First Time chain replacement ..... problem

Klaus

Senior Member
Location
High Wycombe
City Bike with Shima Revoshifters (3 chain rings front 7 cogs back).

Original chain came off not sure why so I thought it's time for a new chain.
Obtained a "Taya" TB-50 which is suitable for 5, 6 & 7 gear bikes.

Having looked at a number of videos and descriptions attempted the job. Chain over large ring in the from and smallest cog at the rear.

First attempt test ride chain slipping badly when changing gears.
Second attempt shortened chain to have derailleurs alingned vertically (as suggested in video). However, chain keeps slipping (making quite a racket) and came off chain ring when trying to change gears "manually" (i.e. when not riding).

I think the chain is still too long but how can I tell, is there some sort of routine to tell whether the correct length is reached, or do I have another problem?

PS. just found thread https://www.cyclechat.net/ which suggests cassette may be worn. There are certainly no stiff links in the chain (new).
 

RecordAceFromNew

Swinging Member
Location
West London
Chain length calculator.
 

Moodyman

Guru
To get the correct chain length it's small sprocket and big ring + one link.

If you've not added the extra link then your chain is too short. It will skip on some of your gears.

Also, cassette could be worn.
 
I use:
Chain on largest sprocket and largest chain ring NOT through the derailleur, then add two half links (1 inch).

In practice, because I always use the SRAM quick-link, which is an outer link of course, it works out as : chain tight on largest sprocket and largest chain ring, not through derailleur, plus one inner link, so that the chain is an inner link at both ends after cutting.

Works for me.
 

rh100

Well-Known Member
michaelrmgreen said:
I use:
Chain on largest sprocket and largest chain ring NOT through the derailleur, then add two half links (1 inch).

In practice, because I always use the SRAM quick-link, which is an outer link of course, it works out as : chain tight on largest sprocket and largest chain ring, not through derailleur, plus one inner link, so that the chain is an inner link at both ends after cutting.

Works for me.
Thats the method I used when I changed mine, worked really well. It continues to work well even after adding a different cassette with bigger cogs aswell.

TBH I just assumed that the deraillieur would take up the slack as long as there wasn't too much, but maybe I'm wrong.

When I first changed the chain initially though, it ran really rough with the existing cassette, replaced for new which solved the problem then as I say I replaced again with a larger cassette fairly soon afterwards.
 

steve52

I'm back! Yippeee
the slipping is nothing to do with chain length, if your chain is worn and u have to replace it chances are the chainring and casset are worn to so nolonger fit an un streched chain, it would seem that cassets chains and chain rings mate for life lol change one change em all ! SAD BUT TRUE
 

tyred

Legendary Member
Location
Ireland
Does definitely sound like worn freewheel sprockets. Even if the chain was too long, the derailleur should take up the slack if it's anywhere in the right ball park.
 
Location
Midlands
To get the right length chain - assuming that I have not put a different size front ring or rear cassette on I count the number of links in the one that I take off (it worked properly at that length so always works well if I keep to the same length) and write it down for future reference - not all chains on the shelf in the shop are the same length - saves buying one that is too short

If I put on the same chain length as last time then any problems have got to be something else - normally gear inner or outer cables

Moodyman - seems about right - my setup is as he says but plus two links
 

Davidc

Guru
Location
Somerset UK
steve52 said:
the slipping is nothing to do with chain length, if your chain is worn and u have to replace it chances are the chainring and casset are worn to so nolonger fit an un streched chain, it would seem that cassets chains and chain rings mate for life lol change one change em all ! SAD BUT TRUE
It's only true if you let the whole lot get worn out.

If you check chain wear and replace the chain after it has 75% wear and before 100% (using a Park Tools guage or just measuring it - see Sheldon Brown) then a cassette and chainrings will last for 3 or 4 chain lives. Until recently I measured them but now have the guage, which is a bit quicker..

After the first 3 chains it's worth checking the cassette and chainrings for wear as they'll write off chain number 4 very fast if they have worn.

I've found that chain life is very variable, so it's no good just guessing that they'll last a certain distance.
 
OP
Klaus

Klaus

Senior Member
Location
High Wycombe
steve52 said:
the slipping is nothing to do with chain length, if your chain is worn and u have to replace it chances are the chainring and casset are worn to so nolonger fit an un streched chain, it would seem that cassets chains and chain rings mate for life lol change one change em all ! SAD BUT TRUE
Thanks for all the replies - as the bike is of unknown age and maintenance record I am biting the bullet and will book it in the LBS for service/repair. Initial call suggests there's a two week waiting list, due to time of year ....
 

swee'pea99

Legendary Member
Seems a shame. Two things for future reference - as someone above said, the easiest way to get the chain length right is to cut it to the same length as the old one. And second, it is possible to determine whether or not your chainset/cassette is worn out - google things like 'worn chainset', to find pics like this.
 
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