Hi,
I want to use my gravel bike to pull my kids with the trailer. Therefore I want to extend my gearing. The cassette is a 11-32 with a shimano 105 rear derailleur. At the front is a power2max powermeter with 34/50 chainrings. I don‘t want to switch the crank, only consider to change the large chainring (46 or 48 is ok). To have smaller gears I would like to ride a 11-42 cassette. I think about 3 options (ordered cheap to expensive):
add a wolftooth road link. Largest cassette is 40 and I‘m not sure how it effects the accuracy of the shifting
switch to a mtb rear derailleur. Not sure if the STI work with an mtb rear derailleur
switch to the grx 812 rear derailleur. No concerns but looks like the most expensive solution.
I’ve got or had an 11-40 on both my mechanical GRX 2x equipped Salsa Warbird and Cutthroat. Both have the 46/30 chainrings. It works but there does seem to be a bit more chain clatter than usual no matter what adjustments are made. Not significant enough though to outweigh the benefits of the extra gearing in steep terrain compared to the stock 11-34.
I considered an 11-42 but was not really interested in going the route of the Wolf Tooth goat link. I’ll probably look into it some more for my Cutthroat once I get more serious about Tour Divide (2023 possibly). Did a 5 day preview ride on part of the route in Colorado this past summer and used every bit of the 11-40 and definitely could have used more gears at times.
I don’t know anything about your second option. As far as your third option goes, into my understanding that the 812 derailleur only works for 1x setups and hence won’t work for what you’re considering. I could be mistaken here but I read that somewhere and quickly put it out of my mind considering the high cost.
The real issue is managing how much chain is needed for that new setup (and you will need a new chain). The Wolf Tooth roadlink doesn’t solve for that, so option 1 won’t work.
Option 2 will work with a Tanpan adapter. However, that adds more money which would make it more expensive than option 3.
Option 3 makes the most amount of sense on the surface. However, Shimano is very insistent that’s a 1x rear derailleur and doesn’t have the capacity for all the chain needed for your setup.
One thing I have tested and have seen on a lot of other bikes is a GRX 810 rear derailleur without any modifications. It will likely shift a bit happier with an 11-40 cassette though. It has the capacity to manage all of the chain associated with a fairly extreme (out of the recommended specs) build and can clear a 40 tooth no problem on any bike. They can typically clear a 42 depending on the bike, but you start to lose the crisp shifting between the 11 and 13 with the guide pulley so far away. My experience was that a Roadlink DM made it ever worse because the guide pulley was even further away. Any of the modern long cage road rear derailleurs should work, but I would recommend the clutched 810 with that much chain to hold on to. You will also have to be very careful with the chain length, there’s not much wiggle room to be wrong.
The real issue is managing how much chain is needed for that new setup (and you will need a new chain). The Wolf Tooth roadlink doesn’t solve for that, so option 1 won’t work.
Option 2 will work with a Tanpan adapter. However, that adds more money which would make it more expensive than option 3.
Option 3 makes the most amount of sense on the surface. However, Shimano is very insistent that’s a 1x rear derailleur and doesn’t have the capacity for all the chain needed for your setup.
One thing I have tested and have seen on a lot of other bikes is a GRX 810 rear derailleur without any modifications. It will likely shift a bit happier with an 11-40 cassette though. It has the capacity to manage all of the chain associated with a fairly extreme (out of the recommended specs) build and can clear a 40 tooth no problem on any bike. They can typically clear a 42 depending on the bike, but you start to lose the crisp shifting between the 11 and 13 with the guide pulley so far away. My experience was that a Roadlink DM made it ever worse because the guide pulley was even further away. Any of the modern long cage road rear derailleurs should work, but I would recommend the clutched 810 with that much chain to hold on to. You will also have to be very careful with the chain length, there’s not much wiggle room to be wrong.
Thank‘s for your thoughts. I thought the capacity of the 812 is 40 but that‘s correct for the 810. If my setting would be out of the capacity ((46-34) + (42-11)=43), it only means there will be problems with the gearing: largest sprocket (42) and largest chainring (46). If I avoid that gearing there are no concerns, correct? Other concern is that a large cassette could hit the rear derailleur, correct?
The real issue is managing how much chain is needed for that new setup (and you will need a new chain). The Wolf Tooth roadlink doesn’t solve for that, so option 1 won’t work.
Option 2 will work with a Tanpan adapter. However, that adds more money which would make it more expensive than option 3.
Option 3 makes the most amount of sense on the surface. However, Shimano is very insistent that’s a 1x rear derailleur and doesn’t have the capacity for all the chain needed for your setup.
One thing I have tested and have seen on a lot of other bikes is a GRX 810 rear derailleur without any modifications. It will likely shift a bit happier with an 11-40 cassette though. It has the capacity to manage all of the chain associated with a fairly extreme (out of the recommended specs) build and can clear a 40 tooth no problem on any bike. They can typically clear a 42 depending on the bike, but you start to lose the crisp shifting between the 11 and 13 with the guide pulley so far away. My experience was that a Roadlink DM made it ever worse because the guide pulley was even further away. Any of the modern long cage road rear derailleurs should work, but I would recommend the clutched 810 with that much chain to hold on to. You will also have to be very careful with the chain length, there’s not much wiggle room to be wrong.
Thank‘s for your thoughts. I thought the capacity of the 812 is 40 but that‘s correct for the 810. If my setting would be out of the capacity ((46-34) + (42-11)=43), it only means there will be problems with the gearing: largest sprocket (42) and largest chainring (46). If I avoid that gearing there are no concerns, correct? Other concern is that a large cassette could hit the rear derailleur, correct?
The official chain wrap capacity of the 812 is only 31 teeth. But you can realistically add 4 to most of Shimano’s published chain capacity number. There’s even bikes coming stock with an 11-46 cassette (in 1x configuration) with the 812. I just don’t think the 812 is what you want for a 2x build.
In theory, your chain (and subsequently rear derailleur) should be fine if you avoid the big-big combo. If you can find a good price on a 46 chainring to replace the 50, that could be helpful as well to prevent mishaps. Assuming you’re using gravel tires, larger tires raise the effective gearing. 50 x 11 on a 25 mm tire is identical to 48 x 11 on a 40 mm tire.
Thank‘s for your thoughts. I thought the capacity of the 812 is 40 but that‘s correct for the 810. If my setting would be out of the capacity ((46-34) + (42-11)=43), it only means there will be problems with the gearing: largest sprocket (42) and largest chainring (46).
Depends on chain length. Sizing your chain big-big-plus-1-inch will guarantee that you’ll be fine in big-big, but the drivetrain will be at risk of going slack toward the small-small combo.
That said, the RD-RX810 has a very long cage and a non-tiny lower pulley, enough to readily handle a bit more wrap than it’s rated for. Shimano’s ratings are usually based on what something is paired with in its component series, not the actual mechanical design: for GRX810 this is “40” because (48-31)+(34-11) = 40.
Hi,
I want to use my gravel bike to pull my kids with the trailer. Therefore I want to extend my gearing. The cassette is a 11-32 with a shimano 105 rear derailleur. At the front is a power2max powermeter with 34/50 chainrings. I don‘t want to switch the crank, only consider to change the large chainring (46 or 48 is ok). To have smaller gears I would like to ride a 11-42 cassette. I think about 3 options (ordered cheap to expensive):
add a wolftooth road link. Largest cassette is 40 and I‘m not sure how it effects the accuracy of the shifting
switch to a mtb rear derailleur. Not sure if the STI work with an mtb rear derailleur
switch to the grx 812 rear derailleur. No concerns but looks like the most expensive solution.
Andy thoughts?
It’s too bad it’s a Shimano setup and not SRAM.
With the SRAM mechanical 10 and 11sp road shifters, one can use a GX 10sp MTB derailleur (all use a 1:1 cable pull ratio, and the 10sp derailleur “plays nice” with 11sp chains and cassettes) which, with its 47T chain wrap capacity, easily accommodates an 11-42 cassette along with any front chainring setup that has a 16T spread (i.e. 50/34, 46/30 etc.).
I actually run this on my road bike with a 52/34 chainring setup and an 11-42 10sp cassette on the back. I call it the “ALLS the gears” setup
A riding buddy of mine runs the same thing, just with 11sp shifters.
So…just a thought…maybe sell the Shimano shifters, derailleurs and brakes and find some mechanical SRAM stuff?
Thank‘s for your thoughts. I thought the capacity of the 812 is 40 but that‘s correct for the 810. If my setting would be out of the capacity ((46-34) + (42-11)=43), it only means there will be problems with the gearing: largest sprocket (42) and largest chainring (46). If I avoid that gearing there are no concerns, correct? Other concern is that a large cassette could hit the rear derailleur, correct?
If I were you I’d size your chain to the shortest that lets you safely run the big/big combination. While it’s a combination you should avoid, if your chain is too short and you accidently shift into this combination you’ll likely rip the rear derailleur off. You’ll probably have to avoid the 2-3 smallest cogs when in the small chainring, but most folks are less likely to use those combinations and while bad things can still happen, it’s not as certain as in the big/big.
My first serious attempt at a gravel bike used a 105 crankset with 46-30 and a 11-42 cassette. I did it with a 105 right shifter and a Shimano XT rear using a Tanpan. Once set up, it shifted perfectly for a while and acceptably for a time after that, as cable stretch and other things began to degrade shifting. I started with all new components which helped, I’m sure. I used a SunRace 11-speed cassette but the Shimano XT cassette that is old spline but 11-speed will also work.
I’ve since been blessed to go to di2 which is unbelievable but it leaves me feeling like passing something on to someone else. If you want the Tanpan and XT RD then PM and I will send them. If it works for you, then you can pay me what you feel it is worth when you can. I can also coach you on set up. If you are not super comfortable doing your own work then the Tanpan is probably not the best option.
Otherwise, most of the advice above about chain sizing and chainring size is good.
I’ve got or had an 11-40 on both my mechanical GRX 2x equipped Salsa Warbird and Cutthroat. Both have the 46/30 chainrings. It works but there does seem to be a bit more chain clatter than usual no matter what adjustments are made. Not significant enough though to outweigh the benefits of the extra gearing in steep terrain compared to the stock 11-34.
I considered an 11-42 but was not really interested in going the route of the Wolf Tooth goat link. I’ll probably look into it some more for my Cutthroat once I get more serious about Tour Divide (2023 possibly). Did a 5 day preview ride on part of the route in Colorado this past summer and used every bit of the 11-40 and definitely could have used more gears at times.
I don’t know anything about your second option. As far as your third option goes, into my understanding that the 812 derailleur only works for 1x setups and hence won’t work for what you’re considering. I could be mistaken here but I read that somewhere and quickly put it out of my mind considering the high cost.
I run an 11-42 on mine and the wifes bikes. A GRX RD812 derailleur works with this ratio and if you have a clearance issue you would install a wolf tooth components roadlink or roadlink DM depending on your frame. I have 3 bikes set up like this with front rings ranging from 38-42 with no issue and great shifting.
I’ve been running a Shimano XT CS M8000 11-40 on my gravel bike for a year. Ultegra Di2 with mid length cage and a road link. A spacer is required behind the cassette as it is a MTB cassette. I have a 52x34 up front. A lot of range for plenty of climbing here in Colorado. It has worked perfectly.
I ordered some stuff (grx 810 rd, roadlink, 11-42 cassette and a 46 chainring) and wanted to build it up today. Roadlink looks like my solution, the manual describes it can handle 11-42 with my rd (dura ace, ultegra, 105 r7000). I bought a sram pg 1130 cassette and I can‘t bring the rd to enter the 42 cog. What cassette did you use? Remember I have a 2x11s drivetrain…
I ordered some stuff (grx 810 rd, roadlink, 11-42 cassette and a 46 chainring) and wanted to build it up today. Roadlink looks like my solution, the manual describes it can handle 11-42 with my rd (dura ace, ultegra, 105 r7000). I bought a sram pg 1130 cassette and I can‘t bring the rd to enter the 42 cog. What cassette did you use? Remember I have a 2x11s drivetrain…
I don’t know the answer to your question as I have t tried it yet but I think by asking s.gentz the question you’re kinda asking an apples to oranges question. He’s using the 812 derailleur which is the dedicated 1x setup and completely different capacity than the 810 which is a 2x system.
The S-Ride Gravel Rear Derailleur supposedly clears up to a 46T cog in a 2x configuration, has 49T of chain-wrap capacity, and should work with any Shimano 11-speed road/gravel mechanical shifters, as well as Tiagra 4700 and GRX 400.
If you do try this, be aware that there is no cable tension adjustment at the derailleur. You’ll need an inline adjuster to set your indexing.
Before this became available, I made a Frankenderailleur out of a Tiagra 4700 GS upper and a Deore LX RD-T670 SGS cage. It clears a 40T cog without a RoadLink or similar extender, and has chain wrap to spare with an 11-40 cassette and 50/34 chainrings. I think* *it would clear a 42 without a link, but I’m not sure. If you have 5800-series 105 and can still find the RD-T670, it would work the same.
The 105 7000 rear derailleur is different, and that cage won’t work. I’m sure if I scoured Shimano’s exploded technical drawings, I could probably find an MTB SGS cage that would mate with a 7000 upper half.
Just to finish that, first thanks to all replies. I switched the big chainring to 46 (now on the crank I have 34/46), changed the chain, mount the 11-42 sram-cassette and leave the 105 rd (7000 series). So far it works good for me, the shifting process is a bit slower but for me absolutely ok.
