Slipping gears after new chain

[Gruff Eddie]

Hi guys

My chain snapped at the weekend and chucked me off.

Keen to get back in the saddle, I duly replaced the chain this evening, but it's now slipping.

Cards on the table - I'm a proper newbie numpty when it comes to cycling!

I think I may have left the new chain 2 extra links in the chain, and have probably underlubed it.

I'm just after a bit of peace of mind that sorting this out is within my capability!

Any advice greatly appreciated!

 

[Pauluk]

How did you set the chain length?

 

[Gruff Eddie]

I thought I had set the chain length correctly, but in retrospect, I think I may have left 2 extra links in. Is that likely to be the problem?

 

[Hacienda71]

If the cassette is old it may be worn and need replacing as well. Do the teeth look quite pointy like shark fins or are they squared off at the ends?

 

[ianrauk]

A new chain doesn't really need lube for a good few miles.
Did you measure the new chain against the old chain to match the same amount of links?

You don't say where the chain is slipping.
At the crankest or the cassette? Either or, if you have used the chain well past it's worn point then it could have worn the cranksets and/or the cassettes teeth making it slip.

 

[Pauluk]

As Hacienda has said, could be a worn cassette, but you need to get the chain length correct first to eliminate that. Did you use the old chain to set the new chain length or did you use large-large cog method

 

[Gruff Eddie]

The bike is quite old, and I'm pretty sure it's the original cassette, but the bike has hardly done any miles.

 

[Gruff Eddie]

I used the large cog method. The old chain was broken, so I was unsure it was a good guide.

 

[Pauluk]

ok and did you allow just one extra inch (two links) once the chain was stretched over the large cogs

 

[Gruff Eddie]

ok and did you allow just one extra inch (two links) once the chain was stretched over the large cogs

I *think* so! Sorry for being vague, I do feel a bit out of my depth, even with the simplest bike maintenance!

 

[Pauluk]

Well if the chain is the correct length then as the other posters have said it could be the rear cassette, but I would split the chain first and recheck the length to rule that out first because its the simplest thing to do. I have an 2 old mtbs (15 years) that have not done many miles and the chain and cassette are perfect.
Can you also measure some of you old chain to see if its stretched, this may give an indication of cassette wear.

 

[Gruff Eddie]

OK, I'll fish the old chain out the bin and measure it.

Another daft question - if, say, 100 links of the old and new chain are the same length, does that indicate that, as the chain is not stretched, the cassette is unlikely to be worn?

 

[Pauluk]

Could be, but then again has the chain be changed before so the cassette is now on its third chain!
Also if you measure the old chain you need to do it fairly accurately over a reasonable length I would think (I've never done it with a rule, only ever used a chain gauge) because you're looking for quite small errors (stretch measurement), don't know if anyone else here has used a rule to measure chain stretch.
By the way, don't throw the old chain away, it may be useful some day (chain whip may be).

Good luck anyway Eddie, hope you get it sorted soon.

 

[Gruff Eddie]

Thanks for your advice everyone. I'll have another go tomorrow. (Greasy) Fingers crossed I can sort it out!

 

[2Loose]

Sounds like the new chain doesn't mesh on the old cassette properly.
I'd put the old chain back on with a powerlink if possible and source a new cassette. Using the new chain with the old sprockets will wear it prematurely AND it probably won't shift or index cleanly.