I saw the ratio mech/rear derailleur received a pretty good review https://nminus1bikes.substack.com/p/ratio-mech-rear-derailleur-review
I see these rear derailleur come in two different versions: direct mount/udh and standard hanger.
What is the point of the direct mount version?
My understanding is the hanger is designed as a point of failure. Ie hopefully it will brakes before your rear derailleur brakes
SRAM’s direct mount rear derailleur were designed to be rather robust. They famously had the guy standing on it.
Looking at the ratio direct mount mech, it looks like it isn’t as robust as SRAMs direct mount rear derailleurs.
Wouldn’t you be better off with the hanger version than the direct mount? If you smash the direct mount you are probably breaking it (thou it is super repairable). Whereas if you brake the hanger version, there is at least a chance the hanger brakes and the rear derailleur survives.
What am I missing?
by AdElectrical643
2 Comments
Eliminates flex. It says so in the review you linked.
1. I don’t think anyone can conclusively say that the Ratio derailleur “isn’t as robust” as SRAM’s Transmission derailleurs without, say, having access to their CADs and running FEA on them. That mounting arm looks beefy, and looks like it was well designed to maximize stiffness and strength for its weight target.
2. Even if that mounting arm is not robust and is more prone to bending, it doesn’t mean you’re destroying the whole derailleur every time. It just means that you’re shifting the failure point from the UDH hanger to the mounting arm, which can also just be replaced nearly as easily. And while a new mounting arm certainly costs more than a UDH hanger, the fact that it’s likely stronger and more robust than a UDH hanger anyway means you’ll probably end up bending it less frequently, and you may very well be spending less on mounting arms than UDH hangers regardless.