Originally written in 2008 – updated with added details on GS500R in 2012
Another tubeless HUBB discussion from  2012
Cyb’s version of the DIY procedure described below (good photos and <100k miles ridden)
Mounting Tubliss liners to my  GS

Tubeless tyres are a Good Thing. Having run them on my desert cars, the ease of quickly plugging punctures is an Even Better Thing, even if this practice is considered a ‘get you home’ measure and even outlawed in some places. All cars and most modern road bikes run tubeless tyres and to me running tubeless presents major advantages for overland travel.

• Cooler; by eliminating tube/inner tyre friction, TL tyres run cooler and so last longer
• Easier; punctures are very easily repaired
• Safer; punctures deflate slowly and controllably (unlike a tube bursting and collapsing
• Lighter; unsprung weight (more relevant to racers)
• No need to carry bulky tubes, but should you have a problem, one can be fitted
• Many tubed rims have the requisite safety lip (see below), though not always on both wheels (as I found on my Tenere, pictured above)

If you can’t do a roadside repair chances are your tyre is well and truly buggered. I’ve had trips where I’ve crossed borders on flat tyres for want of an unobtainable tube. With tubeless all I need is a pump and a handful of plugs, widely used in the developing countries which are after all, the adventure motorcycling zone.

My 2008 XT660Z had spoked rims and tubed tyres so I asked on Horizons if sealing the well of the rim (where the spokes come through and where air would slowly leak out) was a good idea. The discussion concluded it was do-able and had been done. I like to experiment with new ways of doing things, so I went ahead.

Is it safe?
Many riders using online forums proclaim to be strongly resistant to adapting a spoked rim to run tubeless tyres on safety grounds. I’ve yet to read any direct experience, even second or third hand, but some nevertheless claim it’s lethal. When actual reasons are given, the possibility of a tyre coming off the rim at high speed is cited (or perhaps the sealant unpeeling). But were that possible, how is it different from a tubed puncture in the same circumstances?
It isn’t. The difference is a tubeless tyre actually goes down very slowly, because the air can only escape around the [typical] nail pushed through the tyre carcass (or even more slowly through poorly sealed spoke nipples or a bad rim seal). When the same happens to an inner tube, pressure is lost almost instantly from the tube, which collapses with supposedly dangerous consequences should the tyre come off the rim. Sounds lethal and bikes being bikes I’m sure it can be, but in all my years of tubed riding I’ve never crashed a bike as a result of a puncture.

It’s also possible the DIY element puts some off, but to me DIY has always been a part of what’s now called adventure motorcycling, long before you could outfit an overland bike from an online calalogue. Think about it. What’s the worst that can happen, compared to an inner tube blowing out in a 100mph bend? After a DIY conversion you may get an annoying slow leak from an imperfect seal which, if unmonitored, may lead to pressures dropping low enough to cause rim damage on a rocky trail or a highway pothole. And when the rim gets dinged you lose the tubeless seal until that dent is knocked back out. I know because this all happened to me following my DIY conversion (see below).

Meddling with tyres is understandably seen as a risky practise, but how many of us have ridden long highway miles on ‘road-legal’ knobblies like Michelin Deserts or MT21s and have actually felt safe on fast, busy, wet roads? It’s not something I like to do anymore, but I suspect emergency braking on such tyres could have much more lethal consequences than sealing spoked rims to run tubeless tyres.
Of course the best solution would be to have an OE tubeless set up, as found on expensive BMWs and Caponords, but we haven’t got there yet so some of the current alternatives are given below.

Rarely are OE spoked made to run tubeless. The exceptions include BMW GS12s, Aprilla Caponords and old Honda XLMs (see below). This picture of a 2005 Caponard shows the two ways of doing it: on the rear it has BMW-style ‘outboard’ spokes; on the front wheel it uses XLM-style ‘inboard flange’ (AFAICS)

Otherwise, tubeless rims are solid wheels and also have a lip (mentioned in AMH, see image right) to sit and maybe even seal the bead of the tubeless tyre securely on the rim’s edge. It’s also considered a safety feature that stops the tyre coming off the rim should it deflate on the move. But in turn it makes removing and mounting the tyre without bead-breaking tools quite tricky. The difficulty varies from bike to bike and tyre to tyre.
As it happens it seems Yamaha XTs have long had such safety rims on the rear, even though the bikes always come with tubed tyres. (Out of interest, this disproves another urban myth: that you can only stick a tube in a TL rim to ‘get you home’ because it will eventually rub on that lip and burst with terrible consequences. Well clearly not on an OE tubed Tenere, lipped on the rear since the mid-1980s).

To convert the spoked rims to tubeless this lip is actually another good thing, and my 08 Tenere had them on the back wheel. The front rim was normal which might be a risk when running tubeless. But can it be any worse than a tubed tyre puncturing? Tubed tyres deflate faster – and therefor more dangerously – than tubeless tyres, so even without the safety lips on the front, with tubeless you’re already ahead.

Ways of sealing spoked rims
To run tubeless tyres on a bike with spoked rims you need to seal the point where the spokes screw into the rims at the nipples to become airtight. Then you also need to fit a tubeless valve; easily done.
Systems like the US-made Tubliss liner are made for dirt bikes running low-psi, but are  not approved for highway use in the US by the manufacturer, mostly probably due to homologation issues rather than safety. I know people who’ve run Tubliss for years on the road with no problems.

Tubliss work by fitting a tube-like ‘core’ which inflates to seal the bead of the tyre firmly against the rim; the image above depicts the way it works clearly. There core (the red thing) is a highly pressurised tube, but it’s kept away from the tyre sidewall or tread where punctures come through.
I’d have liked to have tried Tubliss on one wheel at least, but they weren’t yet available in the UK in time for my Morocco trip (2008). I’ve since bought a pair and plan to fit them to my current 2012 project bike running 19″ spoked rims.

Another method is the Italian Alpina system pictured right (click to enlarge and read) which individually seals each spoke nipple with a rubber o-ring, and is sold for many road bikes and so must be considered road legal.
The benefits of this system and the Tubliss above is that spoke tension can be adjusted while maintaining the seal, be it nipple o-ring on at the bead. The permanent seal DIY system demonstrated below may not work so well doing this, but as we know we’re usually talking very small turns of the nipple to adjust tension, and should a leak develop it can be re-sealed.

Apart from using airtight cast wheels (the simplest solution but one that’s most likely to fit your bike when transplanting an entire front end) the main way is of course using a wire rim where the spokes attach and can be adjusted on the external perimeter of the rim, such as either the ‘inboard’ rims on old Honda XLMs from the 1980s, the current ‘out board’ design on the BMW GSA12 (right), or even buying something like the beautifully forged Italian Kineo tubeless rim on the left. For a Transalp 700 that’ll be €1000 please.

 DIY RIM SEALING

Not knowing about Alpina at the time (and with no fitting for a Tenere) I took the cheaper DIY option: sealing the well of the rim with a marine-grade 3M adhesive called ‘5200’ (right). It looks similar to the stuff you put round a bath edge, but costs £15 a tube from boat shops and presumably will last a whole lot longer in rough conditions.
My rims were in fairly good shape, being only 700 miles old, and once the near-new Tourances were removed (tried everything except the sidestand trick, but had to go to a bike shop in the end) I dried out any moisture with a hair dryer, cleaned them with petrol and smeared the sealant all along the well.
The 5200 sealant I used was FC: ‘Fast Cure’ so set in a few hours. I used half the 300 mil for both rims. Unfortunately, the 5200 tube doesn’t work with a B&Q sealant gun, so I found it easiest to just cut the tube open and paste it on with a knife. I tried to not leave any air gaps, small holes, or get any on the rim edges where the tyre bead sits. Once dry I refitted the rim tape (right) for added protection.

Now in 2012, it’s interesting to see Cyb’s version of doing the same thing on his spoked road bikes. Rather than slapping 5200 all over the well, he individually applied two coats of  thinner, runnier sealant to each spoke nipple, and then topped them off with a thicker sealant. As he says, it means individual leaks can then be more easily located and dealt with. If I was doing this again, I’d follow his example.

Tubeless valves
Matey at my local tyre shop flogged me some tubeless car valves, but after hanging off the rim trying to pull them through I realised the holes on some tubeless rims, car or bike, must be a bigger 15mm diametre? A tubed rim hole for a Schrader inner tube valve stem is about 8-9mm. I started drilling but before I’d gone too far I got on the web and yes, there are two sizes as well as screw-in, two-part tubeless valves from about a fiver (see above). My local tyre shop had an angled pair which screwed in with a lock nut from the inside around two rubber seals.

I had a pair of new tubeless Conti TKC80s and they levered onto the rims with a pleasing lack of drama. This was much eased by the fact that you don’t have to worry about pinching that darned tube and instead are able to concentrate on scratching your nice black rims. I did make some rim savers out of hose (right), but found they got in the way and could have ended up in the tyre (did that with a lever once in the desert. Took me ages to work out where it had got to!).

Mounting the tyres
This I knew would be the tricky bit. With no inner tube to inflate and push the tyre out onto the rim, it could take time and knack before the air pressure got the bead to catch and seal on the lip and so pop it onto the rim.
It helped that I’d taught myself to do this on my old Land Cruiser’s 16″ rims, learning bead-sealing techniques such as clamping down the tyre with a tie-down, resting the tyre on another rim (or anything round like a bin) to get the lower bead to sit and seal on the rim under the tyre’s weight while putting a soapy inflated 16″ bicycle tube round the top to help make a seal (it worked).
There was even the ‘Icelandic Eruption’ trick (right); squirting gasoline into the tyre via the valve body (valve core removed) and lighting it in the hope that the small explosion inside would blast the tyre out onto the rim’s edges – it’s said to be commonly used in Iceland by off-roaders running huge tyres at low psi. What also helped at the time was having a decent 2.5 cfm Viair compressor attached to my car. Car or bike, a decent pump on the overland is an important accessory.

To cut a long story short it all took most of a day. At one point I looked for answers and ideas on the web. Tex on youtube made it look effortless with a sports bike tyre and a hand pump, but for me even going ‘Icelandic’ didn’t work, or I didn’t have the guts to use enough fuel; the tie-down clamp (right) helped, soap and water didn’t do much, running a bit of soft hose around the edge of the tyre to try and seal the escaping air (like the bicycle tube trick did so well on the Toyota) didn’t work either.
In the end it was just a matter of jiggling and technique: clamping the metal clamp of the tie-down right over the part of the tyre that was not mounted (so forcing the gap onto the rim), as well as manhandling the tyre, sitting on it, pushing and kicking it to get the lipless front tyre on. If you don’t have a chunky tie-down on the road, any rope or tape twisted tight with a stick will do to crush the tyre on.

Emboldened by this small victory after half-a-day’s pissing about, I eventually got the back one on too. The knack here may have been turning the car engine on to give my Viair compressor that extra bit of poke to ram in the air in faster than it could escape out the sides. Important: take the valve core out to get the air in faster; once the tyre is seated on a rim it won’t come off, even at zero psi.
Once the bead ‘catches’ you’re on your way and you’ll hear the long-awaited creak of a tubeless tyre easing over the rim’s lip with that satisfying pop. Now screw the valve core back in and pump back up to normal pressure. I also added half a bottle of Slime (right) as a safety measure. Doesn’t always work I found on my desert car, but still a good idea.

With no air loss over a few days, I went to Morocco as planned.

Summary after 4000 miles in Morocco

For what they are TKCs are great road tyres, you forget they’re knobbly and on the dirt they manage fine, even at the road pressures I kept them at. I’d use them again except that I don’t like to use the same stuff twice; it’s good for my book. I also forgot I was running on experimental tubeless and should have been monitoring the pressures more regularly. Winding around off piste on the way down to Erg Chebbi I did think, heck these shallow-knobbed, road-psi tyres are gripping unusually well in the sands! Turns out the back was down a bit but the front was way down – 10 psi. Amazingly I didn’t notice on the road.

On pumping up (the striped-out £9 compressor pictured above worked fine) I also noticed a tell-tale spurt on the front tyre where the Slime fluid leaked out the sides (pic right) as presumably I hit washed-out creek edges on the Col Belkassim track the day before. The rim was not damaged so this suggested that even on moderate impacts (or possibly too low tyre pressures) the lack of the ‘safety lip’ (see graphic top of the page) was indeed allowing the tyre to collapse into the well or somehow lose its grip on the rim and so lose pressure; handily this was exposed by the Slime stains.

Whatever the cause, it was time to scoot over a couple of hundred miles to Bikershome in Ouarzazate, put the tyre on the operating table and then probably slot in a tube. Unfortunately my urge to tick off a few tracks on the way went too far and I found myself up a pass (the gnarly Tizi n Ouli Ousir) with numerous problems including a flat front. I’d just ridden over some barely rideable rocks following a day of rocky tracks, and in all the excitement hadn’t kept up with the front tyre’s slow leakage. I imagine the under-inflated tyre transferred the sharp shocks to the rim while banging over the rocks; it in turn got dinged enough to lose pressure. Luckily there was one bar on the mobile if I stood on the right spot and Peter from Bikershome came to the rescue that night.

Back at Ozt I’d have like to have tested the wheel under water to see exactly where it was leaking, from the rim/tyre edge or out of the spokes, but the dinged rim would have flawed that experiment. I peeled off the 5200 mastic with unnerving ease. Tellingly there was some very slight Slime seepage under the glue in places. I tightened up some spokes and Peter flattened the ding with a mallet, cleaned it up and slotted in a tube. I also discovered the vital 14mm Allen key I had to buy especially to remove the front wheel (it seems not to be included in the OE Yam toolkit?!) had fallen out of its resting place. Most of my trips have these ‘moments’ but deary me, it was not my day!

So, what have I learned. Well, on the dirt a thin-walled front tubeless tyre can have tough time, taking the brunt of the impacts. I don’t ride hard, especially when alone, but on a long trip there’ll always be times when you take a hard hit – rock, pothole, whatever – that you don’t react to quickly enough. I now think a safety lip on the front is probably important up to the point where a front rim gets dented – then unless you can bash it back you’re stuffed and will need a tube. After this episode I continued and watched the tyre pressures more closely and kept them at near road tyre pressures. Moroccan tracks are mostly rocky anyway.

As has been mentioned on the original HU discussion thread, for some reason tubeless 21-inchers have a bad reputation with holding their air, and outfits like Woody’s in the US which convert other spoked rims sizes don’t do 21s any more. Could it be the relatively narrow tyre profile of a 21-incher in relation to its height (for the same average tyre carcass thickness) allow it to ‘cave in’ under hits where a wider front – typically a 19″ as on BMs or my new bike – will take a hit ‘flat’ and maintain the seal? Is that why my 21″ Tenere front failed and is this why the BMWs F800GS has tubes (front 21″) while the ‘650’ version I used in Morocco has a 19″ tubeless on the front?

I spotted an ancient Honda XLM the other day outside the local cafe which reminded me that 21-inch tubeless fronts did exist back in the 1980s. I ran with one on my first Sahara tour (pic right, 1988) and recall no tyre problems, but I don’t remember if the owner fitted tubes for the tour. I really must get my memory upgraded.

Would the Tubliss liner mentioned above have faired better? One imagines yes, and that along with keeping tabs on tyre pressures, my 5200 sealing was possibly not good enough. Could the Slime have undermined the mastic’s seal? Would a lipped rim off an old XLM work better? Don’t know. A Tubliss liner would be the next easy thing to try, or Cyb’s more precise sealant method. A mate has been using Tubliss with no probs on his TT250 Yamaha for years.

I’ve been there, in the bush and out of tubes and patches. This is why tubeless is a good idea and it’s a shame that in Morocco I didn’t get the chance to establish where the leak was on the front, sides or spokes, but at the time I had a job to do.

The back tyre held up fine, kept its pressure following early loses, and has 5mm left after 4200 miles (left) so it looks like it would have lasted up to 6000 miles. Not bad for a TKC from what I hear. The front had plenty of tread left.

On the Morocco research trip in March 2012 I fitted Heidenau K60 tubeless on a BMW 650 and meet up with a mate who’s been using Tubliss all round on his TTR with no problems. So I’ve K60s with Tubliss (right) to my 19-inch spoked GS500 project bike. More details here. So far, no problems.