What cassette ?? (discussion)

mattyboy199

So last year i completed a new build, bought myself a lovely sram cassette with an anodised ally spider cost about £65 ! i m now coming for up for a replacement due to wear & was thinking do i need to replace my cassette with something that meets the same spec (which is mainly the weight).

Do people generally run a cheaper cassette knowing it will just wear out in after a few thousand miles ?
Will you even notice the extra weight ?
Will the lifespan be the same cheaper cassette cheaper materials ?

please discuss.

The Rookie

Steel is still steel, the expensive cassettes wear out at as fast as the cheap ones. So yes your paying more for an absence of weight, of course if you have an alloy freehub you need an alloy spider or have to accept the cassette will chew it up somewhat!

Simon

njee20

I'd not use less than XT myself, but find the XTR one the hardest part of the groupset to justify. If you change chains you can keep them for longer, but you spend loads on chains. Not worth it on a PG990/XT though IMO.

If its a nice top end build with an alu freehub body, get a nice cassette. If you could improve it elsewhere for the cost difference get a 970/SLX.

mattyboy199

my current SRAM PG990 is mostly mounted on an ally spider but i have noticed the marks the 3 or 4 sprokets leave on the freehub. There is a lower PG model which has less gears mounted on the spider so what difference will this really make ? probably go with an XT as this is a cheaper & lighter than than the 990 unit however will requrie a new chain & middle ring (not cheap on my spec).

The Rookie

mattyboy199 wrote:

There is a lower PG model which has less gears mounted on the spider so what difference will this really make ?

The bigger the rear gear, the greater the torque load and therefor the more it will bite into the freehub.

njee20

Although in reality it makes chuff all difference, particularly as the biggest sprockets are still riveted together - I run an HG50 on an alu freehub on my Power Tap, it's left some marks, but it's not that bad.

I think people really do obsess with the damage to the freehub thing, save for making your freehub marginally harder to remove, it's basically cosmetic.

The Rookie

I think the SRAM ones with a single bolt allow more twist and 'bite' than the lower level Shimano though.....

I have seen a hope freehub where the gears had gone almost half way through the 'splines'.

Simon

nicklouse

njee20 wrote:

I think people really do obsess with the damage to the freehub thing, save for making your freehub marginally harder to remove, it's basically cosmetic.

other than all the designed ramps and cut outs for shifting are now in the incorrect places.

njee20

Chapeau to anyone who can actually notice a degradation in the shifting due solely to a 3 degree misalignment in the shifting ramps... Over and above chain wear, sprocket wear, cable wear, jockey wheel wear etc.

If they all 'bite in' together (as tends to happen) then that's a moot point anyway. In fact it's a case for a non-spidered cassette as they're definitely more likely to all bite in together as opposed to just the smallest sprockets doing it, which will only be negated by use of an XG-999 or XX cassette.

I'll remember that next time I get a mis-shift though, it is most likely be down to the microscopic misalignment of the bottom 3 sprockets!

mattyboy199

I always assumed the spider was there for weight saving ! NJEE don't forget the all the crap ur chain picks up on the trail !

supersonic

It does save weight on some designs, plus helsps the scarring. I have seen some freehub bodies totally destroyed.

njee20

It does save weight on some designs, plus helsps the scarring. I have seen some freehub bodies totally destroyed.

Yeah, but again unless you use an XG-999 or XX you are only limiting the damage. If you are going to destroy the whole freehub body then it probably won't make much difference having half the cassette on a spider!

If you're that much of an animal then you probably shouldn't be using alu freehub bodies anyway!

nicklouse

njee20 wrote:

Chapeau to anyone who can actually notice a degradation in the shifting due solely to a 3 degree misalignment in the shifting ramps... Over and above chain wear, sprocket wear, cable wear, jockey wheel wear etc.

If they all 'bite in' together (as tends to happen) then that's a moot point anyway. In fact it's a case for a non-spidered cassette as they're definitely more likely to all bite in together as opposed to just the smallest sprockets doing it, which will only be negated by use of an XG-999 or XX cassette.

I'll remember that next time I get a mis-shift though, it is most likely be down to the microscopic misalignment of the bottom 3 sprockets!

nope they dont bite in the same amount as differing forces are applied.

and yes some of the riders kept complaining about some odd shifting. Guess what.

supersonic

alu freehub bodies anyway!

Yet they are put on heavy duty hubs with generally no restrictions.

The Rookie

njee20 wrote:

If you're that much of an animal then you probably shouldn't be using alu freehub bodies anyway!

Remembering of course that the same pedal force will give more than three times the loading into the freehub in a 34t low gear than an 11t highest gear, worst still with an 11-36 10sp cassette. I ride with a guy who is 6'5" and weighs about 18stone and he uses an ally freehub OK.......but with the right kit!

Simon

njee20

and yes some of the riders kept complaining about some odd shifting. Guess what.

Well like I said, chapeau to them, I'm even more impressed that folk can do that without introducing any of the other wear factors though!

I disagree on sprockets biting in different amounts as well, never seen (first hand or otherwise) any massive differences across a cassette. Happy to be proven wrong, but Google Images won't oblige either.

Remembering of course that the same pedal force will give more than three times the loading into the freehub in a 34t low gear than an 11t highest gear, worst still with an 11-36 10sp cassette. I ride with a guy who is 6'5" and weighs about 18stone and he uses an ally freehub OK.......but with the right kit!

But again though that's a red herring except on a true 'loose' cassette, of which there are very few, and none of the mass-produced ones, unless people have dismantled their cassette, in which case they're morons.

Northwind

SLX is good- only one less cog on the spider, which IME makes very little difference in terms of freehub wear, and the weight difference isn't much either (a good chunk of it comes from the lockring so if you've got a nicer cassette already, keep the lockring)

The Rookie

njee20 wrote:

But again though that's a red herring except on a true 'loose' cassette, of which there are very few, and none of the mass-produced ones, unless people have dismantled their cassette, in which case they're morons.

Like I said above, the SRAM low end cassettes are 'looser' than the Shimano ones......mind you handy for replacing worn individual gears!

Simon

njee20

But not totally loose. If anyone has a photo of a cassette where one of the largest sprockets specifically has 'dug in' significantly more than the others I'll accept that train of thought. But in 12 years and 60000+ miles on alu freehub bodies, plus the 10 years working in the LBS I've never seen it. Strikes me as a theoretical problem rather than a real world one.

Northwind

njee20 wrote:

Strikes me as a theoretical problem rather than a real world one.

Best sort really.

njee20

Definitely!

Anonymous

I just go with whatever fits, shifts fine on and I can go riding. Oh, that's all of them.

Generally stuck with SRAM stuff for no particular reason. Had 930, 950 and now on 1050 on both bikes. Only issue I've had is the 1050 came undone the other day even though it had been torqued to spec. The lock ring seems shallow on that one, but I understand you can get deeper ones. Don't know if it's anything to do with that, but it was well and truly tightened solid so really shouldn't have come undone. Aside from that, all work and shift just as well as each other.