[quote author=SafetyThird link=topic=13858.msg103115#msg103115
I'd not heard of the chain glider so I'm doing a little research, it does sound like a very good idea, does it cause much friction given that it rests on the chain?
[/quote]
I was very sceptical until I got one. There must be some friction, but on my initial test rides it wasn't enough to notice, although the set up I used for the tests (1/8" chain, rather thick TA 1/8" chainring, 1/8" sprocket) was suboptimal for Chainglider use.
I now have Chaingliders on all the family bikes where it is possible to fit one (6 bikes).
Downsides as I see it:
- friction, not really perceptible in my case.
- some rubbing noise, not noticeable if the thing is properly adjusted.
- some extra weight. I'm not racing, so I don't care.
- only fits some specific chainring/sprocket combinations.
- will not fit on some frames, interference between Chainglider and seat stay.
- some chainrings are too thick and will rub, perhaps causing noticeable friction.
Advantages as I see it:
- keeps the chain much cleaner for much longer.
- as a result, significantly reduces time spent on maintenance.
- another result, significantly increases chainring, chain and sprocket life.
- prevents clothing from picking up chain oil. I don't care much, but my wife appreciates it. Also useful on my visitor bikes.
For fixing punctures I consider it neutral. I have to dismantle the rear part of the Chainglider, but leaving the front part on I find it organises the chain and makes it easier to deal with (less likely to fall off the chainring and dangle in the dirt).
It isn't a total answer, as it isn't completely sealed, so with intensive winter use on muddy tracks some water/mud will eventually get in.
A reasonably fair comparaison is between my current two visitor bikes, both with Nexus 8 Premium hubs and very similar chainrings/sprockets, these two bikes generally get a similar amount of use. One has a Chainglider, and has gone for more than a year without transmission maintenance, the other has vertical dropouts and a chain tensioner and has needed chainring, chain, sprocket and tensioner maintenance 4 times during the same period.
Optimal setup for a Chainglider is with a thin 3/32" chainring, I recommend the Surly stainless-steel reversible chainrings, ideally combined with a 3/32" chain designed for single-speed/hub gear use, although standard 8-speed derailleur chains also work, and a 3/32" sprocket.
Starting out with a new chain gives better results, with the SRAM or KMC chains I have used the factory lube lasts for several thousand kms in ordinary use (all weather commuting, utility riding, on-road touring).