There are no access issues on a V-Strom with regular old rubber 412 valve stems.
The aluminum 90 degree stems are a fragile, leak-prone solution to a problem that simply doesn't exist. Rubber valve stems are dead-simple, tough, cheap, and very damage-resistant. If you just gotta have bling, install the ones with chrome covers, or put some skull valve caps on, or something.
Even on a sportybike with 17" rims and huge rotors, you're far better off buying a right-angle gauge that can reach the valve stem rather than replacing a rubber valve stem with an aluminum one.
I replace rubber valve stems with every tire change. Just get a box of 412 valve stems at Napa -- they're very inexpensive -- and grab a valve stem tool -- use the one that has a cable. To remove the old one, bend it to one side with a finger and carefully cut it with a utility knife. To install the new one, push the puller through the hole, thread the valve stem into the puller, add a bit of tire mounting lube, brace yerself, and pull slowly.
412 valve stems are correct, but they can be a little hard to find (they're primarily used on lawn tractors and such). 413 stems are a lot easier to find -- they have them at Walmart, even -- and they work fine. 413 and 412 valve stems fit the same diameter hole, but the stems are 1/2" longer (1-1/4" for 413 vs. 3/4" for 412).
2002 Suzuki DL1000 V-Strom, Dark Metallic Space Blue
1983 Suzuki GS850G, Cosmic Blue
2005 KLR685, Aztec Red - Turd II.2, the ReReTurdening
Last edited by bwringer; 08-11-2016 at 07:32 PM.