Swingarm conversion

Hi I'm Dunc newbie i was wondering if anyone has put a rd350lc swingarm onto an xj550 I had a measure and it seams to fit i was wondering if there were any problems apart from the top shock mount thanks for looking Dunc .

 

Bought an rd350 lc front wheel to make the bike handle a bit better only problem the 350 uses a smaller axel haven't taken the wheel out the xj to compare bearing yet if to much of a problem will get 350 front end

 

Hi Duncan - what size is the 350 lc wheel - 17" ? Will it make that uch difference do you think ?

I've heard of people updating to later 600 front ends (XJ600 and even R6) but not smaller 350 stuff - probably because any LC bits
are likely to be rather more costly - aren't they ?

 

Hi I've got a 19 " on the xj so I got the lc wheel which is 18" looks the same as the back apart from having a smaller axel I want to keep the wheels because I like how they look going to take the front wheel out tomorrow and have a look see how different the bearing sizes are I've got a mate who's getting me an lc swingarm which will be the next thing to do I've seen the blue xj on the forum with the mono shock and I think it looks cool been looking through mods section spent hours looking through what people have done it's really good if I can't get the wheel to fit on the xj forks will swap to something else thanks for the reply

 

Well it's sure worth a try if you've got the bits. Which blue XJ are you referring to (I've not seen it).? I have seen a magazine special in the UK with a monoshock but again I think that was from R6- looked damned good mind you.

 

If you put xj550 cafe racer into Google you will eventually see it I've measured both lc and xj and they seem to fit it's top mount that will be the problem locating in the right place so it looks and handles alright thanks for the advice about the r6 stuff if I have no joy I wil see if the r6 front end will take an xj wheel with a bit of moding

 

Ah, got it now. I see the problem too - no longer any room for the airbox and in his case even pod filters. The R6 conversion guy used a complete front end via a yoke stem swap if I recall - but that meant a change in wheel style away from the classic 'swirlys'.

 

Had a look at the bike today started it up found the carbs on each end leaking back into the air box order carb kits for them as well as rubbers for the inlet then had a look at where the top mount goes and I'm going to struggle to get any air filter on the carbs had a word with a mate he's to see if we can get some kind of filter on their also the mate who sold me the lc front wheel has got triumph Daytona calipers on the front of his lc with a bracket so they they are the same hole centres as them as on my xj he says it's a common upgrade on the lc and makes hell of difference that's about it for now.

 

Yeah, heard about using Triumph calipers on FZ750s - with those you don't even need an adapter bracket apparently. On swing arms - i never did any mono conversions but it seems that ther might be more room (less hassle) with a 'vertical shock' and linkage. would XJ/FJ600 fit maybe ?

 

You can use the swing arm from the Radian, should bolt right up. Or if you are adventurous like me, graft one from the FZ600.
17"wheel with a disc. YZF forks with 17" wheel. Handles and stops like a modern sport bike.

 

Ha - I know this, saw a German 550 sporting one - you try finding one though. I've been searching ebay for 12 months !

 

I did this on my XJ550 for Pre82 racing and just swapped the bearings to a size the suited the XJ axle size

 

Thanks for the advice I'm thinking of using a swingarm with a linkage like fzr or thundercat it doesn't get in the way of the air box I can weld a top shock mount that doesn't interfere with the air box and I will swap the bearing on the lc wheel so they fit the xj spindle that's the plan up to now

 

Great stuff - make it happen and show us the pics. I have a spare 550 frame I was going to mess about with like this, only lacking that precious resource - time !

 

Hi took carbs off today ready for cleaning took battery box off as well looks like I'm going to have to cut the air box to get it out also picked the swingarm I'm using a yzf125r I will have to weld a bracket on where the rear brake bolts on and the way the shock fits should be ok for the top shock mount the only thing I don't know about is how the bike runs on pod filters instead of an air box that's about it will post some pics when I get the swingarm arm in thanks for looking .

 

Bearing swap fairly simple. 6302 bearing in 550 6301 in 350 wheel. Same outer size. Install 6302 in 350 wheel and check internal spacer length

 

Thanks for that will get some today

 

You shouldn't have to cut the airbox out - but it is damned tricky. Some advise that you can undo the front engine mounts and 'rock' teh engine forward for more space - can't really comment as teh engine was out on mine when I put it back and it was still a bugger. Is there no space for the shock mount with the box in ?

PS these airboxes are getting rarer due to the difficulty in extraction - if you can get it out and save it it could be worthwhile exercise..

 

I think it might be in the way but until get it in and see where the top shock mount goes hopefully i should have it in this weekend

 

A

as you can see the left part of the air box sticks out just have to see where the shock sits

 

interesting project.. a little while back i put together an xj550, cbr f2 wheels, F2 front end, crf450 swingarm mated to a cbrRR shock. ill have to toss a pic up..

im having serious running issues by running pod filters but the space for a conventional airbox just doesnt exist anymore. im planning to construct a crude cardboard/tape box around the set of carbs to help remove some turbulence. see how it goes. ive got more research to do clearly.

lookforeward to this build

 

Remove the starter. Makes a lot more room to wiggle things around.

 

Can you not offset the shock and leave airbox and put battery elsewhere ?

 

Might that be tricky with a stock linkage ?

 

I've got the swingarm but not shock and linkage I'm hoping it fits just under the air box should be here by the weekend I'm going to fit the swingarm and the shock should be ok will keep you posted will have some pics at weekend

 

Hi all took swingarm arm off and exhaust and tried rear wheel in yzf swingarm and the slots are going to have to be milled to take the wheel spindle and going to have cut the wheel spacer down when the shock comes I will see if I can use the air box it's going to be tight will post some pics when I've milled the swingarm that's it for now

 

Why?

 

As you can see I've got the swingarm in shock still hasn't arrived yet but pleased with how it's going will have to go for a lower profile tyre maybe an 80 a 70 would be better will give me a bit more room

 

To answer your question why it's because the suspension is crap so I thought I would put something modern on

 

Good shocks would have been a better way to go, and a lot less of a headache. You're stuffing an 18" wheel into a swing arm designed for a 17" rear wheel. Now your overall length (axle to axle) is presumably shorter, it's going to handle like poop most likely. Spring rates? Shock angle? You're doing it though! (It handles like shit because its an XJ, they were NOT designed to be a race bike. Say it again, not a race bike, they handle like shit at speed.) Are you switching to a 17" front and rear? That would help a bit, maybe. You have no chain adjustment with that rear wheel as is. I'm coming off as a hater, but, it's dangerous in the sense that its not very mechanically sound and money could go so much further. But if this is to practice machining and fabrication skills, I totally get it. Don't let the assholes like me convince you otherwise.

 

They dont have to, good shocks and attention to suspension works wonders on any bike but very few people pay any attention to spring rates, sag settings and think any old shock off any bike will do

 

Yup. I suppose you 4 options for compression on the rear...same up front too. Some of the rear shocks (from the factory, mind you) have 4 ride height/sag adjustments.

 

And are the stock shocks on the 550 coil over air or coil over oil? Either way they're not serviceable and are shot at 30+ years old...I know some people think other wise... If anyone can show me how to set sag on any of the 1982 era XJ's, that would be great.

 

The swingarm is longer than stock by an 25mmm I don't want to have a race bike or race bike handling I just wanted to do something different thanks for the advice on the shocks and I'm using xj wheels because I like the look of them will post more pics when the shock in

 

Hi I've put the shock in top shock mount in I've to put the bottom linkage mount on also lined the back wheel chain sprocket line up ok sorting a new air box that have the same area will fab it at work here's some pictures what I've done so far

 

Looks like good progress - how about a pic from the front? From here it looks like the shock is fixed right smack where the airbox was.
BTW did it come out whole in the end ?

 

Ye I managed to get it out in one piece took a bit wriggling I know what you mean about the shock being in the way I'm going to make one at work I've got a mate who's drawing it up for me so it will fit around the shock when I get the bottom linkage secured I will push it out the shed and post some pics thanks for the support

 

No worries we all need it. My bugger won't start now - carbs again most likely as it will splutter on a breath of ether (easy-start). A bit annoying as it ran up the road last week and now zippo. Ho hum at least all the carb screws are loose from all the tear-downs.