New Chain Pain - Help!

[Gummo]

Chain Issue - as follows:

1. Chain working fine.
2. Random test with chain checker reveals new chain needed.
3. Chain replaced.
4. Perfect test on bike stand.
5. Went for test ride.
6. New chain totally refuses to grip on middle chainwheel.
7. Occasional struggle on small chainwheel.
8. Works perfectly on big chainwheel.

Chainset = Shimano T551 (3 chainwheels)
Chain = KMC X10 with 114 links.
Cassette = Shimano CS-HG500 10-speed

 

[fossyant]

Worn chain rings.

 

[Paulus]

What @fossyant says⬆️.
New Chainrings needed and you might find out the the cassette might need changing as well.
It's often the case that a new chain is fitted for it to slip on the Chainrings, cassette or both.

 

[Marchrider]

if possible (you can't with all) take the middle chain ring off and fit it on backwards (flip it over) if the small one is just slipping a little, ride gently on it for a few hundred mile and the new chain will bed in

 

[Gummo]

I have a new crankset - i bought two, five years ago. Time to replace the heap - I'm 68 years-old in July. After all the responses, replacing the chain every year will prolong the chainrings and cassette, probably the last of changes at my age.

 

[wafter]

I have a new crankset - i bought two, five years ago. Time to replace the heap - I'm 68 years-old in July. After all the responses, replacing the chain every year will prolong the chainrings and cassette, probably the last of changes at my age.

FWIW it seems this has happened because the chain's not been replaced at its wear limit, allowing it to elongate past this and knacker your rings.

Similar can be avoided in future by correctly maintaining your drivetrain (not going into that here!) and checking the chain regularly for elongation. The latter can be done either with a steel rule or using a dedicated go /no go tool.

Also note that the chainrings on your crankset are replaceable so even if you change in en-bloc there's still value in the old one - as such it's worth selling / giving it away to someone else who might find it of use.