13 replies to this topic

[miniallsort]

Hi guys which version of arms are better Huddersfield version or mini spares as I keep hearing conflicting information cheers

[nicklouse]

So which ones?

Links would help as for example MiniSpares do more than one version.

[timmy850]

I used the minispares ones and they were great. I don't have any experience of the Huddersfield ones, although they look similar to the minisport ones. If you are going to be fitting adjustable bottom arms it's a good idea to do the adjustable tie bars at the same time and get an allignment done after. Also add some new bushes and longer tie rod ends in to your order.

 

E.g. kit with tie bars and lower arms 

http://www.minispare...s/MSSK3008.aspx

 

Assuming you are talking about adjustable ones!

Edited by timmy850, 05 December 2016 - 11:47 PM.

[Magneto]

If you're talking about the big round shaft ones, I think Mini Sport and Huddersfield sell the same ones - those are the ones I prefer.

[Spider]

I've tried both and prefer the Huddersfield type. Nothing wrong with either, but the Huddersfield ones are just that bit stringer and I found a little easier to adjust.

[Allrounder]

Having used all three varieties already mentioned i'm currently using and favour the rose jointed minispares version though be carefull as if your running more then 2 1/2 reg chamber you start to run out of a save amount of adjustable thread with the joints supplied, they also do need some maintenance.
I personally would not fit the rubber bushed adjustable minispares version again after having one fail.

[nicklouse]

Having used all three varieties already mentioned i'm currently using and favour the rose jointed minispares version though be carefull as if your running more then 2 1/2 reg chamber you start to run out of a save amount of adjustable thread with the joints supplied, they also do need some maintenance.
I personally would not fit the rubber bushed adjustable minispares version again after having one fail.

Again with any generalised statement please provide details. As the current rubber and Rose jointed adjustable bottom arms are actually identical. So I am guessing the failure was in the threaded part? Or was it an old design?

[Allrounder]

Apologise, bought them late 2013 and started with these

http://minispares.co...px|Back to shop

After less than an a year they failed, shearing the threaded section right next to the bush sleeve. So using the same arms I just replaced the rubber bush end for spherical joints.

I'll see if I can find a photo of the broken one.

I'm sure there is hundreds of minis on the road with these out there but this is my feeling with them and for what I use my mini for, gets nothing but punishment but it's also for road use.

Edited by Allrounder, 07 December 2016 - 01:03 AM.

[Allrounder]

Finally found them...

 

http://i1149.photobu...zpsjho0d0oq.jpg

 

http://i1149.photobu...zpsqplfbaos.jpg

[tiger99]

It is not easy to see from the pictures. Was the bush housing and threaded rod forged as one piece, or two parts welded together? Either way the design is wrong, and the product of dangerous incompetence. There is a severe stress raiser far too close to the change in cross section. The thread should have ended sooner, with the radius thickened and all stress raisers scrupulously avoided. What grade of steel was used? And, if it was welded, were precautions taken to avoid hydrogen embrittlement? You can't be expected to know all the answers but the manufacturer must.

 

Another truly amateurish design from one of the usual suspects. These should be recalled in the interests of safety.

[Allrounder]

As mentioned before, my car is used for motorsport so gets a lot of abuse. But it also gets spanner check at least once a month before events and at no point did I spot the failure coming.

Looking at the type break that occurred i thought it was clear see that it was caused by the arm travelling through it normal arc, up and down. I was running the off set bushes as well for correct caster alignment and checked for free movement after it was set up. Could also see the bushes weren't deformed from incorrect fitting.

The bush housing looked as though it was one piece cast then had had the thread cut afterwards, can't comment on any type of heat treatment/hardening it may of had.

Minispares had the broken part back and they did help me out replacing various parts as a precaution ball joints, steering arm and track rod end etc. (Was traveling at near 60mph when it broke and was glad to have power steering as the broken side wheel toed out pulling me into oncoming traffic). But after a few weeks I had to chase them to see what they thought of the failure, they couldn't give me a reason for it.

[Twincam]

Out of interest (and sorry to hi jack), are the adjustable heavy duty bottom arms just to adjust the camber?

[Allrounder]

Yes, adjustable lower/bottom arms for camber and adjustable tie bar for caster.

[tiger99]

The failure was almost certainly fatigue fracture at a stress raiser, and none of your maintenance checks could have spotted it as it would be an extremely narrow but deepening crack until almost the last minute. The end always comes suddenly. That is why fatigue needs to be avoided by proper design procedures. And, it should never, ever occur in a properly designed steel component. It will always happen to an alloy component after a number of load cycles. Steel is about the only metal with a defined fatigue limit, below which no amount of cyclical loading will result in failure. Alloy eventually breaks, and you have to hope that the manufacturer designed and tested for a number of load cycles far higher than will ever be achieved in the life of the product, and did not underestimate the  peak to peak load, even slightly. In aftermarket products it is rather unlikely that all alloy parts will be safe for long term road use, and I would never trust alloy hubs or radius arms. But this is a steel part, and "should" have been safe for ever, or until corrosion eventually weakened it. You CAN'T overstress a bottom arm by hard driving as the tension and compression are both limited by the coefficient between tyre and road and the weight acting on the wheel, which have a very finite maximum, with a competition car being not much worse than a toad car. And, the residual fore and aft bending load because of where the tie bar attaches is quite small, the residual vertical bending load is due to rubber bush stiffness only, and inertial effects are minimal. So I do not believe that vigorous use will ever get a proper steel bottom arm stressed into the fatigue zone.

 

Kerbing is another thing, and in theory there is no limit to the imposed strain, but generally the wheel, especially if alloy, will break first. And, you don't generally do it very often, so a very occasional excursion above the fatigue limit is tolerable. I don't imagine for one minute that what you did had anything at all to do with the failure. Nor am I at all surprised that the supplier has no idea why it broke. They really need to issue a proper recall of an unsafe product via VOSA but I know they won't...

 

Caveat emptor.