elcyc

Orig price (2004) was roughly $24.00. Not sure what currently-avail. cassettes/cogs can fit my MTB with Rhyno-Lite wheels (as noted, orig was now-discontinued 7-speed cassette). All I really need are the four smallest cogs ....

Please help me find either:

(a) drop-in replacement for entire cassette (any brand -- but not above $40)
...or...
(b) indiv. cogs (source/dealer link would help)

Thx!!

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all about the Shimano HG70 7-Speed 11-28 Cassette
HG70 7-Speed
HG cassettes listed here work with HG and IG90, 70, 51 and 31 chains
HG cassettes are not designed to work with IG30 and IG50 chains

Item Specifications
Color Silver
Cassette Cogs 11,13,15,18,21,24,28
Speeds 7
Chain Compatibility 3/32"
Weight 303 g
Intended Use Mountain
Drivetrain Spacing Shimano/SRAM 7
Cassette Body Type Shimano 7

Item discontinued, but manuf. info here:
Shimano HG70 7-Speed 11-28 Cassette in Tree Fort Bikes Cassettes (cat91)

cny-bikeman

Google shimano mountain cassette 11-28 7 speed

elcyc

Just noticed that Amazon/others do carry an HG50 7-speed cassette, but not 11t. Only 12-28, which I assume will be okay. It's around $23
Amazon/others also carry a HG70 8-speed for about $40.
Not sure about HG50 vs. HG70. I've read, that the higher HGx0 were better quality ... so, HG70 better than HG50???
FWIW, my HG70 lasted 10+ years (or about 5k miles). But that Amazon price of $23 is not too dissimilar to my 2004 HG70 price from (I think) bikeman.com.

cny-bikeman

12-28 is more than OK, it's a lot more sane, even for compact mountain bike cranksets. Higher priced cassettes mostly look a little better and may be a bit lighter.

elcyc

I forgot to mention ... I don't use it as a MTB.
Essentially a utility/commuter/hybrid ... decked out with panniers/racks front and rear.
26" x 1.6" Conti Top Touring tires and a 20.5" Gary Fisher frame. Oh .. and SKS fenders, too

Really, I don't need so many speeds....

Front derail./crank -- only use middle chainring.
For rear, most used cogs are: 13,15,18.
11, 21,24,28 look almost brand new.

Even most-used cogs, 13,15, 18, are hardly sharks-teeth (not even close).

My main issue is skipping or jumping (can't tell for sure but that's what it feels like).

This happens mostly during mildly-heavy (15 lbs) grocery hauling. When starting to pedal (from stop), I may have been in (lazily) one of the higher gears -- I hate downshifting, so when starting from a stop (traffic light), I'm usually in the gear I coasted in from. I am aware of this, so I try to accelerate very slowly/gently ... alas, in approx. 1 out of 5 starts there is a "jump".
Sometimes, there is a jump if I've coasted to a slower speed, and when commencing to pedal, there is a jump (this is hardly hard pedaling, in fact it's orders of magnitude more gentle than dead-stop starting from a very low gear).
If the chain is just-lubed, the jumping frequency is somewhat reduced.

I keep my 3-year-old SRAM PC890 chain, Deore Shimano derailleurs and all other drivetrain parts religiously clean. And I never use bike in dusty or wet conds. Just a 15-mile every-other-day grocery/exercise/errand run, on all flatland, here in Los Angeles.

HillRider

Buy the 12x28. HG-50 is plenty good, just not a pretty. For your use an 11T cog is wasted space. In fact, in the past Shimano made 13x30 7-speed cassettes which would be even better for your use if you can find one.

fietsbob

Bike shop's distributors have back stock of repair parts, Retail Online sellers No longer bother restocking ..

ask at a place that repairs older bikes.. 2004 it seems like yesterday ..

ThermionicScott 

The HG70 7-speed cassettes have been out of production for a long time. Shame, since they looked the nicest.

You can still get Shimano 11-28 cassettes -- the HG-41 Acera is $16 or less. The 12-28 can be found in HG50 silver at $27, or in HG50 black for $18 or less, and there is an even cheaper HG20 option. I believe the HG20s are made in Singapore, or wherever Shimano makes their lower-tier stuff. The HG50s are made in Japan.

If you don't use the full range of an 11-28, a tighter cassette would probably serve you much better. Try a 13-26.

Also, you mention keeping your chains clean, which is good, but do you measure them for elongation (aka "stretch")?

elcyc

Thx for the tips!
I should've noted about stretch: I do measure it every 6mos or so and it's fine. About 600 miles ago, I replaced my prev. staple, the Shimano HG70 chain, with a superior model (IMO): SRAM PC890. It's smoother and seems to be a bit more durable.
Also on the routine (preventative) maint. roster are: checking/tightening cassette; checking tweaking rear derailr.