You don't need to be an 'investor' to invest in Singletrack: 6 days left: 95% of target - Find out more
I have to go to Dubai for 2 weeks in March. Is there any chance I'll be able to get what I would recognise as a proper bike ride in?
I think wildbike are currently in Oman so there's clearly some good stuff in the region. Ask them.
I've only ever rock climbed there, which is utterly amazing.
I spent a few weeks working in the port a few years ago and relied on this trusty machine to get me around.

Really could have done with a bit more seatpost, but it beat walking!
There is a traffic-free road circuit (big - 80km or something with options to go further) down the coast and a bike shop you can rent from close by. Ex-pats I worked with did mountain biking too. Never managed enough free time to try either sadly.
No, but if you go through to Abu Dhabi on a Tuesday, you can borrow a bike for free at the F1 circuit and do evening laps of the track as the sun sets.
I found the Al Qadra cycle track, the 80km one, that looks alright.
There are mountains in-between UAE and Oman. Whether you want to ride in them - with the driving skills they have in the UAE, is another natter.
Takes a couple of hours or so from Dubai - and they are very spectacular - even filled with the quants of utter that the locals seems to find acceptable
"Al Qadra cycle track" had to read that a second time!
Proper looking trail centre at Hatta with bike hire but it's 150km from Dubai. Could be tricky.
There's a "bike park" in Abu Dhabi:
Looks like a fun little trail.
I've ridden up Jebel Hafeet from Al Ain (a fair way out from Abu Dhabi). That's a good mountain ascent with very little traffic as it's a top out dead end.
I think there is some kind of bike park opening up in Fujairah (another Emirate up the coast).
It depends quite a lot on what time of year and then what time of day as to whether it's going to be at all enjoyable though.
Proper looking trail centre at Hatta with bike hire but it’s 150km from Dubai. Could be tricky.
Try and find the UAE climbers group. Pretty sure Hatta crag is one of the places I climbed and you may be able to blag a lift out there for the day to cycle.
I lived and mountain biked out there for 18 months. As others have said most of the mountain biking is on the Oman/ UAE border. Unfortunately Hatta is accessed through Oman (look at a map) and, since I left, boarder posts have been put in place making it much less accessible. I have friends out there who still ride mountain bikes most weekends. Shawka is probably the best area, but don't expect to find the trails without a local. PM me if you want me to put you in touch with someone.