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27 Speed to 30 Speed Conversion?

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27 Speed to 30 Speed Conversion?

Old 06-10-07, 10:02 AM
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27 Speed to 30 Speed Conversion?

Since I have to replace real dérailleur, I'm thinking if I should do more.

I have 9 speed tiagra shifters, tiagra front dérailleur, 9 speed chain, 9 speed cassette. I wonder, if I can convert my bike to 30 speeds if I get 10 speed rear der, and 10 speed chain?

Or do I also have to get 10 speed shifters?

Something inside of me says keep it simple stupid, but also, if I go 10 speeds, I might be getting a better bike for a few bucks more. What you think.
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Old 06-10-07, 12:57 PM
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New shifters too.
RDER doesn't care how many speeds. The difference is in the amount of cable pull FROM the shifter.
What advantage do you expect to gain?
It's not how many gears you have, but how many USEFUL gears you have.
Unless you can find some gear combination in a 10 that you NEED, that you can't get in a 9, I think you would be better served listening to your "inner self".
The 10 is going to be more finicky, especially on a triple.
Post the tooth counts on you rings and your 9, and the tooth counts on the 10 you plan on getting.
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Old 06-10-07, 01:03 PM
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+1 to Bill.

You'd be able to keep your rear derailleur. But you'd need new shifters (expensive! - or at least a new right shifter), chain, cassette - - and for optimal performance, perhaps new chain rings. It's possible you'd need a new rear wheel (it depends).

Not a cheap conversion for just one more gear... I converted a 7-speed to 9, but that was mainly because I wanted STI levers, which a rather bigger difference.
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Old 06-10-07, 01:16 PM
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The above 2 posters pretty much covered it. Unless you have a wad of cash to blow, it's not a very cost effective upgrade for one more gear and faster wearing components.
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Old 06-10-07, 03:31 PM
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What Bill said. As operator said, 10-speed chain and cassettes last less than 9-speed. Heck, you don't really need more than a 7-speed cassette, to be honest, and the chain is stronger and longer-lasting. What matters is gear ratio range, and you can achieve as large a range with a 7-speed cassette, as with a 100-speed cassette. It depends on how much chain can the rear derailleur fold.

I'm sure one could make a case for 7-speed cassettes having some advantages over 10-speed. Weight, for one...

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Old 06-10-07, 04:06 PM
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Tiagra -- is this a touring bike? If so, I'd just stick with 9 speeds. With 3 rings, it's really not worth the cost of conversion. If you ran a compact crank and this were a racing bike, there would be slightly more reason to convert because the gap between the rings is so large.

Even then, I wouldn't bother. I have 9 and 10 speed bikes right now. While I like the 10 speeds, I think it's overrated and frankly the best argument for 10 speed is that with time it will be harder to get STI shifters for the 9. I personally feel that the 10 speed cassette and external bottom bracket are probably the most overrated things that everyone seems to need. As others have already stated, the 9 speed will be less finicky.
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Old 06-10-07, 07:33 PM
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Wait until your shifters wear out or until you get a new bike. The shifters are the most expensive part. To convert from 9 to 10-speed you need to replace at least the shifters, cassette. and chain. You do not need to replace the derailleurs, and with a triple crank you should not replace the front derailleur unless you replace the crankset. The extra cog you gain is usually in the middle of the cassette, like the 16. I ride both and have a slight preference for the 10-speed but it's not a big deal.

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