I've taken passengers on the back in all shapes and sizes, never had any problems though.
The front mudguard extender is a great add on for little money, it dramatically cuts down the shite aimed at your downpipes, especially if you ride during the cold season when there's plenty of salt about.
Depending on where the bike's been stored the brakes may well need a service, the calipers can seize up if not used often or maintained, and they work much much better when functioning correctly and freely.
Over time you can learn how to clean up the brakes yourself, it can be time consuming but once done the results are very satisfying and the more times you service them the easier it will become.
These brakes are VERY good when working right, so don't go grabbing a handful in a panic.
Same again, depending where it's been stored i'd check the chain for any tight spots, and maybe give it a good scrub up and lube.
Put the bike on the centre stand and look at the lower part of the chain and see if there's any links that aren't totally horizontal.
Even if you can't quite spot them a seized chain link will give a knocking feeling on the left foot peg.
It's probably okay, but worth noting.
Other than than, good luck with the test, and take things easy to begin with.
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