Repair: Chain slip at high torque

[Err]

I'm having a problem with chain slip at high torque, ie standing on pedals in low gear, particularly the lowest (11t) on the rear cassette.

Cassette is new but cheap,
chain is new but was broken and rejoined,
no obvious stiff links,
Chain rings are old but not too bad,
Rear derailleur is old.

Can you help me on the most likely culprit?

 

[Grannygrinder]

Slippage

I'd say the chainrings and possibly the cassette bot need changing,but if they have all been running together for a while you need a new chain aswell,sorry mate.

 

[stew-b]

could be the freehub body,ive just slung a mavic crossride wheel in the bin cause the freehub slipped under load and isnt repairable on a crossride

 

[Err]

The cassette is new. It's only happening in the lowest gear. Chain has done about 10 miles. I think it might be insufficient b tension.

 

[cannondale king]

are you using the right chain ie hg ug or 9spd chain 7 spd cassette or 7/8spd chain on a 9spd cassette if so  :roll:  :roll:  :roll: see where im coming from  and what ratio cassette are you running and what does your rear mech cover up to some rear mechs cant handle lower than a 13 tooth cassette if you :? :? dont worry we can help

 

[Err]

12- 28 cassette, sram 830 chain. Acera x derailleur. Chain rings are sugino.

 

[cannondale king]

is that an 8spd cassette then or 9

 

[Err]

I can see the derailleur snapping to the side as it happens, inwards. Towards wheel. Definitely only happening in 12t sprocket, in any front chainring.

 

[cannondale king]

yeah but what size cassette is it :?:

 

[Err]

7 speed.