Bicycle Mechanics - Help w/ Re-Assembling my Topanga SE? Please?!
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03-29-11, 07:20 PM
Alright guys...I could use some help here.
First and foremost, here (https://picasaweb.google.com/111652115584766108486/DiamondbackTopangaSE?feat=directlink) is the link to an album with pictures.
I've had my old Diamond Back Topanga SE laying in the garage for years...I think it's a late 90's model (see pictures). Anyways, in a moment of inspiration and motivation, I took the entire bike apart with the intention of cleaning it, replacing all the cables and chain, and just generally getting it back to mountain biking condition. I realize now that this was a stupid thing to do, as I don't know much about bike mechanics...in fact, i knew next to nothing; I just figured I'd learn about it along the way.
So I've been at it for a couple days now, and as you can see from the pictures, it's pretty much a disaster zone. I'm currently trying to get the brake cable hooked up and got frustrated when I couldn't quite figure it out. There are no diagrams on the web for my model either, so I am even more lost, haha. Part of me wants to just throw the whole thing away and just buy a new bike, but I also really want to fix it up to gain the experience and because I love the bike and don't want to part with it.
If anyone is willing to help me through re-assembling this bike and getting it back in working order, I would really, really appreciate it. I have bought a new chain, 2 new gear and brake cables, a chain tool, and a few other tools I needed when taking the bike apart. I don't really know how to proceed here so any suggestions, advice, or instruction would be a lifesaver. :twitchy:
03-29-11, 07:55 PM
start here http://www.parktool.com/blog/repair-help
03-29-11, 09:07 PM
This photo and component list might be helpful:
Here's the order I would choose:
First, I'm assuming that you didn't disassemble the fork/steerer (for a proper teardown, you would have at least partially removed the steerer to replace its bearings; that takes some experience and training, so don't worry about it for now).
I'm also assuming that you didn't remove the bottom bracket (the axle and bearings for the crankarms) or the crankarms, or the pedals. It's important that each of those be properly tightened to prevent damage or a fall, but we'll assume they're fine.
Details for the following steps are in the Park Tools website mentioned above, and also in the manuals for the various parts, which may or may not be available online.
From your photos, next you need to attach the rear derailleur to the derailleur hanger using the big bolt at the lower center of photo 9. First, make sure the derailleur hanger is not bent; it should be perfectly parallel to the plane of the rear wheel -- the more bent it is, the harder it will be to make the rear derailleur shift correctly.
Mount the rear wheel/cassette on the rear dropouts using the quick-release skewer. It'll be easier later if you already pump up the tire first and make sure it has no leaks.
Next, attach the front derailleur to the seat tube. You want the cage on this to be parallel to the plane of the front chainrings, and set a certain height above them when looking at it from the chain (drive) side.
Now, install a new chain. I strongly suggest one with a hand-openable "master link" such as the SRAM ones, for example the PC 830 here: http://www.amazon.com/SRAM-P-Link-Bicycle-Chain-8-Speed/dp/B00161FWJG
You will likely have to shorten it using a chain tool. The instructions with the chain should show you how to size it correctly for your setup.
Now, you're ready to install and adjust the shifter cables. You'll need appropriate new shifter cables for your grip shifters. There's usually a hatch or similar opening in each shifter through which you can thread the free end of the new cable from the inside out through the barrel adjuster tube (the other end will have the anchor). From your photos, it looks like you might be missing the small threaded caps with holes through them that are the barrel adjuster caps -- be sure to install those on the barrel adjusters before installing the cables.
03-29-11, 09:23 PM
The Park Tool site will describe how to adjust the derailleurs/shifter cables. As far as cable routing goes (and working from your photos and the '97 photo in Bikepedia), I'd run the front derailleur cable (left shifter) along the top right side of the top tube, then down the back of the seat tube. The rear derailleur cable (right shifter) would run along the bottom right side of the top tube, then over to the right seat stay and down that to the rear derailleur.
Save the brakes for last. The front brake cable runs from the left lever down to the metal cable stop centered over the front forks. The rear brake cable runs from the right lever over to the cable stops along the left side of the top tube, then around the left side of the seat tube and into the metal cable stop centered over the rear wheel. You've got cantilever brakes, apparently using the old straddle cable bridging the two shoes with the main cable pulling up on that with a saddle filling; I find these setups more of a pain than the newer Z-links. Once you find out the correct length/angle Z link straddle to buy, you just run your main cable through it to the clamp side of the canti without having to fiddle with straddle length adjustment vs. main cable length adjustment.
03-29-11, 09:39 PM
Well, you haven't done anything where you are doomed yet just keep the hacksaw away from the bike.
Mondoman's suggestions are fine. The front derailluer cage should be about an 1/8" above the outer chainring.
I would then install the shifter cables and housing.
Next install the rear wheel then chain
My final step is to install the brake cables and housing.
03-30-11, 01:04 PM
Alright thanks guys for all the suggestions/advice. I am in the process of heeding your instructions. Let you know how it goes!
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