I have done multiple searches on this forums as well as other forums, nothing really looks at these two specific cassettes under the microscope as I would want.
Now before anyone says “Dura isnt worth the money…” I have opportunity to purchase a Dura Ace 7800 cassette for $80 (local seller), at the same time, Ultegra 6700 Cassettes go for $80 at my local Performance Bike. So now price is no longer a factor. At first, I thought the answer was obvious, but there have been many saying while Dura cassettes have awesome shifting, they dont last that very long. I always thought the Dura has something to do with being Dura-ble. I heard ultegra cassettes are alright but not as good as Dura in performance. I understand that Dura cassettes use titanium on their 3 largest cogs, is titanium really that horrible as a wear parts?
This will be going on my Trainer/Race/Everything bike. Im the kind of guy who takes the time to clean and wipe down his chain, cassette and cranks every other week.
What is performance? It’s not like you are going to be riding a cat 1/pro crit where you actually need precision around corners and for sprints. If you are doing just triathlons, chances are you just changing 1 at a time. For a starters triathletes should take pride in their bike and clean it and get their cable housing changed - that will give performance!
Most cassettes dont wear in the largest 3 gears, typically in the middle where you spend the most time. I havent noticed any difference in durability and on a clean well kept drivetrain they both shift equally (IMO).
If you can get a DA then go for it, you will save a few grams, when its worn then keep the lockring as its nicer looking and a couple grams lighter than the Ultegra.
The name Dura has nothing to do with Durable.
In fact the opposite is true, Ultegra is more durable and the shifting will be the same, the one and only difference is the weight, but if this is going on your every day training bike, I would say that even at the same price you should go with the Ultegra, you will never notice the difference in the weight and it will last longer, plain and simple.
sorry for not being more descriptive in my terminology “performance”
i know a cassette isnt going to make you 1-2 mph faster. what i mean by performance is shift quality. having a crisp and clean shift when you push down on the bar end.
heres an example. my girlfriend’s bike uses ultegra bar ends and a sram 970 cassete with matching sram chain. sometimes on upshifts when inclines comes, she will click the shifter and nothing will happen, she will click up one more time and then it will finally give and shift 2 gears. this is most noticeable in the largest 3 gears on her cassette. my old bike was a zipp 2001 with old school dura components (from early 90’s) and the shiftf worked flawless on it’s 8 speed system.
reading other forums have led me to believe that dura ace cassettes will never miss a beat, always shift when told to. while ultegra isnt quite as sharp on the shifting. it is however touted that ultegra is very long lasting. there arent many other posts online in slowtwitch, roadbikereview, or cycling forums that support these claims so im taking it as outlying opinions that may or may not be true.
my primary cassette criteria are
cost (but both for me are equal in price at the moment)
shift quality
durability
so now im trying to investigate the last two criterias. i was originally making an assumption that 6700 and 7800 cassettes were exact other than that shimano swapped out the biggest 3 cogs for titanium. Im assuming that the teeth design would be identical. tell me how wrong i may be…
Sorry, only now, a day later, do I realize that the cassette was 7800, not 7900. Below I was assuming 7900. You’d think I might read the title of the thread…
The shift ramps are, at least as far as I’ve read, shaped identically between Ultegra 6700 and Dura-Ace 7900. The main difference is weight. And that reduced weight comes mostly from 3 titanium cogs on the Dura Ace (the 3 big cogs) which will wear down faster than steel equivalents on the Ultegra 6700.
If it were me and the price was the same, I’d buy the Dura-Ace but I would bet that there are very people who could tell any shifting difference blindfolded.
For you, since cost is the same and – assuming I’m right – shift quality will be the same – the obvious choice is the Ultegra 6700 cassette. It would last longer
heres an example. my girlfriend’s bike uses ultegra bar ends and a sram 970 cassete with matching sram chain. sometimes on upshifts when inclines comes, she will click the shifter and nothing will happen, she will click up one more time and then it will finally give and shift 2 gears. this is most noticeable in the largest 3 gears on her cassette. my old bike was a zipp 2001 with old school dura components (from early 90’s) and the shiftf worked flawless on it’s 8 speed system.
99% probability this has nothing to do with your cassette, but is a function of maladjusted derailleur/cable tension
So for the average triathlete is it even worth ultegra? I know with 105 you are taking a weight hit, but minimal shifting over a fairly flat course… Whats the consensus?
The chain is more important than the cassette. Get the latest Dura-Ace chain and service it with Mobil 1 OS 30 or 20 for Hybrid engines. Then use the cassette of your choice.
This chain with this lube will give you 5000 miles of use.
in general anything above 105 is being done for bling =)
but sometimes you find really good deals on ultegra/dura ace bits so why not take the microseconds of time savings due to reduced mass?
So for the average triathlete is it even worth ultegra? I know with 105 you are taking a weight hit, but minimal shifting over a fairly flat course… Whats the consensus?[/quote
I think what others have said is really true. You’re not going to be able to tell the difference between them with respect to performance but the Dura Ace does have less rotational weight.
BTW, who ever mentioned that the “clean crisp shift” has very little to do with the cassette is correct (especially if it’s periodically inspected and cleaned). I would tend to agree that it has more to do with the rear derailleur being adjusted properly, proper cable tension, and operating bar end shifters.
The reason for investigating cassette performance rather than derailleur or cable tension is because the derailleur is a respectable 105 and the chain is ultegra and new. The condition where she shifts with no response then shifts up again then finally responds leads me to believe that the chain is not properly engaging the cassette teeth. When her bike is on the stand and the cranks are spun by hand while shifting, derailleur alignment is spot on and shifting is perfect. However in the real world where the chain and cassette are undergoing significant loading, the drivetrain seems uncooperative. This can get very annoying when climbing a hill and she is forced to shift from a 39-23 to a 39-19. Thats a surge of about 20% more torque requirement and does not make happy quadriceps.
I dont want to turn this thread into a “Help me fix my GF’s bike” discussion. I want to focus on cassette performance. Im thinking shift ramps may be a crucial thing to look at. Basically Im looking for a “6600/6700 has the SAME teeth design as 7800” confirmation, so I can just forego the dura cassette. I did a quick look up on which material wears better on a purely material standpoint. Steel has a Brinnel Hardness number of about 1500-1900. While titanium has a brinnel of only about 330. This would mean that steel is 5-6 times harder than titanium am assuming that maybe the teeth will follow the same trend.
Now that SarahConnor brings it up, can automotive oil be used successfully to lube chains? I really want to dig into this.
Quick question, are both the ultegra and dura ace cassettes new? If not, I’m heavily leaning towards the ultegra. Unless you are experienced and know what to look for in terms of used cassettes, you are safer going with new over used especially a ult vs dura discussion.
However, if they are both new, I would go with Dura Ace for bling factor even though it might not last as long but if you are like the rest of us, you’ll prolly toss the bike before swapping to the next cassette.
For some reason, Dura-Ace cassettes have a much higher resale value which is weird to me. I’m not sure why people would pay such high prices for a used drivetrain component especially a cassette!
As far as I have understood, the shift ramps are the same for 6700 and 7900 cassettes, both are updated from the 7800 (and 6600). I run a 6700 casssette with a 7900 chain. I works perfectly. After a season of riding I have no noticeable wear on the cassette. I changed the chain halfway through the season. The only reason I didn’t get a 6700 chain is that I got the 7900 chains on sale. I recently put on a 6600 cassette for riding the trainer, and I think the 6700 cassette shifts a bit better (crisper, faster) than a 7800 or 6600 but the difference is small.
As for chain lube, I have not come across anything that works better than Pro Gold, Pro Link. The disadvantage is that you have to lube the chain before every second or third ride. In my opinion it is worth it.
I have DA 7900 on all 3 of my bikes and I’ve run 6700, 7800, 7900 cassettes. I’ve had no problem with shifting. On average there is about a 40 gram difference in weight between a 6700 and 7900 cassette. I have not had the 6700 cassettes on long enough to tell you if they last longer than 7800/7900 ones. I like the 6700 more than the 7900 because of the cost. Cheapest 7900 cassette I found this morning was around $179 vs $59 for the 6700.
generally I try to keep technology always in the same generation if I can. They made a special chain for 6700/7900 and makes you think it might work a little better when matted with a ‘like’ cassette.