I have an opportunity to get a ‘new’ warranty replacement Power2max, 165mm + 52/36 110BCD Praxis works rings for $1000 from a friend that is not using it. I currently use a Quarq (170 tribike) and DA7900 (172.5 - roadbike) crank with 53/39 130bcd rings and I am comfortable with that. Should I have any hesitation making this switch? Couple of reasons I ask…
Should I embrace the 110 bcd? Will it limit my ring choice for triathlon
Will the 52 vs 53 really have any significant change considering I am looking at HIM and IM distances and not spinning out my 53 as it is now?
I currently have a bit of front knee pain on the road bike at times, but not really on the tri bike - could that be attributable to the shorter crank arm, and is it possible that the 165mm would belp but not really make any huge difference in power output? BTW - I think my saddle is maxed out as I tore my hamstring last year, and going any higher tends to cause the hammy to tighten a bit, and I am thinking the shorter crank is a way to effectively lengthen my saddle height at the top of my stroke without increasing the extension at the bottom.
Would you just buy a new unit for $1295 with 170mm, 130bcd, 53/39 (or 52/36) rings - $300 is not the end of the world if it is worth spending, but if the ‘used’ unit would not really be any different, then saving $300 would be nice.
Sorry it is a lot of questions rolled into one, but I am trying to balance all of them and make sure I don;t make one choice that is a big no-no and completely limits me down the road - Summary: 52/36 vs 53/39 rings? 165/170mm arms? 110/130bcd?
Hey sorry I won’t be able to answer your questions, but if you don’t decide to buy it from your friend, can I buy it? I am looking for a 165mm 110 BCD. Thank you.
Not to add confusion to your choices, but if you haven’t seen it yet Quarq is offering a trade in upgrade through this month. $699 for the Riken and $899 for the Elsa. You can select any BCD, BB and crank length you want for the replacement. They only want the PM spider back so you can keep your exiting cranks and rings. You will receive a complete unit in return. The Elsa offers crank lengths less than 170mm if u go that way.
On the 110 bcd issue I don’t think you are giving up anything with 52/36. 50/34 rarely gives up much and many times allows running more time in the big ring up front with less shifting. YMMV.
Should I embrace the 110 bcd? Will it limit my ring choice for triathlon
110 BCD is a no brainer. In fact, standard (130 BCD) limits your options since the smallest rings you can run are 52/38. Unless you always ride flat courses or prefer to grind a really low cadence, then there are probably situations where you would like a lower gear.
Compact (110 BCD) gives you complete flexibility. Many people are unaware that you can easily find 110 BCD rings in 53t, and I’ve even seen 56t rings. At the other end, compact rings come as small as 33t. Chainrings are relatively cheap and easy to swap. There’s no reason you can’t have options for different courses/conditions, should you feel the need.
Will the 52 vs 53 really have any significant change considering I am looking at HIM and IM distances and not spinning out my 53 as it is now?
Let’s compare speeds for 53/39 and 52/36 with an 11-26 cassette. Let’s say the fastest cadence you can comfortably sustain for a period of time is 100 rpm (cadence and cassette won’t really affect the conclusions):
**53t gives you a 2% higher gear than 52t. **That’s a tiny difference. I don’t know about you, but I’m generally tucking in and coasting around 60 km/h.
Now for the other extreme. Let’s assume that you like to climb around 80 rpm.
**36t gives you an 8% lower gear than 39t. **Ask anyone struggling up a hill on a standard if they wouldn’t trade their top gear for a lower one. Running out of gears on a climb has a much greater impact on your performance than briefly spinning out on a descent.
I firmly believe that virtually all triathletes are better served by compact than standard. I wrote a more detailed article about compact vs standard on my blog: 10 Reasons to Consider Compact Cranks.
Thanks for reminding me: the calculations above are for 700C wheels. Here is a really good calculator for comparing chainring and cassette choices: Compare Bicycle Gearing.
Ok - so I am set on the Power2max, 110bcd, 165mm crank arm length - is there any real advantage to the newer type S over the standard power2max? I know the ability to use aero rings without cutting them, the better designed battery compartment and ~60g less weight…any real value to laying out and extra $200?
My friend may be keeping the crank so i am looking at $1200 for the Rotor 3D and $1400 for the Rotor 3D type S.
Ok - so I am set on the Power2max, 110bcd, 165mm crank arm length - is there any real advantage to the newer type S over the standard power2max? I know the ability to use aero rings without cutting them, the better designed battery compartment and ~60g less weight…any real value to laying out and extra $200?
My friend may be keeping the crank so i am looking at $1200 for the Rotor 3D and $1400 for the Rotor 3D type S.
Yes, but I don’t remember the details. Read DCRainmaker’s review on the Type S. That way, you’ll be comfortable with the decision you make.
@cldtx: you summarized the differences very well. One more difference is the compatibility with BB386EVO and BB86 frames, which has been further improved with the Type S.
Both operate in the same way and are equally reliable and easy to use, so you can safely choose either.
Know its a little off topic, but a big thumbs up for the Praxis 52/36. Been at it for 30 years, and this is best setup I have used. 12/23 flat lands. 11/28 for the hills. Using a Sram chain. Perfect.