Out for a ride on Saturday when my mate pulled to the side of the trail with a mechanical. His rear mech did a 180 and mangled itself round the cassette after the chain dropped between the back of the largest sprocket and got stuck on the spokes.

Reckon those cool plastic disc things could have prevented this one. Anyhoo, has anyone seen a mech do this before?

Even though many parts were bent and a couple missing a trailside fix involving some rocks got it shifting sweetly on all 10 sprockets. I’m always amazed at how much abuse a mech can take!

Mangled Mech by VeeeDubStar, on Flickr

heh, yeah I’ve done that on an old mountain bike, I was just sat in the garden after a good road ride eyeying up the plastic disc on my back wheel and wondering if i should remove it? It does an important job, but wht so big and so ugly? Its like a black shiney dinner plate! If they made it smaller, and out of carbon fibre I’d be all over that!

Should have set his mech up properly

Ahh they’re ugly alright but could have saved us 30 mins on the trail and my mate a new mech… Thinking of buying one and putting it on my bike!

A guy I rode with at FoD said the plastic thingy put a weak spot in his spokes over time. He found himself losing a drive side spoke every ride before he twigged and removed it.

Should have set his mech up properly

exactly! set the mech H-L mech stops correctly there is no way the mech will move up and over the cassette unless its pushed by a foreign object

I did that once but it also ripped the lower jockey wheel off, broke the mech hanger, snapped a few spokes and bent a front chain ring!

In the end it resulted in me buying and Orange Five so I was quite pleased really!!

…unless its pushed by a foreign object

And then when it does it takes half-a-dozen spokes with it as well.

Just saying like

Agreed David, but it’s easy done to let mech setup slide a litte and especially if the back wheel is on/off a lot it. The first thing I always do when I get a bike with one of those plastic things is the rip it off – I always thought the worst that could happen was a stuck chain… How I was wrong!

Agreed David, but it’s easy done to let mech setup slide a litte and especially if the back wheel is on/off a lot it.

care to explain that?

but it’s easy done to let mech setup slide a litte and especially if the back wheel is on/off a lot it

Mech setup is a one time deal unless your fitting different wheels. Same wheel on and off makes no difference.

Well if you’re taking the back wheel off and on every ride and hoying the bike in the back of the motor the mech gets knocked and bashed by the wheel and car.

mech gets knocked and bashed by the wheel and car

shouldnt wont make a difference unless your bending the hanger, in which case a plastic disc will do sod all.

that wouldn’t turn the H-L screws… sounds like you’ve bent the mech hanger and need to look after you kit better

Look fellas – just trying to share an experience had whilst out riding that I had never come across before that I thought might be of interest. Don’t want to argue about my engineering acumen which is evidently non-existent.

*Leaves own thread*

*Leaves own thread*

…to go and find a handbag…….

Quelle flouncage! 🙂

We had to remove the one on my mate’s Camber as it was causing the chain to get stuck.

What I want to know is why as a so-called mate you let your mate leave the garden with it still on his bike? 😈

nickewen.

Not bashing you, just providing ‘technical support’ 😆

We have all learnt these things at some stage, some of us just like to share and dispel myths to prevent others suffering same issue in future.

What just happened?

1. OP identifies a problem and asks for advice.

2. Nice people on STW offer clear and unequivocal advice.

3. OP flounces off.

Confused!!!

IME, something like this just causes the plastic disc to break in addition to the mech.

The day before I was going to de-spoke protector our bikes, my middle son (who had already removed his because it wasn’t ‘cool’) bent his mech hanger and mangled enough spokes to warrant a rebuild.

I’m now smuggly uncool with my spoke protector still in place.

For those that say they don’t work, only being plastic, they are THICK plastic next to the spoke heads, and thinner plastic (merely to deflect the chain) further out. They do work.

If you don’t want to use one, that’s fine, your choice, but don’t make up reasons to justify your choice.

IME, something like this just causes the plastic disc to break in addition to the mech.

Not seen that happen. Photos? What make of protector? Shimano?

Was on a ride last summer where a lad had a spoke protector crack when ‘protecting’ the spokes from something (mech was straight). It then proceeded to jam itself between spokes and cassette on his next run, so no freewheeling. We had to smash it out to get him moving again. Not as bad as bent spokes i suppose but still annoying.

looks like there is a carbon version available…

available at…http://www.wmsracing.com

For those that say they don’t work, only being plastic, they are THICK

nob

Just adjust the rear derailleur probaly. Then there is no need for that disc