jonathanf2

I just picked up an Ultegra RX800 RD and it runs great! This is exactly what I was looking for. Also the chain line appears better aligned for road cranks. I believe even the GRX RD cages are optimized for the 2.5mm offset of GRX cranksets. If you're running a road crankset on a gravel bike, I think the Ultegra RX800 RD is a better choice. It easily clears the big cog on my 11-36t while running a direct mount 46:30t chainring. Shifting definitely has a more road bike precision, but with lower gearing. Though I believe the GRX 400 runs a tad more smoother at the low gears due to the long cage. If I was predominantly climbing in rough terrain like 70/30 percent of the time, I'd definitely prefer the GRX 400 RD even with it's 60-65g weight penalty for the RX800 RD.

jonathanf2

I've added some comparison photos between the GRX400 and Ultegra RX800 rear derailleurs mounted on my 10speed 11-36t XT cassette and 46:30t crankset (using GRX400 10 speed shifters). On a side note, I'm using a GRX400 FD and it works perfectly with road cranks with plenty of H/L screw adjustment leverage. No need for a road specific FD, while still capable of handling GRX 2.5mm offset cranks. From what I'm thinking, the Ultegra RX800 is at it's upper threshold for optimal shifting. Any bigger of a cassette and it won't have that fast, roadie-like shifting.

Though if I decide I want more low gearing I think I would go back to the GRX400 RD due to the long cage design. I've been really curious about the new Microshift Sword 10 speed 11-38t cassette that's starting to trickle onto the market and I wonder if the GRX400 could handle that cassette while maintaining crisp shift performance? Also looking at the Shimano cassette weight and price of the current 12 speed 11-36t cassettes, I somewhat prefer 10 speed. The 10 speed 11-36t Deore XT cassette is cheaper and weighs less. I really don't notice much cadence difference between 2x10 vs 2x11.

rosefarts

I jumped on the TPU tube bandwagon for spares. The price came down a lot, at $12 per tube on Amazon, I'm willing to try.

I got one for my gravel and one for my mountain bike. With a good tubeless setup, I haven't had a flat that required a tube in years, its entirely possible I'll never use either of these. I can't leave the house without a spare, I just can't do it. So this will free up a ton of room in my (intentionally) small bags. Since they'll be in there likely a loooong time, and they're so thin, I have them both in a soft sunglasses bag. Maybe it's time to check my sealant levels.

t2p

what brand / type TPU tubes ?

rosefarts

Ridenow, they’re all over Amazon.

I got one that’s like 700c x35-47mm which will cover gravel. The MTB ones are 29x2.1-2.5 or something.

Very light, very compact. They each come with one stick on patch.

Like I said earlier, with my tubeless setup, I’m not really getting flats, and if I do, it’s more like something that I’d plug. This is just for peace of mind, since I can’t bring myself to ride without a spare. Hopefully, neither of these ever see the inside of a tire.

t2p

now you are definitely jinxed !

I have RideNow tubes in wheels of my 650b bike and 26” wheel vintage MTB - they have been trouble free

I have Schwalbe Aerothan tubes in my 700c bikes - they have also been trouble free with exception of the valve stem guts a bit too eager to unscrew at times

have a pair of Pirelli tpu tubes - they look good but have not used them

also have a pair of Revoloop tpu tubes - have not used them and probably will not … a tad too thin / ‘flimsy’ (for me at least)