I’ve walked through the Chalamain Gap and know what it would be like carrying a bike through it. So doing it with a bike travelling from the ski road towards the Lairig Ghru:

1) is there a good path over the top to the NW side of the gap, and
2) would it be easier/less effort to go that way rather than through the gap

Really? No-one? I know there are loads of people on e forum who know the area intimately, including probably having ridden/carried this. Need the info by tomorrow so all inputs appreciated

Call Bothy Bikes in the morning?

Or ride through to Rothiemurchus Lodge and up from there?

Pop on Trailscotland and ask 🙂 Alanr will be able to help

Or ride through to Rothiemurchus Lodge and up from there?

^ this.

Me and a mate did the Chalamain Gap a couple of years ago with a view to hitting the Lairig Ghru further up than you do when you come round from Rothiemurchus Lodge. It is very seriously not worth it. If you value your time (and ankles) you would get more out of Rothie Lodge -> Lairig Ghru and then riding back up to Rothie Lodge and doing it again.

Definitely prefer to avoid it but we are going to start from the ski centre car park so it has to be that way in. Don’t want to all the way down to Rothiemurcus

You should be able to ride from the ski road car park towards the Chalamain Gap and then squirt NW down a little bit to the lodge. Not too much height lost.

Only ever done Chalamain Gap in deep snow and ice, and ‘lacking’ visibility…

Did this yesterday. The track skirting round the NW flank of the gap is pretty easy. IIRC about 10 mins hike a bike then a bit of pushing. Not even too much wasted height gain. Much quicker and easier than going through the Gap