Gearing problem

[Mark Walker]

I have a giant tcx2 and from new had the gearing changed from the orig 11 - 26 to 11 - 30 to allow me to climb, particularly Rosedale chimney bank.
The problem is more or less every 6 weeks the chain starts to slip .
Tonight i haver tried to re set it but cocked it up ,and will have another go tomorrow.
My question is ,will this bike take a 11-30 cassette ?
Has my LBS made a mistake and why does this keep happening ?
appreciate you raking the time to reply.
regards
Mark

 

[fossala]

They can take up to 30 in the rear.Have you checked the wear on your chain?

 

[Mark Walker]

The bike is relatively new. three ,four month use , the thing is it has slipped on and of on since I bought it , i have taken it back to the shop a couple of times .they tighten a few things and it is OK for a month or so then starts slipping again.
I managed to fix it playing around with the rear derailier adjusting bit (at least i think that is what it is) after watching a youtube video.
The problem is , it started playing up yesterday so I had ago at fixing it today, mistake !
I was struggling to get a clean change from the big ring at the rear so I unbolted the cable tightened it and re bolted , now i am worse of ! I cannot change down at all ,when I press the lever nothing happens.
What have I done wrong and how to fix it ?.
I must have cocked the cable tension up but it does not show how to fix it on any video I can find !!.
This is me I can knock things down but struggle to build them up again,especially anything mechanical
Any ideas ?

 

[fossala]

Shift down to the smallest rear cog with the barrel adjuster tight. Pull the wire hand tight and tighten. Turn the barrel adjuster until it shifts smoothly up. Then fine tune it until it shifts perfectly.

Ask your LBS what they are doing when the "fix" it. I would start asking questions if it's an on going problem with a new bike.

For what it is worth I can easy go through a chain in 2/3 months. I do around 2000miles in that time though.

 

[Mark Walker]

Thanks for the help Fossala.
Had a go last night and Bingo sorted it out na dworked well on the way to work this morning.
Why it does this I do not know ?
I sometimes find myself cross chaining without realizing it , so I might be stretching something somewhere ?
Anyhow good at the moment so thanks for your help.
regards
Mark