Can I sell my ride2work bike?

All the above is correct, esp Rowhan's comments. The legal position is that you never own the bike until the company signs it over to you for either a nominal or otherwise amount. See if anyone else at your work has experience with the scheme and what they did at the end of repayment before you try and hustle them or else you may get stung by them and/or HMRC.

Dan is on the money.

HMRC are alive to many tweaks to the bike scheme which they regard as unacceptable, and are more than willing to come down hard on those involved.

Both you and your employer will be in for, at the very least, some uncomfortable questions if they get to hear about it, or the precise management of the scheme is reviewed at a PAYE Compliance Check, which is sure to be the case.