Monkey_SDMF

one tooth extra on the front sprocket should raise theoretical top speed by about 7mph, making the bike rev less for the same cruising speed on the motorway but sacrificing some acceleration.

one tooth extra on the rear sprocket should lower the theoretical top speed by about 3mph, making the bike rev more for the same cruising speed.

I would probably do what you have done and only add one tooth to the front sprocket, but push the rear wheel right forward so that the chain will fit given the extra tooth. If the chain will not fit then go for one less tooth on the rear sprocket. This will raise the gearing further still, but you should then be able to use the original chain without any worries. The only thing to worry about is how well the engine will pull if you increase the gearing this much.

I plan on doing this when the chain is replaced this winter. Let me know how you get on.