Praxis Chainring - correct chain orientation (heads-up)

GrandPaBrogan

⚡ eGeezer ⚡
Oct 5, 2019
1,329
2,068
New Zealand
Got my Trance e+ from brand new... and first time I took my chain off (for thorough cleaning) I took note of the orientation before removal - in relation to the Praxis chainring with narrow-wide teeth. This is what it looked like, and looking at the graphic printed on the side of the chainring it made sense...

Praxxis 01.jpg


However, when I was about to put the chain back on, I noticed that the machining of the teeth (pic below) doesn't match what the graphic seems to indicate. Maybe it's a poorly designed graphic which can be misconstrued to mean the opposite - but because it was assembled from the factory that way (pic above) plus I didn't notice any chain-suck or noise, I had second thoughts. So reinstalled the chain the previous way.

Praxis 02.jpg


Just wondering if any of you guys (equipped with the Yamaha Syncdrive Pro motor and Praxis chainring) have noticed this chain orientation from the factory?

Just to get a consensus, the correct chain orientation is meant to be like this one below, right? (Which is the opposite of one above)

AMwmd.jpg
 

57 Reaction

Member
May 27, 2019
73
56
United Kingdom
Got my Trance e+ from brand new... and first time I took my chain off (for thorough cleaning) I took note of the orientation before removal - in relation to the Praxis chainring with narrow-wide teeth. This is what it looked like, and looking at the graphic printed on the side of the chainring it made sense...

View attachment 20698

However, when I was about to put the chain back on, I noticed that the machining of the teeth (pic below) doesn't match what the graphic seems to indicate. Maybe it's a poorly designed graphic which can be misconstrued to mean the opposite - but because it was assembled from the factory that way (pic above) plus I didn't notice any chain-suck or noise, I had second thoughts. So reinstalled the chain the previous way.

View attachment 20699

Just wondering if any of you guys (equipped with the Yamaha Syncdrive Pro motor and Praxis chainring) have noticed this chain orientation from the factory?

Just to get a consensus, the correct chain orientation is meant to be like this one below, right? (Which is the opposite of one above)

View attachment 20700

wave.PNG
 

MinusPrevious

Well-known member
Sep 5, 2019
355
298
So.Cal
Good tech tip for sure! I certainly noticed the Praxis asymmetrical chain ring & thought that was cool but failed to note the proper chain installation requirement

To answer your question, the laser etched diagram on the chain ring reads correctly. The outer links are intended to be installed on the thinner more inboard teeth. That One-Up ring does not employ the Wave Tech feature

At least Giant installed mine correctly. I just checked (y)
 
Last edited:

GrandPaBrogan

⚡ eGeezer ⚡
Oct 5, 2019
1,329
2,068
New Zealand
Thanks for the responses guys!

To answer your question, the laser etched diagram on the chain ring reads correctly. The outer links are intended to be installed on the thinner more inboard teeth. That One-Up ring does not employ the Wave Tech feature


It wasn't immediately obvious to me, but I'm now aware of the difference between the "WAVE" tooth technology on the Praxis chainring - as opposed to other "Non-Wave tech" chainrings out there.

They both look so similar but they're actually different as you mentioned. But I had to figure it out in my head first, because I can't just follow instructions blindly without understanding why.

So yeah... if anyone else cares to know, finer details below. Cheers.


Praxis WAVE Tech:
  • The teeth are actually the same thickness, it's just one is offset toward the outer side of the chainring and the next one is offset to the inner side.
  • Looking at it from the top facing down, the alternating offset of the teeth is what forms the "wave pattern."
  • So initially it didn't make sense to me why there would even be a specific chain orientation seeing as the teeth are the same thickness - until I noticed little recessed cuts on the inside teeth that the outside teeth don't have. I guess those recessed cuts are for clearance so the inner chain plates don't gnaw on it. Now that the chain orientation makes sense to me, I can accept it... although I still fail to see why it would be advantageous enough to warrant a patent.


NON- WAVE Tech:
This is the bit that confused me to begin with - because my first eBike has a Bafang motor with an aluminium Lekkie chainring which I'm accustomed to.
  • The teeth have different thicknesses, alternating thick and thin BUT both are centered along the thickness of the chainring. (No wave).
  • The fat tooth goes into the wide chain gap, and the thin tooth goes into the narrow chain gap. Simple.
  • By just looking at both chainrings from side on, they look the same and so I initially mistook the Wave Tech chain orientation to be counterintuitive.
Not WAVE.jpg



All good now... everything is at peace once again in my OCD universe! :giggle:
 

MinusPrevious

Well-known member
Sep 5, 2019
355
298
So.Cal
Certainly glad you brought this up as i was unaware of this important point.

(Good Grief) No doubt these bikes have gained in their complexity & require thought / planning when making changes
 

Pukmeister

Active member
Jul 18, 2019
283
263
Fareham
Thanks for an informative post, you learn something new every day. I shall check my bike tonight when I get home to ensure the chain is mounted correctly on the chainring. After my recent brake pad incident I am taking nothing for granted anymore.
 

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