Bicycle Mechanics - upgrading friction shifter to index

I have an old Raleigh Capri, 12 speed

I've been doing fair amount of cycling lately (~120 miles/week)
My biggest problem is shifting and I would like to upgrade it with index shifters.

I read about the frame so I know it is not worth spending a lot on this steel frame (for the record, it is very stiff and not very comfortable) but I cannot afford buying a new bike so a relatively cheaper upgrade would be fine for the moment.

The six-cog cassette on the back reads "SR6" and the rear dérailleur reads "Shimano SIS". I am assuming the dérailleur is compatible with index shifting. Is that the case? Is the cassette also compatible? What other components should I buy? How much do I need to spend? More importantly, is it worth the effort?

Thanks

All you need is the downtube shifter. Get a 6 speed one used on ebay. I'm sure you can find them for under $20. Everything else will work fine with this.

SIS = Shimano Index System or something like that.. but that is all marketing crap. You can use pretty much any shimano rear derailleur for however manynumber of cogs are on your cassette. It is all dependent on the shifter really. Well and the chain/cassette..but i think you already have that covered.

oh.. is your capri stem mounted shifters.. if so..
http://cgi.ebay.com/Shimano-SIS-6-Speed-Stem-Shifters-NOS_W0QQitemZ190325472688QQcmdZViewItemQQptZCycling_Parts_Accessories?hash=item2c50483db0&_trksid=p3286.c0.m14

if they are downtube....
http://cgi.ebay.com/Shimano-105-6-speed-shifters-shift-levers-SL-1050_W0QQitemZ260454331515QQcmdZViewItemQQptZCycling_Parts_Accessories?hash=item3ca449b47b&_trksid=p3286.c0.m14

Make sure your shifters are not already indexed and set to friction, (don't ask why I thought of that)
Bud

Make sure your shifters are not already indexed and set to friction, (don't ask why I thought of that)
Bud

I was thinking the same thing. Unless someone added the RD after the fact, the shifters would have probably been indexed.

More importantly, is it worth the effort?

Thanks

Honestly, no. Run what you've got and buy a new road bike when you are ready.

Learning to use friction shifters properly takes a little bit of work, but once you "get it", they are not noticeably any different than the indexed jobs. You'll quickly learn to "feel" the gears engage fully; and you have the advantage of being able to "trim" them slightly when needed; something you can't do with the clickers....

Hang in there with the friction shifters. I just got into cycling 2 months ago and drug out my old 1973 Raleigh Super Course 10 speed with friction shifters. I hadn't been on it in close to 30 years, and I've put just over 700 miles on it in two months. I love the mechanics of shifting manually, and there's nothing like nailing a shift with these old bikes. I don't look at the DT or anything. Just drop my hand down and shift. :D I'd never heard of a "double shift" until reading about it here on BF. Did it for the first time the other day. Woo Hoo!! 8th gear to 4th gear in one move. Sweet. :D it doesn't take many shifts to learn how far to move the shifter for each gear to get it centered on the first try.....

Probably not worth it. Index shifting is just a fad ;)

Just ebay 6 speed downtube indexed shifters. Don't bother with upgrading anything else. Waste of ****ing time.

Bluenote157,
It has stem-mounted shifters. Thanks for the links.

Bikewer,
It is funny, every time I try to shift I stop pedaling, so trimming costs me speed (imagine doing it uphill :)
Actually, what do you mean by trimming? Is it necessary with index shifting at all that we can only do it with friction shifters? In other words, is it an advantage of friction shifters?

The reason I wanted to upgrade is that I can only use the middle 3 cogs. The outermost ones caused the chain derailed in the past, now I cannot even shift to those. My instinct tells me the problem is the cable, any thoughts?

Bud and Little Darwin,
How can I understand if they are already indexed or not?

Thanks everyone for the responses

Bluenote157,
It has stem-mounted shifters. Thanks for the links.

Bikewer,
It is funny, every time I try to shift I stop pedaling, so trimming costs me speed (imagine doing it uphill :)
Actually, what do you mean by trimming? Is it necessary with index shifting at all that we can only do it with friction shifters? In other words, is it an advantage of friction shifters?

The reason I wanted to upgrade is that I can only use the middle 3 cogs. The outermost ones caused the chain derailed in the past, now I cannot even shift to those. My instinct tells me the problem is the cable, any thoughts?

Bud and Little Darwin,
How can I understand if they are already indexed or not?

Thanks everyone for the responses

you need to set your h/l screws so that the derailleur can't go past the lowest and the highest gear and end up in the spokes/axel. If your cable isn't completely rusted/etc, you might need an adjustment. Have a look at parktool.com in the repair section to get you started. Once you take care of those things, maybe you can tool around town with those. If your really hate it, you can get those shifters from ebay??

Bluenote157,
It has stem-mounted shifters. Thanks for the links.
Bud and Little Darwin,
How can I understand if they are already indexed or not?

Thanks everyone for the responses

The cap with the little ring on it ,that holds the levers on, has a mark(diamond shaped), that points to
"SIS" on the ring that goes around the outside. When its lined up with "SIS", its indexing, and should click,
when you move the lever...When it not lined up with "SIS", it does not click and is friction.. You turn the cap so it lines up where you want it by using the ring thing that hangs from the cap..If no "SIS", its just friction..
Bud

Trimming.... Often, when shifting the rear DR, you'll get a little chain rub on the front cage. With friction shifters, it's easy to just tweak the lever a little bit and get the proper clearance without actually shifting.
With indexed shifters, no such choice.