Dura Ace 7900/9000 crankset photographic comparison
adamfo
Posts: 763
The 9000 is a fraction lighter according to my scales.
9000 compact 452g, 180 crank arm 179g
7950 compact 477g, 172.5 arm 183g, BB 89g
Ultegra 6800 compact 489g, 172.5 arm 197g
The 9000 BB was a fraction lighter too. Requires a special size plastic ring to tighten which is included in it's box.
Teeth profile, alloy colour, paint type, distance between rings and BB bearings are all different on the 9000.
The crank arms are huge but weigh less therefore the 9000 alloy must be thinner. You can also see the joint on the back of the arm which is a bit ugly.
I can't talk about function, but the 7900 feels a bit better quality in the hand and the 9000 a bit more bling. The gloss black paint finish of the 9000 probably does match more frame colours than the satin grey of the 7900.
7900 teeth alloy is more tungsten in colour.
9000 teeth
Outer teeth more pointed profile on 7900 and inner ring teeth flatter
9000 compact 452g, 180 crank arm 179g
7950 compact 477g, 172.5 arm 183g, BB 89g
Ultegra 6800 compact 489g, 172.5 arm 197g
The 9000 BB was a fraction lighter too. Requires a special size plastic ring to tighten which is included in it's box.
Teeth profile, alloy colour, paint type, distance between rings and BB bearings are all different on the 9000.
The crank arms are huge but weigh less therefore the 9000 alloy must be thinner. You can also see the joint on the back of the arm which is a bit ugly.
I can't talk about function, but the 7900 feels a bit better quality in the hand and the 9000 a bit more bling. The gloss black paint finish of the 9000 probably does match more frame colours than the satin grey of the 7900.
7900 teeth alloy is more tungsten in colour.
9000 teeth
Outer teeth more pointed profile on 7900 and inner ring teeth flatter
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Comments
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More of a campag fan myself, although I do have 7900 on one of my bikes. I have to say, I think the 9000 looks horrible. The new ultegra looks even worse.argon 18 e116 2013 Vision Metron 80
Bianchi Oltre XR Sram Red E-tap, Fulcrum racing speed xlr
De Rosa SK pininfarina disc
S Works Tarmac e-tap 2017
Rose pro sl disc0 -
I took some pics of the new Ultegra. Like the 6700 the back plate of the hollow chain ring is bonded in place and looks messy close-up.
Unlike the 6700 spider which looks seam welded, the 6800 spider appears glued together.
6700 (silver)
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One thing that's been puzzling me is how the Dura Ace chain ring is made. It's hollow so must be fabricated from two parts. On the lower back panel near the crank spider you can see the join but on the outer teeth section you cannot. I've had a look with a loupe and cannot see any fused or welded seam ! How is it made ? 0
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The amount of machining that goes into chainring and cassette teeth never ceases to amaze me.Music, beer, sport, repeat...0
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Terrific photography mate!
How much better is DA over Ultegra?Giant TCR Composite 30 -
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964Cup wrote:
Shimano chainrings are forged, not machined, as it happens.blinddrew wrote:The amount of machining that goes into chainring and cassette teeth never ceases to amaze me.
The blanks are then extensively machined. Five angle on one tooth for example. Note the milling on the 7900 cut outs. Some of the 9000 ones are not machined. A simplified product.
The 7900 is on my Cannondale Supersix the rest is back on the shelves of CRC.
I'll take some pics of Campag chorus in due course.0 -
Vandiesel wrote:Terrific photography mate!
How much better is DA over Ultegra?
I think the 6800 will operationally be very similar to 9000 for half the price. Both have the new teeth profiles.
The teeth on the 9000 main ring are flatter topped and generally smoother finished than on 7900. The teeth appear to be polished on 9000. 7900 has a more technical look.
Conversely the 7900 small ring are flat topped and 6800/6900 higher pointed in profile.
The look of the 6800 groupset didn't really do it for me. Various shades of blue/dark gray vs. gloss black paint and what looks like hand polished alloy on 9000.
The 6800 crankset finish appears smooth anodized. The 9000 crankset may be smooth black powder coated and the 7900 rougher gray epoxy type paint.0 -
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They both are no doubt very very good at their job, but both look awful really. It's as if every individual piece of these modern Shimano groupsets is shouting 'look at me, look at me' and when you put it all together on a bike the bike looks like a dog's dinner of items that are all individually screaming and fighting for your attention. A bit like a family car with loads of spoilers, ducts, flash wheels, over styled headlights, in your face style of exhaust and loud graphics always looks tasteless regardless of the quality of the parts.
One day they might get the aesthetics sorted, but I doubt it.0 -
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Talking of expensive chainsets, does anyone know what sort of money the Dura Ace 7800-C fetch on the used market ?
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An excellent post adamfo, I've really enjoyed reading it
and your photo's are very good too.
I know, I'm sad and should get out more !!!!!0 -
Dura Ace 7800 C New - £549.99 at Sigma Sport !!!!!!0
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madasahattersley wrote:Love the new 9000. Impossibly beautiful, and IMO works better than the other 2 high end group sets.
Seriously? Impossibly beautiful? Seriously?0 -
Adamfo, why :shock: :shock: :shock: ???0
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Merlin have currently got the 9000 crankset @ £285 which is the cheapest I've seen for the compact version
http://www.merlincycles.com/bike-shop/r ... inset.html0 -
OP - FYI I sold a DA carbon chainset about 18 months agi on ebay - it fetched just over £400 as I recall.0
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nochekmate wrote:OP - FYI I sold a DA carbon chainset about 18 months agi on ebay - it fetched just over £400 as I recall.
Certainly seem to hold their value then.0 -
So time marches on and there is a new 105 crankset. I've only seen photos but is that a plastic composite back panel bonded onto the back of the chainring ? It must be of a 2 piece construction because the chainring is of hollowtech construction not solid like the old 5700.
https://www.flickr.com/photos/13647127@N04/sets/72157645790442968/0 -
how new? I've had one for several months now and it's all metal on mine, is there a newer one than this?0
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One thing that's been puzzling me is how the Dura Ace chain ring is made. It's hollow so must be fabricated from two parts. On the lower back panel near the crank spider you can see the join but on the outer teeth section you cannot. I've had a look with a loupe and cannot see any fused or welded seam ! How is it made ?
I did eventually find out the answer! The chain ring is welded up on the front face and the joint machined and polished invisible. One of the reasons for the premium price of Dura Ace and the XTR crank pictured bellow
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So time marches on and there is a new 105 crankset. I've only seen photos but is that a plastic composite back panel bonded onto the back of the chainring ? It must be of a 2 piece construction because the chainring is of hollowtech construction not solid like the old 5700.
The outer chainring is solid metal and not of a hollow, two-piece construction as it is with Ultegra and Dura Ace. It is cheaper to make and weight is kept down by the 'pockets' on the rear of the chainring. I'd guess that they're of a forged construction. The 'Hollowtech' description refers to the crank arms, not the rings.0 -
The outer chainring is solid metal and not of a hollow, two-piece construction as it is with Ultegra and Dura Ace. It is cheaper to make and weight is kept down by the 'pockets' on the rear of the chainring. I'd guess that they're of a forged construction. The 'Hollowtech' description refers to the crank arms, not the rings.
OK thanks, I've got one coming in , I'll take some close up photos.
The German magazine Tour tested the 5800 group set and it was high marks all round apart from the crankset. The torsionally rigidity was less than the old 5700. The teeth metal was a bit softer too although it was noted for the profile of the rider using it, the stiffness level was of little consequence.
google translation:
http://translate.google.com/translate?hl=en&sl=auto&tl=en&u=http%3A%2F%2Fwww.tour-magazin.de%2Ftechnik%2Ftest_center%2Fkomponenten%2Fkomplettgruppen%2Ftest-2015-shimano-105%2Fa34077.html
original:
http://www.tour-magazin.de/technik/test_center/komponenten/komplettgruppen/test-2015-shimano-105/a34077.html0 -
Regarding the forged vs machined debate.... no chainring would be just forged. It would be forged from a solid billet as a first process to give it strength and then machined to a more precise shape as a second process.0
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My guess is cold forged alloy then heat treated for strength. The final machining is extensive as seen in my previous 7900 close up photos.
The crank arms are welded up from 2 pieces. You can see the joint on the back of the 9000 arms.
There used to be a video on Youtube of the Dura Ace production line. I think they removed it when all production was moved to Malaysia
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