Speed triple swing arm in slingshot

[Graeme]

Thinking of going sssa on my 1990 gsxr750.

I know they are heavier, it will be hard to get the suspension working properly, and the look is a little old hat to some.

But, if I decide to go for it, what's involved with getting the triumph arm in?

Pivot is wider right? Easily narrowable? Chain line close enough to tweek to get right? What shock parts combo?

 

I have a lathe, but no mill, but could get access to one if needed.

[wraith]

I've seen it done but not down it, I'm told the Triumph swingarm is very wide and needs a lot of work to get it to fit.

[Graeme]

5 minutes ago, wraith said:

I've seen it done but not down it, I'm told the Triumph swingarm is very wide and needs a lot of work to get it to fit.

I've heard it's wide, but surely can't be hard to cut the pivot width down. I assume that can be done in such a way that keeps the wheel central and chain line right.

I've no idea though.

I guess ducati is another option if I want to stay 3 spoke. Don't know how hard that is either though. Probably a fair bit more expensive too

[Upshotknothole]

I used to have an 05 S3, the swing arm is extremely wide and heavy. Better off using a Duc or VFR swing arm as they're narrower.

[Duckndive]

15 hours ago, Graeme said:

I've heard it's wide, but surely can't be hard to cut the pivot width down. I assume that can be done in such a way that keeps the wheel central and chain line right.

I've no idea though.

I guess ducati is another option if I want to stay 3 spoke. Don't know how hard that is either though. Probably a fair bit more expensive too

Its not that simple its a very wide arm that needs extensive work to narrow ...

i,m not a fan off single side arms but as others have said a Durapi or VFR are better options 

[Graeme]

1 hour ago, Duckndive said:

Its not that simple its a very wide arm that needs extensive work to narrow ...

i,m not a fan off single side arms but as others have said a Durapi or VFR are better options 

I've been looking at pics and it looks like it's not just a case of cutting some off, looks like it would need plates welding back in to close up the casting again.

I'm not sure my ally welding is quite good enough for that.

 

I have found a ducati arm that has cone from a k3 streetfighter so must have already been narrowed, but yeah, maybe vfr would be a better bet.

I admit, I'm not quite 100% convinced I want to convert to sssa, but my bike needs all the shock linkage pivot wear sorting, and the rear wheel has a dent.  

As I'm looking to build something that could have been built in the mid/late 90s, when vfr conversions were considered trick, I'm tempted.

Alot of what I do with this bike may well be considered tacky these days, but this bike is all about teenage nostalgia, not necessarily how id build one now.

[Graeme]

I'm sure all the sssa conversion I've seen have been centered properly, but they never look it. They always look off center and like the bike is going to crab down the road. That's what puts me off slightly about the look, but I'm ignoring that.

Maybe I'll just put an under braced arm in it, or an early K arm. That's not tooo out of period I guess.

 

As long as I don't modify the frame, I can always swap it back out later so not irreversible. 

[Graeme]

There are different versions of the vfr750 arm aren't there? Maybe 2?

Which one would work best if I go that route?

Guess I should check the lengths too.

[graveltrapexplorer]

it's funny I was just searching evil Bay those morning at single arms with same idea for my 91 . I was thinking an arm of a duck monster s2r would look good 

[Graeme]

10 minutes ago, graveltrapexplorer said:

it's funny I was just searching evil Bay those morning at single arms with same idea for my 91 . I was thinking an arm of a duck monster s2r would look good 

Ducati is an option. I've even less idea about what's involved in fitting those though.

 

There have been loads of gsxr sssa conversions over the years and yet I can't really find much info on what's involved.

Don't need a 'how too', I'll work it out. But a rough idea of what issues need solving wpyld help me decide which one to use.

[Duckndive]

you also need to consider if the matching front wheel etc will fit your front end 

[Joseph]

Here's a detailed how to :

here are a few swingarm widths :

Ducati 748/916/996/998 - 243mm

VFR750 (1990-93) - 242mm

VFR750 (1994-97) - 227mm

VFR400 - 192mm

RVR400 - 202mm

Hawk NT650 - 235mm

RC30 - 235mm

RC45 - 250mm

MV Agusta F4 - 255mm

1050 speed triple – 283mm

Edited October 1, 2023 by Joseph

[Graeme]

16 minutes ago, Joseph said:

Here's a detailed how to :

here are a few swingarm widths :

Ducati 748/916/996/998 - 243mm

VFR750 (1990-93) - 242mm

VFR750 (1994-97) - 227mm

VFR400 - 192mm

RVR400 - 202mm

Hawk NT650 - 235mm

RC30 - 235mm

RC45 - 250mm

MV Agusta F4 - 255mm

1050 speed triple – 283mm

Thanks.

Slingshot is 225mm right?

I'd assume the later vfr750 would be easier then, assuming it's width is centered in the frame.

Gsxr k4/5 is 225mm too I believe.

 

60mm out of the triumph is a fair bit! I guess it's a hollow casting with a tube welded in so would need cutting, ends plating, tube 're welding, making sure everything stays lined up.

[graveltrapexplorer]

what about a superduke arm ? being a twin it's prob narrow 

[Joseph]

44 minutes ago, Graeme said:

Thanks.

Slingshot is 225mm right?

I'd assume the later vfr750 would be easier then, assuming it's width is centered in the frame.

Gsxr k4/5 is 225mm too I believe.

 

60mm out of the triumph is a fair bit! I guess it's a hollow casting with a tube welded in so would need cutting, ends plating, tube 're welding, making sure everything stays lined up.

Yeah 225 or 227, all OC/WC arms swap over.

Bear in mind that if it is possible to cut down the pivot width, the hollow casting/body of the arm is approximately the same width so potential issues there to cut/reshape/weld metal in, and depending on how it's built initially...

I'd go with an arm thats been done already and use that, at least you're sure to get the mod finished rather than mess around trying to be a pioneer and get stuck and pissed off

[Upshotknothole]

Some of the rear wheels can be swapped between the different swing arms, but you have to swap the hole hub assembly. Had an old friend that did it with a fireblade, but I can't remember what swing arm he had or what he stuck into it, because it was a fireblade and I just didn't care.

I think I've seen S3 swing arms modified in old street fighter magazines, they had to be machined down, new end plates made up. Out of all of the SSSAs, the Triumph ones have always been the hardest to use with anything else because they're just so damn wide.

There are some on Eblag here in the states for K series 1000s, but they all want stupid money for them.

Eblag swing arm

Edited October 1, 2023 by Upshotknothole
spelling

[Graeme]

5 minutes ago, Upshotknothole said:

Some of the rear wheels can be swapped between the different swing arms, but you have to swap the hole hub assembly. Had an old friend that did it with a fireblade, but I can't remember what swing arm he had or what he stuck into it, because it was a fireblade and I just didn't care.

I think I've seen S3 swing arms modified in old street fighter magazines, they had to be machined down, new end plates made up. Out of all of the SSSAs, the Triumph ones have always been the hardest to use with anything else because they're just so damn wide.

There are some on Eblag here in the states for K series 1000s, but they all want stupid money for them.

Eblag swing arm

I have read that you can make the triumph hub fit the vfr arm but it doesn't sound easy. Needs sleeves and spacers making, which isn't too much of a problem, but needs spindles machining and the are hardened.

I have a lathe so certain aspects aren't too hard.

I have a lead on a pre narrowed triumph arm though, which I'll go look at. If not, I'll go get.

Or sack it of and find an old under braced arm

 

[KennyKak]

I'm not 100% on this but I think the vfr shock is off set and not central so new mounts would have to be sorted. If you do use the early K series swing arm you'll need to move the lower linkage mount to make it work, so I've been told. Had quite a bit of conflicting info on that one (It's what I'm trying to fit)

[Graeme]

1 minute ago, KennyKak said:

I'm not 100% on this but I think the vfr shock is off set and not central so new mounts would have to be sorted. If you do use the early K series swing arm you'll need to move the lower linkage mount to make it work, so I've been told. Had quite a bit of conflicting info on that one (It's what I'm trying to fit)

Yes, I've heard the shock is offset.

I may be missing something, but feels like making a new top mount to move the shock shouldn't be a problem.

[Graeme]

K series arms seems like the easiest way into a nicer swingarm.

Means I then get to play with more modern wheels if I want to too as I'm not limited to whatever the sssa wheel is.

[Upshotknothole]

I have a K4 swing arm in my 89 7/11, either the top shock mount or the bottom linkage mount needs to be moved back to make it work. I have a custom top shock mount on mine, but seen plenty of people move the bottom mount as well.

[KennyKak]

26 minutes ago, Upshotknothole said:

I have a K4 swing arm in my 89 7/11, either the top shock mount or the bottom linkage mount needs to be moved back to make it work. I have a custom top shock mount on mine, but seen plenty of people move the bottom mount as well.

I think I'm gonna do both. I have a K1 750 that's more or less identical that I can some how get some measurements off and get it as close as possible. 

Just waiting for the father inlaw to come back off holiday to turn up 2 swingarm bushes to fit the slingshot swingarm spindle. (From 30mm to 20mm if I remember right)

[KennyKak]

Oh and I've used the K3 1000 swing arm cos it doesn't use a torque arm. Makes it look cleaner

Edited October 1, 2023 by KennyKak

[Joseph]

..

Edited October 1, 2023 by Joseph

[Joseph]

9 minutes ago, KennyKak said:

I think I'm gonna do both. I have a K1 750 that's more or less identical that I can some how get some measurements off and get it as close as possible. 

Just waiting for the father inlaw to come back off holiday to turn up 2 swingarm bushes to fit the slingshot swingarm spindle. (From 30mm to 20mm if I remember right)

I think you'll find that the slingshot bushes will slip into the K bushes which avoids machining stuff or waiting for inlaws