This is a question for all the Renn experts out there. I have a Renn rear disk, which I think is great and which has improved my times noticeably.
Last Sunday I did a race here in the UK where is poured down on the bike leg and needless to say both myself and my bike got thoroughly soaked. While I was cleaning my bike after I got back I noticed that the carbon fibre on the part of the wheel behind the valve recess has bulged slightly so that I now have a valve cut out shaped bulge on the opposite side of my wheel to the cut-out.
Clearly the water has done something to the carbon (although I did have a plastic adhesive sticker covering the whole of the valve recess all the time the bike was in the wet, so its not like there was gallons of water flowing into and out of it) - has anyone else had this happen to them and if so, is it a problem and do I need to do anything about it?
I have the same bulge, however, mine happened before I rode in the rain. Last weekend, the race was rained on heavily, and the bulge didn’t change shape. It is minor, but you can see it.
I have the same disk and the same “bulge”. I purchased mine used so I can’t say if it was there right from the factory, but I suspect that is the case. Looking at the valve stem opening area and knowing a little about composite manufacturing methods, I think the process of removing material from that area of the disk to make the opening probably causes the backside to bulge a little. Surface imperfections on composite parts look much much worse than they really are from a structural standpoint, so I’d say that unless it is actually cracked, or protruding out past the outer width of the rim (and that is one honking wide rim!) it’s not a problem.
Of more concern (to me) is the post-rainy-day part. This was mentioned in an earlier thread too, where the Renn owner noticed a fair amount of water in his disk and soggy-to-the-touch honeycomb core after a really wet race. I have a really hard time accepting bare core material open to the elements. While a good quality adhesive tape over the opening is probably sufficient to avoid this problem, I’m thinking of retrofitting a liner of some sort in my valve stem opening to make my Renn more like the Hed3 in this respect.
If you manage to figure out something that works, I would be interested to know. I too was surprised about the difference in the finish between my Renn and my Hed 3 front wheel and the possibility of water getting into the structure of the wheel