Praxis (chainring) "Break-in" period?

[Hepmike]

New build, so new Praxis rings, new KMC chain, and at the end of each ride i'm finding a fine metallic dust covering the teeth on the rings/chain.

The first ride or two I wasn't that surprised (100 + miles), but now i've got 2-300 miles on the setup and it's still there at the end of every ride (I clean it up each time). I'm not mashing like crazy, not cross-chaining (much), nothing is rubbing, I am doing a bit of climbing (12-15K feet). Am beginning to think this is odd/problematic...

http://i1168.photobucket.com/albums/r483/hepmike/get-attachment-4-1.jpg

[ultraman6970]

Is that chain new or just super old?? never seen stuff like that ever.

[carpediemracing]

I have Praxis rings (currently 53x39 on one bike, 53x44-non-Praxis on the current regular bike). I don't see that kind of wear.

I think I have a KMC chain like yours even. I have 10s. I have 39 cm chainstays so the chain angle is more severe for a given chainring-cog combo.

I set my chain length to "longest possible without dragging the pulley in the small-small". Not sure if you set yours to the Shimano "big-big + 2", which may increase drag?

I rarely, and I mean rarely, use the big-big (11-25 as an example so 53x25). It's accidental. I will pretty commonly use the 53x21 (3rd cog). Again, remember my stays are short.

I don't use SRAM shifters and I don't have a compact set up but for any front derailleur on my bike I'd have it closer by half to the chainring. Since I have Campy I have used Campy and various Shimano front derailleurs throughout the years. Not sure if that might contribute to chainring wear, the slower shifting from a derailleur further way from the cog.

[Hepmike]

All brand new as of two-weeks/300 miles ago.

Will check chain angle, had not thought of that, but would be surprising to me if it could shift cleanly and cause that kind wear (with a bad angle)?

Chain length and RD appear to be set to correct length and limits.

[11.4]

No problems here. I ride Praxis rings on a cross bike with a KMC 11-speed gold SL chain and it's completely clean. I hardly have to clean the chain if I'm riding asphalt.

[donevwil]

I have ~ 2000mi on new Praxis rings running Campy 10 with new KMC chain and don't have that degree of wear. I did notice right away that the Praxis rings did not happily (quietly) accommodate the degree of cross-chaining that the original rings did so I have been extra conscious not to. I never cross-chain to the last two cogs and try to avoid the third whenever possible.

[carpediemracing]

My set up, today, after I cleaned it. I'm not sure how many hours it has, maybe 150? 200? Half of my hours are out on the road and I generally leave it in the big ring (crits and totally flat training). The other half is on the trainer and I leave it in the small ring most of the time. I try to keep my drivetrain pretty clean.

I'm not sure of the hours but between two sets of chainrings I have about 400 hours. I installed these chainrings last fall, I'm pretty sure, leaving the 39T off for some unknown reason.

https://scontent-b-iad.xx.fbcdn.net/hphotos-xfp1/t1.0-9/10462779_10152658597893824_2074645098130737380_n.j pg