Chain Slipping

.dave

I replaced a chain on a trek hybrid it was a new 7 speed chain. But the chain is slipping. its obviously to do with chain tension but i shortened the chain but this didnt help. also adjusted the screw on the derailleur and no joy. Im pretty sure its not ware on the cassette/chainrings. anyone have any idea??

GTDolanator

it sounds like its wear on the cassette.Does it slip in any particular gears?

.dave

thats what i thought also but the teeth look fine

doozerie

It's actually probably not the chain tension. When you press on a pedal you are putting the top run of chain under tension so even if you had a chain that was far too long (or even a chain that was split and was just draped over the rear cog and front chainring with the unjoined ends resting on the ground), and therefore not under any tension, while the bike was stationary you should be able to press on the pedal (keeping the back brake locked on to prevent the rear wheel from turning) and expect the chain not to slip. If the chain were to slip in those circumstances it is because it is not mating properly with the rear cogs and/or the front chainrings, suggesting either an incompatible chain or excessive wear or potentially even a very bad chainline.

Once you are pedaling on the move, other factors come into play, such as whether the lower run of chain is bouncing around as you pedal, whether the rear derailleur is adjusted correctly to sit the chain solidly into gear (otherwise any slipping you experience may be the chain trying to change into one gear/cog higher or lower), whether you are crossing the chain excessively as you change between gears, etc.

.dave

it slips in the lowest gears on the cassette...when its in the highest front chainring and middle chainring...

doozerie

One example of an incompatible chain is a 1/8" chain being used on 3/32" cogs and chainrings, or vice versa.

kona

.dave wrote: »

I replaced a chain on a trek hybrid it was a new 7 speed chain. But the chain is slipping. its obviously to do with chain tension but i shortened the chain but this didnt help. also adjusted the screw on the derailleur and no joy. Im pretty sure its not ware on the cassette/chainrings. anyone have any idea??

What gears is it slipping in? and did you use a split link or a pin? How do you know for certain that the cassette isnt worn?

Now I see more posts haha, Id change the cassette, sounds like its worn. But Its very hard to say without seeing the bike, If your comfortable that you have adjusted the gears as much as you can then its the cassette.

However I wish there was a standard to describe gears, as low gear to some means high to others.
If the Chain is slipping in 3 on the Front and 1,2,3 on the back (numbers refer to shifers), you chain is most likely too short.

.dave

interesting...............thanks for the reply!!

its a touring chain.... 7 speed..i guess its ok...


but thinking about it...i think u are right about it not being the chain tension as it slipped with the previous chain also thats why i changed it but i am thinking maybe its the cassette because as i said it slipped previously.

i think its not to do with chainline, or on the move problems also such as being in the incorrect gear,

.dave

it was split link but then i removed some links thinking it was chain tension.

i think i will change the cassette and see what happens then..