Wednesday, July 07, 2010

Hidden Killer of STI Shifters

Sorry I don't have pictures, but time is tight and it's hard to photograph the way this problem works.

When your shifting gets mildly erratic with STI road shifters, the problem is often bad housing. The inner wires push through the ferrules so that the housing does not provide consistent resistance to the cable moving through it. However, a more sinister problem can have expensive consequences. If you examine your housig and DON'T see collapsing ferrules on the ends, look at the shift cable itself inside the shifter. It can fray in there, causing gradually increasing drag. It gets expensive when the cable degrades enough to spit broken fragments into the shifter itself. These can jam inside the inaccessible mechanism badly enough to ruin the shifter in some cases.

If you find a frayed cable, don't panic. Click the shifter to the highest gear position for the rear or lowest gear position for the front. Undo the anchor bolt at the derailleur. Push the cable just far enough for you to decapitate it with cable cutters. Pull the end out. Then, without pushing the shift levers at all, use a small magnet to pull out any leftover bits of wire.


Steve A said...

So, should reading all this stuff on Shimano reinforce my affection for SRAM or does it have as many warts, but in different places?

cafiend said...

In the early years of SRAM's rise I was convinced that they were a dummy company started by Shimano to make Rapidfire look better. SRAM stood for Shimano Rules the American Market. My affection for SRAM did not increase when they bought and ruined Sachs. They seem to have a trickier-than-thou attitude when it comes to engineering and are as bad or worse than Shi-no when it comes to playing well with others. Their chains (hijacked from Sachs, who inherited them from saintly Sedis)are versatile, but I recently started looking at KMC and Connex. I believe the Connex 10-speed is the only one with a re-usable connecting link.

I dislike brifters in general. Campy's are the most serviceable, but you need to have the parts and the time to service them. Also, Campy's aesthetically beautiful cable routing under the tape is a GIGANTIC pain in the ass when you need to change housing, or even check housing to see if it NEEDS to be changed. I have that issue on the work stand today. AARRGH!

By the end of a sweaty and frustrating day I'm all too happy to get on my friction-shifting 8-speed and toddle home to a shower and a stiff drink.

Steve A said...

Perhaps you need to pick up a "Grumpy" shirt at Disneyworld. You forgot to mention that SRAM routes it's cables under the tape as well. I admit it has improved my ability to reuse bar tape.