Check Your Wheels!

[brewmaster]

Hey All,

I was cleaning up and checking my mag race wheels yesterday and found some cracks! Basically this means I now have a VERY expensive hose reel for the house.

However I am glad I found the cracks this way rather than out on the track! The cracks started from a hole with a cover over it on one of the spokes (see the pic's). Once I removed the cover to clean them the cracks were very obvious.

Bottom line is check out your equipment well now. Before you find out you have a problem the hard and painful way. It really sucks that now I have a big ticket item to replace before the season starts, but that's racing.

[Degsy]

Looks like paint cracks to me. I would have them magnafluxed to see if the cracks are just surface-level then race on them and keep an eye on them after each weekend.

[xsiliconkid]

Hey All,

I was cleaning up and checking my mag race wheels yesterday and found some cracks! Basically this means I now have a VERY expensive hose reel for the house. ]

OUCH!
Hey BM, they look like my old Dymags!

I gave up on real magnesium rims - they are too fragile for the few oz savings over forged aluminum or multi alloy rims....
That’s why I went to spoke wheels op my 77 Duc 900ss racer...(see below) and gave away the original mag wheels.
I can't believe people use mag wheels on street bikes......

Dymag (UK) offer a service where you ship them the rims - they x-ray them - they find stress cracks - the only way you get them back is with big holes drilled though the rims...

Lucky most "mag" rims these days, like the marchesini are more alloy rims - don't even oxidize when metal is exposed to air.

[Degsy]

My bad. Didn't see they are Mag. Can't magnaflux a mag wheel.

Bin them. Dymags all do that eventually.

[brewmaster]

I'm not so sure Degsy. If you look at the holes you can see the irregular edge where the crack starts. That corrosion or casting flaw is a perfect place to initiate a stress riser. As a bit more info the other 2 holes are smooth and not jagged and irregular like that one. Additionally the wheels were re-powder coated once so already so they have had a fairly full life. You probably know that by knowing the previous life the bike had before coming into my garage.

That said it might still be worth it for me to have them checked. However from the people I have already spoken to who are familiar with Dymag wheels like this. They fail in this exact location... not a good sign.....

[Degsy]

yep. see my post above yours. we crossed in the mail.

Drill a hole each side of the crack and zip-tie the two parts together.

[brewmaster]

OUCH!
Hey BM, they look like my old Dymags!

I gave up on real magnesium rims - they are too fragile for the few oz savings over forged aluminum or multi alloy rims....
That’s why I went to spoke wheels op my 77 Duc 900ss racer...(see below) and gave away the original mag wheels.
I can't believe people use mag wheels on street bikes......

Dymag (UK) offer a service where you ship them the rims - they x-ray them - they find stress cracks - the only way you get them back is with big holes drilled though the rims...

Lucky most "mag" rims these days, like the marchesini are more alloy rims - don't even oxidize when metal is exposed to air.

Yes Graham they are your old ones. I was bummed to say the least but hey cracks happen. I'm not so sure what I will replace them with just yet. Suggestions??!!!
P.s.- Those wire rims are spanky on the vintage bike.

[brewmaster]

yep. see my post above yours. we crossed in the mail.

Drill a hole each side of the crack and zip-tie the two parts together.

yeah and then wrap it with duct... I mean racers tape for good measure.

[xsiliconkid]

Looks like paint cracks to me. I would have them magnafluxed to see if the cracks are just surface-level then race on them and keep an eye on them after each weekend.

if they are (were) my rims then they were cold fusion powder coated or some such nonsense - normal powder coating is to hot for mag rims as is even walnut shell blasting bad.

... get them x-rayed if ok, clean off the coating and Magnadyne soak the area...i gave bottle to PK a couple of years back.

the rims were cleaned with soft plastic bead blasting, then magnadyne coated to seal against air/oxidation, then some special undercoat before powder coated --- RObbie Nigl now knows the process...how to deal with real mag wheels- those Dymags are real magnesium.

[xsiliconkid]

Yes Graham they are your old ones. I was bummed to say the least but hey cracks happen. I'm not so sure what I will replace them with just yet. Suggestions??!!!
P.s.- Those wire rims are spanky on the vintage bike.

See what you get for stealing that bike from me.... ps want all the beer back:-)

I would go with forged aluminum rims.. Cheaper, stronger - probably lighter then those Dymags.... can be welded and straightened etc...

[seth399]

Damn that stinks. Not sure what bike you have, but I have a set of Marchesini forged aluminum wheels for sale that were off my 636.