Q: Best Bike Mount Holder for iPhone 6

I've used the Biologic Weathercase for almost a year now:

http://www.thinkbiologic.com/products/bike-mount-weathercase-iphone-66s

it's only weatherproof, not fully waterproof due to its zipper, but I've had no issue so far under light/medium rain. They have some other bike mount options but in my opinion weathercase is best.

I'd suggest checking out Quad Lock iPhone mounts.  The make a super sleek case that attaches to a range of mounts. The bike mount being the main product. Check them out here http://www.quadlockcase.com/

I use all the Quad Lock mounts for riding, running and driving.

I see you joined the forum today just to share that. Isn't it nice when you get so many spam posts in a single thread that they cancel each other out?

I don't know about the others, but I've actually owned and used QuadLock cases since they came out. The bike adapter holds onto the case quite securely and can be put horizontal or vertical and switched easily between bikes and very quick to place on. They sell adapters for tripod mounts, running armbands, a sticker mount, and probably more (haven't checked their site in a while). It seems to use some high quality plastic (rubber for the mounts, metal for the tripod screw).

But instead of passive-aggressively accusing everyone for being paid shills (I found this thread in a search today), here are some honest caveats from years of use:

• Requires their case. This means a purchase of a new case and poncho (~$60) every two years. This alone is a reason I'm thinking of abandoning these adapters despite investment.
• I don't own the running band, but I've used a similar design for the iPod once and find the clip a decided inferior design to cheaper and better armbands like the two piece pass through style (Tuneband) or the one piece oens (Belkin).
• The case is uncomfortable in the hand because of the quadlock mount. It also locks you into the case. (I swap cases when on bicycle.) The swapping of cases negates the sticker mounts which would be surprisingly useful otherwise.
• The tripod mount has a 1/4" screw head. I do my photography on real tripods that use arca swiss and so the cost would be wrapped up in the universal plate. I'd look at different dedicated solutions if I was doing serious iphoneography.

I think if you are okay with the case as your regular case and want a "system", it's probably the only thing going, which will overcome the out-of-scale pricing (plastics, but 2x more expensive that purpose-built universal smartphone equivalents).

If you don't like the case or prefer your own case or none at all…

check out Bikase, www.bikase.com, they have many products including waterproof.  I have 2 products from BiKASE, the Handy Andy for the iphone 6 and the GoKASE which I use as my everyday case, push and turn and you are off to the races!