On Fri, 12 Apr 2019 11:15:53 -0400, Frank Krygowski
wrote:
On 4/12/2019 10:27 AM, db wrote:
My son is set on getting a belt drive for the bike he is building.
What is good about them? You have to have the exact length for your
bike, and if it breaks, it is very expensive to replace.

So, why?

Why? Same fundamental reason as 1x drive trains, disc brakes, daytime
lights, etc. etc. It's trendy, man! And fashion is weird,
unpredictable and powerful.

IMO, belts might make more sense than the fashion items I listed,
primarily because I think the chain and its maintenance are the
ugliest mechanical issues in bicycling. A super clean drive train
(even cleaner than my wax-lubed chain) would be nice.

But for me, it's not worth the cost of its detriments.

Yep, service life and maintenance are the key attractions. For
commuting bikes, not having an oily chain keeps your trousers cleaner.
OTOH, not as efficient as a chain drive and not usable with derailleurs.
The loss of efficiency of a hub gear compared to derailleur systems is
additive, so we won't see pro bike racers on belt-drive Rollhofs anytime
soon.