So, an issue came to my attention. At some point bike top speeds had gotten wonky. We fixed the issue, which was that when a new engine was installed the top speed wasn't passed along. This was resulting in basically no change when a better or worse engine was added/removed.
We have fixed the code and I wrote a quick patch that updated all the bike top speeds that were incorrect. For some of you this means your bike has gotten a bit slower. Sorry, that sucks. Buy a better engine (or tires!) ;)
For more of you, this means your bikes have gotten a bit faster. Cool, try not to die!
If you encounter any issues, please let us know.