Dutch trainer, water bottle & tool company Tacx has a tiny new gadget they say will save your bike’s fancy rear derailleur in a crash. The Tacx Crashpad is an extended alloy nut that threads onto the end of your standard QR skewer to protect the derailleur either in transit or if you wipe out.
Tacx Crashpad derailleur-protecting extended QR axle nut
The idea is that by threading this little 28-30g piece of machined aluminum in place of your regular QR axle nut, you get some added security for your expensive rear derailleur. Whether you drop your bike, transport it with the derailleur attached, or even if another rider hits you from behind, the extended Crashpad nut will divert the force away from the fragile derailleur & hanger (and into the frame at the dropout.)
The concept was to protect ever more expensive, yet apparently fragile carbon derailleurs. (The one’s I’ve broken suffered some serious abuse I don’t think this gadget would have helped.) But to get the benefit, you’ll have to ride around with this thing that looks like a tiny footpeg on the back of your pretty carbon road bike?!
Tacx made the Crashpad light but still work by turning it thin on the lathe from a light alloy, then giving it M5 threads to fit your typical QR skewer. For all those thru-axle adopters, sorry this won’t help you.
The Crashpad is available now for $19/15€ and comes in two lengths. A standard Long version fits most all rear derailleurs, and a Short version for more recent lower profile 2018+ Shimano Shadow derailleurs, both in a single high quality black anodized finish.