I've built a lot of bicycle wheels--something like 14,000 and counting. That's my job and has been for more than a decade.
In the course of that decade I've noticed a trend, or pattern if you will: Heavier riders (aka "Clydesdales") need dependable wheels, but rarely seem to have the $ to spend on them.
It took me a few years to understand why. And I know this doesn't apply to everyone (what one theory does?!) but it seems to fit ~75 or 80% of the clyde scenarios I've seen.
Generally speaking, it works like this:
John (not his real name) either realizes or is told by his wife, doctor, boss, kids, BFF, etc... that he needs to lose some weight. He agrees, and eventually determines that riding bikes is the best way to shed pounds without beating the crap out of his joints. So far so good.
So John buys a cheap bike. After all, he's not a serious mountain biker, so he doesn't need to spend a buncha money just to spin down the bike path or around the neighborhood with his kids.
But then John discovers two things:
1. He likes riding, a lot.
2. He's actually losing weight.
So he rides more, and more. But because he spent so little to begin with, his cheap bike starts to fail. Some of the failures are because John is new to riding, not very smooth, and has a lot of mass to put into the pedals. Chains break, pedal spindles bend, rims get dented, seat rails crumple, freehubs fail, sometimes wheels taco and whole frames crack.
Now John is bummed, because his 'fix' is now broken. He wants to ride but can't until he spends more money. This is usually where I first meet 'John', because he'll send me an email asking for hub or wheel advice. And almost invariably John will say something along the lines of "I don't want to spend more than ~$300 on a wheelset, because the whole bike was only $500".
$300 doesn't buy much for wheels even if you're only ~145#. $300 for a clyde wheelset is basically throwing away money--money that will then have to be spent again in order to get a durable, long lasting wheelset.
So my advice to John is usually some variant on "In order to get you something that will last, and that is serviceable, you need to spend a lot more than $300". Sometimes John 'gets it' and we discuss options, other times he throws up his hands and I never hear back from him.
Moral of the story is that most bikes, especially cheap ones, were neither designed nor intended for true clydes. But that doesn't mean clydes can't happily and aggressively ride bikes all the live-long day--it simply means that they need to choose their bikes and parts wisely. To that end, doing it right instead of doing it twice is less expensive in the long run.