riding the 5 miles back from work was bad enough, I don't enjoy cycling in this heat... it's better than walking though, which I had to do for the last half mile probably after getting a puncture... second in two weeks after two years of none, didn't find any reason last time so now I'm suspecting the wheel has an issue... also got a broken spoke on the front wheel so in for a service in a week. Possibly the wheels, which are the ones which came with the bike, need replacing, it's been three and a half years and they are bontrager wheels so idk, I'd think they'd last longer than that, I don't do huge numbers of miles, 50 miles/week commuting and maybe 10-20 visiting friends/going out/whatever. We'll see what they say at the service.