-
Happened multiple times and you checked FD setup in between
Yep
all I can think of is an issue with the BB (but you didn't swap that?) or the rings themselves
The two Di2 bikes had different BBs - Rotor BSA30 on one, FSA on the other. The rings have behaved perfectly since I fitted them to the Cannondale with the mechanical DA9000 groupset - never a problem.
is it possible to install them backwards or something? I can't remember. I think there's plenty of writing on them telling you which way to install them so unless you were drunk every time you checked? :)
There's a fighting chance I was pissed as a fart every time I installed them, but even drunk as a newt I wouldn't fit them the wrong way round - the recesses for the chainring bolt holes would be on the wrong side of the chainring.
Maybe you got unlucky?
That's my conclusion - I'm just cursed. From now on, no Brommers+Praxis+Di2 combinations.
I'll take them off you. :)
You're too kind, but happily I still have enough bikes with mechanical shifters that I can find a home for them.
Brommers-
So, the issue appeared on both BBs? They were the same size rings but did you change the height of the FD at any time? What size gap did it have over the big ring teeth?
Given it works with mechanical fine, is there actually a measurable difference between cable and Di2 FD cages? If they are the same dimensions then it must've been something specific to the first install. If the FD dimensions are different then maybe there's a reason in that.
Did you have the little offset middle bolt adjusted properly? I know this is sucking eggs theory but the Di2 limit screws work a bit differently to cable limits stops.
I want to take my 10spd cable back to Oz where I don't need to change gears. The cables will last forever and I'll no longer need to buy 10spd parts.
hippy
Happened multiple times and you checked FD setup in between, all I can think of is an issue with the BB (but you didn't swap that?) or the rings themselves - is it possible to install them backwards or something? I can't remember. I think there's plenty of writing on them telling you which way to install them so unless you were drunk every time you checked? :)
Anyway, I've run Praxis rings or at least one Praxis ring for most of my TCRs and stuff and I only remember the one weird thing in the US and that wasn't an under/overshifting thing it was probably gunk on the ring or a hard bump at the same time as a shift that I didn't hear to 'catch' while pedaling.
Maybe you got unlucky? I'll take them off you. :)
I had a carbon ring on the TT bike that never worked properly and totally failed during the Nat 24. They replaced it but we never did get to the bottom of the problem. Other carbon rings from the same guys worked just fine. I still have the BNIB replacement. Think it's a 51T.