I got some good answers a couple of weeks ago, when I first asked about installing a standard chainset on my road bike, but the whole compatibility question is still as clear as mud to me.

Now, however, I have specifics to put before you.

The bike is a 2014 Wilier GTR, with a Wilier-branded FSA compact chain/crankset. I recently replaced the bottom bracket, and because I couldn’t figure out if there was another compatible BB, I just went with a straight swap, and bought this one. [A BB-6200/Di2 MegaExo 24 (68 mm)]

Then, I picked up an FSA Gossamer chain/crankset on Ebay, assuming there would be straightforward compatibility. There wasn’t, but here it is. [FSA Gossamer chain/crankset with BB386EVO impressed on the spindle].

In retrospect, I should have understood the difference, but it is too late now. The only question is: Can I make the new chainset fit my frame?

FSA published this compatibility chart, but I still don’t entirely understand. Especially because – at first glance, at least – the spindle on the Gossamer looks like a 30mm as opposed to a 24mm, and possible longer than the 68mm of the original.

My hope is that you will be able to help me interpret the facts, and tell me if there is a way of swapping my current chainset with the new one I bought, even if it means buying another BB to make it work.

I figure the collective wisdom of STW should be able to do what no single resource I have been able to find online has so far yet accomplished!

https://www.ribblecycles.co.uk/fsa-bb368-evo-road-bottom-bracket/

I reckon

Is this a metaphor for Brexit?

Were the old cranks perfectly fine?  Is re-fitting those one of the options?

The ‘spider’ of the compact cranks is too small for the larger rings of the new crankset, if that answers your question, molgrips.

In retrospect, I should have understood the difference, but it is too late now.

<span style=”font-size: 0.8rem;”>it’s not too late, you could sell the chainset and refit the original. I think I suggested this on your first thread but it sounds like the solution is new chainrings not a chainset that limits your options and costs you another bottom bracket.</span>

Assuming your frame has a 68mm wide, BSA threaded bottom bracket, then to fit your new cranks you need a BSA30 or BB386 bottom bracket  – PX has the FSA BB386 for £25, plus you’ll need a new BB tool as your current one won’t fit.