Wilfred Kazoks wrote:
> Just on a slightly tangential issue. Wouldn't it be better to stop the grit
> getting onto the chain in the first place.
I'm sure that it would. Industrial chain drives are normally fully
enclosed and run in clean conditions. They last (almost) infinitely
longer than bike chains or motorcycle chains. Likewise, things like
timing chains on motor vehicle engines last 100,000 miles or more in
their clean environment, even though they carry far more power than a
bike chain.
I've read many times that utility motorcycles and bicycles with
completely enclosed chains require no chain attention at all.
Of course, using a complete chain enclosure wouldn't be suitably
sporty! ;-)
>
> I was thinking about this the other day. I have a bike with metal mudguards
> front and rear. Occasionally i notice a pebble rattling up the front guard
> and getting thrown out the front. It made me think that whatever smaller
> grit that doesn't go out the front must get thrown off below the lower end
> and the chain is the first thing in line to collect it.
>
> Maybe I'll attach a flap on the front guard and test the theory with some
> double sided tape. See how much grit I can collect in a week.
>
> I can't really see where else the grit can come from the rear wheel has a
> fairly close fitting full length guard, but some could come from the rear
> wheel I suppose.
I usually run fenders on my bikes, even my now-little-used mountain
bike.
But many years ago, I went mountain biking at an old abandoned quarry
and coal mining site. Lots of death-defying climbs and drops on the
piles of tailings, etc. I had fenders on the mountain bike that day,
too, because it's a very dirty place.
After a couple hours of riding, I had to stop and scrape black dust out
of my rear cogs. It actually filled the cogs to the point where the
chain wouldn't mesh with them. Apparently, the dust and dirt in the
area was dropping off the underside of my rear fender, landing on the
rear cogs, and packing in there.
That was an extreme situation, of course. But I think it illustrates
that the front wheel isn't the only grit-slinger.
Still, I'm convinced fenders help chain life.
- Frank Krygowski