Originally Posted by
tgzzzz
Is the big difference in ET mostly due to the weight differential, Swift to modded-but-still-heavy R20, or would you credit the efficiency of the Swift, i.e. the upgraded wheels & hubs/narrow tires, less drag of the derailler compared to the SA8 hub, maybe more aero positioning, ...?
I don't think there is one single thing that makes all the difference. The much lighter weight would be a big thing, accelerating all that extra mass on the R20 tends to tire me and I have therefore less energy left over. But the other items, ie no suspension soaking up some energy, thinner tyres so more aero (this is true of the whole frame, really, especially the forks), and drivetrain efficiency all play their part. Another item where derailers shine is in being able to shift under load - you can just keep pedalling with just a small momentary easing off, whereas with the SA hub you need to stop pedalling for a moment.
Originally Posted by tgzzzz;
On the hub immersion deal, I'm dissapointed to read of rust after one incident when we know your "new" hub was full of oil. The old 3 speeds were indestructable in comparison.
Well perhaps it is not reasonable to expect labyrinth seals to keep water out under those severe conditions. I was disappointed too. Hopefully the silicone grease will tend to mix less with water and not form an emulsion which will cause rust.
Originally Posted by tgzzzz;
When I had the LBS install my sealed BB, she made a big point (too big I thought at the time) about NOT washing the bike. I thought she meant because of the BB, but what's the big deal if it's sealed? Now I wonder if she was warning me about the poor sealing of the SA8 hub. I live at the beach. Rinsing things is a way of life. I don't ride my new DT on the beach, however. It's too cool. And I have my passed-over hybrid for that.
I wash my bikes but take care not to direct a hard water spray near the bearings area. In fact I usually use a bucket with sudsy water and a paint brush, and use a compressor to blow it dry, again not directing an air jet at the bearing seals.