Author Topic: REAR CASSETTE  (Read 3292 times)

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Offline HONDO

REAR CASSETTE
« on: May 06, 2007, 11:11:12 am »
I CHANGED OUT MY INNER SPROCKET FROM A 30 TO A 24 FOR LOWER GEARING WHICH HAS BEEN A NICE IMPROVEMENT HOWEVER I WOULD LIKE TO TWEEK IT JUST A BIT MORE. MY REAR IS 11-32.WOULD CHANGING IT TO 11-34 MAKE ENOUGH DIFFERENCE TO DO IT AND/OR WOULD IT MESS UP THE DERAILER. MY KNEES WOULD APPRECIATE ANY ADVICE. THANKS.


Offline WesternFlyer

REAR CASSETTE
« Reply #1 on: May 06, 2007, 06:18:06 pm »
Hondo,

Harris Cyclery sells a proprietary touring 14-34 cassette for some real money, but I am going to have one before I head south this summer.  It can save the expense of changing your outer chain ring.  And unless you go for the land speed record on every decent it gives you more usable and efficient gears for touring.

Western Flyer
Portland, Oregon


Western Flyer
Western Flyer

We must ride light and swift.  It is a long road ahead.

King Theoden

Offline DaveB

REAR CASSETTE
« Reply #2 on: May 06, 2007, 08:11:42 pm »
The difference will be a 6.3% lower gear. If you have an MTB rear derailleur, it will handle the change.  Check to be sure your chain is long enough to cover the new big-big combination.

Also, please turn off the Caps Lock key. Your posting reads like you are shouting.


Offline ptaylor

REAR CASSETTE
« Reply #3 on: May 06, 2007, 09:17:56 pm »
You may find Sheldon Brown's Gear Calculator helpful.

Agreeing with Dave, I would be surprised if your derailleur would be a problem. Worst case is either you buy a new chain, or not try to use your big-big combination (which you probably wouldn't want to do anyhow)

Paul
Paul

Offline RussellSeaton

REAR CASSETTE
« Reply #4 on: May 07, 2007, 11:10:18 am »
Your frames rear derailleur hanger may or may not tolerate a 34 tooth large cog instead of a 32 large cog.  Only way to tell is to try it.  Rear derailleur is completely irrelevant.  But how the manufacturer put on the rear derailleur hanger is what matters.  Shimano had a spec for how the hanger should be positioned.  If the frame maker gets this exact, no problems with the 34 cog.  If the frame maker is close, then maybe a problem.  When in low 24x34, the rear derailleur pulley will run into the cog teeth.

As for whether 32 or 34 makes a difference, doubtful.  24x32 is 20".  24x34 is 19".  In a blind taste test you wouldn't tell the difference.

Shimano 9 speed cassettes of about any configuration are easy and cheap to make yourself.  No point in paying a bike shop twice the price to do it for you.  Shimano HG50 and HG70 cassettes are all loose cogs and spacers.  These come in 14-25 and 11-34.  Take the first cogs from the 14-25 cassette and add them to the last cogs from the 11-34.  These cassettes are priced at $30 or less before sale prices.

http://aebike.com/page.cfm?PageID=30&action=list&Category=556&brand=367&modelid=3336&type=T


Offline WesternFlyer

REAR CASSETTE
« Reply #5 on: May 08, 2007, 04:00:03 pm »
Russell,

You have a very clever idea with splicing two cassettes together.  I am having a problem locating the cassettes you mentioned, the HG-70 and HG-50, with requisite 14 and 34 tooth gears.  I went to the Shimano website and they showed no cassettes with a 14 tooth first gear ring, which leads me to think it is a discontinued item.  I did find an eight speed HG-50 with a 14 first ring on the web.  Would it be compatible with a 9 speed cassette?  

Also the HG-70 and HG-50 seem to be in the bottom tier of Shimanos product line.  I am aware that what is bottom tier with todays fast evolving bicycle technology might well have been state of the art five years ago.  It also can be their Walmart line. Do you have a sense that they function well, and are reasonably lightweight and durable?

Western Flyer


Western Flyer
Western Flyer

We must ride light and swift.  It is a long road ahead.

King Theoden

Offline RussellSeaton

REAR CASSETTE
« Reply #6 on: May 08, 2007, 04:21:55 pm »
http://aebike.com/page.cfm?PageID=30&action=list&Category=556&brand=367&modelid=3336&type=T

http://aebike.com/page.cfm?PageID=30&action=details&sku=FW8428

http://aebike.com/page.cfm?PageID=30&action=details&sku=FW8421

The above links to AE Bike shows Shimano HG50 cassettes in 9 speed in 14-25 and 11-34.  HG50 is also called Tiagra.  HG70 has the same configurations and is called 105.  Nashbar occassionally has various configurations of HG70 cassettes.

The 14-25 has 14,15,16,17,18,19,21,23,25 cogs.  The 11-34 has 11,13,15,17,20,23,26,30,34 cogs.  I would take the 14,15,16,17 from the 14-25 and mate it up with the 20,23,26,30,34 cogs from the 11-34.  Nice 14-34 9 speed cassette.

HG50 is champagne colored.  Brown.  HG70 is chromed, nickel plated, shiny silver, whatever.  All of these are loose steel cogs with individual spacers between all cogs except maybe the first one where the spacer is part of the cog itself.  In real life use you will never know the difference whether you are using low or high end Shimano cogs.  Same steel in all of them.  The higher end cogs have aluminum carriers to reduce weight.  Big deal on a touring bike.  The ramps on the sides of cogs to speed shifting will be the same across all of the products so they will all shift the same.

On my road bikes I use the cheapest Veloce or Mirage cogs I can find.  All loose steel cogs and plastic spacers.  Mirage is galvanized steel instead of chromed on the Veloce.  I don't care, the galvanized Mirage were cheaper.  And shift just as well.  I have Chorus, Centaur, Record equipped bikes.  I believe in cheap chains and cheap cassettes.  The wear items on bikes.  Nicer shifters and such.

I think you can mix and match a limited number of 8 speed cogs in a 9 speed cassette.  But they are different thickness so you only have room for about 1 or maybe 2 8 speed cogs in a 9 speed cassette.  Better to just buy a 9 speed cassette and not worry about such things.  They are only $30 full price for the HG50 cassettes.  QBP sells them so your local bike shop can order them.


Offline DaveB

REAR CASSETTE
« Reply #7 on: May 16, 2007, 09:19:19 pm »
Just a bried addendum to Russell's postings.  The 14x25 cassette is a bit of an odd-ball since it's intended for Junior racers who's bikes have gear restrictions so it's not commonly stocked by most dealers or mail order shops.  

Mix-and-matching of loose cogs and spacers is a great, and often cheaper, way to get the gearing you want.  As Russell noted, the cogs are all the same functionally.