Shimano GRX gravel groupset tested

A while ago I finally got my hands on a Shimano GRX groupset on my new Tripster ATR V3 to test Shimano’s GRX longer term. GRX is Shimano’s gravel specific groupset taking cues from both their MTB and road range, along with some unique gravel features. I went for about the highest non DI2 spec GRX groupset in RX810 (like ultegra/XT) my detailed spec is the following;

Levers – RX 810 (Ultegra equivilant)

Brake Calipers – RX810 (with 160mm rotors)

Crankset – RX812 (1×11 with 40t option, smallest available from Shimano.)

Cassette and Chain – XT 11:42 cassette option is largest recommended range (some doubt over whether a 46 will work, personally I expect it will get stuck on the 46 when shifting based on MTB experience)

Buy XT Cassettes on sale

GRX – What makes it gravel specific?

Well firstly the gearing works with most Shimano (and Sram) MTB cassettes and the rear derailleur has a clutch so can work as 1x. The RX810 rear derailleur has a capacity up to a 42t cassette or a 22t range. The levers have a different chunkier, grippier rubber hood and a new tackier lever over the road versions – all for more power and control on loose gravel. The brake lever pivot point being 18mm higher helps on hood braking more easily.

The higher end RX810 levers (like Ultegra/Dura Ace) use Servo Wave breaking which is from Shimno MTB brakes and adds a more progressive feel to the braking, to prevent that binary on/off feel. This is important with gravel so you don’t lock up as soon as you tap the levers. It certainly felt less grabby than the SRAM force I have been using.

The gearing options are the biggest discussion point, with most people opting for 1x these days leaves the limited front chainring option on the GRX cranks and the 22t rear derailleur range. I went for a 40t front with XT 11:42 rear cassette to give the best range for my local hilly terrain. In an ideal world I’d swap to SRAM 10:42 with 38 front (which works fine BTW), but this needs the SRAM casette and XD driver freehub and I wanted to try the GRX complete groupset first. A wolftooth 38t front ring is about the only smaller option I can find for the asymetrial 4 arm cranks, but I’m sure this will change in the next few months. For baby trailer bikepacking I’d need to swap to a MTB crankset for a 34t front as my legs can’t get up mountains with 30kgs on the back using 40t!

Initial Thoughts

The GRX groupset feels solid, it shifts light and precise. The lightness of shifting is helped by the ability to switch off the clutch, I find on all but the bumpiest tracks it doesn’t cause an issue with chain drop, but from MTB I know it depends on how worn the drivetrain is. The hoods are good for holding on over rough gravel, a neat design change compared to their road equivilents, but the SRAM Force hoods are thicker and softer rubber so coming from SRAM the GRX is noticably thinner and less vibration absorping, but on the plus side easier to wrap your hands around and hang on. The GRX might be better with smaller hands especially.

The brakes feel progressive, unlike some road discs and with the 160mm rotors it offers more than enough power, with only that hot pad smell on seriously long descents. To be honest I probably couldn’t tell the difference between these and the Force in terms of power, both are excellent.

The GRX brake calipers are the same as road Shimano equivilents, only the GRX levers differ, on the bumpy roads you really benefit from the gravel hood design that the GRX offers.

The cranks already have the graphics worn off from heal rub, but otherwise all working as new after a month of use. They are pretty standard, just a shame they use a pretty unique assymetrical 4 arm bolt pattern so limited ring choice.

I can’t comment further on longevity yet but the GRX feels the same as the Shimano MTB groupsets that I find offer longer, more preceise shifting than the more plastic feeling SRAM, but I can only suspect it will last well based on initial impressions of the quality.

SRAM FORCE or Shimano GRX??

This is the real question for most people! I will ignore costs and focus just on performace. I really like the SRAM force groupset and as discussed the Force hoods suit my larger hands better than the GRX, generally the SRAM feels more ergonomic and has been a reliable performer. The brakes needed a rebleed once but otherwise no issues with the SRAM in 18 months. However I prefer the feel of the GRX braking and I also prefer the GRX shift action, both in terms of SRAM’s double tap being more faff and the actual ease of shifting being better on the GRX. I can’t yet comment on longevity beyond the fact SRAM has lasted better than expected with slick shifting and reliable braking after 18mths and the GRX just feels solid and well made.

Conclusions

The GRX gearing range offered needs to expand down to a 38t and 36t front ring and also the hoods are tacky and grippy in wet but a bit thin rubber for off road comfort. If they improve those it would be perfect, because the shifting, the braking and the quality is all spot on.