Your contract is with the retailer not the manufacturer and your rights under the sale of goods act are ( roughly summed up) that in a case like this it should be replaced.
There should be no unreasonable delay in replacing it. I'd give them 2 wks to have the replacement delivered or return your money. ( thats my opinion NOT the law) Repair / replace / refund - its the buyers choice.
http://www.berr.gov.uk/whatwedo/consumers/fact-sheets/page38311.html
So have a read of the link. decide what fits your case. Go to the shop and tell them ( not ask) for the remedy you want. If they don't comply then go to the small claims court in the end.
having said all that I have never heard of cannondale not replacing in these circumstances.
edit - from the above link
remember any remedy has to be carried out "without significant inconvenience" and within a "reasonable time" for the consumer.