Tubeless rims are more commonly solid alloy wheels with a lip or ridge (left) to help locate and seal the tyre bead securely on the rim. This lip is also considered a safety feature which stops the tyre coming off the rim should it deflate on the move. In my experience the lip works. You will feel the softened tubeless tyre long before it comes off the rim.
But this lip also makes removing and mounting the tyre difficult by the roadside. It varies from bike to bike and tyre to tyre, but usually, with tubeless you only need to remove a tyre to replace it, not to fix endless punctures. And unlike punctures, fitting a new tyre is usually done at a time of your choosing and in a tyre shop which has the know-how and tools, including a powerful compressor and lube to force the new tyre over the lips and into the rim’s groove with a nice ‘pop’.
Oddly, for years and years bikes running tubes also have this safety lip. Old Yamaha XTs had it on the rear wheel. Out of interest, this disproves another tubeless urban myth: you can only stick a tube in a TL rim to ‘get you home’ because it will eventually rub on the lip and explode with terrible consequences. Well clearly not on a stock tubed ’86 Tenere with a lipped DID rim (above). I know because I remember putting that bike on a crate with the rear tyre removed, sticking it in gear and ‘hand-lathing’ off that safety lip with a chisel so that I’d not get stuck in the desert trying to break the bead to fix a puncture. And as importantly remounting it properly with – back then – just a bicycle pump. All this faffing is why we like tubeless.
But to convert spoked tube rims to tubeless, this lip is actually a good thing and my 2008 Tenere (above) also had them on the back wheel. The front rim was normal which is a risk when converting to tubeless. But can it be any worse than a tubed tyre puncturing? Tubed tyres deflate faster and therefore more dangerously than tubeless tyres, so even without the safety lips or humps on the front, with tubeless you’re already ahead. But, as I found, you can get slow leakage along the seal.
Pictured left: the top rim has no sealing lip; the lower rim does. Note also the angle of the tyre bead–rim interface surface; the lower rim with the lip is flat which helps make a better seal. The upper lipless rim slopes in making it easier to change by hand, but it won’t holed or seal a tubeless tyre half as well. I think my 2008 Tenere front-wheel sealing problems where because the rear wheel was like the lower rim – good for tubeless. The 21-inch front was like the upper rim; less good seal.
21-inch spoke rims with safely lips
I have spent hours online tracking down a 21-inch alloy rim with the safely lip suited to converting to tubeless. They are quite rare.
Taiwan-based Giant – the biggest bicycle and motorcycle rim manufacture in the world – makes such a rim with the normal 36 holes (bigger BMWs have 40; lighter trials bikes have 32). In the UK Central Wheel Components can get one for £135 (2.15kg). It may be branded SM Pro. Rally Raid use this rim on their own wheelsets with BARTubeless conversions for Africa Twins (left) for over grand each. They’ll probably do the same for the 700 Tenere which also comes inner tubed from the factory.
A quote to build that rim onto my Himalayan hub and seal it with BARTubeless (done in Italy) came in at £420. Balance that against the cost of buying a rare OEM tubeless 21-inch rim. No sealing required, but it’ll cost you even more.
More research unearthed Japanese Excel Takasago rims also make a 36H 1.60 x 21 rim (left; p/n ICK408), Talon in the UK import them at £165. This rim has an unusually deep well which should make for easy tyre mounting even after you’ve sealed it whichever way you choose.
I’ve just bought a pair of these rims (below) from a place in Italy and hope to fit it to my Himalayan.
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