Shimano front mech question

[Polar Bear]

Does anybody know if the internal width of a Shimano 9 speed and a ten speed road mech differs please?  I can't find anything definitive. 

[Wothill]

Does anybody know if the internal width of a Shimano 9 speed and a ten speed road mech differs please?  I can't find anything definitive. 

I have just been to measure mine (both road triples - a 105 9-speed and an ultegra 10speed) and they appear to be exactly the same. I measured the internal gap in two places just in front of the top pivot: at the wider bit (at the top) it was 13mm and at the narrower bit just below, it was about 10.5mm. Below the pivots they are both more complicated shapes but appear to be very similar to each other.

Alf

[Polar Bear]

Thanks very much for taking the time to do that.