Need new 160mm cranks. Should I get Qrings
Just finished part 2 of my bike fitting and will be switching to 160mm cranks. Rotor is one of the brands that make cranks < 165s, so I am considering the option of Qrings and midcompact. what is the current EN opinions? Haven't seen anything since 2013 in the forums.
Thanks
Rob
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I’ve gone round to Qrings back to round. Could never tell the difference from one to the other in performance or feel. I will say I think the round rings shift better. I will stick with round.
The shifting issue with Q Rings is supposed to better since electronic shifting. If there is no difference I might as well save the $25 and any possible added frustration with the front derauellier(sp?).
@Robert Sabo - i definitly have some shifting issues with Di2 AND now Etap...
as a note, @John Withrow and I had a conversation today about the benefit or not of Q rings based on a meeting he had with THE bike fitter of the twin cities area. Guy is hugely knowledgeable and had some good reasons for long course triathletes NOT to have them.. I am likely going to go back to round rings for a bit.
I am leaning toward 160mm cranks on round mid compact Rotor rings. Thanks @tim cronk and @scott dinhofer
I used Q rings for 2-3 years with Di2 electronic shifting. Went to round this year. Honestly I felt no difference other than the round definitely shifted much better and smoother through the full range of gears.
Thanks @Robert Patrick
I've been using Q rings with mid compact for about 3 years. Haven't had any shifting issues with Etap on the P5. I really like them, think they feel smoother. It may have something to do with my lower than normal cadence or could just be in my head (which is fine too)!
Wow, I'm off the grid for ~5 hours yesterday and this thread gets 8 responses!!!
I had a pre-buy bike fit with a local guy who really seems like he really is the best of the best. The dude was super knowledgeable and seemed to know everybody in the entire bike and triathlon industries. I'm 6'-1" and he actually suggested that I could go down to 155 cranks (and I almost spit out my proverbial coffee). Here's a quote from an email he sent me the next day:
"I do not suggest 155 if using the new Di2, but fine for Sram. Problem with the Shimano is that the automated shifting throws chains on anything but Shimano chainrings, and Shimano does not make 155 cranks, so go with the 165. If you get Sram, best to spec with Rotor 155 cranks. Cobb makes 155's too, but the Rotor are bomb-proof."Regarding the Q-Rings, he told me to remove mine and go back to round which led to a somewhat long and nerdy discussion about it. If you'll recall, I have been a big proponent of non-round chainrings for years. From 2013 until about a month before IMWis this year I actually used the Osymetric Chainrings which are even more pronounced somewhat squared off shape compared to the Q-Rings. My bike always shifted like crap, but I dealt with it because I really liked them. But after dropping a chain in each of my last ~3 Ironmans and the increased frequency I was dropping chains in training, I moved down to the more boring oval shaped Q-Rings (and never dropped a chain a single time with them on my 6yr old 10-speed Di2). I have a Bachelor's Degree in Mechanical Engineering and a Master's Degree in Bioengineering, so it's really hard to shut my engineering brain off and as with many things, I went deep down into the rabbit holes of math and pseudo-science before making the decision to go with non-round chainrings... Fast forward ~5.5 years to this past Tuesday night and my fitter used exactly all of the same logic to come to the exact opposite conclusion that I did specifically for Ironman Triathlon racing...
The reason (theory anyways...) to use Non-Round chainrings is that you get a bigger moment arm (think ~53 or ~54 tooth chainring diameter when your feet are at ~3-O'clock and 9-O'clock) in the power phase of your pedal stroke and closer to a ~48 or ~49 tooth chainring diameter when your feet are at ~6-O'clock and 12-O'clock in the proverbial "dead spot" of your pedal stroke. So even though your feet are still moving around in circles, it "theoretically" allows you to really smooth out the power that is actually coming out on every single resolution. Said a different way, you are able to put out a bigger effort in the part of your stroke when you don't notice it and a smaller effort when you would be more effected by it (every single time your feet make a rotation) so muscle fiber recruitment stays closer to constant throughout the entirety of the pedal stroke. Think of this happening on a micro scale (every revolution of the pedals) the way we inside of EN ride hills (on a macro scale across the entire course). This is exactly the reason I decided to use them back in 2013 and have religiously stuck with them and been a proponent of them every time this debate comes up. I believed in them so much that I was willing to deal with my chain dropping at least once in almost every long ride I took... So even though you all correctly know me to be pretty stubborn in my ways when think I have figured something out... I'm actually open minded in my quest for optimizing all of this stuff and am willing to listen to smart people when they have opposing views...
So my fitter 100% agreed with all of the reasons above. And he said that yes indeed for short course triathlon or stand-alone bike Time-Trials he would actually recommend the Q-Rings. But he said for Ironman he flips the conclusion upside down. He said that even though it would intuitively sound right that you would want to completely smooth out your pedal stroke, that he believes that your muscles actually get a tiny micro-second rest in that "dead spot" near 6 and 12 O'clock. And that over the course of ~5+ hours this micro variation in your power (or micro rest periods) will actually wear your legs out just a bit less which should set you up better for the run (note, the whole reason I was there was to try to figure out my Quad cramping issues on the IM run). Thinking of this same concept in a Macro sense, this would be a kin to a rolling or slightly hilly course (think Vineman or even MT Tremblant) actually being a little easier to run after for many people because it gives frequent position changes and mini-rests (or like when @Dave Tallo will coast down some of the hills to reduce his TSS even at he expense of a higher calculated VI). Contrasted this to the misery my legs experienced while doing a perfectly flat course (Florida or Cozumel) in the same TT position in the same gear at the same cadence for 5 straight hours.
Sooo.... My brain is now completely twisted around on which of these two completely opposite conclusions is more likely to be correct. What he says definitely makes sense (maybe). But the opposite also definitely makes sense (maybe). So I haven't decided which way I'll go yet, but it's more than likely not that I'll be switching back to round chainrings.
Off topic now, but as a side note, the only drastic change he made was to my cleats... I have always ridden with my cleats slammed all the way forward (closest to the front of my shoe). He said this will give a slightly more powerful position, but continual stress on your calves, up through your hammies and partly quads simply is NOT worth it for triathletes (especially IM triathletes). He actually said "Hell, for Ironman Triathletes I'd put your cleats on your heels if the shoes would let me...". He chuckled when he said the last part, but the point was taken.
There seems to be a trend with people moving to 165/160/155 cranks. I'm 6'1 and have 175 on my TT and road bikss. What is the benefit of shorter cranks and how do you know you'll be stronger/faster? Should I be considering shorter cranks, how much shorter? Maybe these are questions for my fitter.
@Derrek Sanks , I've always had 172.5s based on my 6'1" frame as well (mostly torso, shorter legs), but my fitter suggested moving to 165s on my new tri bike, which I did.
The shorter length "opens up" the hip angle which puts less stress on the hip flexors, from what I was told. Because we have to run after getting off the bike, that's a good thing.
At this point, it's still too early to really tell as I haven't raced much since the new bike. What I DO know is that my pedal stroke isn't as smooth as it was with the 172.5s, so much more adaptation than I initially thought. I've still got 172.5s on my road bike, and I don't even know the length of my MTB and GG bikes, I'll have to check those.
I also know that pushing my large frame up hills with 172.5s gave me some nice quad muscles! My female friend calls them "coin slots".
I noticed increased power gains on my trainer this winter but was not in aero. When I rode my tt in the spring and summer my hip flexor would have issues generating power especially flowing over the top where're I was seem to get a tired feeling quickly.
I did a fit which was hooked to a computrainer that had spin scan which showed to much pull and push and a late start to my power phase. We maximized the power at 160mm. 155 was too much. I am waiting for the cranks to come in. I will be riding this setup on Zwift this year and except for sprints or steep climbs, will try to stay aero.
@Scott Alexander - if you speak with most fitters, they are pushing us all smaller. From this conversation, I am having trouble wrapping my head around something smaller than 162.5. I believe that ALL bike manufacturers are specing cranks that are too long on all of their tri-bikes. It's like they just buy one big order of gear from the component Co's to fit ALL of thier needs instead of hitting some different lots for the tri bikes.
Too bad the Kona bike count doesn't include crank length!
@Derrek Sanks I agree w Scott. When I went from 170 to 165 it made my aggressive position feel comfortable most of the time — Opened up the hip angle — It was a game changer. For me at 5’ 9” I could probably ride an even shorter crank but they get hard to find looking for a Quarq in 162.5 or 160 — Not sure if they even make them. 165 has worked well for me though
Thanks for your input. @Scott Alexander @Robert Sabo @Mark Roberts @scott dinhofer This is something I'm going to address with my fitter. I often have issues with my hip flexors on my TT bike.
My switch to 165 cranks was driven solely by an improved aero position. For some unknown reason, I was able to lower the drops once again this summer. But the new position resulted in my thigh hitting my rib cage. So that same day we ordered 165 mm Ultegra. I discussed going lower with my fitter, but for my fit he didn't recommend it
Thanks @Paul Curtin . I'm at the point of any further lowering will have my thighs contacting my body.
@Robert Sabo Fast forward almost a year, what are your thoughts on the shorter crank move to 165s?
I am on 160's and not the elliptical. I like them a lot and now get kinda sore in the quads when I ride my road bike with 172.5mm cranks. I guess I will need a new road bike, right?
Any recommendations on brands for 160mm cranks on round standard or mid compact Rotor rings?
Cobb and ROTOR(the ones I got). I went from a compact in 170mm to mid compact in 160mm