Discussion
phillpot said:
They’re the onesAdrian@ said:
IMHO, it is a rose joint in side thrust, and not how a rose joint works/designed to work. A@
Canley say they’re designed for it and as the photo shows the housing is a beefy lump ! They’ve sold them for 30 years so can’t be worse than the Triumph brass adornment. Can they?
Looking them up online one Elan owner says seriously that there’s nothing wrong with the Stanpart unit as in 40 years he’s only had two fail (!)
Does the original design trunnion fail due to bad design or because it is not maintained / serviced correctly? If the latter then servicing regularly with a replacement schedule may be a simpler solution.
Also as the original design is based on a rotating thread the cars geometry will change slightly when steering, which presumably it would not with the Canley item. Is this geometry change part of the original TVR design to improve drivability or does it detract from drivability. Knowing this may influence your preference for either route.
Moto
Also as the original design is based on a rotating thread the cars geometry will change slightly when steering, which presumably it would not with the Canley item. Is this geometry change part of the original TVR design to improve drivability or does it detract from drivability. Knowing this may influence your preference for either route.
Moto
Dollyman1850 said:
At the risk of being castigated for being cryptic and unhelpful again I would state the following.
THESE UNITS ARE NOT DESIGNED TO WORK WITH TUBULAR WISHBONES.
They may work with an early original Grantura MK3 and they will work with a spitfire and herald which is what they are designed to work with.
I have seen them used with Tubular wishbones but only when modified away from their standard configuration.
N.
Can you say why?THESE UNITS ARE NOT DESIGNED TO WORK WITH TUBULAR WISHBONES.
They may work with an early original Grantura MK3 and they will work with a spitfire and herald which is what they are designed to work with.
I have seen them used with Tubular wishbones but only when modified away from their standard configuration.
N.
I have used the Canley trunnionless uprights on the front of my S2 Vixen V8 but it isn’t a ‘standard’ setup. I made new CDS wishbones which integrated the CC bearing carrier - from what I could see at the time that I did it the concern was that the bolt in bearing carrier block reacts against the lower arm which seems to work ok on the Triumph lower arms but not so well on the carrier plates on the TVR tubular lower arms.
I can see Adrian’s point on the thrust loading of a spherical bearing not being ideal & a true ball joint would be a nicer solution but my take on it was that the general arrangement precludes the chance of pull through which is a good thing, the design of the pin on the upright means you end up with a significantly greater cross section without the stress raisers on the standard “threaded” part which addresses the main failure mode. I also took the opportunity to upgrade to GT6 stub axles with mix & match hubs to keep the PCD correct & enable me to run an upgraded front brake setup. There are lots of other mitigations with Trunnions which if ignored / aren’t understood then will certainly either contribute to or result in premature failure which probably unfairly contribute the bad rap they get.
It’s fair to say though that they aren’t direct bolt on & as with anything done to take a car away from standard spec then it’s done at the owners risk & if there is any doubt then professional advice should be sought.
I can see Adrian’s point on the thrust loading of a spherical bearing not being ideal & a true ball joint would be a nicer solution but my take on it was that the general arrangement precludes the chance of pull through which is a good thing, the design of the pin on the upright means you end up with a significantly greater cross section without the stress raisers on the standard “threaded” part which addresses the main failure mode. I also took the opportunity to upgrade to GT6 stub axles with mix & match hubs to keep the PCD correct & enable me to run an upgraded front brake setup. There are lots of other mitigations with Trunnions which if ignored / aren’t understood then will certainly either contribute to or result in premature failure which probably unfairly contribute the bad rap they get.
It’s fair to say though that they aren’t direct bolt on & as with anything done to take a car away from standard spec then it’s done at the owners risk & if there is any doubt then professional advice should be sought.
^ interesting and good you’ve made it work. Surprising there’s no simpler option by now as it’s about dealing with a single joint, so a plain bar Into the hub with a thread on the end with a cast greaseable rose joint to fit the lower wishbone would suffice. Triumph certainly engineered it complicated originally.
check out also with Caterham...there front suspension was based on those (triumph)trunnions as well.....and its not so long time ago when they changed to trunnionless ones.
this said: there are lots of 70ies racecars with a front- wishbone setup on the track which have those triumph-trunnions fitted.
this said: there are lots of 70ies racecars with a front- wishbone setup on the track which have those triumph-trunnions fitted.
LLantrisant said:
check out also with Caterham...there front suspension was based on those (triumph)trunnions as well.....and its not so long time ago when they changed to trunnionless ones.
this said: there are lots of 70ies racecars with a front- wishbone setup on the track which have those triumph-trunnions fitted.
As Adrian said there’s still an issue with the bottom pivot arrangement to link it to the tubular TVR wishbone. Don’t know if the pivot can be machined easily to ‘make’ it work. this said: there are lots of 70ies racecars with a front- wishbone setup on the track which have those triumph-trunnions fitted.
It seems the only alternative is to make up new lower arms which on the face of it would make the whole thing a complete faff for any benefit!
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