Praxis Chainring replacement.

[Goughy75]

I have a Giant Trance e +3 2019.
The chainring is a steel Praxis 36t Wave 104 bcd.
I ordered a replacement but as you can see in the pictures the mount holes on the replacement are not flat. They have a lip. This will not sit flat on the spider. Can anyone recommend a replacement for this bike?
Cheers.

 

[Goughy75]

Pictures.

 

[Jackware]

Looks like the bike uses the standard Praxis Works MTN Wave 1x 104 BCD chainring not the Ebike version.

 

[Goughy75]

Looks like the bike uses the standard Praxis Works MTN Wave 1x 104 BCD chainring not the Ebike version.

Could be. It's the same weight as the one I ordered so must be steel.
I might just grind down the lip on the new one so it sits flat on the spider. Don't really know what else to do.

 

[KuRi]

Are you sure that it won't fit? I replaced mine not long ago and I had the same issue but it just fitted ok.

Anyway I recently switched to aluminum chainrings, lightweight, very cheap and very easy to install. You just need to buy some bolts and the original screws can be used. The ones you can find branded as deckas, snail, ... in amazon and aliexpress. They work perfect and you can try differente sizes and colours.

Cheers!

 

[andyb2]

the teeth look different too, the original look more square than the new one

 

[Goughy75]

Are you sure that it won't fit? I replaced mine not long ago and I had the same issue but it just fitted ok.

Anyway I recently switched to aluminum chainrings, lightweight, very cheap and very easy to install. You just need to buy some bolts and the original screws can be used. The ones you can find branded as deckas, snail, ... in amazon and aliexpress. They work perfect and you can try differente sizes and colours.

Cheers!

I could make it fit. It would mean the chainring would be about 1-2mm closer to the frame. I don't know how this would alter how the gears worked etc. I could give it a go. The problem is there is no recess at the back of the spider for the lip in the new cainring to fit.
If I bought the alloy one that would fit as it has no lip on the bolt holes.

 

[KuRi]

You are right, I have just checked and the original has no lips but the replacement one I bought is the same as yours. I installed it without noticing it... I thought there was space for the lips on the spider but now I am not sure :S

 

[Goughy75]

I just received this reply from Upgrade bikes.
"
You do not have the wrong ring, you have the new version of your old OEM one.
The tooth profile change is due to the rings now being 12 speed compatible.
The reason for the lip to now be on the front of the ring is for new/better chainline, while still providing minimum depth for the thread to grip the bolt. There are no other options for you unfortunately, this new ring will be seen aftermarket, and also standard OEM.
Hopefully this clarifies the correct ring you have received."

 

[KuRi]

Good to know, anyway my suggestion is to use the alloy chainrings widely available, cheaper and lighter and they work perfectly. I installed a 34t in gold color that has 1000km+ and still rides fantastic

 

[Goughy75]

Good to know, anyway my suggestion is to use the alloy chainrings widely available, cheaper and lighter and they work perfectly. I installed a 34t in gold color that has 1000km+ and still rides fantastic

Do you have a link to where I could get that chainring you have?

 

[KuRi]

These are my favourites:

0.38￡ 97% de DESCUENTO|Deckas platos y bielas dentadas para bicicleta de montaña 104BCD, redondos, ovalados, angostos y anchos, 30T, 32T, 34T, 36T y 38T|104 bcd|narrow wide chainringnarrow wide - AliExpress

¡Compra fácil, vive mejor! Aliexpress.com

es.aliexpress.com

But you need the bolts because these are not threaded:

Page Not Found - Aliexpress.com

 

[Goughy75]

Wow that is cheap. I will try a smaller chainring as I'm curious as to the difference it will make. Thanks for links.

 

[Jackware]

Wow that is cheap. I will try a smaller chainring as I'm curious as to the difference it will make. Thanks for links.

Just be aware that if you swap to a smaller chainring and it fits behind the spider you'll probably need the tool to remove the spider as you may not be able to get the smaller chainring over it.

 

[KuRi]

the 34T can be fitted without removing the spider on the Giant bikes, the 32T does not fit without removing.

 

[DrStupid]

I have been been able to 'pop' a 32T CR over the spider, though it was tight. It may depend on brand.

 

[KuRi]

Which one were you able to slide in? Thx

 

[DrStupid]

I think it was a wolftooth dropstop for the shimano 12 speed. I'll verify this when i get a chance.

Edit. It was this one and it Needed to be "popped." It's not gonna slide over easy, but It wasnt too bad.

 

[MinusPrevious]

I just received this reply from Upgrade bikes.
"
You do not have the wrong ring, you have the new version of your old OEM one.
The tooth profile change is due to the rings now being 12 speed compatible.
The reason for the lip to now be on the front of the ring is for new/better chainline, while still providing minimum depth for the thread to grip the bolt. There are no other options for you unfortunately, this new ring will be seen aftermarket, and also standard OEM.
Hopefully this clarifies the correct ring you have received."

Thanks for the update. Curious if that lip will fall into the spider chain ring hole? or will sit on top of the mounting hole?

 

[Goughy75]

Thanks for the update. Curious if that lip will fall into the spider chain ring hole? or will sit on top of the mounting hole?

On mine it mounts flush with the back of the spider. There is no recess on the back of the spider on mine.

 

[andyb2]

I finally went to fit the new praxis chaing ring, and while it'll bolt to the spider ok, it no longer sits centrally in the chain guide, and therefore the chain wont fit.

did you adjust/replace the chain guide, or just remove it?

 

[DrStupid]

I know there are various blocks for these guides. The 2021 version has a different offeset when compared to one from 2019, and in my case, the 2021 version solved the trouble on my 19 Trance. But I've also used a few washers behind the bracket, if that's the direction you need.

Edit: Correction, the 2019 guide solved the trouble with an offset chainring, when installed on my 2021 X. In my statement above, I had it backwards.

 

[andyb2]

The ring would site closer to the frame, so I'd need to remove material to make it fit, rather than add spacers.

intrestingly, the giant site lists the same chain guide for 2019, 2020 and 2021 bikes:

MRP Chain Guide For Giant E-MTB | Giant Bicycles Australia

Replacement MRP chain guide suitable for selected Giant & Liv e-mountain bikes. Please refer to the compatibility list for suitability.

www.giant-bicycles.com

my sister has a 2021 Liv Intrigue E+ so I guess I'll measure that, and see if there's a difference

MRP sell the guide blocks seperately, but dont seem to have any options:

TR Upper Guide

This is the upper guide for 1X V3 and AMg V2 guides. This will also fit your existing AMg guide and any 1X guide with the previous G3 upper guide. Please note, the bolt is not included.

mrpbike.com

Also, just had a reply from Praxis that suggests drilling out the spider, which is easy enough to do, if a little excessive

I wonder if 2021+ bikes use a different spider with recesses for the chainring, and if that is compatible with earlier years

 

[DrStupid]

This is why you should never trust a gen-X-er. We are getting old and forgetful. Apparently I kept a 2019 chain guide from my first Trance e+ and installed it on the 2021 Trance X, as it fits better with the offset 32T CR.

Here is the OEM guide from my 2019 Trance installed on my 2021 Trance. Note the width of the bracket.

And here is the 2021 bracket on my wife's Trance X which is completely original equipment. The bracket is 2mm wider, thus positioning the guide further away.

Which part you get when ordering for a 2019 is beyond me, if the part numbers are the same.

 

[andyb2]

that's odd, as you'd think the 2021 would be using the newer chainring, thus needing the narrower bracket

 

[NicoMTB]

Do you need to change setting or reprogram anything if you change your chainrings? I have a 36T on my Reign E+1. its not really useful. i'm thinking of dropping to as 34 or 32. climbs around here are just long and 900m up non stop; or more.

 

[DrStupid]

Do you need to change setting or reprogram anything if you change your chainrings? I have a 36T on my Reign E+1. its not really useful. i'm thinking of dropping to as 34 or 32. climbs around here are just long and 900m up non stop; or more.

No changes in software needed. The 32, which I use for the same reason you noted, can require removal of the spider. All the 34s I've used slip right over.

 

[hyfly25c]

Wanted to swap my 38T for a 32T today, but the lock nut to remove spider will not open up!
(Yes - I know left hand thread);it's a second hand bike - so I assume it's been fixed with loctite. Have applied up to 120 Nm
but don't dare to go beyond. Any ideas?