fatnold
Likes Bikes and Dirt
But not once did you exagerate wildly.
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New XC groupsets rant - are ShRAMano run by retarded marketers?
- Thread starter RichJS
- Start date
.. but because the inner diameter stays the same, the outside width of the plates is a lot narrower, thus greatly reducing the area of contact between the plates and the pin. So wear is greatly increased, which is important to the kind of people that are buying SLX or X7 .. even to plenty of XT, and X9 buyers.
Plate strength is also important. I bend plates on an occaisonal basis, due to some habits picked up SSing. (Pedalling backwards when cornering to move my feet for balance, when my chain has jumped on the cassette due to bumps. It twists the chain as it enters rear derailleur.) I don't want thinner plates.
A couple of people here have already said that's exactly what they'd love to see. The greater durability, greater tolerances are just what I want. Shimano - if you're listening; SRAM's 2:1 actuation ratio is nice. Have you thought about 3:1?
I'd suggest this puts you in with a very small minority of riders. Before 2010, exactly who was screaming out for closer ratios on their MTB? Like, 0.001% of people who already had got themselves sorted by using an Ultegra 12-27 9-speed cassette cause that kind of rider don't even come close to needing anything as low as 22-27 anyway.
Don't confuse the number of gears available with a high or lowest possible ratio.
Oh .. then why did Shimano release the FH-M529? (Hint: It was 29er riders using 36t cassettes repeatedly killing their regular hubs.)
Torque = Force * Distance. If there are more teeth on the cassette, the torque is greater because the force is at a greater distance from the hub. If I'm not mistaken, there is actually higher tension in the chain with more teeth on the front, not less.
Probably time to correct an error from my original post: SRAM are putting out triples for cranks.
Don't get me wrong, I'm not complaining about the spread of gears in the new offerings. That said, I spend most of my time in the 32t but do go up and down the entire 11-32 cassette. If I was running 26-39 or whatever up front, I think I'd be shifting up front a lot more, and shifting up front is a lot less pleasant than at the back. It's better to avoid it where possible.
Sure, I might be "whinging about losing compatibility with my existing gear." I think it's very much worthwhile to keep compatibility. We've had half-inch pitch on chains for decades .. cause it works. We quickly went from 6 to 9 speed in the 90s .. and 9-speed has stayed with us for a decade because it works well. I still think the cons outweigh the pros.
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akashra
Eats Squid
The technical problems with going to 3:1 would be tremendous. To gear up (or down, depending on whether it's rapid rise/top normal) would be a huge movement of the shift lever, and you be needing some serious tension in the spring of the mech - not to mention trying to do so without it flying back it throws it too far past the gear you want to select.
Personally I think they would be better off going to 64T cassettes of the same diameter, spreading the load over significantly more pins, possibly even an infinitely geared CVT-like cassette (we already have seen HammerSchmidt with an internal anulus, so it's half way there). This would allow much more fine-grained gearing. The problem with this is you still need to make the links strong, as it's basically two links taking the entire chain tension.
There's an additional problem with narrower chains - teeth *may* need to be narrower to accommodate the smaller distance between the plates.
DaGonz
Eats Squid
You know... I have NFI what you're doing on your bike. I spend some long hours on a dirty shitty bike that's been through mud, dust, over lubed with a tried sloppy rider on board. I havn't bent a plate on a chain ever...
Again with the hasty generalisations... Ultegra 12-27 is nice in theory, doesn't have the mechanical range to be practical. I know a few guys that have tried it and gone back to 11:32 or 11:34
I'm not. Find me an 8speed casette that has a) decent shifting and b) decent mechanical range. As far as I'm aware, the MTB varieties ended at 28t. 9speed allowed them to go to 32/34 without too big a jump between gears. Sure you could got 14:32 or something I guess if you built a new casette. Or you end up with those low end casettes with massive jumps from the last sprocket. They kinda suck....
22:36 no doubt? I know 'cause I've considered it...
I am willing to be corrected here ('cause lets face it, 1st year physics was over 10 years ago) but I'm pretty sure Torque at the axle is a factor of the mechanical advantage being applied regardless of the size of the cogs. 29ers are a special case because a) the resisting torque is higher to start with and b) people are running 22:36 which means the mechanical advantage is higher. you're using a corner case without sufficient science to justify your reasoning. But Like I said, I'm willing to stand corrected... "show me the numbers son"
Have you tried the new SRAM front shifting? or perhaps if you only ever use your front 32, a nice 10speed spread out the back with 32:36 1x10 would be sweet...
Again, a negative comment without actual experience on the product
and I don't doubt the MTB manufacturers disagreed, otherwise we would have had 10speed on mountain bikes 10 years ago when the roadies got it. It may work, it may flop in a heap. SRAM are betting big that it's the way forward, shimano are betting either way. Time will tell I guess.
Cheers
spoonie
McBain
Likes Bikes and Dirt
XT came in 11-30 flavour.
DaGonz
Eats Squid
So to put this one to bed (and unless someone can correct me) Dredging through my head on the train. The torque at the axle is proportional to the mechanical advantage (ie gear ratio) being applied and not the size of the sprockets being used. Larger sprockets have the advantage over smaller cogs of more chain wrap and less chain tension. Less chain tension is achieved as you said, because the torque at the axle is the same, but because the cog is further out from the centre, the tension in the chain has to be less. Because there is more chain wrap too, more teeth (cogs) are applying force to more rollers so the shared force is less. Result is less strain and wear on the chain and cogs. Efficiency is also increased because the chain bends less as it is moved around the sprockets, so less friction on the pins as the chain pivots and again less wear.
So big/big is better! I think...
But again, that's dredging up first year physics and thinking about it a little. I could be wrong.
Your comment about the chains and surface area doesn't gel with me either, but I'm not going to comment further on that 'cause I don't know (and really that interested to check to be honest) exactly what it is they are changing between a 9 and 10 speed chain, other than the physical distance between the two plates... In some ways, a wider chain is more likely to wear on a geared bicycle because it's generally stiffer and less prone to bending sideways. a narrower chain I imagine would place less torsional load on the outside of the pins... (same chain tension, shorter lever)
Anyway, it's new technology, and new technology comes and goes. I'm sure people were equally bitching when we went from 7 to 8 speed "what do you mean I have to replace my hub to a free hub?" or even more when the "standard" road bike rear dropout width increased...
*shrug*
Cheers
Spoonie
Not even a little? Lucky you. I'm not alone in having done so.
b) SRAM PG8n0 are all available 11-32.
a) I don't know SRAM 8-speed cassettes are up to your standards shifting wise, but you've already admitted to a preference for the top end (carbon chi-chi) stuff, so XX is already there for you. The HG50 8-speed on my road bike shifts fine, even though it's low tech. I'm sure it's only "fine" because Shimano haven't bothered to put any effort into a more modern design, and nothing to do with the number of gears on the cassette.
Also, 42-24 * 11-36 still offers a slightly lower overall range than 44-22 * 11-34.
Yes, you're correct - you'd need an overall lower ratio, (IE by using a 22t) to apply more torque. 29ers are doing it though, so I wouldn't call it a corner case.
I use my front shifter - just as little as possible. Front shifting will never be as good as the rear, because of the bigger ratio and teeth count involved.
I still think the great majority of riders benefit more from better tolerance, wider range, higher strength and reliability of the lesser-speed systems VS the closer ratios of 10-speed.
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DW-1
Dirt Works
and it wan't difficult to buy (obtain) a 32T (34?) and bodge up a decent loaded off-road touring 8-speed cassette.
I have a "made-up" 8 speed down the back on an old touring wheel.
Elvis.
DaGonz
Eats Squid
How is that unique to the new SRAM 10 speed group sets?
while you are probably right, SRAM are claiming a "significant improvement" with their 2x cransets and that whole 1.5ratio thing. I think you would have to try it before saying that it's not practical or not efficient enough to do on a regular basis. Besides, they have triples as well, and you can chose a crank set that best matches your desire ratio levels. Personally I switch between big and middle a lot. It's common practice to put it in the dog on downhills to improve chain slack issues. Doesn't everyone?
Again I fail to see how this is an issue with 10 speed group sets? Perhaps your preference for crankset ratios arn't entirely met, but I'd dare say you'd be the exception than the rule. Besides, with 2x10 we've already established you can use the entire cassette width in either gear. Doesn't that mean less changing on the front?
Err wider range? didn't we just go over that's why we have 10speed? Reliability? of what? you're expecting the new groupset to spontaneously fail? how is that any different to any other new groupset?
I think your only claim you can make with any facts behind you (apart from chain strength, which I'll go into in a bit) is the tighter tolerances. So I started thinking about that too...
According to the Late Sheldon Brown, there's a 4.8mm spacing difference in the 8speed cogs, vs 4.34 for 9 speed and 3.95 for 10speed. Assuming you have to be over half way to shift then that means there's less than 10% tolerance difference between 8speed and 9, and similarily for 9 and 10. Divide that by two (for either side of the sprocket) and we're talking a +/- 0.4mm tolerance difference at the deraileur. In reality, the difference is probably less because well... the chains are a different thickness as well
(ed: I checked chain widths, and the loss in tolerance is still +/- 0.4mm)
In terms of cable pull that equates to:
Shimano (1.7:1): ~.24mm at the shifter
SRAM old (1.1:1): ~0.4mm at the shifter. possibly more noticable
SRAM XX (1.3:1): ~0.3mm at the shifter.
Assuming that the chain thickness differences reduce this a little, the tolerance differences here between it being one gear or the other are SFA between 8 an 10, though admittedly on "old" SRAM shifter you'd probably notice the difference in terms of making the cable up, between 9 and 10, I'd be surprised if you noticed the difference. That's +/-10% difference in tolerance between 8 and 10.
What would be of interest is to play with your 9spd drive train and see what .4mm of cable pull does. Would you really notice it in real life? or are we really talking peas and matresses here?
So on the chain strength front, I couldn't find any numbers of repute in my google search, but Wipperman claim their 9speed chains are as strong as their 8spd chains, despite "less metal". 10 speed chains do have less thickness in the plates but it's load spread across the surface of the plate. I don't know enough about material phsysics to figure out what the difference is (has more to do about cross sectional area I think. There are claims that other manufacturers have 10speed chains as strong as their 9speed. Wipperman is not one of those. From what I can make out, the rest of the kit (teeth etc..) are the same. in terms of width (2.2mm) so yes the chain will be weaker, may stretch easier, but wear well... we'll see really.
So after all that, we can say that:
* Depending on what your option you chose you get either more usable gears, closer ratios or wider spreads. We've already established for 99% of mountain bikers, one of these options is desirable
* The groupset as a whole is lighter
* the difference in tolerance is +/- 10% over 10speed or about 5% over 9spd Fractions of a mm loss in tolerance. Enough to notice?
* "increased torque" on the hub is either a furffy, or not unique to 10spd depending on what you're talking about
* Yes chain strength will probably be reduced but not sure by how much and if it'd be an issue. Effects on Wear and tear is yet to be defined.
* The 2x gives you better front shifting with the 1.5 ratio
...I'm sorry, what was the problem with the new groupsets?
*shrug*
Cheers
Spoonie
This is no longer true. XX uses 2:3 ratio between smaller:larger chainrings so that every 2nd/3rd tooth lines up. This makes changing gear at the front better than at the rear.
I have the 2:3 ratio chainrings setup on two of my bikes:
1) 2x9 X0 gripshift using 24-36 Blackspire chainrings with an 11-26 cassette. This front setup shifts better than it ever did as a 3x9 even though the Blackspire chainrings aren't ramped and pinned for the 2:3 ratio.
2) 2x10 XX 26-39 chainrings with an 11-28 cassette. This shifts unbelievably well, I'm still used to thinking ahead and pushing my front shifter slightly early so the change has time to occur before I really need it. Now, the change has already happened before I've finished pushing the lever.
I also prefer closer ratios on my cassette as this also seems to improve rear shifting and I no longer throw away worn out cassettes with brand new 30+ cogs on them.
My other bike is a three speed: 32x14 either sitting or standing; and walking.
bear the bear
Is a real bear
Good to see no one is taking this too seriously....slow day at work?
DaGonz
Eats Squid
yeah well...Good to see no one is taking this too seriously....slow day at work?
*shrug*
Cheers
Spoonie
jmcavoy
Likes Dirt
Wow, someone forgot his morning coffee
i only use 22:32 rarely. I have to drive a long way to find a big and steep enough hill to need that gear. Most of the riding i do middle ring is fine. That's with 8 speed gearing. Been running it for years. Works ok for my needs.
i run XTR 8 speed cassettes that are 11:32. I still have a brand new one here. I bought a stack a few years ago. They have lasted me a few years. The only problem i have is getting decent 8 speed shifters. I should have bought a stack of XT 8 speed shifters as well!
10 speed will be good for some people and not so good for others. I'm still living in the past running my 8 speed XTR cassettes so i'm probably the odd one out here.
Enduro Pulse
Likes Dirt
2x10 in 2010
So.... does anyone have the inside scoop on when 2x10 X0 or X9 will be available in Oz? Keen to spec it on a new ride but not sure if it's weeks or months away.
Cheers
So.... does anyone have the inside scoop on when 2x10 X0 or X9 will be available in Oz? Keen to spec it on a new ride but not sure if it's weeks or months away.
Cheers
+1 on the would be happy with 8 speed
If you're running 3 chainrings I can't see the need for 9 or10. 22-32 may be a slight advantage over 22-30 but I've never found the 34 any better for climbing and always replaced them with 32s. Even the 32 is often a little too low for tech sections where you need a little more drive - it's more a take it easy gear than a pinch gear
I thought the load on chains was theoretically at least taken on the roller. The roller on 8sp chains is wider than on 9spd. This should spread the load over a greater area and I believe also holds more chain oil. My experience of lubing 8sp vs 9sp chains was that the 8sp chain always took more oil but didn't need lubing as often. When my primary bike was 8sp I lubed it once a week, nowadays with 9sp it seems to be every ride or at least every second.
If you're going a single ring front maybe the bigger spreads are worth it. Otherwise I'd be happy going back to 8 speed. (Admittedly I have been known to ride singlespeeds but not so much recently)
If you're running 3 chainrings I can't see the need for 9 or10. 22-32 may be a slight advantage over 22-30 but I've never found the 34 any better for climbing and always replaced them with 32s. Even the 32 is often a little too low for tech sections where you need a little more drive - it's more a take it easy gear than a pinch gear
I thought the load on chains was theoretically at least taken on the roller. The roller on 8sp chains is wider than on 9spd. This should spread the load over a greater area and I believe also holds more chain oil. My experience of lubing 8sp vs 9sp chains was that the 8sp chain always took more oil but didn't need lubing as often. When my primary bike was 8sp I lubed it once a week, nowadays with 9sp it seems to be every ride or at least every second.
If you're going a single ring front maybe the bigger spreads are worth it. Otherwise I'd be happy going back to 8 speed. (Admittedly I have been known to ride singlespeeds but not so much recently)
bear the bear
Is a real bear
Not sure they are...
If you got to SRAMS 2x10 website they are only promoting XX & X7. There was mention earlier this year of X0 and X9 being 10spd but whether they are who knows.
tomacropod
Likes Dirt
They will be - at least early press releases depict the X0 and X9 groupsets as 2 * 10, using XX-esque cranks and cassettes.
Regarding your earlier outburst, your subsequent posts reinforce my point. My concern is not for the racer, wannabe racer or hardcore e-biker, thus not anyone reading this thread. My concern is for the consumer, the punter. X7 and SLX are priced very accessibly and found on bikes down to $1000, almost a throwaway price these days. I believe that longevity and low maintenance requirements of gear at this price level have more to do with positivity of experience than performance or gear range does.
As for your personal attack on my experience - I work on around 2000 bikes per year, ranging from shitters, to mid range, to high end road and mtb. I'm in a good position to correlate bike type with user-maintenance, miles done, and subsequent wear. I also work on the retail end, selling bikes, parts and talking to riders about their experiences with their bikes. I've been racing and riding all sorts of bikes for over 10 years. It's foolish to attack people you don't know, no matter the forum. My Jack Russell will never learn that, but you might.
My experience tells me that 9spd drivetrains (chains, cassettes, chainrings) wear out slightly faster than 8spd drivetrains, but that 10spd drivetrains wear out significantly faster than 9spd drivetrains. I'm not an engineer, but have theorised that this is due to the narrower load-bearing surface in the 10spd chain coming in below a deformation threshold with typical rider power inputs, maybe an engineering student here can help with that one.
Chain wear aside, there are also issues of shifting accuracy as has been mentioned in this thread already. The more sprockets you have to squeeze into a 130 or 135mm dropout, the closer they are, and as such the smaller the detents in the shifter ratchet. This requires that a smaller unit of cable pull is utilised in order to make the derailleur pull across the smaller distance to the next sprocket. With 100% efficient cable this is not an issue, but no shifting cable transmits force with 100% efficiency. There is always some compression of the outer cable, some stretch of the inner cable which reduces this efficiency.
With new cable and perfect adjustment, 10spd systems shift fine. In reality though, it's a bicycle. It gets ridden outside, dropped, leaned against things, left in the elements and generally neglected. The efficiency of that cable is only going to get worse the minute it leaves the shop or workshop. Let it get below a certain level and shifting goes to rubbish - and that level is higher for 10 spd systems than 9, for 9 than 8.
That's just cable, when you include issues such as jockey wheel and bushing wear, misaligned hangers and derailleurs, worn cassette teeth etc, it gets much more complicated.
See you at the races.
- Joel