Cracked or a Join?

BlakeysFC

This may be a stupid question, I'm not sure, but I'm a bit worried about it so just thought I'd ask...

Just inspected my Defy 1 after a 5.7 mile ride earlier and I've discovered what looks like either a crack or a join.

On each Rim there's only 1 of these black lines down the Silver Wheel Rim on both sides, it looks like a join but I'm worried it could be a crack in the wheel as I heard a couple of snaps when I was riding today (obviously this could've been stones or a stick cracking underneath the weight of the wheel).

Can anyone help, need to know whether I need to take it back to my LBS tomorrow or not?

I should add the tyres aren't deflated atall, and fully pumped up.

Scotteesh

Where abouts on the rims are the cracks/joins?

BlakeysFC

Scotteesh wrote:

Where abouts on the rims are the cracks/joins?

On the side-wall of the wheel on both sides:

Front Wheel:

By blakeysfc at 2012-07-26

Back Wheel:

By blakeysfc at 2012-07-26

sandyballs

I'd say joins, my Mavics have quite pronounced joins that look exactly the same, even though they say they mill then smooth after welding you can still pick them up with your finger nail.

mouth

Joins.

alihisgreat

Its a join. Look the same on mine.

BlakeysFC

Thanks everyone.

Its put my mind at rest now

ugo.santalucia

Rims are beams of extruded aluminium alloy... the beam is cut to length and curved into shape at temperature. The two ends are then joined either pinned or welded (or both). What you see is the point where the rim has been joint.
Carbon rims are built with a different process, as carbon composite cannot be extruded or welded, so if you see a "joint" in a carbon rim, that's a crack...

lakeland

Definitely a join.