chain tension causing tension - ideas?

[kedab]

hey lovely people, hope you're all well.

here's the thing - took my bike in to the LBS for a tune-up a few weeks ago - mainly because i noticed the chain tension had dropped and it was bothering me. (they sorted the gear sync out too which is lovely), it's a fairly new bike and Giant had done the 1st service gratis a few months before.

LBS peeps were great, local family, local business and complimentary about my bike too - which was nice. so, i do a few more weeks of commuting and notice the same thing; the chain seems to be losing tension. my mind, i think, it's all in my mind...that was until fate would have it that i switch up a gear, stand on the pedals and hit a bump all at the same time resulting in a worried kedab with his chain off at the rear popped the slippery blighter back on no trouble but still, i was rather vexed.

now bear in mind that i've got shimano alfine hub so there's no cassette gubbins at the back, is it an easy job for a weak minded fool like myself to re-tension the chain rather than have to run my baby back down the LBS? i need details here ladies and gentlemen details - as in, how to do it and what work tools are required
thoughts/opinions/derisory remarks all welcome here folks

 

[Zoiders]

Is this a Giant "Seek"?

As all the adjustment is done at the bottom bracket using what is known as an ecentric BB, I could set it up myself, I could even talk you through it step step but your best bet is to take it back to the bike shop if you are new to mechanical stuff.

You lost tension when you stood on the pedals, this is because the BB carrier was not bolted in tight enough, so the BB it self has dropped slightly which at the same time moves it back slightly.

 

[Moodyman]

You also need a special tool to adjust the BB and chain tension - Hollowtech 2 spanner

Though easy with know how, you're best getting yourself to the shop to have this done. Watch them do it and then buy the tool for later use yourself.

Chains stretch on hub gears too, though not often, and require adjusting from time to time.

 

[kedab]

Zoiders - Moodyman,

Thanks for the advice - i'll take it back down there and watch them do what they do and how they do it - if it's a fairly obvious procedure, i'll see about getting the right kit for myself.

Zoiders - it's a Giant CitySpeed - i love it, perfect for what i do.

Moodyman - yeh i thought it may only be a bit of stretch but after Zoiders assessment, it does make sense that it's a bit more than that this time.

thanks again - big help as always on CC

 

[sbseven]

Here's some instructions (with pictures) for adjusting the Eccentric Bottom Bracket (EBB) of a Giant Seek with a Alfine Hub. Your bike is probably pretty similar. Should be easy enough to do this operation yourself.

http://doulogos.blog...-eccentric.html

 

[kedab]

Here's some instructions (with pictures) for adjusting the Eccentric Bottom Bracket (EBB) of a Giant Seek with a Alfine Hub. Your bike is probably pretty similar. Should be easy enough to do this operation yourself.

http://doulogos.blog...-eccentric.html

i could do that! i think i may leave it until my next few days off and get it down the LBS to have a watch first though. like they say in teaching hospitals - 'see one, do one, kill one'

many thanks for the link though, i have b/marked that bad boy

oh and that Giant Seek is similar to my CitySpeed - apart from the fact it's butt ugly

 

[kedab]

People, I have done it!

thanks to all - the link with the pics gave me confidence and looking at my 2011 CitySpeed made it even easier - 6mm hex spanner and robert was my father's brother - Giant have obviously made the EBB <<< yeh get my knowledge

easier to use - two bolts in the bottom bracket and only 1 in the eccentric part - loosened off bolts, gently turned eccentric bit, chain loosened, turned t'other way, chain tightened - touch.

one of the bolts in the bottom bracket did loosen off easier than the other, i certainly didn't give it much pressure, so maybe that was the cause of the loss of tension so soon...anyway, all good. i spun the bike up and down the road for a few miles and it's sweet.

thanks again to you guys and CC - i have become a better person today

 

[Angelfishsolo]

People, I have done it!

thanks to all - the link with the pics gave me confidence and looking at my 2011 CitySpeed made it even easier - 6mm hex spanner and robert was my father's brother - Giant have obviously made the EBB <<< yeh get my knowledge

easier to use - two bolts in the bottom bracket and only 1 in the eccentric part - loosened off bolts, gently turned eccentric bit, chain loosened, turned t'other way, chain tightened - touch.

one of the bolts in the bottom bracket did loosen off easier than the other, i certainly didn't give it much pressure, so maybe that was the cause of the loss of tension so soon...anyway, all good. i spun the bike up and down the road for a few miles and it's sweet.

thanks again to you guys and CC - i have become a better person today

Even though I offered no help at all I still salute you Sir!