Kimmo 

Just scored my RED Black brifters (slight scarring; won em for $212.50) in the post, and they reward inspection


SRAM have some really clever engineers; DoubleTaps are a spectacular bit of packaging. Mind you, they copied a lot of the basic layout from Campy.

Forgot to mention a few points:

The brake lever pivot pin just punches out like a Campy one (no messing with a potentially seized 2mm allen grub screw), and has no loose bits that can get lost, unlike Shimano's pivot spring and bushes and cable anchor parts. So very neat.

The grooveless barrel will show up any wear, which if it happens (doubtful) will affect the accuracy of the shifter. With a grooved barrel such wear would be invisible (if it's indeed an issue). And the lower stress concentration has allowed SRAM to use plastic for these parts on the RED shifters.

More importantly, the larger diameter of SRAM's cable barrels should reduce or eliminate cables fraying inside the shifter, something that has led to the butchery of many an STI.

It's worth repeating that the greater cable pull employed by SRAM's rear derailer increases the signal to noise ratio of the cable system, meaning vastly more reliable indexing. And also much finer adjustment as a bonus, so you'll never find yourself a click out of place by mistake.

Maintenance-wise, pretty much all the ancillary mechanism (all the pivots and stuff) looks as if it could be happy to be ignored its entire life, with only the part where the magic happens (the interface between the arc of ratchet and the two pawls, and their interface between each other) requiring very occasional attention.

I'm inclined to stick my neck out and say the grease they're lubed with probably isn't the best thing; it just seems to get pushed out of the way. I'd recommend a couple of drops of heavy gear oil every 3000km or so. Otherwise the sliding friction these parts experience could eventually create enough wear to screw the pooch... there seems to be a bit of tolerance for wear there, but not a great deal.

A couple of bummers:

The inner brake pivot boss is slightly vulnerable to breaking in a crash, effectively junking the whole lever I suspect, but then this is a weakness on any brifter with a paddle behind a fixed brake lever, another point for Shimano.

And having disassembled the lever to the state you see in the vid, it isn't obvious how to continue. The shift pivot pin is retained by a little plastic-thread countersunk phillips screw just like the three retaining the cover plate - it goes in from the outer side and simply pokes through behind it. But as to how to remove this pin, that's mysterious. Can't seem to find anything online that goes further than removing the cover, either... but if there's a simple trick for that, then the rest seems pretty straightforward. STIs and Ergos often require lots of persistence to reassemble, but DoubleTap looks like it could go back together quite easily, with a bit of luck.

Can't wait for my Yaw FD to rock up

chriskmurray

I love the feel of double tap levers, from the shape of the hoods to the shifting action. The only real weak point I have seen is the shift lever has a tendency to break off entirely. Well, at least it did. I have not seen it happen for a while but I did see a number of the earlier models have that problem, it happened to one of my personal shifters as well.

Kimmo 

The ergonomics are just superb, aren't they.

So you're referring to RED levers? Where exactly do they break? Is it the carbon flipper, or the little cast frame it attaches to?

I'm guessing the latter...

Kimmo 

Couple more things, I got the Yaw FD today and it's a marvel. The quality of design here is making me a big SRAM fan...

And I figured out the trick to full disassembly of the DoubleTaps. It's so easy to get these apart and back together that I'd do it just to demonstrate; I'll see about shooting a vid with a proper camera before I put them on the bike.

In the meantime, here's the basic rundown:

The first part that needs to be removed once the cover and brake lever are removed (as mentioned in the vid, the brake pivot pin just punches out), is the removable pawl. With the flipper held all the way in, the end of the pin and its circlip is exposed; carefully prise off the circlip with a jeweller's flat screwdriver (with your finger on the clip to prevent it flying), and you should be able to remove it by pressing on it so it sticks to your fingertip. Out comes the pin, the pawl and its spring.

With the brake lever out of the way, the front end of the shift pivot pin is kind of exposed; once the screw behind the pin is backed out you can push the pin back with a flat screwdriver (there's a bit of a shroud occluding the end of the pin with a slot in it)... then you need like a 2mm allen key or something to poke the pin a little further in - you'll feel the mechanism shift as the end of the pin comes free from the housing, at which point you can grab the back of the pin with some pliers.

And that's it. The handful of parts now all come out, and if you missed how they go back together it's hardly worth looking at the other lever; it's a cinch.

I figured out the tricks to reassembly in a few minutes. They are as follows:

The cable drum, ratchet and clock spring (what I usually call a counterspring, but it goes the other way on SRAM; only the ratchet counters the derailer's spring) are a single assembly. You only need to wind up the spring a little to get the assembly in; locate the tail of the spring and rotate the drum until it pops into place. The spot for the cable end is your reference. Slide the pivot pin through the drum/ratchet assembly, but not out its end.

The next bit is the flipper assembly with its attached pawl, and it has a loose spring with a plastic bush inside. Leave the spring and bush out of it until you've manoeuvred the flipper into place... this can seem a bit tricky at first because of the forward projection off the ratchet but once you figure it out, it's easy. Hard to describe though - wiggle it. Once past the projection it should fall into place.

The spring is a bit of a fiddle. The long end pokes down through the cage of the flipper bracket, and you just need to push it down into place as you push the pivot pin forwards through the plastic bush. It doesn't take much force, but the bush or spring can get snagged on the cage, it might take a little patience. Once you're into the bush, you just need to put a thumb over the mechanism and move it around a bit as you push on the back of the pivot pin, and thanks to its chamfered ends, it pops into its location pretty easily. Push it all the way home and remember to do up the little screw that holds it in.

The second pawl is the final piece of the puzzle. This one can seem like a right bastard, but again, I suspect it's easy once you know how (I'm interested to see if I can do it quick the second time). At first I was thinking about the spring, and trying to get it oriented properly because I assumed it needed to be wound up some, and I was getting nowhere for a bit until I realised getting the pawl to engage with the other pawl was the main thing. I just pushed the flipper a bit to lift up the other pawl, and jiggled it a bit and it popped right into place, the spring wasn't a problem. Sliding the pin into place is pretty simple (maybe you need to wiggle the pawl around a bit), and then you need to hold the flipper up out of the way while you replace the pin's circlip. You either need to be quite steady and deliberate here, or get someone to hold the flipper for you, or rig something up, because the risk of losing the circlip spikes right here... years of experience have led me to plan every move when attempting delicate work with not enough hands and springs to hold at bay. Nestle the circlip into its slot and use something pointy to align it around the shaft at a good angle to come at it with some longnose pliers. Done.

Once again, these are such an impressive bit of design. I counted a mere ~48 individual components, for the entire DoubleTap assembly.

I like that a lot. It's how I'd do it; save money on manufacturing in the long run by trucking the stuff on pallets to the guys who design the gear.

This kit has been CADed to the hilt; it has FEA written all over it. I bet there were a zillion iterations...

Wow, I just thought of something: if SRAM was to offer spare pawls and ratchets, it would probably actually make economic sense to have your LBS service worn DoubleTaps. Imagine that.

RubeRad

I'm quite impressed by the concept of the Yaw FD. It seems as fundamental a design idea as the slant-parallelogram RD, I'm surprised it hasn't come along sooner. I've been thinking maybe the ideal drivetrain would be a touring triple up front, corncob in the rear, touring/mtn RD to take up the big tooth difference of the triple, and a Yaw FD. The triple up front and corncob in the rear would be to minimize gear ratio overlap between the chainrings, and the Yaw FD would allow best use of all cogs from all chainrings.