XS11 swing arm stretch?

[crazy steve]

I have a guy who does automotive drive shaft extensions and he doesn't see it as a problem to lengthen one of these.

I know there are going to be unforseen difficulties, but nothing ventured, nothing gained. There are probably a million reasons why it won't work, but if it hasn't been tried, how will we know for sure...

I don't see stretching the swingarm as being an insurmountable problem; like I said, if you 'jig' it to maintain correct alignment you should be ok.

But the driveshaft would give me pause; the OEM shaft is a small diameter (only .67") high-strength heat-treated piece quite unlike automotive driveshafts. This would be much more akin to shortening/lengthening an automotive axle or transmission shaft, and you'll have real difficulty finding anybody that recommends doing that. Welded axles are banned by all the major racing bodies, and for a reason; they break. You'll only have roughly 20% of the weld area that you would have on a automotive-type driveshaft, and being on a much smaller diameter the 'leverage' stress will be much higher. Granted, a motorcycle has far less torque, but the reason those aftermarket Vmax shafts exist is because of breakage; and the Vmax shafts even stock are larger than the XS shaft.

If the shaft is lengthened by sleeving then re-heat-treated after welding, you might be ok. I wouldn't trust anything less.

[fredintoon]

The reason I am asking is because I want to build another old,(really old), style custom like this one I built. - - -
This was a 1074 Honda CB750. I stretched the swing arm 8 inches on it. - - -
I have a 1978 XS1100 that is just begging for the same style treatment. - - -
Does anyone have a swing arm and drive shaft assembly they may consider selling for reasonable?
I would like to try stretching one and then installing it if it works out, but not left without a rear end if it don't.

Hi Bill,
how about stretching the shaft by cutting it in halves and joining them with a sleeve?
About a 12" length of heavy-wall tube counterbored 2" deep each end to fit the shaft and silver-soldered together to keep the temperature as low as possible?
Cut'n'weld with tube stock should be OK to extend the swingarm.
As you say, if you use salvaged parts, you can put the stock parts back in if the stretch don't pan out.
But what about the frame?
I'd suppose you'd leave the stretched swingarm's stock shock mounts in place and leave the frame alone to do a trial run before stretching the frame to match?

[scrapvalue]

Hi Bill,
how about stretching the shaft by cutting it in halves and joining them with a sleeve?
About a 12" length of heavy-wall tube counterbored 2" deep each end to fit the shaft and silver-soldered together to keep the temperature as low as possible?
Cut'n'weld with tube stock should be OK to extend the swingarm.
As you say, if you use salvaged parts, you can put the stock parts back in if the stretch don't pan out.
But what about the frame?
I'd suppose you'd leave the stretched swingarm's stock shock mounts in place and leave the frame alone to do a trial run before stretching the frame to match?

Good opservation. I will be stretching the top of the frame also. But only about 2/3rd's as far.
This will lay the shocks down and lower the bike.
The stock shock mounts will be used, It is just a matter of streching the tubing between.

[Trikerneil]

The FJ900 shaft is about 5" longer than the XS1100 and the splines fit both ends.

HTH

Neil

[natemoen]

The FJ900 shaft is about 5" longer than the XS1100 and the splines fit both ends.

HTH

Neil

Good to know!

[scrapvalue]

The FJ900 shaft is about 5" longer than the XS1100 and the splines fit both ends.

HTH

Neil

That just might work out perfect then.
A 5 inch stretch would be plenty for what I am trying to do.
Thanks

[cowboybob998]

Question

The FJ900 shaft is about 5" longer than the XS1100 and the splines fit both ends.

HTH

Neil

Got a question on the fj 900, i cant find that they even made one, found fj 600,1100 & 1200, any one know about this ?
Did they make them in the UK and not here in the US
next question would be would the 1100 and 1200 have the same splines

[cowboybob998]

Got a question on the fj 900, i cant find that they even made one, found fj 600,1100 & 1200, any one know about this ?
Did they make them in the UK and not here in the US
next question would be would the 1100 and 1200 have the same splines

FYI the FJ is chain drive and the XJ is shaft drive acording to bike bandit.com
Yall got me thinking about doing this to one that i have, a project bike that just keeps changing shape every time i do something to it

[Crusty Snippets]

Driveshaft

The joys of being young with so much energy and ideas.
Here is an alternate idea for all that enthusiasm.
Sail boat, beer, girls. You can spend countless hours, days even with this set up. Meanwhile the stock bike will be at the dock waiting for you.

FYI. I had a 53 Bentley for many years, had a 37 Ford hearse that we put a 312 Thunderbird motor in, along with a Dodge gearbox and rear end.
Also had a much modified ( one of the fastest ) Nortons with a Suzuki swing arm.

Uncle Crusty

[natemoen]

I posted this over in your wanted thread too.

I think the fj900 is the european version of the xj900. Could be wrong but that seemed to be the answer as I was doing some research.

[cowboybob998]

The joys of being young with so much energy and ideas.
Here is an alternate idea for all that enthusiasm.
Sail boat, beer, girls. You can spend countless hours, days even with this set up. Meanwhile the stock bike will be at the dock waiting for you.

FYI. I had a 53 Bentley for many years, had a 37 Ford hearse that we put a 312 Thunderbird motor in, along with a Dodge gearbox and rear end.
Also had a much modified ( one of the fastest ) Nortons with a Suzuki swing arm.

Uncle Crusty

Sail Boat, Beer, Girls, "been there done that" The Sail Boat sunk, I drank all the beer, and the girl left me, lol, and i have a stock bike.
Now i can put all my time, money in what ever i want, i have a bike that i am working on that is made up of a lot of outher bikes and i like the chooped low rideing custom bike, when you pull into a place and every one wants to know what it is.