Cassette compatibility question

Question

I am planning to replace the cassette on my bike. Currently it has a Sunrace CSMS1-TAV 10 speed 11-34T. Unfortunately, this exact model seems that is not available anymore but very similar ones are available, such as CSMX0 or CSMS1-TAW. I wanted to ask if there is a compatibility problem between these ones. Looking at the information on Sunrace website I can see that some characteristics don't match.

First, the number of teeth I am pretty sure it's not a problem, the largest cog has more teeth but that will just affect the ratios and maybe require longer chain, but I just wanted to check that my thinking is correct.

Second, and what I am more concerned about since I don't really know what it means, it's the "Sprockets on spider" spec. What is this exactly? Also, will it cause a problem if it's not the same as the original cassette?

Lastly, and assuming they are compatible, what are the differences between the CSMX0 and CSMS1, I can see that the first one is slightly more expensive but is it better in some way? Is it worth getting the slightly more expensive one?

Thank you in advance for your help

Answer 1

They are all 10 speed cassettes, so have the same width.

The 11-36T will function identially to the original, the 11-34 will be slightly lighter but not offer the same low-low climbing gear.

As long as you match Speeds and freehub interface, other brands of cassette will work just as well.

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If you have a look at the inside of your current cassette, it will have a structure that supports the larger sprockets, like this:

I think this picture shows "4 on 2" because there are two distinct black spiders, each of which holds a sprocket in front and another on the back.

The two spiders are rivetted/bolted together and to the smaller sprockets which tend to form an additional part (far side of photo) and then the lockring.

So 5 on 2 or 3 on 1 is merely describing the structure, which may have an implication on weight savings. It may facilitate replacing a single worn sprocket, but realistically noone does that any more.

There are cassettes cut from one monolithic block of metal, but they cost a lot more.

Historically, the spider is the part of the crankset that holds the chainrings with 3-5 chainring bolts or maybe rivets.

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Differences between the CSMX0 and CSMS1 - the 0 has an aluminium spider, the 1 has a steel spider which weighs more but costs less. Functionally they're identical, but need separating at recycling time.

The 0 has "red anodised aluminium spacers" but the 1 has "engineering polymers" which means plastic. These are the small rings between each sprocket.

Honestly there's no significant difference, but the 1 is the "lower spec" cassette. This should be reflected in the price difference between the two.