Who Knew.

It needs to unscrew, as you turn the 90 deg connection this takes 3 or 4 turns and being so close to spokes and hub is pretty fiddly so you lose maybe 3 or 4 psi so then you need to guess and allow for that. OCD cracks in for me at that point. I used to run Radial Trials tyres on the rear of my Dirtbike and they can run as low as 6psi so I usually use digital air gauges to get this as accurate as possible. I absolutely used to hate those pen-style gauges with the pop-out centre, you might as well guess what they said. It's kind of interesting how this topic has created a bit of a stir.
 
The one I had would psss quite strongly for 3 to 4 seconds when unscrewing. That's why I would leave it connected, for 10 years without trouble. But then it would inconsistently leak and then not leak. It had to go.
 
On the subject of losing air, we before Covid would do a monthly day run. The day before I would check pressures, cold, using the compressor I own with connected gauge. So I use 37 front and 60 rear. After a month of sitting on the centre stand, they would be down 3 or 4psi. On the last ride, I tried 34 front and didn't like the effect, a bit of bump steer. So it's going back to 37. For multi-day rides I set pressures again the day before leaving and touch nothing over the days ahead as any loss would be negligible, I am fussy but 1 or 2 psi is not worth the trouble. I do like the idea of dash mount remote tyre pressure monitors, but that's not happening anytime soon.
 
Just like the caricature in Hunter S Thompson's Fear and Loathing in Las Vagus who wanted better handling in his Cadillac, aka The Great White Whale, by pumping up the tyres to 95psi, I always run at least 60 psi for a firmer ride. And to answer by again referring to Fear and Loathing, nothing a few drugs won't fix re fitness. Where is that Ivprophan script? Just in case, THIS IS A JOKE, don't do 60psi or 90psi in anything
 
Rule of thumb (from a Metzeler technician); depressing the valve insert for about a second releases around 0.1 bar (1.4psi). That's a lot more than the "pfft" that goes out when disconnecting the adapter.

piet
 
I got an email back from the place Cam posted in the USA assuring me that yes they did sell 18inch Metzeler tubes with 90deg valve connections and a link to their eBay page with a pic of their add with exactly what I wanted. Except in the description, it said it had a TR4 valve, that's a std straight valve. So I emailed back asking to confirm it defiantly was a 90 and I couldn't find another anywhere including the Metzeler website. I then got a reply saying the pic was wrong and they didn't have any with 90deg valves and they would remove the pic on eBay. So that just about ends my search for this Unicorn.
 
Bugger. Don't you hate it when that happens?

It's a pity you can't run tubeless, otherwise you could fit these to the rims.
www.ebay.com.au

Motorcycle 90 Degree Angle Tyre Tire Valves 11.3mm. Aussie seller. Suit Japanese | eBay Australia

These angled tyre valves are a great upgrade for your motorcycle. These high quality billet aluminium valves outperform traditional rubber valves in many ways. Motorcycle Angled Tyre Valves (pair). These angled valves virtually remove the possibility of the centrifugal force forcing the internal...
www.ebay.com.au
 
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I have a habit of wanting stuff that never existed. What set me off this time was seeing one of the newly finished Laverdas on last weekends ride sporting a 90deg valve attachment, but it was a cast wheel so it's probably been converted to tubeless with a bolt-on 90deg valve. It looked incredibly easy to get at so I WANTED ONE And then while on another site a read a post where someone was inferring that having 90deg valves was easy on spoked wheels and showing 2 pics. One with a straight valve std spoke design and one with a 90. BUT the 90 was on a BMW rim with outer rim type spokes that run tubeless so that also was a separate bolt-on type valve and that's what I said and added there are NO 90deg type tubes around. And then someone said he had exactly that on his bike. And off I went looking. The problem was his bike ran 16-inch rear wheel. So here I am wanting something that doesn't exist again.
 
Well, I could convert my spoked rear wheel to tubeless and use a bolt-on 90. I first heard about these conversions being don't by Woody Wheel Works on big Adventure Bikes out of Colorado in the USA years ago. There are concerns that Borani style rims are not designed with the lip that holds a defeating tyre safely on. We do have experimenters who have done it here in the Sydney Laverda Club. I am a bit leary, mucking about with deflating tyres on group rides is a nightmare as we found out recently. It takes a lot of tedious work to seal completely, but now I have stable spokes, checked recently with my Spoke Torque Wrench I might do exactly that.
 
What? You'd convert a poke wheel to tubeless just so you could run a 90 degree valve stem??

I coped for decades with the std rear drum, and always managed to get even the long servo inflaters onto the valve - i used to thread the thing in through the middle of the hub.
 
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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I have a 3.00 Morad rear rim instead of the std 2.50 Borani, don't know if that reduces or increases access to the standard straight tyre valve. I have easy access to adjust tyres at home with the gear I have so this isn't urgent especially with a new rear tyre. Marty is your 90deg tyre valve 8mm or 10mm and where did you get it from. Good to know the rim profile allows these to seal and bolt-on.
 
What's the trick to getting it to seal inside? There is/was a place called Jupiter heels (IIRC) that did tubeless spoking and they had a trick o-ring in the spoke nipple itself.
 
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