Gear adjustment question

[Steve Beard]

I have a problem getting my bike to shift to the highest gear on the rear cassette when I am in the big ring upfront.

I don't think it is a rear derailleur alignment issue as it is fine when in the small ring upfront. Also, if I quickly drop the front gear from big to small and back to big, then the rear will shift to top gear. But, the rear won't shift to top gear if the front is already in the big ring.

Any ideas why? I have new campy chorus shifters, new chorus chainset and an athena 11s rear derailleur.

Any ideas appreciated. I built the bike myself, but can't figure this one out.



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[freeflow]

The symptoms you describe could be cause by a chain that is too short.

[Samuel D]

For the avoidance of doubt: are you having problems with the smallest or largest sprocket of the cassette?

If the former, it may be that your combination of derailleur-hanger geometry, cassette size, chain length, and derailleur tension adjustment is incorrect. You would then need to adjust the spring tension (using the screw under the derailleur) to move the upper pulley closer to the cassette. I think Campagnolo recommends 5–7 mm on the largest sprocket. Is yours in that range?

What cassette are you using?

[Steve Beard]

I will try the spring tension and check chain length. Thanks.

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