Replacing cassette, will this cascade to changing a lot more?!?!



tanggoman

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Sep 22, 2003
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I currently have an 11-23 9speed cassette and would very much like to change it to a 12-26 or 12-27 9speed cassette... Does this needs changing the chain too??!?
 
Originally posted by tanggoman
I currently have an 11-23 9speed cassette and would very much like to change it to a 12-26 or 12-27 9speed cassette... Does this needs changing the chain too??!?
Maybe, maybe not, since the original chain may have been measured different ways. There is a chain length calculation formula which I never use,since I size chains on the bike with cassette installed.Maye someone else knows it. If the chain has much use on it, it may be a good idea to change it anyway. Middle line Srams work well and don't cost alot.
 
You may have to limit yourself to a 12-25 depending on your rear deraileur reach. I went from 11-21 to a 12-25 on an 8-speed cassette and just had to slightly adjust the alignment of the deraileur limits and have to be carefull not to try using the 53/25 combo (never go past the 19 when on the big ring anyways). This is with a Shimano 600/Ultegra setup.

If you need to go bigger than a 25 on the rear then you may have chain and arm issues to deal with, worst case is you may have to swap out your deraileur, again depending on what you have on there now.

Hope this helps some. YMMV.
 
Originally posted by tanggoman
I currently have an 11-23 9speed cassette and would very much like to change it to a 12-26 or 12-27 9speed cassette... Does this needs changing the chain too??!?

"The best technique for setting chain length is to thread the chain onto the large/large combination, without running it through the rear derailer. Mesh the two ends on to the large chainwheel so that they could be connected (outer link meets inner link), then make the chain one complete link (one inch) longer than that. In almost all cases, this will give the optimum length."
cut right from Sheldon Brown's web site at URL:
http://sheldonbrown.com/derailer-adjustment.html
If you chain was sized exactly this way, you will need a longer chain. As mentioned by another poster, you may want to change the chain if it is at all worn to get the best life and performance from your new cassette.
 
Originally posted by daveornee
"The best technique for setting chain length is to thread the chain onto the large/large combination, without running it through the rear derailer. Mesh the two ends on to the large chainwheel so that they could be connected (outer link meets inner link), then make the chain one complete link (one inch) longer than that. In almost all cases, this will give the optimum length."
cut right from Sheldon Brown's web site at URL:
http://sheldonbrown.com/derailer-adjustment.html
If you chain was sized exactly this way, you will need a longer chain. As mentioned by another poster, you may want to change the chain if it is at all worn to get the best life and performance from your new cassette.

I bought the bike brand new and from there I've put on 400miles on it, and I lube it every week...
 
Originally posted by tanggoman
I bought the bike brand new and from there I've put on 400miles on it, and I lube it every week...

400 miles is not significant, if you've been taking care of things (which it sounds like you have been).

personally, chainlength-wise, i think you're going to be fine, since you shouldn't be in the big ring/big cog combo anyways. if anything you're going to be one link off.

when i was racing, i'd use cassettes from 11-21 to 12-26 depending on terrain. this was on the same bike without changing chain-length. no problems at all.

i sized the chain for a 12-23 cassette and for the 21 it was a bit long over optimal and for the 26 a bit short.
 
What kind of bike (model/brand), and what gearing setup does it have currently (double or triple rings on front, XT or roadie derailer in back)? This will help people help you better.
 
Originally posted by treebound
What kind of bike (model/brand), and what gearing setup does it have currently (double or triple rings on front, XT or roadie derailer in back)? This will help people help you better.

Thanks for all the reponse!

The bike's Giant TCR1 with a 39/53 front and 11-23 9speed rear. Hope this helps. Thanks.
 
Originally posted by tanggoman
I think what you got was the 2004 models, mine is 2003.

http://www.giant-bicycles.com/us/03...r=2003&bikesection=8830&range=136&model=10647

either way, the ultegra rear derailleur has a 27T max cog and 29T total capacity so a 12-27/53-39 is still feasible, but you may not get the big/big combo depending on your chain-length. and you shouldn't be in the big/big combo anyways. even the top couple cogs.

with your mileage thus far, chain-wear is probably not an issue. chains aren't too expensive though, but i'd swap the cassette out and then deal with the chain length if it becomes an issue.
 
Originally posted by treebound


If you need to go bigger than a 25 on the rear then you may have chain and arm issues to deal with, worst case is you may have to swap out your deraileur, again depending on what you have on there now
The old 8 speed shimano stuff was speced for a 28 tooth and would handle more.Currnet shimano road RD are speced for 27 and handle more. Cage(arm) length has nothing to do with it. The B ension scwew ofthen deeds fiddled with .
 
Originally posted by daveornee
"The best technique for setting chain length is to thread the chain onto the large/large combination, without running it through the rear derailer. Mesh the two ends on to the large chainwheel so that they could be connected (outer link meets inner link), then make the chain one complete link (one inch) longer than that. In almost all cases, this will give the optimum length."
cut right from Sheldon Brown's web site at URL:
http://sheldonbrown.com/derailer-adjustment.html
If you chain was sized exactly this way, you will need a longer chain. As mentioned by another poster, you may want to change the chain if it is at all worn to get the best life and performance from your new cassette.
That's the way to do it if one has the casette. He said he didn't.
 
here are the rear derailleur set-up instructions from shimano. (these are for DA cause the Ultegra actually linked to their STI lever instructions)

http://bike.shimano.com/product_images/RD/si_images/RD_7700_SI.pdf

there is a blurb on chain-length and it is based on smallest cog, largest chainring. then it is the RD capacity that will deal with the cassette sizing between smallest cog and largest cog.

based on this, and the one tooth smallest cog diff between 11-23 and 12-25, it appears that chain-length (according to shimano) wouldn't really change, if the original setup was done according to these directions.

i assume that the ultegra instructions would be similar.

edit: 105 RD instructions for chain-length are the same. http://bike.shimano.com/product_images/RD/si_images/RD_5500_SI.pdf
 
Originally posted by drewski


personally, chainlength-wise, i think you're going to be fine, since you shouldn't be in the big ring/big cog combo anyways. if anything you're going to be one link off.
Even though you shouldn't be, it happens. I'd hate to tell a guy 'it'll be fine' and then hear he trashed something. There is a way to size a chain so that it will handle the range of cogs/chainrings the RD was speced for. There is also a specific formula for the cogs chainrings being considered,if one 'just wants to know'. Guessing just does not pay in this case.
 
Originally posted by treebound
What kind of bike (model/brand), and what gearing setup does it have currently (double or triple rings on front, XT or roadie derailer in back)? This will help people help you better.
None of that matters.
 
Originally posted by drewski
either way, the ultegra rear derailleur has a 27T max cog and 29T total capacity so a 12-27/53-39 is still feasible, but you may not get the big/big combo depending on your chain-length. and you shouldn't be in the big/big combo anyways. even the top couple cogs.

with your mileage thus far, chain-wear is probably not an issue. chains aren't too expensive though, but i'd swap the cassette out and then deal with the chain length if it becomes an issue.

When you make the cassette change, put the the chain on the large ring, slowly and carefully shift the rear towards the largest cog. Watch you rear derailer as you go. You will see and feel if your chain is too short.
I agree with other posters that you should never shift to or use the large front with any of the largest rear cogs, however, it would be a disaster if the chain is too short and you pulled the rear derailer too far. I saw this mistake twice and both times it resulted in bodily harm and broken parts. There is no need to risk the problem, even if you "never make mistakes".
 
Originally posted by drewski
either way, the ultegra rear derailleur has a 27T max cog and 29T total capacity so a 12-27/53-39 is still feasible, but you may not get the big/big combo depending on your chain-length. and you shouldn't be in the big/big combo anyways. even the top couple cogs.

with your mileage thus far, chain-wear is probably not an issue. chains aren't too expensive though, but i'd swap the cassette out and then deal with the chain length if it becomes an issue.
I would not guess about it. Getting in the big cogs is a possibility. If nothing else I would stick the cassette on and with the bike on a stand try the big/big to make sure nothing gets ginked.In the meantime,I'll find the formula for determining chain length without the guessing, misinformation and speculation you guys are so prone to.
 
Originally posted by tanggoman
I currently have an 11-23 9speed cassette and would very much like to change it to a 12-26 or 12-27 9speed cassette... Does this needs changing the chain too??!?
Every method of determining chain length is availabe at www.parktool.com in the repair and maintenance section, including the long and short versions of the formula. It's a good site to be familiar with.