’ tread that I think looks a little too veteran for the likes of the OB.  But it depends on your personal tase and what is available in Australia.  Lambrook does export, and probably so will the others.  

Regards,

-Doug

Offline Ian

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Rim size for beaded edge tyres
« Reply #3 on: 12 Nov 2004 at 09:19 »
Thanks Graeme and Doug - looks as though I have the right ones.