overmind
My other bike is a Pinarello
- Location
- Reading, Berkshire
I recently came across some really poor service by the following bike shop.
BikeLux, Newbury
A friend of mine had a problem with the drivetrain on his bike. Essentially, the chainwheel and cassette was badly worn and needed to be replaced. This should be a pretty simple job for anybody with experience.
Steps
- remove chainwheel securing bolts with hex key
- use crank puller to remove cranks and chainset
- replace chainset
- replace chain
- replace cassette
- re-align.
They failed at the first step!
They managed to completely b****r the hex bolt - I suspect some ham-fisted mechanic used a hex wrench in an aggressive way and damaged the bolt meaning on all subsequent attempts the tool just slid out. They then tried to drill out the bolt and got about 1/2 cm in and gave up.
They replaced the cassette and the chain and returned the bike to the owner. The bike was un-rideable. They then charged the owner £130 for this now un-rideable bike; since the chain slips on the chainwheel teeth which are worn out. Unfortunately he paid. I would not have!
They took 6 weeks to do this! They claimed the delay was due to inability to source parts.
-------------------------------------------------------
I visited this friend and found out about the problems. I offered to take a look.
I managed to remove the non-drive side crank very easily. I used a long hexkey with a big adjustable spanner and a 2ft cheater bar for leverage. I increased the torque very gradually until the bolt suddenly gave way and then I was able to undo it with just the hexkey.
I tried the same of the drive side but the bolt was completely wrecked. I tried glueing the hexkey into the bolt with epoxy but this was not strong enough (I have since found a very good video on various techniques to do this which I will use in future).
View: https://www.youtube.com/watch?v=WDOWPekMX44
Since the chainwheel was basically worn-out anyway I decided, as a last resort, to have a go at it with an angle-grinder. The chainwheel is a SRAM 3 speed one-piece unit and the middle ring teeth are completely worn out causing the chain to slide badly.
This consisted of grinding the crank down to expose the bolt to allow me to get some mole-grips around the bolt and perhaps turn it off. This did not work. In desperation, I ground the entire bolt off all the way to the end of the tapered spindle. This also meant any possibility of using a crank puller was now impossible since that part of the crank had been vapourised.
I then used a big metal fork (similar to a crowbar; I think it is called a pickling fork) to try and remove the crank by force. I had to be careful not to damage the bottom bracket area of the frame. This did not seem to make progress. Finally, I was hitting the chainwheel with the hammer at 3 o clock, 6 o clock, 9 o clock, 12 o clock ... repeatedly (from the inside). I had almost given up when suddenly the whole thing just feel off. Result. :-)
The sealed unit bottom bracket was worn out - badly wobbling. I very carefully, and slowly removed this successfully and replaced it with a new UN55 unit. I found an old chainwheel from my daughter's old bike and it fitted perfectly.
The bike is as good as new and my friend is very happy.
The whole thing took me about 3 hours.
Thoughts ?
BikeLux, Newbury
A friend of mine had a problem with the drivetrain on his bike. Essentially, the chainwheel and cassette was badly worn and needed to be replaced. This should be a pretty simple job for anybody with experience.
Steps
- remove chainwheel securing bolts with hex key
- use crank puller to remove cranks and chainset
- replace chainset
- replace chain
- replace cassette
- re-align.
They failed at the first step!
They managed to completely b****r the hex bolt - I suspect some ham-fisted mechanic used a hex wrench in an aggressive way and damaged the bolt meaning on all subsequent attempts the tool just slid out. They then tried to drill out the bolt and got about 1/2 cm in and gave up.
They replaced the cassette and the chain and returned the bike to the owner. The bike was un-rideable. They then charged the owner £130 for this now un-rideable bike; since the chain slips on the chainwheel teeth which are worn out. Unfortunately he paid. I would not have!
They took 6 weeks to do this! They claimed the delay was due to inability to source parts.
-------------------------------------------------------
I visited this friend and found out about the problems. I offered to take a look.
I managed to remove the non-drive side crank very easily. I used a long hexkey with a big adjustable spanner and a 2ft cheater bar for leverage. I increased the torque very gradually until the bolt suddenly gave way and then I was able to undo it with just the hexkey.
I tried the same of the drive side but the bolt was completely wrecked. I tried glueing the hexkey into the bolt with epoxy but this was not strong enough (I have since found a very good video on various techniques to do this which I will use in future).
View: https://www.youtube.com/watch?v=WDOWPekMX44
Since the chainwheel was basically worn-out anyway I decided, as a last resort, to have a go at it with an angle-grinder. The chainwheel is a SRAM 3 speed one-piece unit and the middle ring teeth are completely worn out causing the chain to slide badly.
This consisted of grinding the crank down to expose the bolt to allow me to get some mole-grips around the bolt and perhaps turn it off. This did not work. In desperation, I ground the entire bolt off all the way to the end of the tapered spindle. This also meant any possibility of using a crank puller was now impossible since that part of the crank had been vapourised.
I then used a big metal fork (similar to a crowbar; I think it is called a pickling fork) to try and remove the crank by force. I had to be careful not to damage the bottom bracket area of the frame. This did not seem to make progress. Finally, I was hitting the chainwheel with the hammer at 3 o clock, 6 o clock, 9 o clock, 12 o clock ... repeatedly (from the inside). I had almost given up when suddenly the whole thing just feel off. Result. :-)
The sealed unit bottom bracket was worn out - badly wobbling. I very carefully, and slowly removed this successfully and replaced it with a new UN55 unit. I found an old chainwheel from my daughter's old bike and it fitted perfectly.
The bike is as good as new and my friend is very happy.
The whole thing took me about 3 hours.
Thoughts ?
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