Who Knew.

Oh, very top secret! The vid kinda let the cat outa the bag ... not that I have any ideas about going tubeless. I think I've only ever had one flat in my motorcycling life - that was about 100km east of Mt Isa in 1974-5 - so not too worried.
 
martymoose said:
Sf2 enduro converted to tubeless with a right angle valve. Now you really want one don't you Vince.......

Conversion has been tested for 5000km now, no problems.
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Is the conversion more than a well-sealing rim tape? Please share details.

Have you done anything to try to retain the beads on the rim in the event of rapid deflation?
 
You might ask one of the Sydney blokes who after hitting a 4 inch bolt and getting a rear flat used my Foam fix a flat in a can that barely did anything and rode 20ks on a defeated tyre. That fully deflated tyre stayed fully on the rim for that whole ride, it was completely destroyed but never moved off the rim.
 
I totally agree that an angled valve stem would be a useful thing, but you want something that can be permanently attached without the risk of it coming loose or leaking.

At the risk of being accused of over-thinking a problem (over thinking is better than not thinking enough) I offer the following:

Rather than go to all the hassle of converting to tubeless, I reckon a simple solution might be to remove the valve core out of the (straight) Schrader valve in the inner tube, then screw an angled adaptor into the internal thread using some strong thread lock (Loctite) on the thread to seal it against air leaks and fix it in place so it won't unscrew. As it goes inside the valve stem, the tube could still be fitted/removed with the adaptor in place, assuming you could wangle the angled spigot through the hole in the rim. A 45° adaptor rather than 90° might make that job easier, and still be accessible with a service station tyre chuck.

If you don't like the idea of relying on Loctite, you could solder it in place with soft lead solder. Use a heat sink or water bath to protect the rubber tube while soldering.

The only problem with the above solution is finding an angled tyre valve adaptor with a male thread to go into a Schrader valve stem (another case of wanting something that doesn't exist). However, it might be possible to make one. Simplest approach might be to modify the usual type of adaptor by cutting off the female threaded swivel bush and cutting a male thread in the remaining stem that will screw into the tyre valve. All you need is a die to cut the thread on the end of the adaptor tube.

The internal thread in the valve stem is 5V1 (0.209 in x 36 TPI), dies or die nuts for which also seem to be impossible to find (did someone mention wanting something that doesn't exist?). Not to worry though, a 12-36 UNS is the same pitch but 7 thou larger in diameter (0.216"), so it'll be a nice tight fit. 12-36 UNS dies are readily available from that country that we're not allowed to mention.

www.ebay.com.au

1pcs 12-36 tap + 1pcs Die Thread Tap And Round Thread Die Right Hand HSS Taper | eBay

Modle：12-36 tap and die<br><br>. No blocking, fast efficiency. Drill chuck, drill, alloy drill, cutter, alloy cutter, milling cutter, milling cutter. Round Die: Not easily broken tooth chip fast, abrasion resistance and long service life.
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I've seen spoked alloy rims with the valve hole drilled off-centre to allow easier access to the valve. Don't see too much of a problem with that, at least less than what motocrossers were doing many moons ago... simply drilling through the tyre sidewall so the tube could creep/spin with the tyre at their impossibly low inflation pressures.

piet
 
All the details of the conversion are in the enduro build thread. One roll of 3m sealing tape and a couple of valves. Very simple. Polished the inside of the rims.

My record is 4 punctures in one week. I have had lots of flats over the years. Trying to change a tube on the middle of nowhere is not my idea of fun. Plug and go
 
FOUR in. one week?! How the hell does that happen? Were you riding past the same building sdite every day?

I reckon we've been in lockdown too long to be putting this much effort into a problem that doesn't have to be a problem - how many Laverdas have been running around on the planet with straight valve stems for the past half a century? I can understand Marty going tubeless cos he's gonna hit the backroads, but ...

Put more air in than you need, reduce and check with an accurate tyre pressure gauge - job done. Then get on and ride it!
 
sfcpiet said:
... simply drilling through the tyre sidewall so the tube could creep/spin with the tyre at their impossibly low inflation pressures.
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I've never seen that. Sounds like a tyre valve waiting to be ripped off by a rock or something.

I once saw a bloke on an old British thumper on an off road adventure. His wheel would spin inside the tyre if he gave it too much throttle in first gear. A closer inspection revealed that he had no tube in it at all. It was an ancient knobby tyre with very stiff sidewalls. It was so hard and stiff that zero PSI inflation pressure seemed about right, so why bother with a tube? He did get a lot of grass caught between the tyre and rim though. No worries, just drop a smoking rim-spin inside the tyre to chew it all up!
 
Well, I could make a comment about, no better not. It's not a be-all and end-all issue but for the life of me I cannot see why it's fine to convert a cast wheel to tubeless and use a 90 while you're at it and get a finger wag if it's a spoke wheel. There are more reasons why including less unsprung weight, ease of puncture repair. The later on a std spoke wheel instantly becomes a trailer job. My last puncture happened 5ks from home at the local shops buying a copy of Classic Bike. It went down so fast, the rear, I couldn't get off the bike as the tyre was so flat I couldn't physically deadlift the bike onto its centre stand on my own. I rang my brother on the mobile who went to a Service Station and bought a can of Finnyleak. That at least got me the 5k home before going flat again where I pulled the wheel and took it to be fixed. From memory, I have had maybe 4 or 5 flats over 50 very odd years of riding and 2 of those were those 90deg extension failures mentioned earlier on day rides. I had a rear deflate mid-corner once, which resulted in the biggest butt pucker I ever had, I managed to ease over to the roadside after the bend. The previous bend tipped me off that something was not right.
 
One of the ye old off-road tricks to stop tyre creep at low pressures was to drill the rim edges and insert short self tapper screws into the tyre sidewall. The trick with using super low pressures required by Radial Trials tyres, down to 5 psi is using 2 rim locks. Too much creep and it tears your valve out of the tube. It helps to not do the valve rim nut up tight as well.
 
Peak hour combat riding Q, breakdown lane, gutter, footpath. It's all fair game. Some of the Toorak taxis are getting so big I'm seriously thinking about a trials bike so I can ride over them.you don't have traffic in Melbourne?
 
Vince said:
One of the ye old off-road tricks to stop tyre creep at low pressures was to drill the rim edges and insert short self tapper screws into the tyre sidewall. The trick with using super low pressures required by Radial Trials tyres, down to 5 psi is using 2 rim locks. Too much creep and it tears your valve out of the tube. It helps to not do the valve rim nut up tight as well.
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Yep, did that on sliders. When down to 6psi on a slick track, with the wheel spinning the whole track length, something had to hold the tyre in place.
 
Tried the self-tappers trick on my TLR, ripped them off within an hour! Three on each side, probably should have used 6mm jobbies...

My old Bantam had a stone-hard 4.00 knobbly on the rear, it stayed on nicely after I managed to rip off the valve (after I had punctured the tube while refitting). That bike provided a steep learning curve, 12 "snake bites" in one tube after fitting with inadequate tyre levers. Took another few attempts to finally fit a tube that actually held air afterwards!

I've had a few flats in the past, usually far from home. Although I usually carried levers and spare tube, it was never fun doing it on a roadside. Finding a Gommista in Italy that is open on a Saturday afternoon is pretty fruitless too.

Fitting tubeless rims/tyres was meant to ease repairs in case of a flat, never suffered another since!

Vince, probably quite OK to leave the adapter attached if you restrain yourself to speeds less than 120km/h, above that, I can imagine centrifugal forces to rise above what the valve stem can manage. There's a lot of weight and leverage involved, all acting on an ultra-thin-walled valve stem. As you surely know, not fitting valve caps can cause deflation at high speeds. The valve insert seal is, at a guess, less than 2 grams in weight and is lifted from its seating through centrifugal forces alone, against the pressure of the sealing spring! The adapter weighs what, around 20 grams? The 90° valves used on cruiser tubes are integral with the tube and quite a bit lighter than such an adapter, expected speeds on bikes such equipped would be slightly lower than expceted from a rip-snorting Laverda. The 90° valves used on cast wheels are solidly mounted to the rim with no "vertical" part on which the "horizontal" part can exert leverage.

piet
 
Fair enuff, Vince. I can understand the need if you've been left ion the shite a few times. I hope when I finally ride the beast again I don't experience any m ore flats than I used to - ie one!

Don't like riding in Melbourne much Marty. Prefer to cycle in peak hour and avoid busy roads. But those emergency lanes are litter traps!!
 
90 degree valves on the Benelli Tre and some of the Zane bikes. No issues with them (yet), but that’s perhaps because I ride them soooo slowly...😇
 
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