If I were to upgrade from a complete Shimano Sora R3000 9 speed groupset to a complete Shimano Ultegra 6800 11 speed groupset (excluding hub) on a Giant Defy 3, do I need to get a new hub too or can I just reuse the old hub?

I have never changed the groupset before since I never had the need to change it so I do not know what else do I need other than the groupset itself but since my old groupset is dying on me, I have to change it soon and I though why not upgrade it to an 11 spread instead of simply just replacing the old groupset to the new one

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    @JBeurer Sora to Ultegra very much is an upgrade! And there is no reason why a 10 or 11 speed drivetrain would wear any faster than a 9 speed. May 9, 2018 at 11:01
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    @JBeurer 11 speed uses newer materials and manufacturing processes. In all honesty I have been getting longer wear life from 11 speed than 10 speed, and I didn’t notice much difference between 9 and 10. I would classify this as a myth.
    – Rider_X
    May 9, 2018 at 12:59
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    @JBeur Having ridden Ultegra, 105 and Tiagra I know there is a difference in shifting performance and 400g is not negligible. Shimano is not so stupid as to make their groupsets indistinguishable. I do agree that this upgrade proposal does not make much sense as the rest of the bike is still Sora level. May 9, 2018 at 15:03
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    Do you have a source on any of this, or are you just making it up as you go? The finish on the chains makes a huge difference. I haven't seen testing on Sora to compare to the 11 speed chains, because they only test reasonably high end components, but have a look at the testing done by Zero Friction Cycling. They found that the Ultegra chain lasted 4.5% longer than the 105 before reaching the same elongation (chain wear and elongation are functionally the same thing). They even found that a Dura Ace chain lasts 30% longer than a 105. Mar 17, 2019 at 9:08
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    @JBeurer I'm sorry but you're talking nonsense. 10/11-speed sprockets are not "super-thin": just eyeballing them, I can't see any difference between 10-speed 105 and bottom-of-the-range 7-speed Tourney. (I have nothing to measure them with, but it 10-speed really was "super-thin", there'd be a visual difference.) Of course, the cut-outs on higher-end groupsets don't make them more durable, but I've never heard of anyone breaking a cog: cassettes get replaced when the teeth wear down. Mar 17, 2019 at 13:04

3 Answers 3


On road drivetrains the freehub body was made a little wider for 11 speed to accommodate the extra sprocket (34.75mm for 8, 9 and 10 speeds to 36.75mm for 11 speed), so unfortunately the 11 speed cassette cannot be mounted on your hub.

I believe there may be some hacks to get over this, but I cannot provide any information.

Edit: Some 11 speed cassettes will fit on an 10 speed freehub body, specifically larger sizes where the large sprockets can overhang the inboard end of the freehub body, I believe.

You could upgrade to the 10 speed Tiagra group which would still be a substantial bump up in performance and reduction in mass.

It could be said that going to Ultegra is not worth the cost as the rest of the bike is still at Sora level. Also, separate groupsets are relatively expensive, and you have to take into account the cost of installation. Very often it's a better idea to simply buy a new, upgraded bike and sell your old one.

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    Aren’t most hubs from the last few years 11-speed compatible? OP might have an 11-speed compatible hub with spacers installed. Only measuring the freehub body can tell for sure.
    – Michael
    May 9, 2018 at 11:18
  • @Michael I guess that is a possibility. I would not know how to tell without removing the cassette though. A Sora equipped bike from Giant is likely to have unbranded hubs so it would not be possible to look up the specs of the hub model. May 9, 2018 at 11:47
  • I do plan to change the entire sora level stuff to ultegra level since I'm changing the groupset. There is a clearance sale on CRC that sells a ultegra groupset that includes 2 shifters, a 11 speed cassette, the chain, front and back derailleurs, front and back brakes and a BBR60 bottom bracket, so if the hub that I'm using isn't compatible with the 11speed cassette, I'll simply have to buy the new hub. That's what I'm thinking but I'm not sure if that's doable or not since I have never done upgrading...
    – Lavenger
    May 9, 2018 at 16:30
  • By 'the rest of the bike' I primarily mean the frame, forks and especially wheels - they will still be entry level. May 9, 2018 at 16:35
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    an 11-34 Ultegra hub will fit on a 10spd cassette
    – Paul H
    Mar 18, 2019 at 23:17

Posting in case anyone else is thinking of doing this: as pointed out already, 9/10s Shimano hubs won't typically take 11s road cassettes, but they will take the 11-34 H800 (Ultegra level) and H700 (105 level) cassette, which will require the medium cage rear derailleurs to work properly. I believe the 9/10s hubs will also take 11s MTB cassettes, and I have heard the smaller ones can also work with medium-cage RDs, but I do question if most people will need them.

These cassettes work because the last cog is cantilevered over the drive-side flange of the hub.

11-34 has a bit of a big jump between sprockets, however, so do take note.

  • An 11spd, 11 - 34 cassette has similar jumps to the 9spd, 11 - 27 cassettes of days past, just more of them
    – Paul H
    Mar 20, 2019 at 3:19

Although I typically favor preservation by timely, routine maintenance along with replacement/upgrades that are first, thrifty and second, actually an improvement to the machine. It's very easy in this business/hobby/passion to be guilty of putting lipstick on a pig. That is not to imply any sort of poor thinking when one wishes to experience Ultegra instead of old Sora. Pretty logical, in fact, as the kilometers tick by day after day. I spent about 25 minutes doing a little web-surfing research as I thought about your situation, and here's what i think:

This Giant freehub body is 11 speed, swap-able with your current Defy hub and costs a reasonable 20 pounds. I doubt your rim is trashed and it can be made rideable again. One consideration may be the degree of wear on the rim's braking surface (though i didn't see it specified, it's likeliest your 2-3 year old Defy 3 has Tektro caliper rim brakes). The Giant SR2 rim has a machined groove around its circumference which is a wear indicator common on rim-brake rims. The rim's useful life is about done if this groove is worn smooth. I mention this because, it may be a better value to obtain an entirely new wheel that comes with an 11 speed hub. The repaired, old rim becomes your backup.

There are several listings on Ebay for new (and used) Ultegra 6800 groupsets. They're running around $700 with shipping costs considered. Obtaining just the derailleurs, shifters, chainset, and cassette (that's the minimum of components needed going to 11 speed) will run into the neighborhood of $400. Neither of these options consider the cost to put these components on and get them in tune.

According to Bicycle Blue Book, a 2016 Giant Defy 3 is valued somewhere between $2-300. A high quality groupset represents the greatest chunk of a bike's consumer cost, so I'm not trying to point out the discrepancy in the bike's value "as is" vs. new component cost since I'd be willing to venture that in a cost analysis of a new bike's price, the components comprising the "groupset" represent 2-2.5x the cost of all else that makes up a complete bicycle. That said, this discrepancy does give one pause when considering the "upgrade."

Finally, note that a 2018 Giant Defy Advanced lists for $1685. This gets you a carbon composite frame, disc brakes, and the 10 speed Shimano Tiagra Groupset, which should be very close in quality and performance to Ultegra 6800. Interestingly, if it happens to be Tiagra 4700, this model number utilizes the same shift actuation ratio as Shimano's 11 speed groups. Relevance here is that, presumably, one could do a future upgrade to 11 speed Ultegra a bit more conservatively--piecemeal, if you will--since the 4700 Tiagra shifters would correctly control 11 speed Ultegra derailleurs that you could pair with an 11 speed Ultegra cassette when the Tiagra cassette wears out. Conventional wisdom states one wears through two cassettes (and at least 2 chains) before the chainwheels need replacing. If you keep to your current bike mileage pace, in a little over 2 years time, you'll be fully Ultegra on a bike whose material and geometry remain in the upper tier of the bike world. In this case, buying new at a well-defined cost(and acquiring the benefits of warranty and one or two free services for the new ride) far outweigh the expenses and risk of this proposed upgrade.

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    Hmm. I don't think the Tiagra shifters have the same shift actuation ratio as the 6800s. The relevant metric for shifters would be cable pull, i.e. cable pulled per shift. And in any case, the 6800s have 10 clicks, and the 4700s have 9. So, the OP will need to replace the Tiagra shifters anyway if s/he wants to go to 11s. Now, the derailleur actuation ratio may be identical, so the OP could maybe just put 6800 shifters on. artscyclery.com/science-behind-the-magic/…
    – Weiwen Ng
    Mar 21, 2019 at 18:54
  • @Weiwen Ng The most expedient evidence i can provide that Tiagra 4700 is engineered along the lines of 11 speed 6800 is Shimano's Dealer Manual for road rear derailleurs. Specifically listed together are the model #'s 9000, 6800, 5800, and 4700. At any rate, the differing number of detentes between the shifter models is a key point I've overlooked in my "solution." You're suggestion to go with 6800 shifters likely works since the extra click can be limited out at the derailleur should they choose to keep the 10sp on. Thanks!
    – Jeff
    Mar 22, 2019 at 5:46

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