LBS, not alwys the best choice.....

[eileithyia]

Had abit of trouble with gears last week, chain began to jump around a bit on sprockets and Mech appeared to be running slightly out of line.
Then finally the bike had it's revenge as chain slipped, caught in wheel and I was brought to an abrupt halt (still have various chain ring teeth marks to verigy where leg caught the chain ring in several places, ..... now what was that about bash guards?).
Expected to find mangled wheel and drop out, or at least a few broken spokes.
What I found was the mech totally broken off from the hanger at the point where it freely pivots around the fixing bolt, but wheel was intact.
Now to my mind that is some force that breaks through that amount of metal unless it was already fatigued.

Just outside a small town I had 20 min walk back to town to a bike shop. No problem they had an appropriate mech and suitably fixed it and I was soon on the road again.
However he also commented that he had taken an link out implying chain was too long, it had never appeared to be a problem before.
Commute to work today, for the first time since, I was using big ring and changed into big sprocket And was brought to a halt!
There was inadquate chain to accommodate such a gear, and once stopped I could hardly turn; wheel, pedal, chain in order to try to get chain off either the sprockets or the chain ring, so tight was the gear and chain pulled. In fact it was all so tight that I am surprised it even changed onto the sprocket in the first place!

So once again it was a call to the knight in shining armour to come and sort me out and get me back on the road to work, while some cursing bike shops who clearly got it wrong on this occasion.

[gaz]

Went to my LBS last week for a tyre for my son's bike. They produced one from the basement for £9.99 but with no ETRTO sizing on it - I turned it down.

Went to my LBSOS (you can work it out) yesterday. They told me they had a range from £6.99 to £9.99.

I said I was a bit price conscious so hooked a £6.99 one off a rail and I checked for ETRTO. Too wide, so he hooked down another, good size but £9.99 on the price tag.

Don't worry he said, rang it up on the till, applied a discount, I paid £6.99.


Apart from the discount I had expected the LBSOS to be selling the unlabelled stuff, not my LBS!

[meic]

I guess that he removed a link because it was damaged and would have prevented you riding.
He did at least tell you he had done it to warn you.

I much prefer to do my own and be responsible for my own mistakes.

Which are not unheard of

[Romeo Whisky]

Er, I think your problems may be of your own making. Don't use the big sprocket when you ar on the big ring, and you will find not only that your chain doesn't jam, but also that your rear mech doesn't break int eh first place. Change down to the smaller chain ring before you need the three biggest sprockets. All IMHO of course. Go give your LBS a hug

[meic]

The rear deraileur will not have been damaged by a large to large combination.
Give it a try in the workshop and you will see that the deraileur will shape itself around a perfectly taut chain.
It is the chainring teeth that will suffer.

Dont be so quick to criticise, or you may end up looking foolish.

[Romeo Whisky]

Just relying on Mrs W's experience. Bolt holding the hanger in place sheared when she went large to large, after months of being told not to because 1. it wears the chain, 2. knackers the teeth, and 3. you don't need to to find your desired gear.

[meic]

I wouldnt do it intentionally myself either.

But sometimes I dont pay attention to which front ring I am on.
Especially in the dark or when tired and of course both of them tend to occur together.

I rember a few times thinking "This hill is harder than I thought, better change down yet again."
rather than
"oops, wrong chainring".

[hamster]

Exactly, nobody intends to use big- big but it does happen occasionally. And for that reason, it should be doable.

I think the LBS should have checked it. I've seen it happen where it stuffs the mech into the wheel, rips off the mech hanger and a few spokes...not pretty.

[Si]

When LBSs go bad:
Case 1: my first adult bike - now that I knowa bit more about bikes I know that I take a 22" road frame, this shop sold me a 26" frame telling me that it fitted me perfectly.
Case 2: bike shop was meant to put new inner and outer rear brake cables on while they were doing something else, the bike had girvin vector forks and they routed the cable around the outside of the fork shoulder, thus attempting a right turn caused the rear brake to lock up.

Needless to say neither of these remained my LBS.

[eileithyia]

Er, I think your problems may be of your own making. Don't use the big sprocket when you ar on the big ring, and you will find not only that your chain doesn't jam, but also that your rear mech doesn't break int eh first place. Change down to the smaller chain ring before you need the three biggest sprockets. All IMHO of course. Go give your LBS a hug

Hi meic, they never said it was removed due to damage but implied it needed removing due to too much chain, not previously an obvious problem.
i do not generally use big - big, with my small bikes it is too much of an angle on the chain, however on this occasion, as meic said, did not take much notice how far down the sprockets I had changed, even so there should be enough slack in the chain to allow for big - big, even if it is not recommended.

Romeo whiskey, the mech did not break cos I was using it in the big - big combo, in the first place I was on small - big and was nowhere near the big sprocket when chain started to jump about erratically in the original incident.

When you are 30 miles from home and a bike shop is within 20 mins walk, you use what is necessary to get you mobile again, and avoid calling OH out of work, or removing mech and shortening chain to make a singlespeeder for the ride home. Had I done any of those options a new mech would still have been required and would have needed fitting at home, restoring the chain length.


I still find it hard to believe that the mech fractured through at such a point without ripping out any spokes and causing further damage to the bike, it seems highly suspicious that there was some fatigue there.

[fylbiker]

Hi meic, they never said it was removed due to damage but implied it needed removing due to too much chain, not previously an obvious problem.
i do not generally use big - big, with my small bikes it is too much of an angle on the chain, however on this occasion, as meic said, did not take much notice how far down the sprockets I had changed, even so there should be enough slack in the chain to allow for big - big, even if it is not recommended.

the chain was the correct length prior to the accident. the new mech was the same, short cage, as the old one. i've had to fit two links into the chain - just as well it was a normal chain and not one of these special shimano ones that can only be adjusted with the special pin. wouldn't care but for as long as i can remember (mid 70's) shimano have had the same, simple, method of obtaining the correct chain length, providing of course that the teeth difference is within the range of the mech which it was in this case

[DaveP]

I still find it hard to believe that the mech fractured through at such a point without ripping out any spokes and causing further damage to the bike, it seems highly suspicious that there was some fatigue there.

There might be a clue in your opening post:

chain slipped, caught in wheel and I was brought to an abrupt halt

Its been a while, and I'm in no hurry to repeat it, but last time I had this experience the chain ended up very tight. If the wheel gathered up enough chain to pull the jockey wheel into the sprockets then the sort of damage you described doesnt seem too surprising.
Hope the scars fade soon!

[eileithyia]

Davep Well on the way to healing, thanks.

Going back to chain length, I would have thought if the chain was damaged necessitating the shortening of it, then I would have expected the mechanic to a, explain this. b, point out that there was now not enough chain to ride big - big, c, to suggest putting on a new chain to replace the damaged one!

Indeed I would have expected any self respecting mechanic/lbs owner to grab the opportunity.

With regard to not riding big - big, it was easier in the good ol days when I started, with down tube ratchet levers and only 5 sprockets. You knew from the position of the lever which sprocket you were in, with multiple close ratio sprockets it is less easy and looking down is not necessarily an option.

[Flinders]

Things can fail in time even if there wasn't anything wrong with them to start with, though. I had a similar failure which wrote off my back wheel and bent the rear forks. Over many years a small pivot had, without my knowledge, been wearing through the part of the mechanism it was attached to, and eventually, going uphill, it tore through, and the rear mech exploded (no other word for it) into the back wheel.
The wear by the pivot was totally invisible from the outside of the derailleur, and I'd always kept all the pivots carefully lubricated. It was just one of those things.

The extent of the damage from such a tiny failure was amazing. I had to have the frame sent back to the factory for new rear forks.