anga

Series : Altus
Model No. : CS-HG31-8
Speed : 8 Speed
Combination 1 : 11-30T (an) (11-13-15-17-20-23-26- 30T (an))
Combination 2 : 11-32T (aw) (11-13-15-18-21-24-28- 32T (aw))
Combination 3 : 11-34T (ao) (11-13-15-17-20-23-26- 34T (ao))

My proposed 8-speed cassette:
11-21-24-26-28-30-32-34
11T first position cog to lock the cassette. Will not use 11T.
If 11T is not needed, will use 18T instead to get
18-21-24-26-28-30-32-34

Will this cassette work with 8-speed shifter and RD-TY300-SGS?

icemilkcoffee 

The cogs are all contoured to facilitate going from one cog to the neighboring cog. it's a matched set. You cannot just mix and match them. Also- jumping from 11T to 21T is a big jump. The derailleur will not like that.

SoSmellyAir

On a Frankenstein cassette, the shift ramps between adjacent cogs from different donor cassettes would not be aligned, which lead to poor shifting. Why not just install (a) smaller chain ring(s)?

noobinsf 

What is it you're trying to accomplish? Are you looking for easier gearing and to preserve index shifting? Your choices are pretty specific, but they may not be the best way to go about it. Depending on what you want the final outcome to be, you may be better off with small chainrings and a more standard cassette. It's hard to guess, though, without knowing the type of riding for which you want to tune this bike.

70sSanO

I think this a an addendum to the lowest gear thread.

Your 2t cog gaps in your 24-26-28-30-32-34 really stink for actual riding.

What cassettes are available in your area?

Can you get any 11-34, or 11-36, 8 or 9 speed cassettes in “any” brand that are Shimano compatible?

If you can get an 11-36 9 speed cassette, just get that and never shift into the 11t, or 13t.

Most people who tell you you can’t mix and match different cassettes/mfg’s have never done it. The only rule I have found is that you don’t want to run a 1t tooth change cog with a 2t+ gap.

John

Iride01 

Turn the bike into a 11 speed bike and you can have most all of those cogs on the rear that you are wanting. And if that's too much money because of the cost of 11 speed STI's, then 10 speed will give you almost the same. Tiagra and other 10 speed shifters can usually be found at a lower price point.

dedhed

It's as if none of you ever rode old bikes with unramped and 3-4 tooth difference cogs that people had no issues riding and shifting.

anga

Have a knee issue and I live in an area where the roads go either up or down.
Looking for a way to ride that will put little load on the knee till it heals. Just fast enough to maintain balance. Hence the need for large cogs and small steps. Need it for no more than a few months.

The crankset is 22x30x40.

Will not use the 11T cog. Only use is to lock the cassette.

Question
Will the derailleur work with a 11-21-24-26-28-30-32-34 cassette?
Starting at 21 and ending at 34.

rccardr 

The answer is, yes, it will work.

Camilo

Why not just use a 11-32 or 11-34 8 speed cassettes? Are the jumps in a standard cassette like that not workable for you? You'd need a Shimano 8 or 9 speed rear MTB rear derailleur, but they are readily available new and used and whatever price point you want. They work with 8, 9 or 10 speed cassettes and road sifters - I've done it several times. (I might have missed it - road or MTB shifters?) I usually buy mine on EBay, used Deore, XT, etc. I think there's new ones too. You just need to make sure the RD will go as large as 34 or whatever you're shooting for. Sometimes you can fudget a couple of teeth on that. I don't think 10 speed MTB RDs will work with road shifters.

But, regarding mixing sprockets from two cassettes and shifting quality, if you really think you need to do that, it will most likely be just fine if the jumps between gears isn't crazy.

Mine isn't a Shimano example, but Campagnolo 8 speed indexed. I mixed from two Miche cassettes. The rear shifting is fine. Frankly, I think it's perfect-or close to it. If "perfect" is A+, this shifting is A- at worst. My guess is that it would be similar with a Shimano mix and match cassette.

You will be limited to the lock ring that is matched to the smallest sprocket on one of your donor cassettes. If I were you, I'd try whatever combination will get you a small sprocket you can live with and not make a crazy big jump to the second sprocket. Maybe look for a "junior" 8 speed cassette as one of the donors because they come with 13t or 14t would have an appropriate lock ring.

In my case I was only trying to get a 11 or 12-28 which wasn't available. What was available to me, time, place and cost, was 13-28 and 12-21. So I used the 12t small sprocket and 12's lock ring. Then I just chose the sprockets from whatever cassette that gave me the jumps that were reasonable (not difficult for a 12-28.... your case will be different). Getting up to 34 and not needing the high gears, it makes sense to get that small sprocket and lock ring as big as you can.

But based on my experience, yeah, the shifting might be sub-optimal with non aligned sprockets, I doubt it. Even so, my guess is that it would be satisfactory to you, definitely worth a try.

RCMoeur

Seems like a jumbo-size corncob (might need extra butter).

The upside is that it will give you gear steps even smaller than one-tooth steps in a more-typical corncob cassette - but the downside, as others have alluded to, is that the shifting performance is going to be at minimum "unpredictable", given that no standard cassette is designed to have most of those cog sizes next to each other, and it'll be pure dumb luck if the ramps end up aligning.

Any rear derailleur that'll clear a 34t cog (e.g. most long-cage derailleurs) should work with this, but may get rather close to the 24 cog as the slant on the parallelogram is designed for a 'normal' (e.g. logarithmic) cassette / freewheel. You might end up having to use a hanger extender to clear the "smaller" 21-24-26 cogs (unlike most setups where an extender is intended to provide big cog clearance). With a 40 large ring up front and standard chainstays, a standard-length chain should work, but might use most or all the links.

Keep us posted as the experiment progresses.

anga

I will use only the 22T chainring.

rccardr 

In that case your larger problem may be interference between the upper pulley and the larger cogs. Prepare to play with chain length, axle location (if dropouts are horizontal) and B screw length.

rm -rf

This custom setup has extremely close gearing with your small chainrings. You'll want to shift 2 or 3 cogs to feel much of a difference. And you'll be limited to very slow speeds.

It doesn't seem useful to me at all. Shifting through the full 7 usable gears in the 22 chainring, it will only change by about 1 mph at slow hill climbing cadences, and just 3 mph at a fast spin 100 rpm.

(11 not shown) 21-34 and 22/30/40 chainrings:
22 chainring in red, 30 in black, 40 in blue. Showing an extremely wide range of cadences from 33 to 100 rpm.

The 22 chainring spins out at a top speed of about 8 mph. The 40 chainring gets almost to 15 mph.
the calculator link 21-34 calculator.

What is this chart showing? Each gear combination is a colored row. The bar shows mph speeds from the slowest (33 rpm cadence) up to the fastest spin cadence (100 rpm.)
The bottom red row is the 22 front / 34 rear. At 33 rpm, 1.6 mph-that's difficult to balance at such a slow speed. At 100 rpm, just 5.0 mph. (the calculator has a tab labeled "Speed" that shows mph numbers instead of a chart.)


~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
Compare:
A stock 12-32 cassette with the same 22/30/40 chainrings. Note the change of scale in mph on the chart.
calc link 12-32 calculator

The 22 chainring still has close shifts, but they are usefully close here.

rm -rf

I like your plan to use very low pedal pressures at slow speeds.

Just stay with the 4 biggest cogs on a stock cassette similar to this:
Easy spinning cadences still have small gaps between shifts:

70sSanO

If you don’t want to use the 11t, just block it out with the high (H) limit screw to align under the 21t.

Then just release the cable, 1st position on shifter, and set up to shift 7 cogs with an 8 speed shifter.

John

hokiefyd 

I'd say it's a definite maybe.

The cassette itself will be fine. As others have noted, shifting may be degraded some due to shift ramp discrepancies, but this is not a big deal.

I think what you need to watch out for is upper pulley (jockey wheel) clearance on the 21t and 24t sprockets. Those are much larger than intended for their positions (2nd and 3rd, counting from the smallest/outboard), and most derailers are designed to pivot that jockey wheel up as the cage extends rearward to keep the chain close to the sprockets for clean shifting. With those sprockets much larger than intended in those positions, you may have a hard time maintaining clearance between your jockey wheel and sprockets. You may need something like a road link (derailer extender hanger) to physically move the derailer downward for clearance here.

Edit: I missed the response from rccardr above...my post is a strong second to that first advice you received!

70sSanO

This may be the rare case where an extended derailleur hanger, Wolftooth RoadLink, is necessary to improve the “smaller” (21t-24t-26t) cog shifting.

John

anga

Thank you so much.
Again Wolftooth Roadlink is not available here.
$22 in the US and $101 if imported!
Too expensive.
Will look for alternatives.

70sSanO

There are a ton of knock-offs. It is probably as low tech as you can get. Hopefully you can find one in your area.

John

Hondo6

This appears to be available on Amazon India. It might be what you need. If I've done the currency conversion correctly, it appears to cost the equivalent of <$20 US. Not sure about shipping/handling costs to your location in India.

https://p-y3-www-amazon-in-kalias.am.../dp/B08GQ48ZQG

There may be others available on Amazon India, or locally, at lower cost. This was the first I found.

Best of luck, both with the bike and the knee.

estasnyc

Going slightly off-topic, why do descriptions for Miche Shimano-freehub cogs go out of their way to state that these are not designed to be used with other brands of cassettes?

Supposedly, you can build up a cassette for a Shimano freehub using Miche cogs but can't mix any of these with those of any other brand such as Shimano and SRAM.

(That's why I say "Shimano-freehub". I would think saying "Shimano-compatible" would imply that you CAN mix the cogs.)

What may be the technical reason for this incompatibility? Or might there be some legalese involved?

Bringing this back towards being on-topic, Miche does offer a 16t first-position cog. Might be something that the OP may want in case of a ghost-shift? (Shouldn't happen if the derailleur limit is properly set to lock this out though.)

t2p

8 speed ?

Get a Shimano 11-28, 12-28 or 12-32 8-speed cassette (or equiv) and be done with it.

22/28 and a 22/32 (especially) provides an extremely low gear ; drift down hills or find a way to use the 30 or 40 chainring.

Hondo6

The article at this link might explain why. An excerpt:

70sSanO

I’ve never used individual Miche cogs. Individual cogs used to be pretty easy, and cheap, to get on eBay.

But I have used 7, 8, 9 & 10 speed cogs from Shimano, SRAM, and Sunrace; although primarily 8 and 9 in 8 speed setups.

I’ve never compared an individual cog, for example a 21t, side-by-side to see if the ramps and teeth configurations from different mfg’s match. I haven’t had shifting issues, but have not tried to build a 10 or 11 speed (can’t imagine a full cog offering).

I haven’t found cog thickness to be an issue, but I don’t use standard spacers with different cog thicknesses. While it may be a bit more than most people would do, I adjust spacer width to get the correct center-to-center cog spacing.

If I do build a cassette and find a particular shift not to my liking, I’ll use the barrel adjuster to see if I need to swap a couple spacers with slightly different widths. Unless there is a finicky shifter, I have a downtube with a sloppy detent, it ends being smooth and quiet and doesn’t need any more tweaking.

John