Hey, figured it was time for an upgrade soon, and love the maguras. However, will the rear brake “cable” fit through a Cervelo P3 classic? It is a 2013 so made after the Maguras came out… So will they work?
It should. I haven’t measured it with calipers, but the brake line for the hydraulics is pretty much the same diameter as the normal brake housing.
Sweet, thanks for the answer. I heard somehow that they won’t work on a p2 so I was just wondering.
Hi TriathlonKid,
Just (carefully!) drill out the aluminum cable stop. Leave off the removable rear stop.
Use a good (new) bit, high speed, low feed. Don’t overheat it. Be careful not to let the drill motor chip the paint on the head tube.
For some folks it might be worth having an experienced drill operator do the deed. 
Cheers,
Actually I just went and looked at the P3 I’m about to sell. You are going to need to drill out the first cable stop on the top tube. It’s there as a cable stop so that the bare cable runs through the top tube and exits at the removable rear cable stop. It should be an easy ‘fix’. If you need to re-sell the bike, you can just run the rear brake cable housed the entire way if you want to keep the maguras.
Does that make sense?
Edit: What Damon said!
Thanks for the reply Damon, I might just have to do it now:-) ps. I have one other non Magura question. Would it be possible to use a Aduro on a P3 Classic? I don’t have one but if my lbs has any take offs, would the cable routing be an issue?
Hi TriathlonKid,
The Aduro is an awesome aero bar. We’ve not tried it to know, but the potential issue is exactly as you said: cables come out the back/bottom of the Aduro stem, not really designed for bikes other than the P5 and new P3.
Depending on number of spacers, it seems like it could work, though that’s not an official endorsement - ya gotta try it on your own set up to really know.
Cheers,
When you mention spacers, are you saying it could possibly work with more or less spacers?