Flying with your mountain bike shouldn't have to be difficult. It shouldn't leave you with aching shoulders; nor should it risk damaging your bike. The reality though, depends a lot on your choice of bike bag. For transporting a mountain bike, the Scicon AeroComfort MTB is a great choice.
Easy packing for all mountain bikes
The Scicon AeroComfort 2.0 (Road) Bike Bag and the Scicon AeroComfort MTB Bike Bag share the same 'suspension' frame design; where the bike is held upright on a metal frame by its axles. The difference with the MTB bag, is that the frame is longer, to accommodate longer wheelbases on mountain bikes; it is also made to accommodate thru-axles, rather than standard quick-releases.
How to pack the Scicon Aerocomfort MTB 2.0 TSA Bike Bag in 7 Easy Steps
Step 1: Remove the wheels, and fit the bike to the frame
Fitting the bike onto the frame is a piece of cake: you simply remove the wheels and axles, place the bike in position on the suspension frame, and then re-fit the axles through the frame to hold the bike in place. The frame is made to take 12mm thru axles on the rear, and 15mm axles on the forks; adaptors are then provided to make the frame usable with anything smaller than these sizes. The frame extends outwards, so it should also be able to accommodate a whole breadth of frame sizes; right up to large and extra-large sizes.
Step 2a: Remove the pedals
With the bike on the frame, you can use a pedal wrench or long hex key to remove the pedals, and safely stash them in the pocket on the inside of the bag.
Step 2b: Remove the bars from the stem, and store next to the forks
With the bike on the frame, you can also then use a tool to remove the handlebars from the stem clamp. Put the clamp face back in place, for safe keeping.
There is then a specific padded envelope to wrap around the bars and levers, and you then strap it in place on the right hand side of the fork; making sure the stem and bar end are roughly at the same height.
Step 3 (optional): Remove rear derailleur for extra safety
This step isn't essential, but many like to remove the rear mech, and zip tie it under the chainstay; it keeps it tucked away, and reduces the chance of a bent mech hanger during transit.
The alternative, is that you use the provided derailleur protector, which bolts onto the end of the quick release skewer.
It is also worth zip-tying the chain to the chainstay, with it still wrapped around the front chainring, and the cranks positioned horizontally. This helps to protect the teeth of the chainring, and the cranks.
Step 4: Remove or drop the seatpost
Depending on your frame size, you can either completely remove the seatpost and saddle, or just drop it down so that it will zip inside the bag. If you do remove it, Scicon have provided a neat carry bag for it.
Step 5: Deflate the tyres, and place the wheels in the side pockets
For flying, you need to let some of the air out of your tyres, so that there is room for pressure changes within the plane's hold.
Once you've done this, you stash the wheels in the pocket on either side of the bag, and zip them in; they'll even accommodate pretty big 29er wheels and tyres on the Scicon Aerocomfort MTB.
Step 6: Fit the top-tube protector and strap the bike in
Scicon provide a wrap of foam, to put over the top tube of the bike; this is to protect the tube when you then clip the connecting strap together, and pull the two sides of the bag in towards each other.
After that, it's just a case of zipping up the bag, and locking it with the provided TSA approved combination lock. Simple!