Chainline and q factor questions

JamesB
JamesB Posts: 1,184
edited May 2013 in Workshop
I`ve just put a Middleburn Duo setup on a road / CX frame (Cotic X so generous chainstays, take 28mm tyres + gurads no issues) in order to get a lower inner ring; used a 110mm square taper BB and have looked at resulting chainline. Which seems quite far out, ie distance from centre seat tube to outer ring is 51 mm (Sheldon Brown indicates 46 mm) and a straight chain line is seen with outer and 3 rd smallest sprocket.

So should I be OK with it as it is?, all gear change OK I would use outer with top 7 sprockets on a 10 block; inner with lower 5 only. OR try to fit a shorter BB (eg Token do a 102 square taper)

Along with a wider chainline the Q factor is now increased by about 20mm from original Campag double, Q factor is about 150mm with teh Middleburn chainset; is this likely to cause issues when I swop to another bike with a narrower Q factor or not an issue (I`m 6ft tall, ride with saddle surface > centre BB @ 770 mm so quite a long distance)

thanks
:)