Got a little carried away on eBay and bought a Rotor 3D+ crankset. Came to fit onto Ridley Helium SL frame and found out the axle is too long, about 25mm too long.
Have I made an expensive mistake?
25 or 2.5mm ?
It sounds like you're just missing some spacers - likely if the cranks came from a bike like a Cervelo
The Rotor 3D+ manual is here: https://rotorbike.com/catalog/default/downloads/dl/file/id/62/product/56...
For PF30 it looks like you'll need two 11.5mm spacers and a 0.5mm spacer. They are both available at Bike24.com:
You can relax now!
Cheers those spacers look the job.