Next gen Dura Ace

[xiyuwang]

Anyway, I am currently happy with my new 11-34 cassette that no longer makes the noise. I hope Shimano can refund me that old 11-30 cassette taken down from another bike of mine (probably an early batch cassette). It's totally normal that early batch products can go wrong, this has been the case in many industries and I wouldn't be surprised if this also applies to Shimano. Still, ultimately it is burning my time to go through all these processes and argue with distributors. (It's hard enough to get nerds here to believe the story... LoL)

Another interesting story I heard from a shop mechanic I am familiar with: 7170's brake caliper can sometimes have a very narrow gap and the disc rotor can rub the pad non-stop. This is in total contrast with Shimano's claim about a 10% larger gap that is supposed to make aligning the disc rotor easier. They had since then claimed a ew times to Shimano regarding this caliper quality issue.

Let's just steer away from this so what boring topic that is off the original intention of this post.

[Shiny]

Oops, double post

[Shiny]

Shimano really needs to step up their game when it comes to power meters, SRAM is way ahead with their Quarq chainring and spindle PM.

What i'd like to see is, similar to SRAM (actually, exactly like SRAM) a modular crank with carbon crank arms to drop some weight and a spider based PM.


Rest of the groupset: I really don't know where Shimano wants to improve.
(other than these super annoying, sticky Ultegra pistons, but that might have to wait)

[Styp]

Shimano really needs to step up their game when it comes to power meters, SRAM is way ahead with their Quarq chainring and spindle PM.

What i'd like to see is, similar to SRAM (actually, exactly like SRAM) a modular crank with carbon crank arms to shed some weight and a spider based PM.


Rest of the groupset: I really don't know where Shimano wants to improve.
(other than these super annoying, sticky Ultegra pistons, but that might have to wait)

Especially for gravel, I see a massive need for spider-based PMs.
The crank arm is just too exposed. This doesn't mean it will break immediately; it's just more wear and tear and expensive replacement costs.

[Lelandjt]

You can expect a new proprietary charger cable connector that is incompatible with the ones you already have.

It would be smart for Shimano to go full wireless. Not because end users want it but because it cuts labor hours required to build bikes.

Gear range could be addressed by going to 13s.

"Improvements" that do nothing for fast riders while adding weight. Sounds about right since that's a description of my 9200 vs my 9000. Sucks when parts get worse (and more expensive) over a 12 year period.

[xiyuwang]

13 speed seems to only make sense if they want to come up with some 11-34 cassette that has a 16t cog. I found cogs from 17t-14t much more important than smaller ones simply because I cannot reach that fast. With a 50t chainring and cadence at 90rpm, 16t is perfect for riding at around 31-33kph. If I use the 11-34 cassette, I have to either choose 17t with a noticeable higher cadence, or 15t with a lower cadence... unless I use a 52-36 chainring to compensate for the lack of 16t. I do like the 34t og, it saves me on steep climbs multiple times.

Still, Shimano could easily come up with a 12-34 12 speed cassette that does have a 16t cog and just remove the useless 11t (at least to me in 98% of cases). Back in the day of 11 speed, you have so many different cassettes to choose from, you have ones that have fewer small cogs and you also have ones that are packed with small cogs.

[cleanneon98]

I know exactly what you mean about that 16t, my old 11s 11-28 didn't have one and it was less than ideal even with a 52/36. The 12s 11-30 does have a 16t but maybe not enough of a bailout gear for some people in hillier places than mine

[BdaGhisallo]

A 12sp 12-30 cassette would be great. I have no need for the 11 and it would be nice to get the 18 back.

[wltz]

At the moment it seems Shimano either gave up on the battle for market share with ubiquitous Chinese vendors, or are having manufacturing issues. They released 12sp GRX with just 2 already existing Ultegra and 105 cassettes, which is baffling.

This is the kind of choice I'd love to see from Shimano: https://edubied.com/products/dubied_mon ... 5043604630.

Alas, this will never happen: tighter ratios in the middle with bigger jumps on the low end just goes against Shimano's philosophy. Their 11sp 11-32 Ultegra cassette had a nonsensical 14-16-18-20-22 in the middle. I've been using SRAM XG-1190 cassettes with r8070 for this exact reason, and I'm getting an Edco 11-32 12sp cassette for my first Shimano 12sp build.

54/39 with Edco 11-32 at the back is the closest match to 50/34 with 11-28 I'm coming from, with the added top gear I'm currently missing. I'd take a DA cassette even with a weight penalty if it was available, but it ain't gonna happen I'm afraid. 34t largest cog is too much for an aero bike and the kind of riding I build it for - I have a dedicated climbing bike for massive climbs, and 16t is the new 15t now that the chainrings have grown big asses again.

[Hexsense]

Maybe it's purely my wish alone but can we get rid of 53/39 and replace it with wider range front rings?
Currently it is 50/34, 52/36 and 53/39, then 54/40 and finally 56/42.
Does it look weird to you?

In the age of Di2 front shifting+ auto shift compensation and wide range cassette, I don't see the need for small range front rings anymore.

IMO, it should have been
50/34, 52/36, 54/38, 56/40.

[XCProMD]

Shimano is still on the page of cold-forging their cassette cogs. To be fair, this tech is fine and it is what they are famous for. What could go wrong with it is that manufacturing errors can accumulate when they are putting every separate cog together. They have to maintain a very high level of precision and consistency across different molds for different cogs... So when it comes to putting 12 different cogs together... what a nightmare it could be.

Plus, molds do wear out eventually if they solely rely on their experience of when to replace the mold... though they probably will do measurements, but molds are expensive to replace. Check what Intel is doing for their wafers and just selling bad CPU to the market (if you also build PC yourself, you'd know what I am saying).

Machining seems easier in terms of making sure the manufacturing error is consistent for a particular cassette. But machining is more expensive as well, which Shimano definitely doesn't like. They are likely to prefer what could produce the most amount of products in a shorter time. Their lower-end products are flooding the market because it is dirt cheap to make and manufacturing errors don't really affect the final performance.

The cogs are not cold forged. A boron steel / titanium cold rolled sheet is out into a transfer press and submitted to different cutting/forming stages (hence “transfer”) until the final shape is acquired. Then the steel cogs go to an induction austenitizing furnace and are quenched to give them the hardness needed in service (Shimano=around 35 HRC bulk hardness) after that comes pickling (to remove the austenitizing/quenching scale) and final hot dip coating.


Skickat från min iPhone med Tapatalk

And this process is what gives shimano cassettes their toughness and durability. It seems to be a general consense that shimano has 'better' shifting than sram. If the CNC cassettes were so great, why wouldn't shimano at least make their dura ace cassettes this way? Because their stamping process may be cheaper to mass produce parts but the initial setup cost will be much more expensive than a CNC machined cassette and produces better quality.

That process does nothing to give toughness. Boron steel + quenching gives hardness, oftentimes at the expense of... toughness.

The way a cassette lets the chain go from a cog to another is related to cog design and phasing, but has little to do with the manufacturing technology as far as it allows for enough precission to accomodate the tolearnces needed by the design. Which stamping does in the case of HG / HG +/ Linkglide, as far as the tools are kept in good enough shape.

This doesn't preclude the fact that machining is a technology that allows for better precision / tighter tolerances. It can't be otherwise as the tools used for stamping are... machined. Any process can only be as good as the preceeding process is a mech engineering joke (yes we do humour too here and there).

As I said, coating is becoming critical. spacing is getting so tight and cog design so detailed that any undesired material accumulation during coating results on noise or worse.

[satanas]

Maybe it's purely my wish alone but can we get rid of 53/39 and replace it with wider range front rings?
IMO, it should have been
50/34, 52/36, 54/38, 56/40.

Actually, SRAM's smaller gaps between the chainrings are something which IMHO make more sense. If you have a close ratio cassette like 10-28 or say 11-30 you can have 1T jumps over a very wide range, but with 16T chainring gaps (especially 50x34) there are bigger gaps in the middle, right where I don't want them.

Some of the e.dubied cassettes linked to above do indeed look very useful, more so than the stock Shimano options.

[TobinHatesYou]

Especially for gravel, I see a massive need for spider-based PMs.
The crank arm is just too exposed. This doesn't mean it will break immediately; it's just more wear and tear and expensive replacement costs.

Crank arms are one of the worst places to put a power meter due to non-rotational forces causing lateral deflection. A modular spider is isolated from crankarm flex and only experiences minimal lateral deflection from cross-chaining. Pedals as well do well in ignoring lateral deflection.

I expect crankarm power meters to basically disappear from the market entirely at some point.

[wltz]

Maybe it's purely my wish alone but can we get rid of 53/39 and replace it with wider range front rings?
IMO, it should have been
50/34, 52/36, 54/38, 56/40.

Actually, SRAM's smaller gaps between the chainrings are something which IMHO make more sense. If you have a close ratio cassette like 10-28 or say 11-30 you can have 1T jumps over a very wide range, but with 16T chainring gaps (especially 50x34) there are bigger gaps in the middle, right where I don't want them.

Some of the e.dubied cassettes linked to above do indeed look very useful, more so than the stock Shimano options.

Would you front shift big-small-big to progress smoothly through the middle range (gear ratios between say 3 and 2)? That's one of the selling points of the new TRP x Classified groupset if you are after such feature.

[Hexsense]

Maybe it's purely my wish alone but can we get rid of 53/39 and replace it with wider range front rings?
IMO, it should have been
50/34, 52/36, 54/38, 56/40.

Actually, SRAM's smaller gaps between the chainrings are something which IMHO make more sense. If you have a close ratio cassette like 10-28 or say 11-30 you can have 1T jumps over a very wide range, but with 16T chainring gaps (especially 50x34) there are bigger gaps in the middle, right where I don't want them.

Some of the e.dubied cassettes linked to above do indeed look very useful, more so than the stock Shimano options.

The reason small range front ring doesn't make much sense is that you got so much gear overlap with big range cassette.
When the cassette was 11-23, you have 2.09x range cassette. The front shift gear change 1.4x ratio (52/36 = 1.4). That leave you only 2.09-1.4 = 0.69x of overlap range.

Now, let say we have 11-34, it is now 3.09x range cassette. The front ring shift ratio (52/36) is still 1.4x. That leave you a lot of range (1.69x) that overlap between big and small ring. So, you can stay on big ring on climb far more than in the age of 11-23 cassette. You aren't forced to shift nearly as much as before.
So I think it'd be more valuable of the gear range to reduce overlap gears between big and small ring by making them more different.

Fig 1: how much gear overlap we now have with bigger range cassette. Top was 11-23 with minimal gear overlap. Bottom is 11-34.

Fig 2: Compare 54/38 vs 53/39. Even with bigger spread front ring, we still have a lot of gear overlap between big and small rings. It'd be better use of spread if front gain more ratio difference so that we need less range from the rear (thus tighter jump in the back).