New Red crank info, must read! :)

Discuss light weight issues concerning road bikes & parts.
odin99
Posts: 187
Joined: Wed Feb 16, 2011 7:46 pm

by odin99

LVGH wrote:I bought a Token TK877EX from Ebay (around $35 shipped) to go with my Exogram GXP. Make sure you get the version with Sram road washers. It weighs 91g without the central plastic tube. My crankset weighs 570g btw (175mm compact GXP with 50/34 stock rings). Haven't ridden the combination yet.


excellent thank you. that will save 20g. and you know, 20g is 20g!

NGMN
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by NGMN

It's not just 20 grams; it's 20 grams for $35! Thats a pretty good bang for the buck.

NWSAlpine
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by NWSAlpine

I have a new frame I pick up next week. Going from CAAD10 to the NeilPryde Alize. I ordered the new Sram Red Exogram GXP 172.5 53/39 and the standard Sram team gxp BB. I have the rest of the new Red on my drivetrain now to swap over.

Currently have hollowgrams and praxis classic rings on my CAAD. I'm not sure if I should keep the Praxis rings and move them over to the Exogram. I kind of like the look and shifting will be similar. I will have to see how it performs once I get it all setup.

Imaking20
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by Imaking20

It depends on your priorities. If you favor looks and/or weight - use th praxis. If you prefer function above all else stick with the exogram rings
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nathanong87
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by nathanong87

LVGH wrote:Has anyone tried to fit Red Black rings to the Exogram crankset? I don't like the new ring design. Does this fit and shift properly, also with older Red front derailleurs?


this is a terrible idea.

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js
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by js

nathanong87 wrote:this is a terrible idea.

He's right.

Red made the new rings on the Exogram WAY thicker/heavier/stronger to address one of the major shortcomings of their previous group, the front shifting, which those old Red rings played a part in. So if you are going to swap them out for aesthetic reasoning, at least switch to Praxis.

Furthermore, if you're going to run a normal, 5-arm ring on the 4-arm (plus-hidden) on the Exogram, then you'll need to accept that you're going to give up a lot in terms of the timing of the shift ramps, which will now be at least 36deg off. Of you could flip the rings, but then you've lost use of all the pins & ramps.

LVGH
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by LVGH

Yep I realize that. I'll probably stick with the stock rings for now, I'm more or less getting used to the looks and they match alright with the grey logos on my frame. If anything, I might exchange them for Stronglights.

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prendrefeu
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by prendrefeu

js wrote:Furthermore, if you're going to run a normal, 5-arm ring on the 4-arm (plus-hidden) on the Exogram, then you'll need to accept that you're going to give up a lot in terms of the timing of the shift ramps.


False.

The rings are timed for each other. The two rings should always be aligned together, and if they are rotated together the timing remains the same. Heck, even in this very thread it's been covered and Praxis acknowledges that it works but can not be stated "officially" purely for marketing/sales purposes. If you take another pair of chainrings and install them on the Exogram, rotate to fit, it will work perfectly fine and you will not notice a difference in shift quality.

This thread, quite literally, has already covered everything with these arms and chainrings. It even covered the difference between BB30 and GXP crank arms with chainring compatibility.

It's surprising that on the 16th page of this thread people are stating things that have been proven otherwise earlier in the same thread.
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jooo
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by jooo

@prendrefeu - You do realise that timing of the shift also has to do with the angle of the cranks and not just the relationship between the 2 rings?

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prendrefeu
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by prendrefeu

@jooo You do realize that you won't notice the difference? We're not talking about oval-shaped rings here, obviously, as those are designed more for the crank arm's position relative to the ring shape.

The Praxis chainrings, rotated, still shift great. They shift pretty much 99% the same as they would on a normal crank without hidden bolt. This is even acknowledged by Praxis, in this thread, regarding shift timing. So when a company that thrives on their excellent design for shifting between chainrings, alignment and timing, acknowledges that it will work fine, you are saying that it won't? Really?

But, I forget, there are supreme athletes on this forum that are ultra sensitive to every .05 NM difference in stiffness between their components. So yes, you are right, it's a total game changer. Heck, a change in chainrings might mean the difference for people on this forum between winning the Tour de France this July and catastrophic injury - heaven forbid a perfectly shifting set up not be within .00000000000000001% of the nanosecond timing if they had used the standard manufacturer chainrings.
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js
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by js

prendrefeu wrote:False.

You don't have to yell.

Pre - you're usually pretty good, but jumping to shout out that the rings would still be aligned seems to beg for a bolded 'Well duh'.

I was in fact talking about the timing of the shift in your rotation, not the alignment of the rings, which would obviously be maintained as the small ring would also be rotated 36deg forward.

Ridiculously, what I missed there is that while a rotation 0.5 'arms' ahead would bring that shift alignment out of sync, moving the ring 2.5 arms ahead (ie. rotating the ring 180) brings things back in line completely... just break off the pin. Sadly, I only realize now that this is what Adam from Praxis was talking about on Thursday when we met.

In fairness, I've been sick this week!

jooo
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by jooo

@prendrefeu - A point, which you fail to mention (that some people may actually like to consider for themselves) is pointed out and you respond with such a constructive post...

Do as I say and not as I do?
prendrefeu wrote:Please, read carefully and calmly before replying on an international forum

:?

Imaking20
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by Imaking20

No points that haven't already been discussed multiple times in this exact thread. If they weren't understood by the readers, for whatever reason, why ask again in the same thread?
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deek
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by deek

jooo wrote:@prendrefeu - You do realise that timing of the shift also has to do with the angle of the cranks and not just the relationship between the 2 rings?

You do realize that rings should work just the same if rotated 180 degrees? (I assume most rings are designed with two legs in mind)

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CharlesM
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by CharlesM

You do realize that the pattern doesn't repeat it's self twice

Image

Your logic makes sense to some degree, but the finite space on a chainring doesnt really allow for two complete repeats of the pickup pattern relative to how quickly the chain can get up and engaged.




Pren's right...

Some might not like it, but it is what it is...



. Probably time to lock this thread. These ultra long threads become a gigantic pile of useless BS that's too hard to find good info after a while...

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