Claus butler criterion to ?

mr-tino

Hi guys Ive had my criterion for a year now and its time to upgrade. I honestly think these are poorley built as I always get a puncture.. I'm looking to start riding twice a week now with 30-50miles per ride. Hopefully at some point next year my dad has a crazy idea of doing the lands end to jog so I'll be dong that too...a lot of training needed I know. If anyone has done that I'm all ears for advice....I regress....would a 20gear bike be much as f a upgrade or should I be looking for more.....I have 600 to spend on a 2nd hand bike....been looking at the Boardman but don't want to rush into buying the wrong bike