I like the chainguide. Did you notice any drag when riding?
Not while riding, no. I'm sure that if I did back to back tests, one after the other, I would be able to notice a difference, but when you take the bike out in the morning to work it's not something that is readily apparent.
However on the workstand it feels like a BB with stiff bearings - the cranks won't free spin very far. Also in the workstand, you can hear the chaincase gliding on the chain as it goes around. It's an ugly sound, but it is drowned out by tyre noise when you're actually riding. (I was skeptical at first, given how loud and nasty the gliding noise was.. but it works!)
You have to make sure the chainline is dead on perfect, and there's a limit to how wide the chain can be (the super wide BMX chains are too much). Get either of these wrong and it makes a real racket.
They are designed for 440-480mm chainstays; my bike was 425 or so, and had to take to the ends with a knife. There's normally a series of tabs locking the parts together; since I cut those off, I had to put bulldog clips over one end so prevent them from shimmying around with the chain too much.
Don't try to ride them on a gravel or dirt path in the wet though.. the watery gritty sludge does get into the chaincase somehow, and the grit paste, now trapped inside the chaincase, will cause really bad scraping noises and pulverise the chain into submission.
Looking for a 700c/29er tyre option... I'm heavy and currently commute on a 26 x 1.6 Continental. But they don't offer much in a really wide 700c or 29er slick/commuter/touring specialist tyre.
I've had the Schwalbe Marathon Plus recomended to me in a 700 x 45 or 50 wide. And there is also the option of the 29 x 2.2 Big Apple... anyone have any feedback on any of these?
A shame Conti don't make a 29er version of their Sport Contact slick, eh.. I use the same 26x1.6 tyres on my commuter. In fact the derailleur based commuter has a frame designed for 700c, but use 26"ers for better wide tyre options - comfort foremost (I'm heavy too), as well as a more secure feel on gravel and dust trails in the wet. The lower BB height from having 26" on a frame designed for 700c was nice around the city too (stopping at traffic lights etc.) Just no MotoGP style cornering, with those pedals hanging so low!
There are some "Extralight" versions of the 700x42 Continental Contact that weigh about the same as Sport Contact 26x1.6ers.. heard a lot of good about Schwalbe trekking tyres too.
Building commuter bikes with parts that were never meant to be put together is fun.