Can any body recommend a bike shop in Chiang Mai that has a good selection of downhill gear?  Looking specifically to replace a full face helmet and not finding what I want in any of the bike shops I visited so far.

How do you get to the top of the hill?  Is any helmet needed to go uphill?

59 minutes ago, chingmai331 said:

How do you get to the top of the hill?  Is any helmet needed to go uphill?

For the trails on Doi Suthep, you can just ride your bike up the main road (Siwichai Alley) that everybody uses to get to the top of the Doi, or catch a songthaew by the zoo for the ride up.   I think they charge an extra 100 baht to throw your bike on the roof.   You just need a regular helmet for the ride up or down on the road.  Full face helmet is just for the downhill trails through the woods.

Visit the helmet and 2 wheeler safety gear shop close to Suriwong Book Center, Sridonchai Rd., opposite road side (N18 46 52.4 E98 59 49.3).
You may most probably find what you need.
Staff's English skills are "limited", but you may find everything by looking around.
Don't expect highest western quality but imho it's O.K. for everyday DH use (and the prices). If you want to ride really race-like or the "champion's trails" you should visit the shop at "Bike Park Chiang Mai" in Mae On (https://www.actionsportasia.com/land-sports/cycling-in-thailand/where-to-go/bike-park-chiangmai/), or order the professional stuff via internet.