Angled valve stem adapters..

[Bazil]

Sounds obvious, but if you're going to use the adapter make sure there's adequate clearance to the brake caliper before you ride off into the sunset.   

On my Mark IV with 16" front wheel I managed to get 100 yards down the road before handling became "interesting". The adapter clipped the caliper, shearing off the valve stem ( below the valve of course). Wasn't going to push it home, so I threw away the broken bit of valve stem, screwed the adapter back on, re-inflated the tyre with my trusty mini compressor and rode back home to remove the front wheel and get a new valve stem (right angled) installed. Doh!!

[Guzzibrat]

I always assumed that they weren't meant to be left on all of the time, but installed only when needed. In any case, that's how I use mine.

+1 Keep one in my toolkit and one in my riding jacket pocket.
Also means you can rescue the chap at the garage/supermarket airline who hasn't bought them
All the best
Steve

[jbell]

I always assumed that they weren't meant to be left on all of the time, but installed only when needed. In any case, that's how I use mine.

  :1:  used 'em for years, myself.

[CrazyBiker]

Does anyone know the diameter on the griso/1200 8V bikes? I am assuming they are same as Aprilia at 8.3mm ?

[73 sport]

    I've always used 14.6 PSI in my tires and never had a problem of losing pressure. After long fast runs the pressure would increase three or four pounds.

[moto-uno]

^  At that pressure they're already flat 🤐 .

[lucky phil]

I prefer something elegant in alloy myself. Example of many variations.

 https://parkitt-performance-motorcycle-racing.myshopify.com/products/90-degree-metal-angled-valve

Ciao

[Mayor_of_BBQ]

Hi Luap, I'm a firm believer in Kurvy Girl.  Yep, that's my source for angled valve stems.
https://www.kurveygirl.com/shop/index.php?cPath=169

No kidding, this is the place to get your valve stems.  Now, for tube type tires...you are screwed.

Peter Y.

holy crap thats a lot of valve stem options!

[elvisboy77]

Sudden tire deflation can occur when the centrifugal forces of the spinning tire cause the stem to deflect slightly. The cap end will be forced towards the rim. Honda "discovered" this after several "incidents" on the wing/barge. This led to the addition of that little stem support plastic thingy. Of course, I wonder about the forces acting on the stem valve for the straight type. At what point does the force overcome the spring? From there, only the stem cap keeps the air in. Soooo, make sure your caps have the seal in them. I have first hand experience on THAT one.

A friend with an HD Ultra put those adapters on and at speed one got chopped off (back wheel) by the frame.  Did not end well for him.  I'd rather just struggle with a fill hose lol.