Shimano cassette replacement question.
 

I am rebuilding my '99 Trek 8000. As you will quickly find out this is my first bike build - I know nothing...

I have taken the bike down to the frame and have had pretty good luck researching replacement parts, processes and upgrades (greatly from this forum, thanks).

1) What I'm having trouble determining is what to replace my worn (and not readily available) Shimano CS-HG70-9 cassette with? Will any Shimano 9sp cassette work?

2) With that, how do I match a crankset (If the cassette is worn does that warrant an automatic crankset replacement)?

3) Will I also have to replace the original Shimano Deore derailleur (works fine)

I realize the chain will need to be replaced I am just not knowledgeable enough to determine what is and isn't compatible.

Thanks in advance for any advice,
-Matt

Below is a picture of my cassette and a link to the original bike specs for my 8000:

http://www.bikepedia.com/quickbike/B...rek&model=8000

http://bikeforums.net/attachment.php...hmentid=319366

Matt- 1- Shimano 9 speed cog spacing is the same. There can be a slight cassette width difference but not too much and it's generally thought that all Shimano 9 speed cassettes interchange (as far as fit and shifting goes).

2- Chain rings usually last longer then cassettes do, for a number of reasons, by a factor of 2x+. But if the chain is run to a REALLY worn point and if the rider never shifts off the ring in use then the ring's life might be ,more like 1x. The better cranks have removable rings so if it's worn the crank might not need replacing in total. But ring replacement can be tricky, there's more variation in crank's rings then cassettes.

3- The der. likely won't need replacing. But it's upper pulley should be checked for the end play (about .5mm and normal) vs wear/slop (the pulley rocks and doesn't just shift side to side). Pulleys can be replaced, usually packaged in pairs.

Many will just replace the chain then ride the bike and find out what else is going on. Andy.

Thanks Andy.

Expanding on my first question, in your opinion would I gain anything from going to a different brand cassette or should I stick with Shimano? Would you have any suggestions for either? I don't think I need super high performance parts but I'd like them to last - I mainly bike to work and back and haul my two youngsters around in a trailer.

-Matt

The HG-50 is fully compatible and is still available in 11-32 9-speed.

Thanks much for the recommendation. I think I just looked at that one on Amazon.

IMO Shimano has the best tooth shape designs for shifting, both cassette and rings, SRAM is close but still in second place (AFAIAC). The main reasons to go other then Shimano is cost or availability. Andy.

IF you never use the 32T cog, maybe you want some more like an 11-28 or 12-25/27?

No in fact I don't use the 32 cog very often. If I were to go to a closer range cassette do the dimensions remain the same (ie width)? Still a 9 speed just less mechanical advantage between each gear? Or would I be going to a 7 or 8 speed?

No, you would stay with a 9 speed (as above they are all interchangeable), but with smaller steps between each cog. This makes it easier to tune your gear to your preferred cadence.

Thanks all for the help. After much deliberation I went with the HG30 (partially because its black). Thanks Bezalel for pointing me in the right direction.

Macro question: there will be without a doubt several more issues that I will need to utilize the forum for. Would proper eddicate be an individual post for each question or would I continue this thread?

People may be knowledgeable in different fields, so if your question was, for example, about headsets/steerers etc., you should probably start a new thread.
If it's about chains, cogs or general drive train questions, this would probably still work fine.

Sounds good Bill Thanks.

I think you were going for "etiquette"... not that I'm picky about spelling or anything. :rolleyes:

A good reference is the Park Tools site: http://www.parktool.com/blog/repair-help . Just point your mouse at the part of the bike you're interested and you'll be linked to several how-to articles.