Okay, sorry didn't join earlier.
Worth taking a trip to Bernard for a service if your bike needs it. He charges $15 ph. He's okay. French guy, been here for years. He can hire bikes out if you wanted some reasonably well maintained wheels whilst your bike off road.
There's a Cambodian guy who's partnered with a Swiss bloke on St 130 - just a block or so from the riverfront. He's got some bikes imported from Switzerland. Couple of BMWs, Suzuki VStrom. He had a Triumph Tiger too. That's one option for others coming to Cambodia - rather than import your own or pay one of those tour companies thousands for an escorted tour - buy a bike and leave it with one of the reputable shops, like Bernard's Bike Shop, to sell for you after you leave.