Derelict Goldwing, Day 45:- (Monoshock Shortlink Mounted)!

Added: 2026-05-30

[00:00:21]Right, good morning. Welcome back.

[00:00:23]Now, if you're following this Goldwing project, you might remember in the last video I rectified the cockeyed crossmember cockeyed from the factory so that I can weld the short link mechanism to it in order to make a monoshock system at the rear. Now, I wanted to get it all finished in the one video, but these things have a habit of evolving in the execution and this one did exactly that. And evolving in a good way because I came up with an idea halfway through doing it to actually make it even stronger and make it so that I can grind away at the level that I've created and get it absolutely perfect. And now I have. Ready to weld a plate on top of which will double thickness it and then put the mechanism on top of that. But let's show you how I got it bang on at this point, where it is at this point so far. All right, this piece of tube parked through here, that represents the swing arm. And if I take the spirit level and I clip it to that, that shows that with the frame strapped to the lift, I've got the swing arm sitting absolutely dead level.

[00:01:20]If we ignore the top face that I've now rectified, if we go on that face which is still unmodified, I'll show you how much runout that crossmember had by just magnet clipping that on the crossmember.

[00:01:34]And you can see there just how far out the crossmember was. Now, on this, the mounting face for the short link, I've now got that with this tapering fillet of steel absolutely bang on.

[00:01:51]So, when I take my steel plate that I'm going to weld on today, put that on there, it's touching steel all the way along and absolutely solid sound base underneath it.

[00:02:08]And that is also, as you can see, absolutely perfect.

[00:02:13]Right, if this is a bit confusing and none of it makes any sense, then I apologize for that. I just briefly explain for those who don't know and maybe are interested in knowing and hopefully not to bore those who do know.

[00:02:23]This is your short link mechanism. This is underneath every monoshock motorcycle. That's the linkage that connects the frame to the swing arm to the suspension unit and one of these in particular, where are we?

[00:02:37]Where are we? It's Right, that one. That linkage there.

[00:02:42]That's got a needle roller bearing in it and it has to bolt to two tabs on here.

[00:02:47]And then the whole thing when the bike bounces up and down with this part of the mechanism bolted between two tabs firmly on the frame, it goes up and down like that as the bike moves. And this end of the linkage goes to the shock absorber. So, that's literally how your suspension will work.

[00:03:07]But when viewed from the rear, you can see how important alignment is because whilst the mechanism is bolted to the frame, if that's cockeyed, these two plates are bolted to the swing arm which is at this angle. So, you've got something at this angle holding it, but the mechanism, the bearing that runs through there is going to try and twist and bend that way.

[00:03:26]So, I hope that kind of explains it. I need the whole contraption to move in one single plane of movement. I've got the swing arm which is moving directly up and down and this bolt here bolts to a bracket on the swing arm which I've got to weld on later. And once it does, that's going to be pushed straight up and down. But if this part of the swivel is bolted to a cockeyed crossmember, it's going to be slightly cockeyed. Not by much, but enough to cause the up and down movement of this part to then fight that movement. I've got two different directions of movement fighting each other and it's only fractional, but what will happen is the bearings in there, the needle roller bearings, they will knock out in no time. It will gall up and it will bind on them, break them very quickly and also the suspension itself wouldn't even move very fluidly.

[00:04:09]It would move very sticky and be awful.

[00:04:11]So, it probably wouldn't even get out the door. Absolutely has to be right.

[00:04:14]So, today I've got to weld that plate on and keep it just as flat as that is and then the two tabs with the two holes so that everything remains absolutely square like it is now.

[00:04:23]Let's get on with it. Wish me luck.

[00:04:25]All right, first task, weld my pre-prepared 3 mil plate directly to my tapered fillet with seven plug welds and then weld it all the way around, give it a little tidy up and check it to see if it's still level.

[00:05:00]>> [snorts] [snorts] [snorts] >> All right, quick check to see if that's level.

[00:06:47]All right, swing arm's level. That gives us our datum point.

[00:06:50]If we just zoom out, you see that gap above the spirit level.

[00:06:57]This is the original line of the crossmember. Look at the gap that side compared to that. That's running miles out.

[00:07:04]Now, let's put it on top which is our working platform we need.

[00:07:12]Make sure we are level.

[00:07:16]And by the looks of it, we are absolutely spot on.

[00:07:23]So, now I've made a platform to mount the short link mechanism onto that is absolutely perfectly level and identical to the swing arm. The two of them are 100% parallel. They will both operate up and down in exactly the same plane of travel and work together. That's perfect. And at the same time, I've also made this crossmember probably three times stronger than it was and as it wasn't designed by the factory to carry suspension, that is also something else that I needed. Now, I just got to weld two tabs on there with holes in to bolt the short link onto.

[00:07:52]Next.

[00:08:57]>> [snorts] >> Okay.

[00:09:02]All right, hole needs to be 12 mil.

[00:09:43]All right, let's just test fit the bolt that goes through it.

[00:09:54]Yeah, perfect. Nice fit, as well.

[00:10:05]All right.

[00:11:19]All right.

[00:11:20]Quick test fit.

[00:11:21]Through the linkage.

[00:11:28]And they will weld on there.

[00:11:32]Reducing amount for the linkage.

[00:11:37]Easy.

[00:11:39]And obviously, the distance that they are apart is critical, and it has to be exactly correct. And there's no way I can just take them off like that.

[00:11:49]And sort of guess it with a tape measure. I've got to mount them on the bolt.

[00:11:54]That lines up the two holes perfectly.

[00:11:57]Also, if I put it through there, you see that the when these are pinched in really tight, the mechanism still swivels because the tube in there, the inner race of the bearing, is a little bit longer than the casting, just a fraction. And it allows the casting to move whilst the bolt pinches down on this. So, I don't have to have that anywhere near the welding and all the heat, risking those little needle bearings getting damaged or the rubber seal that's in there.

[00:12:34]All I've got to do is put the spacer on there, and then that tab on there, and weld them on like that. And that will give me the exact spacing and the exact alignment for the bolt at the same time.

[00:12:52]Now, they don't want to be completely tight and solid cuz then I won't be able to slide that in between the tabs once they're welded on. It wants to be no side float that way, but just a little wiggle. So, there's just a bit of clearance to get that in.

[00:13:10]That's it. Perfect.

[00:13:13]All right. I've been put all this effort into making sure that that surface is absolutely parallel to that surface.

[00:13:18]I've also got to make sure that whilst that's correct, I get that correct, as well. And easiest way to do that is take a steel rule, put it up against the back of them cuz they're both identical cuz I ground them as a pair, and then make sure by looking down that my steel rule lines up with the line along the front of the axle or this tube that represents the axle for the swing arm. And once that lines up that way, I know I've got it square that way and that way.

[00:14:00]All right. So, there's the swing arm, or the tube that represents it.

[00:14:05]And there's the two tabs. And if I put that on there, it's quite hard to do with two hands.

[00:14:13]Hang on.

[00:14:16]And that line follows parallel.

[00:14:21]So, the line between those follows the line of the swing arm.

[00:14:43]>> [snorts] [snorts] >> All right. Quick check to make sure that it has stayed correct that way and that way.

[00:15:27]Absolutely perfect.

[00:15:34]All right.

[00:15:36]Swing arm level.

[00:15:41]Tabs level.

[00:15:43]Bang on.

[00:15:45]Damn it, that's good.

[00:16:01]That's right there. That's where it normally lives.

[00:16:37]Okay, two things in closing. Yes, first of all, I know my welding is rough. It doesn't look pretty, but it's hot. It penetrates fully, and it's always absolutely rock solid. My welds never break, and that's really all I'm concerned about. If it bothers you, then get over it and go and watch some of the pretty welders who make the exhibition welds. I'm really not interested. This is about getting my suspension connected to the bike so it don't fall off. And secondly, I know for sure by checking and double-checking that I've got all the engineering principles of this job so far absolutely correct. The mathematics is right. All the tolerances are right. Everything's aligned and perfectly correct in that way, and I know that it will work. It will function properly and safely. And for me, that is more important than anything else. So, join me in the next one. We'll put the swing arm in the frame and start working out where to put the mount points for the dog bones so that this cantilever principle functions correctly. There's a lot of maths involved in it, and I'm really looking forward to it. I'll see you next time.