After crashing my Aethos frame, I am contemplating a few different scenarios of what to do with the parts.
The first thing that came to mind was entering the assisted replacement program, and get a new Aethos frame. All the components on the Aethos seem relatively fine.
However, in my stables, the Aethos is clearly the most niche bike, that offers the least benefit over the others.
That, and the fact that I’m bored while confined to the couch, got me thinking:
I could also transfer the groupset (9200) to the Crux (currently SRAM Force Wide), and make it an all-road/ gravel bike.
Two things are currently holding me back on this:
- after years of using SRAM AXS, the only negative I have experienced when switching to Shimano 12s is the low tension on the RD. The OSPW that is set to a lower tension is definitely part of the problem, but even smaller bumps in the road have the chain hits the chain stays.
I’d probably set the OSPW to the highest tension.
Nevertheless, I am a little worried that this might become a problem when riding over rougher terrain when shifting.
- The gearing is 50/34 11-34. That’s great for road and all-road, but for gravel this can become a little tough.
I have laid an eye on the 11-36 that’s due to be released with the 105 Di2. A more immediate measure could be a sub compact 48/32 chainring combination. I have not found anything 12s specific there and most of the 11s ones are either non round, or not 110BCD 4-arm asymmetrical. Maybe I just haven’t looked close enough.
If you have experience with new 12s for off road or an idea where I can find said rings, I am happy to hear from you.
Also, any other input is very welcome.
Thanks in advance.
Sorry to hear about the crash and demise of the Aethos….heal quickly and well!
As to the question, I don’t have a direct answer, but can relate using 11 spd Ultegra mechanical, which would have some of the issues you are concerned about - gearing and low tension RD.
I am running it w/ a 40t 1x chainring and have had zero issues with the the RD tension, or losing the chain on the front. No clutch RD, etc. just a straight 1x system.
I do use a Wolf Tooth RD adapter so I can run a 40t XT cassette and anything where a 1:1 ratio doesn’t work for me on gravel, I’m probably walking anyway. So your 2x system w/ 34/34 would be fine, IMO. Technically, Shimano says that 12 spd DA and Ultegra cannot run the new 36t 105 cassettes, but we all know Shimano is very conservative in their gear recommendations, so my guess is that, size wise, it will work just fine.
Note that 105 is only going to be Hyoerglide and not Hyperglide+, as Ultegra and DA are, though. Not sure how that may impact shifting.
Thanks for the reply.
8000/9100 will probably very similar in terms of tension or shifting performance.
I am contemplating the Praxis 48/32 rings. I will need to get a 110 5 arm spider, but the smaller gears will definitely be great for off-roading.
I wish Shimano made a DA 11 -34 in 11 speed. Those cassettes are expensive but so much lighter than the GRX.
Regarding your question, I personally would not run a DA derailleur on a gravel bike. Yes, some people will say how they did it with no issues… good for them. In my experience (and I imagine my experiences are common with Shimano adding clutches to the GRX line) the chain just bounces too much on bumpy descents and it is easy to throw a chain. I can tell the difference on how my chain acts if I forget to switch the clutch back on my derailleur.
Regarding gearing, thats obviously location dependent… but for me that wouldn’t be enough. The GRX I have is 48/31 and 11-34. My FTP is north of 300, and on certain climbs I still run out of gears.
I have been looking into lightening the groupset I have by going to some DA stuff, but I just can’t get it to fit with my requirements. Maybe if I upgraded to 12speed? Problem there is Shimano doesn’t make a GRX 12 speed derailleur yet. Maybe XTR? But now I am changing too many things, and am I losing benefit?
All of these questions are why I haven’t changed yet. Hopefully Shimano releases a top tier gravel groupset above GRX (or maybe it is top tier already?). If so, I am in the market.
I won’t pretend to be an expert on gearing but didn’t Sofia run a dura ace drivetrain in her crux for unbound? I’m trying to find the picture that she posted on either Strava or instagram
Unbound isn’t particularly tough in terms of gradients (to my knowledge). For 95% of my riding 32/34 would be a low enough gear, and steep ascents in my area are something I can push through.
In the forests however, I can use a little lower than that. At 20-25% 32/34 gearing will require me to push 450W, which on a long day of riding better doesn’t exceed a minute at a time.