Matt's Stradale

[strat24v]

I'd contacted marvic about their uprights but at 2.5k a pair, they were a bit too much money. Similar items were available elsewhere and have been for a few years but I was advised against them due to issues with cracking of the castings. By the time you factor in the stratos bearing and hub, they get pricey so I've gone down the route of a more modern machined from billet version, similar geometry to the original stratos but with a 5 x 108 pcd cartridge style bearing kindly supplied by listerbell. Radial mount ap 6720 calipers, wheel speed sensors and a few other features. With some careful design, wheels from marvic, roin, listerbell and hawk can all fit under a group 4 arch.

[strat24v]

What diameter are the struts that fit in the marvic upright?

[maxlouis]

These are my wheels, refinished by Ian Jemison http://www.ianjemison.co.uk who repair and refinish magnesium wheels, but I didn't think to ask him to X-ray etc - anyway I'll use them but not 'in anger'. Those uprights look quite different to my Stradale ones (below) - they must be for competition are they?

[QUOTEtt=LM mic;22772]I recently sourced Magnesium set of wheel from Marvic ; they are ( Just to me!) more accurate than Ronin ones and done properly as original ones where done and just for
You to know ; they are also able to supply with reasonable price the original Stratos upright





[/QUOTE]

[Fingers]

Any cracking in magnesium is usually easy to see visually due to the coarse grain structure, the same with cast alumimium. The dye checking method Michel mentioned is probably the easiest method for crack detection, but won't work if the material has been media blasted (depending on the type of media) as it moves material and can close over the cracks. Dye checking requires the item to be very clean an also paint stripped. It's easy to miss cracks when x-raying thicker material, but doesn't require paint stripping, it's time consuming and expensive. Eddy current inspection is my favourite, it's quick, easy, doesn't require paint stripping and is very sensitive, you can use different fequencies to look for cracking at different levels in the material, high freq for surface, low freq for sub surface. It requires a refence standard made of the same material as you're going to inspect with a sample crack to calibrate the machine but any NDT firm would have dosens of these. If you lived close I'd do the eddy current on them for you.

There will be NDT firms around that would do it for you if you're concerned, it's not usually cheap though. I'm lucky, I walk down to the end of our hangar and do it myself, I was in our NDT dept for three years and they still let me use the equipment. The thermal infrared is a cool toy to play with!

Alodine/Alochrome are brand names, the conversion coating is chromic acid, diluted of course, not too harmful on metal, not very friendly for your body. If you can get an alodine touch-n-prep pen use that, they're great, just apply and wait for it to dry, no need to flush the area.

[maxlouis]

Thanks Paul; I will investigate the Eddy route as they have already been refinished and am not sure there will be much left of them if I repeat the process!

Any cracking in magnesium is usually easy to see visually due to the coarse grain structure, the same with cast alumimium. The dye checking method Michel mentioned is probably the easiest method for crack detection, but won't work if the material has been media blasted (depending on the type of media) as it moves material and can close over the cracks. Dye checking requires the item to be very clean an also paint stripped. It's easy to miss cracks when x-raying thicker material, but doesn't require paint stripping, it's time consuming and expensive. Eddy current inspection is my favourite, it's quick, easy, doesn't require paint stripping and is very sensitive, you can use different fequencies to look for cracking at different levels in the material, high freq for surface, low freq for sub surface. It requires a refence standard made of the same material as you're going to inspect with a sample crack to calibrate the machine but any NDT firm would have dosens of these. If you lived close I'd do the eddy current on them for you.

There will be NDT firms around that would do it for you if you're concerned, it's not usually cheap though. I'm lucky, I walk down to the end of our hangar and do it myself, I was in our NDT dept for three years and they still let me use the equipment. The thermal infrared is a cool toy to play with!

Alodine/Alochrome are brand names, the conversion coating is chromic acid, diluted of course, not too harmful on metal, not very friendly for your body. If you can get an alodine touch-n-prep pen use that, they're great, just apply and wait for it to dry, no need to flush the area.