[Closed] Replaceable Mech Hanger - Essential?

I remember having a Monitor HT frame with a non replaceable hanger. Not great, but not the end of the world.

Is that one of those direct mount mechs which have their own breakable mount, so you don't bend the frame and just replace the mech?

Btwin Rockrider 100 BSO

You may find a new frame is about the cost of a mech hanger...

Is that one of those direct mount mechs which have their own breakable mount, so you don’t bend the frame and just replace the mech?

Maybe, that's why I'm asking really, mech hangers seem ubiquitous so it's a surprise to find there isn't one. I'm wondering if there are established/viable alternatives.

I'm not disatisfied in any way, just curious.

You may find a new frame is about the cost of a mech hanger…

🤣

done something clever

Did it come with a big protective cage to protect the rear mech?

Did it come with a big protective steel cage to protect the rear mech.

Can those be retro fitted to protect my X0 AXS 🤔

I have seen a normal hanger fail to break and destroy the frame, or the swingarm anyway, ripped the dropout apart, so having a replaceable one is no guarantee it'll work.
To be fair to Marin I took it to a dealer well after the warranty had run out and showed him. He said 'yes, that's a mess, leave it with me'
He rang a fortnight later and said theres a new swingarm and all new bearings on it, good as new. I said 'how much do i owe you?' and he said 'no,no, that shouldn't happen, that's a warranty issue' Top service.
I dont know if BTwin are as nice as Marin but it does seem odd to introduce a weak spot where none is needed (or not where one is needed, you know what I mean)

Did it come with a big protective cage to protect the rear mech?

Interesting point. I noticed some on display had them, and that was a feature I approved off. However, when I picked this one up from a different store there wasn't one and I noticed none of the others had them, either. It was closing time and I wasn't that bothered so didn't ask. Perhaps I should have.

I wonder if the staff are supposed to fit them when they do the assembly and then forget. Or if they're some kind of optional extra.

That potentially answers my question: "They mitigate it with a bolted on chuck of iron."

It's a shame they're too tight to put disc mounts on so you could upgrade the brakes yourself...

But yeah, that's suboptimal to say the least, and those cages don't protect against stealth stumps either. But I'm guessing your daughter isn't going to be storming down rocky descents with enough speed for this to be a concern.

bruneep

Can those be retro fitted to protect my X0 AXS 🤔

Since i fitted AXS, I found myself wishing for the old "wing" my Lapierre had to protect the mech. It still seems a good idea.

But I’m guessing your daughter isn’t going to be storming down rocky descents with enough speed for this to be a concern.

Yeah, this bike was/is for a 9yo to ride into town/tow path/New forest tracks/family Moors Valley rides and it's a statistical likelihood she will outgrow it before she clouts the mech. My question was born of vague academic interest in bike design rather than any concern.

Yeah, this bike was/is for a 9yo to ride into town/tow path/New forest tracks/family Moors Valley rides and it’s a statistical likelihood she will outgrow it before she clouts the mech. My question was born of vague academic interest in bike design rather than any concern.

Based on my experience of my sons (currently 11 and 12 years old) they have a habit of thwacking mechs on a regular basis.

Back when I were a lad, no bikes had replaceable hangers.
Thinking some more, my old rockhopper did, my wife's less old inbred didn't. It's steel Vs aluminium thing isn't it.

Meh. Just weld it back together if it breaks

The sticky out protective cages seem barbaric but they're ace for kids bikes where they don't so much break mechs by whacking off rocks while riding, and much more while just manhandling the bikes, they get dropped on the ground a lot more...

My old 26" Cotic BFe frame didn't have a replaceable mech hanger. I'm guessing they still don't. I actually managed to bend the steel frame hanger in a mech destroying crash. Had to heat it up 'till it was almost red hot to bend it back into the correct position. Maybe it's a steel frame ?

Yep, that's a steel vs alu fatigue thing, alu is much more likely to break when bent and straightened.

(cotic switched to replacable dropouts when the CEN rules came in but I think purely because it was lighter? And now they use the syntace axle and replacable dropout standard)

A wise man once told me:

it’ll be fine.
until it isn’t. And then you’re ****ed.

I remember back in the 90's buying an aftermarket bolt for my Shim mech. The bolt that holds it to the frame.

It was a sacrificial part that had a narrow machined into it to create a weak point that would break rather than take the frame with it in a crash. I don't think I ever tested the theory out I'm glad to say.

I once had an (aluminum) Kona AA hardtail which didn't have a replaceable rear mech hanger.

Second or third ride in muddy North Wales and the mech wrapped itself around the cassette before pulling itself out of the frame.

Shop didn't want to know (not a manufacturing fault) and it couldn't be repaired locally (as it was Alu rather than steel) so had to send it away somewhere to get repaired.

A couple of hundred £££ and a couple of weeks without bike. Grrrr.. Yeah, not a great idea Kona...

https://clee-cycles.co.uk/esite/P1583/product

Breakaway bolts are derailleur mount bolts designed for frames that don't have a replaceable mech hanger. Designed to break before the mech hanger on your frame.
Fit all pre-Shadow Shimano derailleurs