Different companies, different sprocket sizes?

Manc33

I have been on 8-speed for ages and have always used SRAM 11-32T cassettes.

On SRAM the cassette spacing is:
11-12-14-16-18-21-26-32

On a Shimano 8-speed 11-32T cassette it is a bit different:
11-13-15-18-21-24-28-32

Looking at the SRAM it goes "lower quicker" towards the bigger sprockets, while the Shimano is more of an even pyramid looking cassette.

Just wondered why one company has them totally differently to another?

Is one actually better? I mean I don't want to start arguments but I have noticed the shifting from the 26-32T on the SRAM is sometimes a bit iffy. Its a 5T difference, whereas on the Shimano there is no such thing. Before the 32T on that you have a 28T.

Its gonna feel weird riding on this cassette.

The thing is I trust Shimano more lol. They have been at it since whenever it was, 1920 or something. If they are doing it that way there's probably a reason. Also, maybe SRAM differs just to be different? :roll: "We can't make the cassette with those ratio's, it will look like we're copying Shimano" kind of thing. The inane corporate stuff that goes on in boardrooms.

Chunkers1980

It is more percentages. Different strokes for different folks. It's not a conspiracy

The Rookie

Depends on the bike and usage really for a Hybrid then I think I'd prefer the SRAM with closer spaced ratios towards the faster end and selecting the front chainring to use them, for an MTB I'd probably prefer the Shimano gearing in the basis that it gives 'more similar' ratio gaps all the way across the cassette so front chainring choice is less critical in terms of the shifting feel at the rear.

If you look for example at the SRAM 8th to 7th is a 9% ratio change, 3rd to second is nearly 25%, that would be very noticeable when riding! the Shimano has most in the 15-20% bracket.

Manc33

I was thinking to "look at" the Shimano looks more normal. The SRAM looks like 4 small sprockets, then 4 large. I wonder if any of it affects the quality of shifting up around the bigger sprockets. The worst place is between 2nd biggest and biggest sprockets on that SRAM, which happens to be a 5 tooth jump.

The Rookie

It will shift just fine, the old Shimano mega-range Freewheels were 28-34t for the biggest shift and many people are using range expanders giving a 36-42 shift

Manc33

Swapped to the Shimano cassette and the front mech started changing off the granny, here we go... it seems the Shimano cassette is slightly nearer the rear spokes than the SRAM cassette was. One thing I hate is ar$ing about with FD indexing. :evil:

The Rookie

Not very logical, I doubt they are any closer at all, if they are it's fractions of a mm, coincidence I think.

Manc33

I just set it up so it does rub slightly when on middle ring and biggest sprocket, thats my "guide" to know everything else will change fine assuming the limit screws are also set right.

Now its set up the Alivio cassette seems to change gear better than the PG850 did, it seems to have removed a tiny bit of stuttering over the SRAM one. The Alivio is about 10% heavier and £2 cheaper.

When I first use it, the drivetrain felt like it had a vibration coming through the pedals but it went after 5 miles, is that just the sharp edges of the cassette teeth? :? I mean 5 miles and its worn off. I guess the chain has to have some wear into the cassette before it becomes smooth?

Never even bought a new Shimano cassette before, its always been SRAM and every bike I have bought in the last 5 years has had an SRAM cassette. I just used to buy SRAM because they were lighter, but now with a Shimano cassette I swear its changing gear better. What I noticed is my shifters are more "forgiving" in that I can tighten it up a bit so the upshift is crisp - without it having a delay when I do a downshift, which never quite seemed possible on the SRAM cassette. So the Shimano seems to be a better machined cassette than the SRAM. It looks nicer though, the lock ring has a quality to it and the 11T is nickel plated.

With Shimano there's the trickle down effect just not present with SRAM. The tech on something like an Alivio cassette is probably something like an 8-Speed XT or even XTR cassette used to be back then, hence decent shifting. The SRAM cassette never went through all those modifications! This is what gets me about it. When Shimano give us a cheap component now in 2015 like say Shimano 105, you're getting last years Ultegra which itself was the year before's Dura-Ace. Not sure how it can work like that with SRAM when the company was only founded in the late 1980's.

"I never had a problem with an SRAM cassette" me neither, its just that cheaper Shimano cassettes change gear better. :P

Chunkers1980

No - it's all just the HyperGlide tech. All that is is the teeth profiles. It's the materials and builds that differ.

Here's more info: http://en.wikipedia.org/wiki/Hyperglide