After replacing my cassette from a 11-32 Shimano 105 to a 11-34 Shimano 105 (Im going to see the Tour de France at the top of the Ventoux in two weeks I need as much teeths I can have ahah).
On the first 200m after the replacement, I noticed when I put my chain in tension the cassette make a really metallic sharp sound. So i overlubricated my transmission. And did several « clang ». I put a lot of power for 1/4 of a second and stop and start again right after. To test the sound.
So while doing that, my chain derailed. Quite hard, I still cannot understand how my chain can have done knots like this, I had to remove the rear wheel to put my chain back.
Do some of you may know why my bike make this sound ? And why the chain derailed ? Now Im afraid the bike can derail if I sprint
by Sam__sc
10 Comments
Probably need to index your derailleurs.
Follow the installation instructions for your derailleur (you can find it at si.shimano.com)
Did you adjust the B limit screw after installing the bigger cassette?
Regular thing for me…
https://preview.redd.it/zu298bwo7nbf1.jpeg?width=4032&format=pjpg&auto=webp&s=f541f437968d967dd6afa96e99de6182286a3f8f
I’m unconvinced by the (alleged) clutch on my derailleur.
https://preview.redd.it/3lnxitz18nbf1.jpeg?width=3024&format=pjpg&auto=webp&s=d227ac8881cf2fea8c2e687e3f24aaf1a6abf001
Is the chain long enough for the two extra teeth?
Check your indexing. Check your limit screws. Check you chain length. Don’t keep pedaling when it derails to avoid the knots.
Too many factors to say anything for certain here, but a new cassette does not adequately explain why your chain popped off of the big chainring like that, as those things are typically unrelated. You need to start first with checking the high limit screw on your front derailleur.
That said, if you came in my shop describing a long metallic sound when under load with a new cassette and an old chain as crusty looking as that one, I’d be looking at that as a culprit.
Post picture of bike with chain correctly mounted, in big-big gear combination. Speculating too-short chain to accommodate the new cassette…
First, check that your derailleur is indexed properly. But if you replaced the cassette, it’s likely that you also need to replace the chain (and possibly even the front chainrings). I had a chain slip issue with my bike after replacing the just the chain, and it turned out that I needed to replace both cassette and big chainring to keep it from slipping. Two years of commuting in gritty, wet weather wore everything out.
I think you need a new bike