Switching road bike gearing to GRX. Good idea?

Recently bought a GRX-equipped gravel bike and after lots of research will be using a stages left side PM.

My current road bike is a Canyon Endurace with Ultegra with a Stages PM. I used to swap the PM between my old gravel bike and road bike with no issue and used on the trainer. So 1 PM for all. I would like to do the same.

My thought was to get a 48/31 GRX 2x (and front mech) for the Endurace and replace the cassette with an 11-30 (currently has 50/34 11-34). Beyond PM swapping, I think this may be a better set up for the way I ride. I only lose slight top end, and gain smaller gaps in smaller cogs (which will make outside TR workouts easier), with the same climbing range. I don’t race fast crits, but do fondos/gravel races, etc… A few times a year I do some brutal mountain climbs with sections of 25% grades, steep gravel, and long climbs.

I know the q factor will be a little wider, but anything I am missing?

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Im a fan of wider gear ratios on the road, but does the Ultegra power meter not fit your GRX chainset?

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I think just the only issue is top end speed based on what limited knowledge I have with grx.

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The Ultegra PM doesn’t clear the chainstay on the gravel bike unfortunately, which was the fatal flaw.

I like the 11-34 cassette for the mountains, but for the flatter/rolling hills around me where I most often ride/train, I find it hard to get the right cadence. I don’t mind it for group rides, fun rides, but when trying to hit target power on an outside TR workout, it is hard. The differences in the top 5 gears are:
11-34: 11, 13, 15, 17, 19
11-30: 11, 12, 13, 14, 15

I have a 48/32 crankset and an 11-34 cassette. Not once have i regretted having an extra lower gear. I have spun out the top gear at most twice a year. even then its only a few seconds.

My logic when switching gears is pretty simple, I cant pull at 50 km/h for an hour or even 45 so why do I need such a high top gear.

also to note, GRX shifters are (according to reviews) amazing at braking due to the servo wave tech and also a higher pivot point for the brakes which equates to less effort for one finger braking.

Definitely definitely not a bad idea to swap to a GRX even if you race. Also, why not keep the 11-34? those 25% climbs sounds absolutely brutal

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Only the di2 levers have the higher pivot point. I believe all the road hydro levers have servo wave too.

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did not know that. thanks for the info.

Had to to do a bit of research on servo wave. Apparently its been around for a while. It goes back to the ugly RS505 shifters.

the list of servo wave shifters can be found here:
https://bike.shimano.com/en-EU/technologies/component/details/servo-wave-action.html

The ultegra R8020 and R8025 (short reach) shifters have servo wave as well. and the grx 810 and above models.

If anyone has experience with how the servo wave shifters please let me know.

Hope it helps

I live in Richmond, VA, which is rolling hills all day long, but there literally isn’t a climb over 10 minutes anywhere! But, I live an hours drive from the Blue Ridge Mountains, where I tend to do events, races, rides with friends a few times a year. Would def have the 11-34 on for those. But around RVA I almost never use the 34. I may just keep it on. It wouldr me to do most rides without ever switching from the big ring up front. Like I mentioned, was thinking of tighter gaps to help with TR outside workouts.

Also, looks like I have 600 level shifters, so don’t have the same action. I def notice a bit of difference in responsiveness compared to my Ultegra on the road bike. They aren’t bad, and I didn’t really think about it until I read this post.

I have the GRX build on my Aspero 48/32 and 11-40 in the rear. The 11-34 stock was not enough for the climbs where I am. I also have Ultegra Di2 on the road bike and I have to say the GRX brakes are so much better than my Ultegra brakes. All you have to do is rest your fingers on the Ultegra brake levers and the squeal to high heaven, they are so embarrassing and brake fade is really bad on them. I’ve talked to others and they really like them. On the other hand the GRX have so much modulation and never make a sound.

I have a Stages for my road setup and never thought to swap it between bikes but it sounds like it won’t work. That’s a shame.

As others have said only the GRX Di2 have the high pivot point.

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It’s not uncommon for shimano brakes to leak fluid past the caliper pistons. I went through a few sets learning this the hard/expensive way. Try cleaning the rotors and fitting new pads. If the problem persists than you may need new calipers

I’ll try this first! I‘ve replaced the pads once then assumed I contaminated the rotors and then the pads but, haven’t purchased new pads yet. Is there a fix to the problem you described about leaking fluid?

I went this route you are talking about (GRX on road bike), but I went with the 46/30. That definitely put me in a good position for the 11-30 cassette, with tighter differences on the top end.

I don’t race, but I ride long´, long endurance rides (brevets, randonneur events). I thought it was silly to ride around with 50 in front and 11 in back. I used that combination about 180 seconds a year, downhill. Now I use the whole cassette.

I’m not propagating for 46/30. I wondered if not 48/31 would have been a better way to go, but not wondering enough to do anything about it.

I use the GRX front derailleur (it is fiddly to set up and adjust), but I do use brifters that are not supposed to work. They do well enough. So I didn’t go with the GRX version. Had no choice. I don’t use disc brakes.

This link could be helpful:

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Amen. RVA, Ashland, Goochland, etc: Never leave the big ring with 28-30 in the back.

Blue ridge: 11-34 all day long.

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I only have experience with RS685(6800) and R8000 both that have servo-wave and they are great. I have felt the GRX levers at the shop and they feel very similar to the r8000 with progressive resistance.

Yeah, change the calipers unfortunately. I’ve read (but not seen for myself) that the calipers arent all that serviceable. After i’d been through a few sets I swapped them for Hope RX4s. The braking performance isnt any better but atleast theyre fully rebuildable