Best way to extend Swinging arm?

borderer

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regarding my last thread (dilemma) I am now looking at ways of extending the swinging arm on a 1981 g/s. As far as I can see theres Moorespeed
at about £600 :eek or the option of a 50mm spacer and extending the drive carrier?
advice/ contacts appreciated
Ideal scenario: Pub owning engineer with over sexed daughter will carry out conversion overnight for £50:00:augie
 
Hi - I am deliberating exactly the same issue myself on my project bike.

http://www.ukgser.com/forums/showthread.php?t=242551

I have a friendly neighbourhood machinist who has my mono and is considering the work. Unfortunately the nubile daughter isn't also available :augie

We have examined the monolever and it has lots of complex curves on it, caused by bending the original thin walled tube through the 90degrees. Its important that the extended mono's face is exactly parallel to the original when its done and he rekons it'll take time and he'll have to make a couple of jigs to get it done. Unfortunately he has had a bereavement in the family so can't get around to doing it for at least 4 weeks.

I contacted Richie about doing it but he's really busy so even if i stumped up £600 and two drive shafts he rekons its unlikely before the new year given all the work he has on.

So options are buying the kit as you mentioned - for around €380 (unless you have found a cheaper one) or making the block and extending the drive shaft which my machinist can do a bit quicker.

Interestingly you can't do a block longer than 50mm as over this length the wheel rim would foul on the 4 bolt plate on the mono.


50mm or 100mm?

My forks were the same length as yours - I rekon as they are not the super long WP ones that 50mm will be ok, as they will raise the height of the rear by 60mm. With your using the g/s shock mount point it will only raise the height by 18mm so to get higher you'd have to move the lower shock mount point along the arm towards the swing arm pivot. (I've got a spreadsheet that does all these what if calcs for me if you want it)

This is a picture of my GS with forks and mono rear end

IMG_4394.JPG


If my machinist makes the jigs I might be able to persuade him to do yours . I haven't offered him any money yet but if we both offer some it might motivate him to do it...



How much of a hurry are you in?
 
newguy said:
Extending 50, but raising it 60? how much are you increasing the angle on the driveshaft by? What will this do to the life expectancy of the shaft?
Click to expand...

Well spotted - glad someone is paying attention :thumb2

60mm would be in the scenario with a 50mm extension, using the existing lower GS shock mount point and the paralver upper mount point. In the picture this is how the bike is set up (without the extension). It is clear that the angle is way to extreme!!

My other monolever doesn't have a lower shock mount point yet: I will move the mount point back to reduce the angle. I don't have the calcs with me now but I'll state the original and final effective swinging arm angles tomorrow.
 
Hi Pete thanks for the info.. am not in a great hurry so I would be interested in whatever your machinist can offer.
 
Hi Pete,

I was going to send you a PM today regarding the same question as Borderer.

If you can check with your machinist cost and if it would be better for him to rather do more than one.

I would be interested in a 100mm extension + drive shaft extended on my monolever - in no rush at all so next 2-3 months would actually suit me fine :beerjug:
 
There used to be an extension piece available as a kit - A section of swingarm with a shock mount in place which you welded in, and a section of shaft which was a straight fit and mated with the bevel input end and shaft end.

Used to be very popular, I think wudo used to sell them. I look after a wudo built GS special and that has one fitted.
 
Steptoe said:
There used to be an extension piece available as a kit - A section of swingarm with a shock mount in place which you welded in, and a section of shaft which was a straight fit and mated with the bevel input end and shaft end.

Used to be very popular, I think wudo used to sell them. I look after a wudo built GS special and that has one fitted.
Click to expand...

That sounds like a much easier solution. Does anyone have any pics of the bits & pieces of this setup?
With the driveshaft extension kit- was the original one cut & the extension welded on? Or was it possible to bolt the extension to the original driveshaft.
 
Padmei said:
With the driveshaft extension kit- was the original one cut & the extension welded on? Or was it possible to bolt the extension to the original driveshaft.
Click to expand...

No bolting or welding - it was a double ended splined section, one end mated with the end of the orignal shaft, the other end mated with the bevel box input spline
 
I tried the Wudo website but my German isnt up to translating it and Google dosnt seem to work there Anyone fluent enough to see idf they still make this Kit?
 
borderer said:
I tried the Wudo website but my German isnt up to translating it and Google dosnt seem to work there Anyone fluent enough to see idf they still make this Kit?
Click to expand...

I don't seam to be able to PM you. I may be able to help out - PM me back.

cheers

-Pete
 
pete.keys said:
This is the kit sold by CTI which shows the parts (nb there is a warning thread on the reliability of this company elsewhere on airheads)
Click to expand...

Doesn't look much to it really. Almost looks like you could DIY most of it. Almost....

The tricky bit to make would be the steel thing on the right of the pic (I assume a drveshaft extension although not being familiar with airhead shafts, I can't quite work out how it fits :confused: ). Some interesting intersecting cuts on that bit :augie If it's also splined internally, then I take back what I say - broaching internal splines isn't a home workshop thing for most people (certainly not me :D )
 
if you can get them for $400 then thats a good deal. Sure it isn't just one off?
I looks really well made too.
 
Nippy Normans supply Touratech, Wunderlich, Desert Fox and many other makes of accessories.
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