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I have an 8 speed 2005 Specialized Dolce with Sora shifters, front derailler and tiagra rear derailler. I want to begin to upgrade some of the components, but have no idea where to start. Can I upgrade the shifters and rear derailler without changing the cassette? Could I upgrade the rear derailler to a shimano 105 and keep the front derailler the same?
thanks.
I guess the question to ask is why you want to 'upgrade.' Is it to improve shifting performance, save weight, have a wider/different choice of gears, or some other reason?
If my memory of 8 speed is correct, it uses a Hypergiide cassette, not the older freewheel, so if you wanted you could put a 10 speed cassette, better rear derailleur (105 or Ultegra) and 10 speed shift/brake levers. You would probably also need to replace your chainrings, and of course, your chain, with newer 10 speed ones. Big job that would need quite a bit more than couch change... The shift levers would probably be in the neighborhood of $300 new and about $80 bucks for an Ultegra 10 speed cassette. Then add chainrings and chain, then the cost of the rear derailleur. So you see it adds up real fast.
Last year, I started out wanting to upgrade my bike, but after seeing the cost I decided to just save up some more and get a new bike and I am glad I did.
On the other hand, if you keep your 8-speed shifters and cassette and crankset, you can upgrade the derailleurs. Derailleurs don't care how many gears there are, the shifters determine that. Just make sure the shifters can handle the range of cogs you have. If you wanted to upgrade the shifters to 105, you'd have to look for an old 105 shifter from the days when 105 used 8-speed (guess it's now 10-speed) or convert to 9 or 10 speed.
9-speed components are getting hard to find...especially shifters. If you decide to upgrade to 10-speed, you might want to compare the costs of upgrading your present bike to just getting a complete new bike with 10-speed.
I would upgrade the shifters, rear derailleur, and cassette.
If you have a triple crank, you need triple shifters and triple front derailleur. The front usually "doesn't care" what the rear is doing.
Go to a bike shop or talk to a mechanic that you TRUST. :) Luckily, my fiance is my mechanic!:D
I'm finally in the position to make some changes to my bike and this is exactly how I'm planning to start. I'm leaning towards a 10-speed 12/27 because the 9-speed 12/27 doesn't have a gear ratio close to the one I currently use the most on my 8-speed 12/25. Aside from the comment about 9-speed components becoming harder to find, are there any other pros/cons either way? Since 10-speed chains are thinner, are they more susceptible to breakage if one tends to occasionally shift like a drunk monkey?Quote:
Originally Posted by LoriA
And a question about rear derailleurs: How do I interpret the Maximum Chainring Difference and Total Tooth Capacity to know whether I need a short-cage or long-cage to pair with my 48/34 compact up front? Can someone explain what this means and how it should be taken into account?
10 speed chains are still durable in terms of breakage, though you might have to replace them more often. If you're worried about the superlight, super thin chains, then just get a cheaper, heavier (and more durable) 10 spd chain. Functionally, there will be no difference, though with some newer stuff that likes ultra narrow or unidirectional chains, you might have a little more drivetrain noise.
Thanks for the info. I'll be going with a (relatively) cheap chain, anyway, so it's good to know that might be the better choice for other reasons, too.
Someone correct me if I'm wrong, but I'm pretty sure this is it: Maximum chainring difference is the difference in number of teeth between your largest and smallest chainrings. With a 48/34 it would be 14, so as long as the derailleur will accommodate 14 or more, you're good. Total capacity is your chainring difference plus your cassette difference - with a 48/34 and a 12-27 it would be 14 + 15 = 29, which is the maximum for a short cage Ultegra RD.Quote:
Originally Posted by Kalidurga
That's how I was interpreting it, as well, but I wanted to make sure I wasn't just confusing myself. Sounds like a short-cage will do, unless I were to decide to put on a bigger cassette in the future.
Let the component shopping begin :D