Help Shoulder Pain

Are you sure it's the same reach and stack?

Reach in particular, the frame reach might be the same, but is the stem length the same? What about the reach of the handlebars (e.g. the distance between the horizontal section of bar and the hoods). I've even heard that Campag hoods are 1cm longer than Shimano, have you changed groupsets?

Maybe the hoods are rotated further forward, which would increase reach?

I ask as I was having shoulder and neck issues, they were partly related to stack and reach, i.e. I was reaching forward and down too much meaning I had to raise my head further, but they were also related to distance, as I've gradually increased the length of my rides the neck pain has gradually subsided, I guess as the muscles get stronger.

Massage can help, I've had two recently focussing on shoulders and it's definitely loosened them up.

I sometimes get a stiff neck during a long ride, which may or may not qualify me to offer some advice...

Could it be related to the numb hands? Perhaps you're putting too much weight on front. Perhaps you could take more weight with your core, which would help relax everything from your shoulders to your hands. Bent elbows and so on.

When i notice a stiff neck i also take it as a reminder to do more shoulder checks, which aside from the safety benefit, avoids you keeping things fixed in one position too long.

Steve, have you tried adding more spacers, so that you can be a bit more upright? The problems may be related to the angle you need to crane your neck to look forwards.

Also, how strict are you with stretching exercises? Find some good stretches that concentrate on your back, shoulders and neck, you might find an improvement - it certainly won't do you any harm, and as you get older it's something you should be doing as regular as clockwork anyway (although I am all too aware that a half hour stretching session is sometimes the last thing you want to do after getting out of the saddle!).

I suffered from shoulder pain at work for no real forseeable reason, and found out I was magnesium deficient. This proved to be the issue in my case!

Difficult question to answer. Could be the Defy is more compliant than the Canyon resulting in a harsher rider with the Canyon. Another thought is the Canyon wheelset adds to the harshness. Have you tried lowering the psi? Last thought is your bike fit is off.