105 9SP triple can it replace a sora 7sp triple?

[Nigelnaturist]

Has the question poses, I am looking to upgrade front and rear over the next few wks/month or so, but I need to replace the front as it got slightly bent.

 

[Lee_M]

I could be wrong ( I probably am) but not sure if 7sp vs 9 sp will make any difference on the front except if the chain size is different (ie a 9 and 10 sp chain are different dimensions). If the chain is the same dimensions then its just number of teeth and therefore the length of the chain that is affected

 

[Nigelnaturist]

A 9sp is a little bit narrower, so there might be a little more chain rub on the 7/8 sp chain, but it something I am preparred to live with if it's a short term thing. I think for the difference between 8 and 9 sp sprockets .02mm I could use a 9 speed chain if I only went to an 8sp (it's all cost and what I can get) but a the difference between a 7 and 9 sp is 0.12mm not sure how this would effect things.