Both the SM and XS will fit.
171cm, I would go for the XS. SM will work but you may not be able to get your position correct on it.
Originally Posted by
Johndan73
Hi, Can you help me out with bike sizing, I'm 5' 8" – 171cm, inseam 32” - 81cm I been told I need a medium size , most medium size frams are 21” - 54cm, on canyon’s built insizing tool on their web site I put in my height and inseam and it told me I'm a XS 18.5 47cm can you advise thanks