GET BENT: all about mech hangers
and why you should care
Someone emailed us the other day saying their tour guide's required packing list included a spare mech hanger: what was this and did we sell it? So I thought it would be helpful to write an explainer for everyone!
We are increasingly seeing bent mech hangers in the workshop, and this is both good/not good. Here's why.
What’s a mech hanger?
It's a small aluminium piece that attaches your rear derailleur (aka rear mechanism or 'mech') to your frame, like a conduit. They look like small embryos. The part is separate from the actual frame of your bike, it is proprietary to your bike frame make/model, and it's designed to fail.
The gift of the derailleur being an external and easily serviceable part is also its curse. What would inevitably happen is a crash, or the bike would just fall over, or it gets shoved into a boot funny-like, or someone would barge into the bike...and then the rear mech and/or hanger would bend inwards. Leverage, innit.
Why is this bad?
A bent mech will manifest in poor shifting: the gears won't do what you tell them to do, they may skip a sprocket or not shift at all. What’s worse, even if you have your limit screws set up properly, if the mech is bent inwards and you shift into your lower gears (larger sprockets), the jockey wheel cage could get sucked into the back wheel and tear off.
It could destroy the spokes on the wheel (a consumable that can be replaced), it could destroy the mech itself (also a consumable). But this is the moment the mech hanger has been waiting its whole life for: it’s designed to break off to spare the life of the frame (not a consumable).
On some vintage bikes the mech hanger is part of the derailleur and not the frame. But on others, the mech hanger is actually part of the frame. We still see this being manufactured on new bike brands like Temple, Brick Lane Bikes, and Tokyo Bike.
You can "cold set" steel, (bending through brute force), because it is a remarkably pliable and strong metal. However, please note that any time metal of any kind bends, it is still deforming the molecules, and becomes weaker. I don’t really understand why they’re using it on newly manufactured bikes now, except to cut corners/costs. Once these kinds of mech hangers are bent, they are not the easiest to bend back and they often never go back to being straight.
How to mitigate damage?
You can’t prevent this from happening, but you can push the odds in your favour by...downshifting into your lowest gear when you park your bike. Putting the rear mech into the biggest sprocket on the cassette/freewheel means it's located closest to the wheel, away from potential mech benders.
But don’t do this when you need to take your back wheel out, it will be impossible to remove. Just be sure that any time you need to lay your bike down, you lay it on the non-drive side (the side without the chain). Treat your rear derailleur like the precious.
Your front derailleur can…get bent 🤣
LOL just kidding, but you don’t really need to worry too much about your front mech getting ravaged like your rear!
Your homework is to look at how your rear derailleur is attached to your bike. Is it attached directly to the frame, or to a part that looks like this?
If your mech hanger is a separate piece, it is designed to sacrifice its life so that your frame may live to see another day (like Jesus). Again, this martyr is proprietary to your frame, meaning its shape is specific to the manufacturer/make/model and fits like a piece of a jigsaw puzzle.
Here we see a small selection of embryos hangers - it sucks being a bike mechanic sometimes!
These hangers are made of brittle aluminium, and are not able to be reused/revived once they bend past a certain point. Here in the workshop we do have a derailleur alignment gauge (Park Tool's DAG-2.2) that can straighten out little bends. But they don't work miracles, and you probably don't really want to use your derailleur as the tool to straighten it either (I mean, maybe if you were in a pickle) so just get a spare mech hanger. This is something we don't sell, you'll need to get it through your bike's manufacturer, the shop where you bought your bike, or an after market retailer.
Is anyone trying to change this proliferation of specification? For those of you with quick release hubs, the Problem Solvers Universal Hanger is a short term solution. And Sram's Universal Derailleur Hanger has made a splash onto the MTB scene for those of you with compatible MTB thru-axles (sorry Roadies, they're not being used for you...yet?) Note that you still have to have a compatible frame to use the UDH.
If you are going on a tour, you should probably carry a spare mech hanger, just in case. If you want to learn more about roadside repairs, guess what chicken butt: WE DO A CLASS 👇👇👇👇👇👇👇👇
EMERGENCY ROADSIDE REPAIRS
Whatever your fears are, we’re here to allay them. There’s no point stewing around in ‘what ifs’; you need to build up your confidence. The more you have exposed yourself to simple repairs, the more you are familiar with your bike, then the less you will have to fear because you’ve been here before. And even if you haven’t, consider it part of the experience.
The main things to remember:
1) the only way out is through knowledge and practice. I call this process making educated mistakes
2) something WILL go wrong so make peace with that now
3) you're not stuck/lost, you're having an adventure! If everything went perfectly, it would be boring and you'd have no stories to tell. I often say, "You'll laugh about this later." 😜
Prerequisites: Intro to Maintenance class - you MUST be able to fix a puncture already. We will not be covering this, so if you don't know how to take your wheel out and tyre off, you must take our Intro to Maintenance class.
OOH LA LA! BUY MY BOOK
You gotta crawl before you run! What better way to cut your teeth on mechanics than to convert an old geared bike to a single speed?
Grab your limited edition signed copy here.
That’s all for now friends. Don’t want gears anymore? I leave you with another super useful masterclass, How to Single Speed a Bike, filmed during the darkness of lockdown. There’s a bunch of these on our Vimeo page, and even more hiding on my hard drive, but we are going to stop paying for Vimeo as we’re not using it anymore. So I’m thinking of posting these onto Youtube soon…which I am TERRIFIED of doing. They are longform videos, they are filmed live, there are gaps and ums and out-of-focus camera moments…the content is great but the delivery is unpolished. I have no idea why I’m so concerned about trolls.
Anyway, Happy Solstice, remember to drink water, and put a lil bowl out for the birds.
Ride on,
Jenni x
ps. does anyone have a sturdy laptop that they’re not using anymore? We’re transitioning from a paper based system to HubTiger. We could use something like a chromebook for the workshop (we can’t have nice things 😅)