|105 or Ultegra Cassette||Ron AKA|
Sep 22, 2002 7:26 AM
|I'm rebuilding my rear wheel which has a Tiagra hub and cassette. Any comment on the value of replacing the cassette with Ultegra or 105? It has about 2000 miles on it. Is it possible to put a 105 or Ultegra cassette on the Tiagra hub? Value of changing the hub as well? The rest of my bike components are 105. The bike manufacturer cut some corners on the hubs and cassette.
Thanks for any advice,
|So how's your chain?||Spoke Wrench|
Sep 22, 2002 11:19 AM
|Chain wear shows up as elongation. New chains have two pins spaced exactly 12" apart. As the chain wears, those pins will gradually migrate farther apart. If you replace your chain before the pins migrate to 12 1/8" apart, your cassette will generally handle the new chain without problem. If you wait too long to replace your chain, your new chain will "skip" in the gears that you use most and you will have to buy a new cassette.
When you have to buy a new cassette anyway, that's the time to upgrade. You won't achieve any benefit by doing it sooner. The higher end cassettes weigh a little bit less and are more nicely finished.
If everything else is equal, if two riders coast down a hill, the rider on 105 hubs will coast a little bit faster than the rider on Tiagra hubs. The difference isn't great enough to notice while you are pedaling.
|So how's your chain?||Ron AKA|
Sep 22, 2002 11:57 AM
|Thanks Spoke Wrench,
I just measured the chain, and I seem to be doing well there. It measures exactly or even a hair under 12" with a steel ruler. I've wondered about the KryTech lube I use, but it must be working.
The other issue I have with the cassette is the gearing. Where I bike there are significant hills. On some of them I'm a bit underpowered near the top with my current 12-23 range. I was also thinking of going to 12-25.
Anyone have any idea what a Tiagra 12-23 cassette set weighs? Trying to rationalize this change somehow!
|Why do they sell recreational bikes with racer's gearing?||Spoke Wrench|
Sep 22, 2002 1:35 PM
|Don't feel alone in feeling that you need easier gears for the hills. Virtually all newer riders would benefit from a gearing change.
Frankly, going from a 23 to a 25 isn't much of a change. As long as you are changing, you might as well go to a 27. If you do replace your cassette, you probably should replace your chain with one that is a bit longer too.