The “Impossible”: 9-speed to 11-speed conversion
Goal: Give a 2002 Klein Quantum a lower granny gear and an update. It came with a Shimano 105 5500 9 speed road triple chainring setup with a granny gear of 32 gear inches. In 2002, this is how you got both low gearing and wide range. However, it is still significantly higher than either my gravel or mountain bikes. Of course, being a road bike, it also topped out at 115 inches for speed in the flats. This is much higher than the gravel 1×11 (88in) or even the mountain triple (100). But things have changed in the world of drivetrains in the last 20 years.
Let's go for a bit of a journey into the changes in road componentry in the last two decades:
- The most notable change has been the ability to put wide-range cassettes on the back. Back in 2002, this bike was equipped with a conventional (for the time) 12-25t cassette to go with a less conventional (on a non-touring bike) 52-42-30 triple set of chainrings. Modern non-race road cassettes regularly go to 32T and some higher.
- In addition, there has also been the advent of the ‘compact’ chainring setup at 50-34t instead of a more traditional 52-39 which allows for some lower gearing
- The Klein was also originally a 9-speed configuration while the world has moved on through 10, 11, 12, and even 13-speed rear setups. (Are you old enough to remember when a road bike was called a “10-speed” because it had a 2×5 setup?)
- The rear hubs have had the same axle spacing and freehub since the 8-speed days in the 1990s. This carried all the way through 10-speed configurations officially. This included both Shimano and SRAM using a common freehub ‘driver’ design known commonly as an HG (for HyperGlide) driver. This is a standard, splined cylinder on the hub that holds all of the sprockets of the cassette and allows freewheeling. But, the advent of 1x drivetrains has designers wanting both bigger AND smaller sprockets so the XD standard was released by SRAM (and now offered by everyone but Shimano) to support 10T (now common) and even 9T (SRAM hasn’t done it yet but others have) small cogs which when paired with a 52t top ring makes for amazing range. So, 12-speed SRAM gear wants XD drivers and Shimano 11 and 12s gear wants yet something else different.
- Other things have happened too. Brakes are better engineered for more and more modulated power delivery to the brakes. Cables are now ALL routed under the bar tape for a much cleaner layout. Shifters and derailleurs require much less force and travel to make the shifts (the 5500 series front triple requires a wrist-wrenching ~45 degree twist to the lever)
But how to do it?
I first started down the rabbit hole of the intermediary 10-speed configurations. Why? Because 10-speed is a drop-in upgrade on my solid (aka strong) wheels (being a ‘Clydesdale’ rider, I don’t mess with wheels that don’t break) and brings most of the range I want. Rear derailleurs are rated to 30T and widely reported to work fine to 32t. Cassettes are available in that size. The later 10-speed generations have nearly all of the refinements of the following 11-speed generations. And since it would be used gear, I could move up to Ultegra tier and still have it be relatively inexpensive. In theory. A bonus is that the first generation of 10-speed components still have the right vintage look for an early 2000s bike even though they are a decade newer. The second-gen 10s and later go away from the ‘silver’ color schemes to grey then all the way to black and more angular styling. Nothing wrong with that, but it’s different.
So I began the search.
Yes, it was going to be complicated finding a 10s group set that had the GS (longer) derailleur cage AND the compact crank (most have 52/39) AND 175mm crankarms (most are 170). In fact, it turned out to be downright exotic. That combination was technically available in the 6700 series Ultegra, but nowhere to be found.
Ok, shift to collecting the parts individually. GS derailleurs tend to be a bit more expensive and much less available but they are there. Although they tend to be priced nearly as much as a new 105 series one. Shifters are a challenge to find in good condition. It seems that grinding your shifters into the ground is a common reason for upgrading so the old ones are often beat up. But the real deal breaker was the crankset. 175mm compact configuration is less common and other people have figured out that the compact setup is better. Thus pricing ends up 2x or 3x the price of more common configurations. Used parts were reaching or exceeding the price range of a new 11-speed Shimano 105 R7000 territory. That’s silly. (But look for another page here where 10s comes back to the garage)
What about that 11-speed 105 R7000 configuration?
By all accounts, it is excellent. It is value-priced. Looks good (although not vintage). And it is the end of the line for Shimano mechanical shifting. They just released the new 105 with Di2 and say that is the future. And being also 'obsolete', some retailers are starting to deeply discount (Update: Turns out Shimano figured out people still want 105 mechanical and came out with it a year later)
Nope! No Way!
Can’t be done with an 8-9-10 speed driver. No way says nearly everything I find online for days. You’d need a new wheel (or a rebuild with a new hub) they say. Search after search says the same thing. Then a glimmer of hope appears. In fact three with varying complications:
- Use an MTB 11-speed cassette. For some reason, even though they are the same number of sprockets and mount to the same driver, they are 1.8mm narrower than a road 11-speed and thus can fit onto a 10-speed HG driver. Why is this true? Why is it so poorly documented? Why do so many people on the Internet not know this? No idea. But it is an option. The only real downside is that most 11s MTB cassettes tend to run larger than makes sense on a 2x road setup with the small ones having a 40T. This would then probably require running a MTB rear derailleur which is questionably compatible. And unless you go to an XTR range ($$$) they’re heavier.
- Another option several people share is to lathe out 1.8mm from the back of a cassette. There are even a couple of companies that will do it for you. Then it seats down properly on the 10s HG driver. Ok. That works. But you’ve got to ship it away and will have to be done again if/when it wears out.
- Replace the 10s freehub body with a very similar (1.8mm shorter) 11s version. It turns out these can usually be replaced as a spare part and Shimano has basically used interchangeable parts on them for decades. However, there are some less clear implications here. First off, there is no replacement 11s freehub sold that is marked for compatibility with an older 9s hub. So there is some futzing to do. Also, it appears that doing so alters the axle alignment and means the wheel should be re-dished (ugh).
The answer
Then the REAL answer shows up thanks to helpful people on a great Facebook group “Home Bicycle Mechanics“: Shimano makes an 11-speed cassette with the 10-speed spacing. In fact, they make TWO of them. What? Why is everyone insisting that it can’t be done or needs contortions to make it work? Why is this not listed as an obvious upgrade path by Shimano or most of the web pages, videos, etc. out there? I cannot explain it. But I document it here in the hope that in the future someone will find it and it will help them.
For the record, the parts are either an HG700 (105 level) or an HG800 (Ultegra level). These are 11-34 ‘road’ 11-speed cassettes that are “compatible with both 10 (and thus 8 and 9) and 11-speed freehubs”. For what it’s worth, it appears the reason Shimano is comfortable making this one is that the large 34t sprocket is large enough to clear the receding spoke line even with the hub recessed the extra 1.8mm. In effect, they are taking the same approach as the machine out a recess custom solution. They even include a 1.8mm spacer if used on an 11s driver afterall.
Conclusion
So there is the answer to the “impossible” upgrade from 9-speed (or frankly 8-speed) components to 11-speed in the Shimano world. Not impossible at all. In fact doable with off-the-shelf parts. You just have to ask nicely.
Note: All Shimano cranksets after 9-speed are incompatible with a 9-speed bottom bracket. With the move to 10 speed, they also went to external bearing bottom bracket and crank axles as part of the drive side unit that slides through to a clamped on left crank arm. But changing out the bottom bracket is straightforward as my frame uses the archaic BSA size and thread standards that is still in wide use and this must be done no matter what the upgrade path.
Results
How did it turn out? Fantastic. I did a full teardown and overhaul in about a day (not rushing and not having done such work in years). The only real glitch was that for some reason the normal Shimano bottom bracket for 105 and Ultegra is the BBR60. But they changed the size a while back and the standard tools no longer fit it. For a while, they included an adapter, but have stopped. This came as a surprise to me and several mechanics. And the tool is really hard to find in a hurry. Full thanks to Mike at Chain Reaction Bicycles in and Gebhard at Veloro Bicycles in Redwood City for going out of their way to make sure I could do my project on time while we waited for Shimano to late-ship the tool.
The improvement in shifting over 4 generations is actually surprising. The original 105 5500 was pretty solid. But R7000 is remarkably better. Crisper shifting with less effort, and it shifts under (moderate) load without complaining. The brakes are also notably more powerful and easily modulated (with the same pads and rims) and the cranks are also noticeably stiffer. I’m quite pleased.
Before
9-speed Shimano 105 5500 Triple
52-42-30 Chainrings
12-25 Cassette
Low Gear: 32 gear inches
Top Gear: 115 gear inches
Range: 359%
After
11-Speed Shimano 105 R7000 Double groupset (Said to be the last mechanical 105 groupset)
50-34 ‘Compact’ Chainrings
11-34 Cassette
Low Gear: 26.9 gear inches
Top Gear: 122 gear inches
Range: 454%
Both a lower AND a higher ratio for more range
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