An update 6 years on based on my long-running yet ultimately successful removal of the swinging arm from my Kanguro X (which I believe is sufficiently similar to an X1 for the rest of my comments to be relevant)
My swinging arm was also seized in. Firstly there are chrome coated plastic caps on either side of the frame that cover the swinging arm pivot. These can be gently removed, best clean them first to remove grit, grime, dirt that may make removal harder than necessary. I used GT85 to lubricate the caps before I removed them using a flat screwdriver blade and wiggling the caps by hand to reduce the strain on the surface I was levering.
If you've a standard pivot (and probably most replacements) then either size has an M22 nut on it. The one on the right side is intended to come undone, it's a locknut for the pivot which also screws at least 6 turns into the RHS of the frame. Undo and remove the RHS nut if you can. I used a 1.2" 'breaker bar' and a good quality 6-sided socket.
The nut on the left isn't supposed to come off entirely, it's supposed to have a couple of turns of movement AFAIK before being restrained by what seemed to be a peened-over end of the pivot shaft. In my case the peened-over end ended up being partly separated from the end of the pivot bolt with the repeated work I did to remove the pivot, I'm not sure what quality the end was before I started (I learned what to do as I did it, by experimentation and through reading posts here and online)... In my case the nut undid until it reached the peened end and then got stiffer (probably as it was trying to cut through the peened end) but didn't turn the pivot shaft. However, after some experimentation and serendipity I noticed that the pivot turned when I moved the swinging arm up and down (I'd removed the monoshock before I started all this).
So I ended up playing a complicated game of trying to turning the LH nut with the socket and breaker bar at the same time as I lifted the swinging arm (then they could move together) and then held the breaker-bar in place so it didn't move while I pushed the swinging arm down again (to try and get it to turn (i.e. pivot) around the pivot shaft). This worked a bit but wasn't very successful. I then did a couple of things, one was to drill a 5mm hole in the centre of the swinging arm and then tap the hole with an M6 tap to fit a grease nipple. I then pumped the swinging arm's guts full of grease, I saw hints of it come out of the LH bush area, but it didn't flow through much. I also welded the end of the RH nut (impatiently as it's not very deep and galvanised but I got bored of waiting for the M14 x 1.5mm pitch deep hex nuts I'd ordered). I fastened this onto the end of the RH of the pivot bolt and then used the breaker bar to turn this while I lifted and dropped the swinging arm. I also tried using a powered impact driver but that ended up ripping out the threads from the nut
For several days I spent an hour or so doing the same sort of exercise with the LH nut, undoing the LHS with the breaker bar and socket combination, while moving the swinging arm up. Quite often I'd need to reverse the process and tighten up that nut down onto the pivot bolt to do as much as I could to reduce the chance of totally destroying the peened lip that held the nut on the shaft.
After several days my 5 * M14 stainless steel deep nuts arrived, I managed to get all of the first one on the RH shaft (leaving about 1 turn available otherwise the following won't work) and then used a second one as a lock nut, however it only went on about 3 turns (it'd have been useful to also have some shallower M14 nuts for the lock nut exercise later). Once I'd pinched up the second nut (thankfully I didn't need to hold the first one in place as I wouldn't have been able to do so with any of my current tools) I then repeated the synchronised exercise with moving the breaker bar + M22 socket and the swinging arm up and down to suit.
After about 1 turn of the pivot bolt (since the locknut combination was enough to get the pivot bolt to turn albeit reluctantly), I then undid the locknut about 1 turn, undid the inner nut by about a turn and then nipped up the second nut (i.e. tightened the second nut against the first), and repeated the exercise. After several repeats of the turn, undo both, nip up, ... exercise I'd managed to get the shaft to turn through 3 - 4 revolutions, a positive step. The nuts I had were now too deep to use as a pair so I removed them from the RHS and returned to the same exercise using the breaker bar and socket on the LHS nut. Eventually after another few successful revolutions of the pivot bolt I ended up with the LH nut and shaft tightening markedly. It seems I'd run into a similar problem to that mentioned by Steve Brown in
viewtopic.php?f=8&t=5871#p32436 where the LH thrust washer stopped the shaft from undoing any more (it turned with the pivot bolt). I used a pin punch (a 4mm diameter head ish) and a smallish hammer to tap repeatedly against the outside edge / lip of the thrust washer, then managed to turn the nut, pivot, swinging arm, etc. about 1/2 turn before it jammed up again. I used a combination of repeating the taps with the pin punch, spraying the moving parts with GT85, and the nut+pivot+swinging arm exercise many times until the pivot had eventually turned perhaps 15 revolutions. At this point things got a bit easier and I could undo the pivot using the put alone (tightening the nut back onto the shaft many times both during the previous stage and this stage to protect the peened lip which was nearly completely severed by now). Eventually the pivot bolt was completely undone from the thread on the RH on the frame. The pivot still didn't want to come out.
After yet more taps of the thrust washer and liberal use of GT85 I then used various lengths and widths of punch to get the pivot bolt most of the way out and finally used a very long screwdriver as that was all I had left that was long enough to finally push the pivot bolt out.
I hope these fairly detailed notes help people in a similar predicament. I'll sum up with what I believe where the main techniques that should help undo the pivot bolt.
- Buy some M14 x 1.5mm pitch (assuming you have the same threads as I did) hexagonal nuts in 2 widths if you can, deep (around 11mm) and shallow (I'm guessing around 6mm)
- Buy a grease nipple (generally M6 x 1mm AFAIK), fit it, and pump the pivot area full of grease. You might find spraying brake cleaner in first may help, ditto GT85 or your preferred spray lubricant before you fit the grease nipple (but after you've drilled the hole near the top of the centre of the swinging arm so the sprays can reach the inside area of the pivot).
- Try the synchronised swinging arm + breaker bar undoing, the seizure may work in your favour and if they move in tandem then as the pivot turns it places sideways pressure which helps to free up the seizure.
- Be persistent, try a combination of techniques, and very patient. I spent about 10 elapsed days getting my swinging arm free from my Kanguro
Of course, if you're successful then check and decide what to replace, repair, refurbish. I'm hoping I can recover the peened area through welding on a lip to the LHS of the pivot bolt. I've also bought thread restorer tools for M14 x 1.5 pitch (which is the same as some car wheel studs and nuts so there are special suitable tools available relatively inexpensively (£20 in 2020)). For this evening I've sprayed the pivot with GT85 after cleaning up my tools, the bike, floor, and pivot bolt. I'll check it properly tomorrow, likewise the bushes, etc. Now I can finally work on repairing the side stand pivot on my swinging arm (the joy of an X model...).