So I did several races with a bike that was built with di2 1X. These races were quite flat and did not require a lot of crazy gearing. I then returned to 2x. But with my thoughts of wanting to return to 1x and mechanical where is the line for gearing?
Races this year include some good climbing.
So what’s the thoughts on large cassettes for tri. Is it worth 1x if the cassette is a 11-36 or bigger 11-42.
FWIW, my Sram Axs build has a 48 crankset and a 10-33 cassette. My coach thinks the 48/33 combination will allow to manage climbs up to 10% gradient. So for you something similar with a 11-36 cassette would be a 52 crankset (I guess?) which also sounds good for flat stuff.
Why?
See pages 55 and 56 here:
https://zerofrictioncycling.com.au/wp-content/uploads/2019/05/Key-Learnings-from-Lubricant-Testing-Round-1.pdf
I struggle to see the point in running 1x set up.
The gains are almost imperceptible.
I have a 50t, 10-28 SRAM AXS 1x build on one of my tri bikes. I’m a strong cyclist and there’s zero fucking chance I’d ride a hilly race with that setup. Zero.
I struggle to see the point in running 1x set up.
The gains are almost imperceptible.
I just like the idea of how simple it is.
I struggle to see the point in running 1x set up.
The gains are almost imperceptible.
I just like the idea of how simple it is.
imperceptible gains aren’t a bad thing. 1X is also much easier to use. It cuts out the thinking and reduces the amount of accidental shifts in the wrong direction. It should also be cheaper.
The gains are almost imperceptible.
Many worthwhile gains are imperceptible. E.g. latex tubes.
There were folks running 1x at Savageman this year. I’m not sure what gear ratio they were running, but it had to be something significant.
DI2 Syncro-Shift is about as easy as you can get, and should give you a lot better gearing (shorter jumps on the cassette).
11-36 is my regular cassette for 1x tri bike, works well for training and moderately hilly races. I’ve also used an 11-42 cassette and that worked well also. But, I don’t mind the bigger jumps between gears. The tighter ratios, like 11-25 and 11-28 (11 speed) I find to be too close together. Just personal preference.
I struggle to see the point in running 1x set up.
The gains are almost imperceptible.
I just like the idea of how simple it is.
imperceptible gains aren’t a bad thing. 1X is also much easier to use. It cuts out the thinking and reduces the amount of accidental shifts in the wrong direction. It should also be cheaper.
That’s the problem, just like latex tubes, there are no gains.
Seriously, who accidently shifts their gears? I know you guys are triathletes but come on!
Not cheaper since most folk convert a 2x to a 1x so have therefore already invested in the 2x.
Fishbum that’s probably the only answer that makes sense, well done. 
Maybe “I like the way it looks”. would be a fair comment to.
What’s the gearing on your 2X? What’s the front ring on your 1X?
Can you define “good climbing” a bit more specifically? Max/Avg Grade? elevation change?
What would your target climbing power be?
How much do you and your bike weigh?
What is your preferred climbing cadence?
Its all about gear ratios. Specifically your Tallest and shortest gears.
That’s the problem, just like latex tubes, there are no gains.
Really?
I trust this guy:
That’s the problem, just like latex tubes, there are no gains.
Seriously, who accidently shifts their gears? I know you guys are triathletes but come on!
Yes, it happens with mechanical bar end shifters. Mechanical FD bar end shifters suck—my FD was a friction shifter…no indexing, essentially old-skool downtube shifters. In aero, with hands resting on the ends of the extensions its pretty easy to go over a bump and have the shifters and hands bang together and knock the shifter levers. This usually happens while in the small ring, bouncing up into the larger ring—sucks mid-climb. the opposite can happen from the big ring while pulling hard on the extensions—you end up pulling the lever up and dropping onto the small ring.
Also because of their location and orientation, they have a long moment arm. I’ve had a couple of bumps knock the FD out of my selected gear, without ever hitting my hands. Obviously, this is “just not a thing” on a road bike with STI.
Then there is the dreaded chain rub on the FD cage—for whatever reason, I spent a lot of time tweaking the FD shifter to get the cage just right. Again with STI, you just give it a half-click up or down.
Not cheaper since most folk convert a 2x to a 1x so have therefore already invested in the 2x.
Have you taken a survey?? I honestly don’t know what others do, but not buying an etap FD or Clics/blips/chainring probably saved me $500-700. I assume that most who try 1x start from scratch, which is what I did, or those who convert, would then sell the parts they aren’t using.
Regardless, those savings are perceptible to my wallet. I have an entirely wireless etap set up that cost me less than a mechanical 2x set up.
If pure speed is the only consideration, I can see why this debate may rage on. For me, I like the looks, simplicity and savings of 1x. We all make equipment decisions that cost us some time because we make the determination that the benefit outweighs the cost. If running 1x costs me 10 seconds in a sprint, I can live with that.
But, to answer OP’s original question, I personally wouldn’t stay with 1x if I need a 42 cassette and maybe not even if I need a 36. I run 50t with an 11/30. Is that perfect gearing for all conditions? No. But, its pretty darn good for where I live and I can live with minimal time losses for perhaps not having the absolute perfect gearing for every situation. I mean what are the consequences on most courses if the gearing is slightly less than ideal?? You have to stand up and your HR spikes a bit. This is, after all, a hobby.
What’s the gearing on your 2X? What’s the front ring on your 1X?
Can you define “good climbing” a bit more specifically? Max/Avg Grade? elevation change?
What would your target climbing power be?
How much do you and your bike weigh?
What is your preferred climbing cadence?
Its all about gear ratios. Specifically your Tallest and shortest gears.
Those are some good questions that I don’t necessarily have all the answers to. The Viking question is a size large speed concept. The race that makes me question it is Lake Placid. I know roughly what the total elevation gain is but I’m unsure of what the max climb percentage is.
When I’m in good shape I’m usually around 155 lb but as for what wattage I intend to climb at I don’t really know as I train with a power meter but race off a heart rate. When possible I prefer to spin when climbing but obviously that is not always an option. On my felt da my one x set up was a 50 tooth chainring and 11/34 rear cassette.
The 2x setup on speed concept is an 11-28 cassette and a 52/36 chainrings.
I was thinking I would at least have to do a 50 tooth chainring up front again and then be prepared to either go at least to a 38 cassette if not larger for something like Placid.
First off. No one even bother engaging with Mario S. Dude is the Slowtwitch equivalent of a flat-earther.
I don’t know if you’ve done Boulder 70.3 or Santa Cruz 70.3, but I did both of those on my 56t with a 11-32. I think in boulder I only hit the 32t on one very steep short section. Santa Cruz I’m not sure I ever got there. It may be because I haven’t ridden a bike with 2x in literally 3 years, but I think people overestimate how hard it is to climb with a 1x setup. Or they’re not doing any overgear work during training. After a block of a lot of overgear work, including a couple of 2x20min FTP @ ~75rpm, the idea of having to ride 300w at 60-70rpm for 5 minutes on a climb isn’t bad at all. I don’t think that takes any more out of me than riding at a normal cadence.
1x is simple and effective, and if you do your gearing correctly, provides a near perfect chainline for 90% of your race, even for a course with hills.
There were folks running 1x at Savageman this year. I’m not sure what gear ratio they were running, but it had to be something significant.
I also raced Savage man this year and I saw one or two people with one x bikes which is absolutely insane on that course.
That’s also where I witnessed another di2 failure.
Without commenting on your race strategy…
Even if you plan to race by HR, you should still be around the 80% FTP range, could be less if its a hot/humid day. But, that is enough to ball-park the gearing question.
Some good info on IMLP:
https://www.slowtwitch.com/Lifestyle/An_Ironman_Lake_Placid_guide_3785.html
Of particular interest:
What is the hardest hill on the course and what gearing do I need?
As previously mentioned there is no hardest climb. There are many moderately difficult climbs. 34x25 or 34x27 small gearing is recommended for most riders. If you don’t have a compact with a 34 tooth small ring, it would be beneficial to upgrade the cassette to a 12x27 or 11x28. Those on Shimano drive train can actually go with an SRAM chain and SRAM 11-32 cassette. It works with the B screw set all the way back. Unfortunately this won’t actually work on an SRAM drive train unless you go to a long cage rear derailleur.
34x25 = 50x36
34x27 = 50x42
or you could drop to a 48t in front. Then you are trading at what speed you spin-out on the downhill. You will likely trade some additional drivetrain frictional losses with a setup like that. How much that matters to you is a personal choice.