Swapping out Forks and Derailleurs

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Swapping out Forks and Derailleurs

Postby RainForeverRain » Thu Feb 21, 2008 2:37 pm

Hi all, I'm in the process of gradually modifying a 21 speed entry-level hybrid into a practical commuter and I need some advice on swapping out the current forks and derailleurs.

The current forks have the impressive title of 'Mozo C-51 suspension fork' but they don't actually do anything but go in and out and make 'pffft pffft' noises. I figure this is a waste of energy so I want to swap them for a rigid fork. Question is, what measurements do I need to know so that the new one fits and doesn't affect the steering geometry in a negative way? Ditto any special tools that might be required to make the change?

The derailleurs are Shimano Tourney (i.e. bottom of the barrel) with Altus/Acera Ci- Deck Plus V-brake/shifters and while they work ok when they are adjusted properly, they don't stay in adjustment for very long. The spring on the rear derailleur is also a problem as it is far too strong. I would like to swap the current front and rear derailleurs for a better Shimano product (possibly Deore) while leaving the shifters alone. Is this possible or is the current cable pull too long/short?

Finally, and this is a curiosity thing, does anyone know what the unused nozzle/hole is for on the shifters? It looks like it might take a cable attachment but on my bike it doesn't do anything.

Thanks in advance for any and all help.
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by BNA » Thu Feb 21, 2008 3:49 pm

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Postby europa » Thu Feb 21, 2008 3:49 pm

G'day mate, welcome to the nuthouse.

Rigid forks can be had for about $30 at your lbs. Just take the bike in and let them match things up. The geometry isn't going to be much of an issue, there's no need to match what you have exactly. A bigger issue might be length. To be honest, you might be better off looking for a second hand set off an upgrade or a wreck.

You know, although bike bits are relatively cheap, so are the total price of bikes. You may find that you're better served just buying a new bike. A really good bike can be had for $700 and as soon as you start messing with the major components, you'll find yourself heading that way very quickly and still have an old bike under you. I'm not saying 'don't do up the old girl', I'm saying 'be aware that a new bike might be a more cost effective option'.

Richard
I had a good bike ... so I fixed it
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Postby Kalgrm » Thu Feb 21, 2008 3:55 pm

G'day RFR,

Welcome to the forum and I hope you have fun here.

When you swap out the forks, you need to try to maintain the distance between the base of the head tube and the wheel axle. (The head tube is the part of the frame that the forks are attached to.)

Regarding the rear derailleur (RD), you won't get much improvement by simply swapping the RD. It only goes where the shifter tells it, so poor shifting is mostly due to poor shifters. If you want to improve your shifting, change the shifters before the RD.

However, with an entry level hybrid, you're always going to be fighting a losing game by upgrading it. In the same way that a chain is only as strong as its weakest link, the bike's performance will be limited by the weakest component. The trouble is, at entry level, all the components are weak and you'll only be happy once every one of them has been swapped out. That will cost you more than buying a new, good quality commuter bike.

My advice is to ride this one into the ground, learning and saving as you go, and when the time comes, buy a decent bike with the money you've been saving by NOT buying parts for this one.

In the mean time, see if you can lock these forks out by tightening up the knobs at the top of the fork. One or both of them should be for preloading the forks: preload them so much that they are locked out.

Cheers,
Graeme
Think outside the double triangle.
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Postby RainForeverRain » Fri Feb 22, 2008 9:33 am

Sigh. You guys make a lot of sense even if it isn't what I wanted to hear.

While the tyre and the pedal upgrades were worthwhile, I have to admit there is no original component that I'm completely happy with (including the frame) and the replacement process probably wouldn't stop with the forks and derailleurs.

Replacing the entire bike piece by piece is obviously going to be more expensive than just buying a new one so I guess it's back to saving. Damn.

Thanks for your help.
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