Bicycle Mechanics - Replacing shifting cables/wires

Hi guys. I bought a 2010 Trek FX 7.3 from Craigslist. All of the brake and shifting cables/wires have rust on them, so I want to replace them. I think replacing the brake cables will be easy, but I'm worried about replacing the shifting cables.

It looks like the cable is attached inside of the shifters. I'm a complete bike rookie, so I'm afraid that if I open it up, it may be complex, and I might not be able to put it together again. So is there any way to replace a shifting cable without opening up the shifter?

And if not, how would I go about opening and replacing the cable? My shifter is the Shimano EF60, 8-speed trigger. Thanks.

Usually there's a hole in the shifter, sometimes plugged with a fairly large plastic screw. With the shifter in the position with most wire released, push the wire backwards and the end should come out of that hole. No need for major surgery.

Invest in proper cable cutters. :thumb:

Check out the DIY stuff for this at Park Tools. Your online one stop guide to bicycle maintenance.

www.parktool.com/repair (http://www.parktool.com/repair)

^^This^^

and

Zinn books

caunyd: Don't skimp on new cables, use a good quality set of cable wires and housings. Stainless steel is a must and die-drawn inner wires will run much smoother, as will lined housings. Be sure to properly prepare the cable housing ends after cutting (with proper cable cutters); grind or file them flat, use a pointed object to ream open the inner liner and use the appropriate ferrules on the finished ends.
Here's a link to the shifter assembly drawing:
http://techdocs.shimano.com/media/techdocs/content/cycle/EV/bikecomponents/ST/EV-ST-EF60-2A-2744_v1_m56577569830630796.pdf
It looks like you remove 2 screws and pop off the top cover and mechanism is right there. It should be clear how to replace the wire. AS dabac said, you might not even have to open it that far.

I have those same shifter / brakes on one of my bikes. Just remove the cap (careful no to lose those small screws), and push the old shifter cable through. Make sure the shifter is in the lowest (most relaxed) setting...chain on the smallest sprockets. Installation is reverse of removal.

Watch a few youtube videos for tips on installing the cables. There are several tips that make things easier, such as making sure you have the fine-adjustment knobs in the correct position prior to attaching the cables to the brakes/derailleurs.

It's really best to replace the cable housings when replacing the cables. If the old housings are the correct length you can simply cut the new housings to the same length.

Also, keep in mind that the spiral-wound brake housing can (usually) easily be cut with wire cutters. This is not the case with shifter cable housing. Get the proper tool (click for example (http://www.amazon.com/Park-Tool-Professional-Housing-Cutter/dp/B000OZBINY/ref=sr_1_2?s=sporting-goods&ie=UTF8&qid=1317071183&sr=1-2)), or risk damaging the cutting surfaces of your other tools. Also, make sure you have a sharp, pointed object (pick (http://www.amazon.com/Sheffield-Tools-58780-Hook-Piece/dp/B002KHNCSS/ref=sr_1_1?ie=UTF8&qid=1317071275&sr=8-1), awl, finishing nail, etc.) to open up the inner lining of the housing that you just crushed by cutting it.

As others have stated, the newly-cut end of spiral-wound brake housing will have to be filed/ground down to remove the metal bit that usually gets crushed during cutting. Precision use of angle cutters can suffice in a pinch, but it's not recommended. If you have a file or grinding wheel, use it.

Amazon.com usually has decent prices, and free shipping on many of the tools & supplies you'll need.

A cable puller (http://www.amazon.com/Avenir-94-27-403-Third-Hand-Cable-Puller/dp/B00165P4PO/ref=sr_1_3?ie=UTF8&qid=1317071141&sr=8-3) will help out, too.

caunyd: Don't skimp on new cables, use a good quality set of cable wires and housings. Stainless steel is a must and die-drawn inner wires will run much smoother, as will lined housings. Be sure to properly prepare the cable housing ends after cutting (with proper cable cutters); grind or file them flat, use a pointed object to ream open the inner liner and use the appropriate ferrules on the finished ends.
Here's a link to the shifter assembly drawing:
http://techdocs.shimano.com/media/techdocs/content/cycle/EV/bikecomponents/ST/EV-ST-EF60-2A-2744_v1_m56577569830630796.pdf
It looks like you remove 2 screws and pop off the top cover and mechanism is right there. It should be clear how to replace the wire. AS dabac said, you might not even have to open it that far.

A file and awl are cheap and very useful to have in your bike tool box.