Shifter/Derailleur Compatibility

[Hoy]

After a long time not owning a bike I picked up an old mid 90s 21 speed Mongoose Switchback for mostly fitness/paved trail riding. The bike is in pretty good shape considering its age but there are a few things I'd like to upgrade to get some experience working on bicycles. I do plan on investing in a nice new hybrid for next season so I'd like to keep the costs down on these repairs. I have lots of questions, hopefully you folks can help.

The big question I have as a total newbie is figuring out what parts are compatible with the bike. The shifters are shimano index shifters, marked "EZ Fire". I'd like to change these to rapidfire.

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Are Shimano SL-MC40 STX a good value that will fit onto the existing mounts?

I'd also like to replace the derailleurs as well. The existing ones are Shimano 70GS. If I did my research right the front is Top Swing, Bottom Pull 28.6mm.

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Any recommendations on derailleurs that would be a good value?

Thanks in advance for the help

[xerxes]

Your first issue will be the shifters, your existing ones look like they are integrated with the brake levers, so you'll need new shifter pods and brake levers. If you go ahead, make sure you get the correct brake levers for either V-brakes or cantilever brakes, depending on what you have.

The Shifters you've linked to are part of Shimano's Alivio range and I would suggest using them with the Alivio front and rear derailleurs: http://www.amazon.com/s/ref=nb_sb_noss?url=search-alias%3Dsporting&field-keywords=Shimano+Alivio&ih=1_0_0_0_0_0_0_0_0_0.2357_1&fsc=-1&x=9&y=18

However, your existing rear derailleur also has an integrated hanger, whereas the Alivio is designed for use on a frame with a hanger on the dropout, so you might have a problem there as well.

Most of Shimano's dearer derailleurs and shifters now work with 9 speed, so you'll have trouble using them with your existing 7 speed cassette, so the Alivio range is probably your best option for compaitibility.

Having said all that, I also have a bicycle with similar shifters and derailleurs to yours and they work very well, so while the Alivio set-up might be a little lighter, I doubt it will actually perform much better. Given the cost, the fact that you might replace the bicycle soon and the problems you might run into with the brake levers and the rear mech hanger, it might not be worth the hassle upgrading the gears you have.

You might find that your existing set up works very well if you give the existing derailleurs a thorough clean and re-lubricate them, clean and re-lubricate the shifter pods and replace the gear cables. The cost of a new set of cables, some degreaser, oil and possibly some spray grease will be far less than replacing the whole gear set-up and the oil etc. will be useful for any future maintenance jobs.

You'll find video tutorials for servicing the gears and replacing the cables here: http://bikeride.com/guide/

In particular:
http://bikeride.com/jockey-wheel/
http://bikeride.com/rapid-fire-shifters/
http://bikeride.com/lube-brake-shift-cables/
http://bikeride.com/inner-shift-cable/
http://bikeride.com/replace-cable-housings/

[JonB]

Quote:Most of Shimano's dearer derailleurs and shifters now work with 9 speed, so you'll have trouble using them with your existing 7 speed cassette, so the Alivio range is probably your best option for compaitibility.

Actually you can use a 9-speed derallieur with a 7-speed cassette, just not the other way around, as a 7-speed cassette is the same spacing as an 8-speed (usually with a spacer where the largest cog would go), and you simply set the limiter screw very far in to remove the 8th gear. Most shimano shifters are marked 8/9 speed so they will work. 9-speed is the same width as 8th overall, but the distance between the teeth is smaller, hence the narrower chain.

This is however largely academic because with that derallieur you cannot remove the mech hanger, no do I believe you can get a separate one to mount another derallieur on. You could ask in your Local Bike Shop whether they can find you one, but the answer's probably no.

[Hoy]

Looks like I'll be replacing cables and cleaning/lubing the derailleurs and shifters when I have some free time. Thanks for the info guys,