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Stiffest?? 110 BCD or 130 BCD both with aero qrings?
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Road racing...

PF86 bottom bracket on Giant Propel Advanced sl and I use Qrings. If I went with a rotor 3D+ I can use BB30 or I can use the regular 24mm spindle with the 3D cranks. If I can decide on a which crank to run, which combination of BCD and chainring will be the stiffest (run 110 BCD with 53 (aero)/36 qrings or run 130 BCD with 54 (aero)/39 qrings)???? I have searched the net and it used to be the case that the 110BCD in size 52,53 were deemed a bad choice because of flex but I will be using eh aero qring and they are very very solid. To me it seems that the 110bcd is perhaps stiffer due to the smaller spider so that is why I ask about going from a 52T or 53T 110BCD or roughly the same in a 130 BCD????


Thanks in advance.
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Re: Stiffest?? 110 BCD or 130 BCD both with aero qrings? [xntrickly] [ In reply to ]
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the compact one will be less stiff but it rarely matters.
If you aren't getting ghost shifting issues when sprinting, you are good.



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Re: Stiffest?? 110 BCD or 130 BCD both with aero qrings? [jackmott] [ In reply to ]
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Thanks Jack.... you don't think that the smaller 110 BCD crank spider will be appreciable stiffer than the 130 BCD to offset the more flexible rings of the 110?

Cheers.
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Re: Stiffest?? 110 BCD or 130 BCD both with aero qrings? [xntrickly] [ In reply to ]
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When you think about all the new four arm cranksets coming out all sharing the 110ish standard (Campy has to be diff ofc) and pros are riding with this new stuff, then I'm sure its stiff enough for you and me.
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Re: Stiffest?? 110 BCD or 130 BCD both with aero qrings? [snaaijert] [ In reply to ]
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snaaijert wrote:
When you think about all the new four arm cranksets coming out all sharing the 110ish standard (Campy has to be diff ofc) and pros are riding with this new stuff, then I'm sure its stiff enough for you and me.

So on this bike I can ride 24 spindle or 30 spindle if I run Rotor cranks. Any performance advantage to running one over the other given that I can run 53/36 with 110 BCD or 53/39 with 130 BCD?


Thoughts?
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Re: Stiffest?? 110 BCD or 130 BCD both with aero qrings? [xntrickly] [ In reply to ]
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Ride based on whatever gives you the best gearing for the course, with just enough gearing to get you up the steepest hill, then the closest spacing you can get while leaving enough for some fast down hill/wind situations.
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Re: Stiffest?? 110 BCD or 130 BCD both with aero qrings? [xntrickly] [ In reply to ]
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So if we disregard the potential stiffness, then it doesnt really matter. I dont have a rotor crank so i dont know what the diff is between a 24 and a 30 spindle but let me put it like this, you can put a 39 or larger on a 110 bcd, but you cant put a 36 or 34 on a 130 bcd.
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Re: Stiffest?? 110 BCD or 130 BCD both with aero qrings? [xntrickly] [ In reply to ]
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The 30 spindle will lock you in to ONLY Rotor (or Quarq) cranks. The 24 you can use pretty much any other crank. Or you can set up for using GXP cranks too.

The Rotor BB that lets that frame accept a 30mm spindle is really pushing the envelope of what is possible space wise. The bearings are super thin so I would be a little concerned about durability. However, several other ST users have reported good success with this exact setup (Rotor 4130 bb and Rotor or Quarq 30mm cranks). I will be setting up my Propel with the 4130bb and 30mm spindle - only because I already have the crank and have all of my other bikes converted to fit it.
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Re: Stiffest?? 110 BCD or 130 BCD both with aero qrings? [JesseN] [ In reply to ]
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JesseN wrote:
The 30 spindle will lock you in to ONLY Rotor (or Quarq) cranks. The 24 you can use pretty much any other crank. Or you can set up for using GXP cranks too.

The Rotor BB that lets that frame accept a 30mm spindle is really pushing the envelope of what is possible space wise. The bearings are super thin so I would be a little concerned about durability. However, several other ST users have reported good success with this exact setup (Rotor 4130 bb and Rotor or Quarq 30mm cranks). I will be setting up my Propel with the 4130bb and 30mm spindle - only because I already have the crank and have all of my other bikes converted to fit it.


Thanks for all of the replies and yes durability of smaller bearings was a concern... I was also looking at the lightning crankset but it is also 30mm. I'm thinking that Kittel is on 24mm spindle and it doesn't slow him down any. Now I just need to decide whether the 53T aero qring 110 BCD is too flexible thereby necessitating me going to 130 BCD. Final question though that remains to be answered is whether a 110 BCD crankset is stiffer than 130 BCD because of the smaller spider? I've searched and not found any deflection numbers comparing for example, a Red 22 130 BCD to a 110 BCD??

Cheers.
Last edited by: xntrickly: Nov 20, 14 14:31
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Re: Stiffest?? 110 BCD or 130 BCD both with aero qrings? [xntrickly] [ In reply to ]
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Conventional wisdom that I have always heard (for whatever that's worth) is that the 130bcd will be more stout. It also limits your choice of rings should you wish to go with a mid-compact or something else in the future. I honestly think it does not matter much. Like Jackmott said if you aren't ghost shifting it's not an issue. The 30mm diameter has potential to be more structurally efficient than the 24mm (better stiffness for a given weight) if engineered properly, however I suspect the net performance difference is small. Shimano, for whatever reason, has decided to not back the 30mm 'standard' (even though they apparently have no qualms about press fit BB's). Their cranks are still highly regarded.

Spindle length, rather than diameter, mostly determines frame compatibility these days as you can get a BB or adapter for just about anything, so long as you have enough spindle to get through it.

If you're set on 53t and up chainrings now and forever there is no reason to not get the 130. If you think you might want to try some other size at some point and don't want to buy two cranks, get the 110. You will have a hard time finding rings larger than 53 on a 110 bcd.

I road raced compact for awhile and now I ride standard. I still know lots who use compact or mid compact. They do equally well.
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Re: Stiffest?? 110 BCD or 130 BCD both with aero qrings? [xntrickly] [ In reply to ]
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I'm not an expert but I guess that a chainring is generally less stiff than a spider. The total stiffness will thus depend more on the chainring than on the spindle. Starting with this theory, the combination with the 110 spider will be less stiff than the combination with the 130 spider, although the 110 spider alone could be stiffer than the 130 spider alone. This theory though holds only, when the 110-chainring is as thick as the 130-chainring. In the end, if you want to be sure, you'd have to have both combinations and examine them.
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Re: Stiffest?? 110 BCD or 130 BCD both with aero qrings? [xntrickly] [ In reply to ]
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At a guess I would say a 110, when used with solid rings, would have less movement in relation to the rotation of the chainring. But due to the nature of the chainrings, which I would presume to be weaker than the spider, would expose more lateral movement.
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