Check you upper wishbone mount rods now and again, plus new bushes

[copperleaves11]

Re: Check you upper wishbone mount rods now and again, plus new bushes

I've had powerflex bushes installed at the front since 2004, but they are red in colour. At the rear i've got the purple variety.Colour does denote different properties/applications, whether for road or track use.

[stevejgreen]

Re: Check you upper wishbone mount rods now and again, plus new bushes

I've had powerflex bushes installed at the front since 2004, but they are red in colour. At the rear i've got the purple variety.Colour does denote different properties/applications, whether for road or track use.

I know of no universal standard colour code that can be applied to suspension bushes, certainly not Superflex.
Powerflex however offer four colours Red, Yellow, Purple and Black in increasing stiffness, but not every bush is available in every colour/stiffness.

[jhaines]

Re: Check you upper wishbone mount rods now and again, plus new bushes

Do be careful to temper them adequately after hardening otherwise they will be unacceptably brittle.

[milliemarlin]

Re: Check you upper wishbone mount rods now and again, plus new bushes

I would council caution when fitting the more rigid bushes. Cabrio forum readers will be familiar with the problems caused by rigidity in a compression strut replacing a relatively soft rubber mounted anti-roll bar. Cars for road use will certainly experience harsher surfaces than those on a track. Suspension for cars used for rallying can be considerable different. Both Rally and track cars will usually be checked rigorously after every race.

I did fit polyurethane inner track control arm bushes which are still in place. I purchased rear trailing arm bushes but I don’t plan to ever fit them.

The Powerflex web site makes it clear that the stiffer black series is for track, rally and race.
Paul

[Patrick]

Re: Check you upper wishbone mount rods now and again, plus new bushes

Thanks for all the input everyone. Been a bit busy at work so not had time to check back last few days

[acbluemarlin]

Re: Check you upper wishbone mount rods now and again, plus new bushes

I'm not sure any kind of hardening is a good idea for a suspension component that is obviously undergoing some bending stresses. Increased toughness maybe, but hardening probably not. The chap who reckoned his bent pins had done their job was pretty much on the money for me.

[Alan c]

Re: Check you upper wishbone mount rods now and again, plus new bushes

I agree unless you have hardness testing machine you wont know what you have. Buy material of known spec - cheaper than a funeral

I'm not sure any kind of hardening is a good idea for a suspension component that is obviously undergoing some bending stresses. Increased toughness maybe, but hardening probably not. The chap who reckoned his bent pins had done their job was pretty much on the money for me.

[Patrick]

Re: Check you upper wishbone mount rods now and again, plus new bushes

I've not done anything with them yet, I had a bunch of stuff, including broken seat that held me up. I'm considering making brackets to go on the outsides of the wishbone mounts which would greatly reduce the stress on this part.

I think I may try the new ones as is, then see what happens after a couple trips around the area (roads are terrible here). If the new ones bend I’ll make another set and look at hardening. If they don’t it’s all good. I prefer bend to break as at least you get warning.

[acbluemarlin]

Re: Check you upper wishbone mount rods now and again, plus new bushes

Bending rather than breaking is precisely why I wouldn't try and home harden this part. If you want something a bit stronger maybe try something like EN16 or EN24

[272berry]

Re: Check you upper wishbone mount rods now and again, plus new bushes

The pin looks as if it may only be supported in 2 locations next to each of the bushings allowing bending inside the supporting steel box member via deflection within the bushings? Thought occurred that if there was a steel sleeve for the pin that supported its full length between the bushings the unsupported length would be reduced and the pin forces would be limited to the leverage over the bushing length . This would mean however that the pin would take more shear force in shock loading and there would be no transfer of such forces into bending of the pin which might be the intention of the original design---My Sportster kit is coming mid June (hopefully) hence guessing a bit on the detail

[Patrick]

Re: Check you upper wishbone mount rods now and again, plus new bushes

Yeah it's only support in the centre, not on the outsides. The poly bushes have a metal sleeve on the inside. Im using large washers either side of each bush to prevent the polyurethane from moving off over the nuts that hold them. I've double stacked them on the outsides.

[Patrick]

Re: Check you upper wishbone mount rods now and again, plus new bushes

I know of no universal standard colour code that can be applied to suspension bushes, certainly not Superflex.
Powerflex however offer four colours Red, Yellow, Purple and Black in increasing stiffness, but not every bush is available in every colour/stiffness.

In the case of the ford TCA bushes needed for the Sportster you can buy the purple or black. How hard the material is measured with a shore durometer; there's a nice set of examples on wikipeadia https://en.wikipedia.org/wiki/Shore_durometer

Powerflex list the shore of their bushes here: https://www.powerflexusa.com/how-to-choose