Does anyone know what this is on the Shimano rimsurface

[PinaRene]

Hello,

Just got my hands on this Protottype C35 tubular wheel. The rimsurface is a lot lighter at some points, but you can see a bit more dark line in it where the brakepad hits the rim. I thought it could be caused by some heat problems during descending some hills. But the surface is flat and there are no spots equal on both sides.... there are on both sides but not at the same point at the rim. If anyone knows where this comes from, please inform me

[PinaRene]

No one has a clue ?

[sungod]

hard to tell from photos

if i had to guess, maybe it delaminated in those areas so there're now extra air-solid interfaces which relect more and cause the lighter patches

a possible way to check is apply pressure with a fingernail at the boundary, it there's an air gap you might see some variation in appearance

[oreoboreo]

While cruising Ebay, I saw a c35 for sale with the same look. Had to pass since it just looked odd. Not sure what it is, but definitely not correct.

[cnbky]

I think its shimano you need to ask

also, i would refrain from riding them hard.

[cnbky]

double post