Jump to content

Adjustable wishbone bracket?


Recommended Posts

Hi Folks,

My GT6 Mk3 - early rotoflex has a misaligned bracket on the rear suspension which needs to be replaced. Canley show the part as being adjustable. My question is simply, why does it need to be adjustable? A further question - is this bracket simply welded on to the chassis?

REAR WISHBONE BRACKET ROTOFLEX LH - ADJUSTABLE
Part No. 215747

 

triumph-gt6-mkiii-chassis-frame-fitted-up-to-ke_kf-20000.thumb.jpg.61d4aee98ca3c9cf96a3ebe1fabbad46.jpg

Link to comment
Share on other sites

The ones Canley do are re-manufactured and have three mounting holes for the wishbone , top middle and bottom.

I have them on my converted Vitesse, I think it is to allow for adjustment of camber, I have mine on the middle setting and the wheel sits vertical at rest. I do have a TriumphTune de-cambered spring from back in the day which makes it more negative than standard. It handles like a go cart.

I think the originals were one mounting hole.

Steve

Edited by Steve P
Link to comment
Share on other sites

2 hours ago, Steve P said:

The ones Canley do are re-manufactured and have three mounting holes for the wishbone , top middle and bottom.

I have them on my converted Vitesse, I think it is to allow for adjustment of camber, I have mine on the middle setting and the wheel sits vertical at rest. I do have a TriumphTune de-cambered spring from back in the day which makes it more negative than standard. It handles like a go cart.

I think the originals were one mounting hole.

Steve

Three mounting holes!   Wow!  I did that in about 1996, when I was re-building Old Blue Vitesse.     An article from long, long ago when the Courier was called "Turning Circle" described in engineering detail the nature of the Rotaflex suspension, and how it might be improved.   The author ( C.K.Eikhoff - his article was "Rear Suspension Talk" Turning Circle No.14, Feb '89, pp. 9-15) found that lowering the wishbone pivot point by 60mm (2.4"!) would minimise camber change and reduce Rotaflex plunge, while a lesser drop of 44mm (1.7") would abolish plunge. 
 

As I was fitting Rotaflex to a previously swing-axled car, I made three sets of wishbone brackets, to match the OE dimensions, those of Eickhoff's 60mm drop (Eikhoff 'B') and another set, used by other racers which dropped the eye only 1" but also pushed it out by 5mm:

Bolt-onwishbonebrackets2.jpg.17ca95e5ebe35373b97f1f5cd488c6ba.jpg
 

As you will note, they were designed to be BOLTED, not welded to the chassis rail so that I might compare and contrast each set.   I regret, for my scientific reputation that I tried out the "Racing" brackets and was so impressed that I never tried Eickhoffs!

Has anyone used the triply drilled Canley brackets?      What are the dimensions of the three holes locations?      If only I'd patented my designs, I could sue Canleys!!
 

And, has anyone heard of Eickhoff ever since?

JOhn

 

  • Like 1
Link to comment
Share on other sites

Gosh, this is all very interesting. I'm temporarily refitting my "bent" suspension in order that I can get the car to a suitable welder's facility. Getting the radius arm bush into place is proving awkward as the bush is out of alignment with the bracket's inner hole by about a millimetre. I have made a "slug" to lead the bolt into the hole. The slug is a cut down bolt with a tapered leading head.

Link to comment
Share on other sites

Unless it's distortion in the camera, that bracket is deffo bent!  Has the weld failed on the rear side?  In the circumstances, a hammer might be used to 'adjust' it, and bring the radius arm back into alignment.

For your welder's information, Canley's has the correct dimensions for the bracket location: Rotoflex Chassis Dimensions : Canley Classics

John

Link to comment
Share on other sites

The welds are solid enough and are skewed at the same angle as the bracket. There's insufficient room to swing a hammer with anywhere near enough force to shift the bracket. I fear that the welds might crack if there were enough force applied. Think its a case of grind off the old and on with the new.

Link to comment
Share on other sites

  • 2 weeks later...

I ordered the replacement bracket from Canley - excellent service as usual. It has arrived and I find myself confused when I look at it. You can see in the photograph that the front upper horizontal edge (furthest from camera) is not the same as the rear. If this bracket were placed directly on the chassis and welded on, it would be at the same sort of angle that the existing "bent" bracket is. I'm assuming that it should sit perpendicular to the chassis in the vertical plane so that the lower wishbone mounting bolt sits in a parallel line with the chassis. Why is there this difference in the two horizontal mount points as more clearly seen in photo 2 with my mugshot?

There's an additional question in my mind... The WSM 5.106 appears to show this bracket with the two bolt holes on the top which then begs the question, should the bracket be bolted on rather than welded?

WIN_20240107_10_13_44_Pro.jpg

WIN_20240107_10_33_50_Pro.jpg

Link to comment
Share on other sites

I wonder if those brackets arent for converting a GT6 to rotaflex not for one that started like that. The chassis look different with the non rotaflex having a downward curve around the axles which means those brackets are welded onto a non horizontal surface...

Link to comment
Share on other sites

Took both rear wheels off and photographed each side. The chassis does have a downward curve and there are definitely no holes for bolting the bracket to the chassis so welded it must be. Perhaps I will revisit the "hammer it back" suggestion... The rearmost angle on the brackets both sides are 5.58 inches as near as I can measure, which is correct.

IMG_20240107_115001778.jpg

IMG_20240107_115446429.jpg

Link to comment
Share on other sites

No pictures but when I did my Vitesse Mk 1 conversion I just welded it as specified in the chassis diagram, and it sits vertical perfectly in line with the wishbone position relative to the top spring mount.

Steve

Link to comment
Share on other sites

On 07/01/2024 at 10:37, Stratton Jimmer said:

There's an additional question in my mind... The WSM 5.106 appears to show this bracket with the two bolt holes on the top which then begs the question, should the bracket be bolted on rather than welded?

The two top holes are probably tooling holes to locate the blank when the sides are 'raised' to form the U shape. The original Triumph brackets have the holes and the part formed using press tools however for the Canley brackets the manufacturing process will be different and they could possibly be deleted. 

Would it be possible to make an extended cover bracket bolted to the original via the top hole(s) and the wishbone holes (with a spacer tube) and had say 25mm lower holes for the new fixing? Spacer washers the same thickness as the original bracket would be needed to maintain the correct internal width. 

Iain 

Edited by Iain T
Link to comment
Share on other sites

That's certainly worth thinking about Iain. It's funny when you look again at the photos that it is clear that the nearside bracket's "vertical" sections do not form right angles with the top. The rear section is probably nearer to a hundred degrees while the front is correspondingly less. The line of weld suggests that the bracket was already bent that way before being welded into position. My thinking now is to grind out the vertical welds, bend the plates back to perpendicular maintaining the gap to fit the wishbone and then re-weld them. I will remove the driveshaft and wishbone as a complete sub-assembly before doing this.

Link to comment
Share on other sites

Don't worry about breaking the vertical welds the bracket will bend before the welds fail. With the wishbone off you should be able to get a bar in to hit wiv n 'ammer or prize over. I would be more worried about rewelding anything to the chassis unless all surfaces are ground back to clean metal. 

As to the over bracket say in 3mm steel I'm not sure the eye of the wishbone would clear the original fixing hole unless the new hole is possibly more than 25mm lower. I'll take a look when it gets a bit warmer!

Iain 

Edited by Iain T
  • Like 1
Link to comment
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now
×
×
  • Create New...