Ah, the bewildering world of bike parts..

mraonghus

Have had this road/hybrid bike (not really sure of the terminology) for 3-4 years as a commuter bike, so it has had a good bit of use. I brought it in to get the brakes replaced and the guy in the shop also replaced the chain for some reason. The result was serious chain slippage at low gears, so I called back in but he had thrown away the old chain so was stuck with the problem.

Would replacing the crank-set, cassette and chain likely solve this?

I also want to replace the shifters as the covering of one was vandalised and they were both stock basic ones to start with.

Would the following combination of items work together?

Shimano 105 Chainset Octalink Triple 5505
170mm 30.42.52

Shimano 105 Cassette 7 Speed HG70
13-21

Shimano Deore STi Brake & Shifter Combo M510
9 speed RH & LH Set

KMC Z50 Chain 7 Speed
116 Link

I figured that 3 at the front would be more reliable and 7 at the back was a somewhat arbitrary choice. I presume my current rear and front derailleurs would have enough range for this stuff. At present there is 2 at the front and maybe 7 at the back (the bike is in another house so can't view it right now).

Any help much appreciated, as this is all quite confusing for newbie!

IM0

your much better off bringing it into the shop and asking, as they will see the bike (we cant ) and you dont seem to be sure about what is actually on it tbf.

to get you started no using those wont work, a 7spd and 9 spd parts cant be mixed like that.

also you might need a new cassette or just an adjustment, briung it back to the shop and explain what happened when you changed the chain.

blorg

Your cassette was probably worn. You probably just need a new cassette. Cranks are more than likely fine. They probably replaced the chain as it was severely worn, if you do this when needed you don't need a new cassette each time but if you leave it too long you will ruin the cassette. The fact that the gears are slipping NOW means that the chain did need replacement.

As me@ucd says I would bring it to the bike shop. You can't just slap on a triple crankset onto a double, 7 speed and 9 speed etc. There are several different crank/BB standards besides that, do you even know your BB is Octalink! Bring it to the shop who can diagnose.

Golfanatic

your shifters are 9 speeds and your chain and cassetes are 7 speed so there not gonna work here some that will
7sp shifter with brake lever 31 euro
7sp crankset

Golfanatic

if you tell us the bike you have we could help you more i wouldnt purtically reccomend that crankset but it will fit just make sure its a 7 speed