Rear wheel change

[Salad Dodger]

A genuine question, arising out of an incident I saw on TDF on TV this afternoon...

A rider got a rear puncture. He stopped and a mechanic exchanged the rear wheel and sent the rider on their way.
So my question - wouldn't the rider have trouble with gear selection? Or are racing wheels set up in some special way to ensure that the derailleur will align correctly with different wheels and sprockets?

 

[Sittingduck]

What you mean trouble with alignment? Identical wheel likely being switched out, same cassette size and Di2. likely to be near on perfect in terms of indexing if that’s what you mean?

 

[ianrauk]

It would be a like for like change most probrably.

 

[Ming the Merciless]

Same hub, same cassette, what alignment problem?

 

[Dogtrousers]

I broke a spoke in my rear wheel recently. I swapped a spare wheel in and didn't need to adjust the gears.

It wasn't quite as fast as the pros do it. I did it at home and had to swap the cassette over, so I took the opportunity to clean each sprocket individually as I did it.

But the gears worked fine.

 

[presta]

Bear in mind that the guide pulley on a derailleur has a small amount of lateral play to accommodate tolerances, so the pulley guides the chain whilst changing, but the chain aligns the pulley with the sprocket whilst running.

 

[DCLane]

It's not an issue. They're trained to select the highest gear for a quick change and possibly remove the wheel if they have time, the mechanic pops a replacement wheel in, gives them a push to get started and they get going again.

The wheels will all be 12 or 11 speed, same cassette size usually per team, etc.

 

[Salad Dodger]

Thanks, folks.
Yes, it was gear alignment that I was thinking of, and failing to explain correctly.....

 

[midlife]

Or drop the chain on the portacatena back in my day if you were a pro lol