STI Shifter
repair
The rear derailleur cable adjustment screw backed out to far and the thread were smashed on the male and female parts. The threads are 5.8 metric. I bought a 40 piece metric tap and die set from Harbor Freight for 14 dollars and cleaned the thread on both parts. I will be careful to watch the cable adjustment in the future.
A field repair to keep you going until you can get to a shop
Several responded on the rec.bicycles.tech news group have suggested flushing the shifter with WD-40. Other's suggest spraying "ProLine's Super Lubricant" into the shifter. If that doesn't work, try my method below;
Rubber Band field repair for Small lever not indexing on a Shamino Ultegra STI shifter
Shimano warranty this unit for two years, however, my unit was replaced and it was more than two years old. Contact Shimano via their webpage or at this phone number 949 951 5003 X 2900.
A more serious repair, could get you a few more thousand miles of riding without needing a complete replacement unit.
The spring could be made on a lathe or a spring winding machine. It is made
from square spring wire and is call a Torsion
Springs
However the setup time to manufacture a small number is prohibitive. I have email a few spring manufacturers for a quote on buying a small quantity but I haven't received any replies. The customer service people at Shimano wasn't able to direct me to a source either.
An example of a source http://www.centuryspring.com/Century/GateWayServlet However, one need to know all of the engineering specifications for the spring to order.
(To make only one on my lathe, Once I was able to acquire the square spring wire of the correct size, I would set the lathe up as I was chasing threads with a single point tool, the size of the mandrel would be determined by trial.)
The spring above is located behind Lever A, long lever. To replace the spring, not on the part list, or modify the lever so that the same spring will gives more tension. Not a job for anyone mechanical challenged. However, the only challenging is replacing the spring. The order of removal is also important in order to reassemble the unit correctly. Washers are used for spacing shims, each must be replace to the place that it was removed.
Pry cover from top, remove Philip head screw, #3. Turn unit around and remove Philip head screw holding level A and level B together. Note position of two washers before completely removing the screw. Return to front and remove 8mm nut. There is one washer and the spring. If the spring is only weak, a new leg hole can be drilled in lever A. The present hole is about 6:30 on a clock face. I suggest about 7:30 for a new hole. Check that all mating parts are smooth and burr free and not bent from a fall.
After drilling the new hole reassemble the unit part way, with the clamp holding the spring in place, leaving the 8mm nut loose, remove the clamp. slide the loop turners between the two levers and around the tail of the spring and pull it back to the new hole. Remove the loop turner and secure the 8mm nut. Replace the two Philips head screws and the cover.
Thanks to Sig of Chicago, on the rec.crafts.metalworking news group for the suggestion to use a Loop turner as a tool to use to reattach the spring.
There are other parts that may have worn or bent to cause level A not to return to the resting position, so this is not a complete rebuilding of the STI, But if you are not ready to put out a hundred dollars plus .for a replacement, this could be is your answer.
A friend replaced his shifter prior to long trip because the old one would miss shift sometimes. I practiced on this unit, I disassemble the unit and drilled a new hole to give the return spring more tension.
I have the part list from the Europe site but it only lists replacement parts outside the index unit.
Picture of the "Loop Turner" from a sewing shop and clamp I made to hold spring in place. The clamp is made from a hacksaw blade, bent as a open box, to hold the spring while assembling the unit.
The loop turner is sold as one piece, mines broke by accident.
Service instruction and part list For STI Shifter Shimano Europe site.
Exploded View and part list for ST 6510
http://www.thethirdhand.com/index.cgi?c=Shifter&sc=Shimano%20STI%20Road&id=87295127338
8 speed
Shimano shifters are available at the above webpage.
http://www.chainreactionbicycles.com/noisystilevers.htm
How to stop a noisy shifter and poor shifter.
http://groups.google.com/groups?dq=&hl=en&lr=&ie=UTF-8&th=9cc2823bae82c38f
|
Subject:
Re: Ultegra Shifters
Newsgroups:
rec.bicycles.tech |
Kristin->Are the Ultegra Shifters still riddled with problems or have they
since
>been fixed?