Monday, November 10, 2008

A Smoldering Rage (Portions of this rant were previously taped)

Any company that sold a bike with head tube cable stops owes their customers each a new frame if the old one can't be reconfigured to put the stops on the down tube or top tube where they will actually work.

I spent hours last night trying to figure out cable routing on a Serotta Legend Ti that wouldn't destroy the cable housing within weeks. The longer I worked the options with no success, the more I hated whoever came up with the idea in the first place and whoever else thought it was good enough to slap on several model years' worth of what would have been decent bikes. The idiocy was industry-wide. Stupid, stupid, stupid idea. It cured the problem of cable chafe on the head tube at the cost of far greater functional problems with the shifting and steering systems.

The black bike defied my efforts to get a good picture of the setup in its mangled condition as I started the repair.

In this case, the problem is aggravated because the rider is a triathlete using aero bars with bar-end shifters. The pricey carbon aero extensions are drilled for internal cable routing. The stiff housing index shifting requires has to make two radical bends to get from the exit hole in the bar to the stop on the head tube.

The original housing, CD 4 mm, had broken through the alloy ferrule in the head tube stop. Incidentally, the ferrule was corroded into the cable stop because of the constant bath of salty sweat that poured onto it as the rider used an indoor trainer. The housing had twisted itself up into a strange curl under the wide wing section of the bar.

I had to drill the remains of the alloy 4mm ferrules out of the cable stops so I could install brass 5 mm. I still haven't solved the routing riddle. One option would be to remove the threaded stops and take the housing through the part welded to the frame, but that would look even more cluttered on the sleek road frame than the rat's nest of curled brake and shift housings at the head tube already does.

Trying to overcome gratuitously stupid design drives me INSANE. It's even worse when I'm trying to fit this repair in with a wad of other important stuff, for a rider who has trusted me numerous times with her race prep. So far, I've managed to come through every time. This is her last big race of the year, and it's in Arizona or something, so the stakes are high.

Like all tri bikes, it's crusted with sticky and salty deposits from the energy drink and perspiration that get poured over it day after day. The crust on the rear brake has actually hardened into rock candy. If she runs short of energy out in the desert, she can hop off and lick the brake for a while.

Speaking of sticky, this $5,000-plus marvel also had another of my nemeses, sticky-back cork bar wrap.

There is absolutely no reason to have aggressive adhesive on the back of your bar wrap. It just makes repositioning or reusing tape impossible and makes it more difficult to remove old tape to put on new. Unless you're some kind of twine-wrapping shellac-slapper, you WILL re-tape your bars. Just to change this rider's cable housing I will have to replace the little sections of cork wrap on the aero extensions because the sticky backing shredded what would have been reusable tape. I know this is just a nuisance, but it does add the cost and time of wrapping bars to a lot of repairs where it would not have been directly relevant.

Suppliers should say in the product description whether a model of wrap has adhesive backing.

5 comments:

getinlost said...

Golly, that's a shame, that on such a fine frame an engineer vomited stupid on it. Is there any chance of abandoning the existing stops and installing old school clamp-ons? I also am against sticky back cork.

Ron said...

Great post. I'm sure setups such as these provide routing challenges in the confines of many bike shops. This brought up another thought in my head. While electronic shifting may only be within the reach of rich boys and girls, think about the all these cable stops and other routing annoyances they'll eliminate. Now you'll probably just have to figure out how to bundle some wires together into a manifold.

cafiend said...

I thought about a clamp-on stop. No one makes a really sexy one anymore. I don't know if I could find an old one in the somewhat large diameter of this down tube. Running the cable housing THROUGH the welded-on parts of the existing stops would eliminate movement at the head tube and gain a couple of degrees of motion. It would move the torque of that movement away from the stress riser of the ferrule. Sawing off the welded part would be tough and ugly.

Electronic shifting would mean just flexible wires heading back on the frame, but requires an electrical system with its additional needs and vulnerabilities.

How about a really gnarly single-speed triathlon league?

Anonymous said...

I have to be devils advocate here and ask a couple of questions.

Was the problem the stops, or was it that the owner did not properly care for their bike? I understand you sweat, but can you clean it?

Also, was the problem due in part, or wholly, to the fact that you were using aerobars on the bike? Just curious.

cafiend said...

Anonymous, you're coming with me. Grab your things and bring your comment to a new post.