Rail chain line

Philly G

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Hi everyone, happy new year...my apologies if this has been answered elsewhere, I did do a search...just double-checking the chain line for the 2020 Rail is indeed 52mm? Needing a new chain ring, I'm looking at the RaceFace , looks to be good value for money
 
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52mm or sometimes described as 3mm offset is for boost ( 148mm rear end) so yes its right.
 
Thanks @Mikerb , I was interested to read in this thread, discussion around the steel e13 chainring having 52mm chainline, but the alloy version 53mm, which helped with chainstay clearance..
I see RaceFace are also offering a 55mm, which makes me wonder if this would allow going up to a 36T if so desired. But how much would this difference in chainline affect shifting?
 
as far as I can work out a chainline is always a compromise given that the designers seems to aim for a "straight" chain line on the middle sprocket of the cassette. So the chainline always gets more extreme towards the largest and smallest sprocket. If you fit a chainwheel with a bigger offset the danger would be the chainline being even more extreme on the biggest ( lowest) 2 sprockets.

It all gets more confusing when a spider plus 4 bolt chainwheel is used rather than a direct mount chainwheel since the spider can provide the necessary offset for a boost rear hub using a 49mm chainwheel!!

You can see how marginal all of this is becoming especially with 12 speed cassettes by how close even 32t or 34t chainwheels are to the chainstay on some bikes!!
 
My E13 34t steel chainring went bad much faster than the SRAM 34t steel chainring. I can't say if it's the same in every case because there's so many variable but I will stay in cheap SRAM direct mount chainrings or do the spider + 104BCD.
 
@Hamina I'm not sure if the Sram ring would work well with my Shimano chain...the RaceFace is designed for Shimano. Then again it could all be BS 😉
 
@Hamina I'm not sure if the Sram ring would work well with my Shimano chain...the RaceFace is designed for Shimano. Then again it could all be BS 😉

Did you buy Raceface chainring? are you satisfied? Ordered Raceface steel chainring but i can update order and buy E13 steel instead. (changing sram nx to shimano xt)
 
Did you buy Raceface chainring? are you satisfied? Ordered Raceface steel chainring but i can update order and buy E13 steel instead. (changing sram nx to shimano xt)
Yes I just bought a couple of the Raceface chainrings in the weekend, from BikeInn, so I'm waiting on delivery...will post back when they arrive, but I don't expect any issues, I've used RaceFace cranks and chainrings on my accoustic bike for years. I'm not a huge fan of E13, their components seem overpriced to me
 
Yes I just bought a couple of the Raceface chainrings in the weekend, from BikeInn, so I'm waiting on delivery...will post back when they arrive, but I don't expect any issues, I've used RaceFace cranks and chainrings on my accoustic bike for years. I'm not a huge fan of E13, their components seem overpriced to me
Any reports??? 55 chainline ok ?
 
Any reports??? 55 chainline ok ?
I can't comment on the 55mm since I got the 52mm....but quite a few people are running bigger chainrings with more offset...have a search around the forum you'll find the information you need
 
Any reports??? 55 chainline ok ?
I have been running the RaceFace 36T 55mm chainring for about 3 weeks and it's been fine. But honestly, I'm looking for a 38T as +2 teeth just didn't gear it up much. But for <$30 it's a great option when it's time to replace the original 34T.

 
I have been running the RaceFace 36T 55mm chainring for about 3 weeks and it's been fine. But honestly, I'm looking for a 38T as +2 teeth just didn't gear it up much. But for <$30 it's a great option when it's time to replace the original 34T.

Lobot. You have a pic of the chainstay gap? Im curious to see this gap with 36t.

Thanks man!
 
I posted a few photos in this related thread:


I've got over 500 miles on it and no issues. Great mod for the price.
 
I also wanted to replace my original 34T chainring by a 38T on my Trek Rail 9.7 NX 2021. With help from this thread i found the Sram 38T 55mm chainline chainring: 11.6218.058.001
1709626626804.png


the gap is fine:
1709626325300.png
 
I also wanted to replace my original 34T chainring by a 38T on my Trek Rail 9.7 NX 2021. With help from this thread i found the Sram 38T 55mm chainline chainring: 11.6218.058.001
View attachment 135727

the gap is fine:
View attachment 135726
Does the chain roll off the chainring from the bottom when wheeling the bike backwards? Annoys the crap out of me having to loosen the chain guide to refit the chain...
 
Does the chain roll off the chainring from the bottom when wheeling the bike backwards? Annoys the crap out of me having to loosen the chain guide to refit the chain...
Also no problem there, the only thing is that in first gear the chain is not really in a straight line, but i do not use the first gear a lot so i am happy. by the way, since i use narrow wide chainrings on all of my 1x bikes i never had to refit the chain
 
Also no problem there, the only thing is that in first gear the chain is not really in a straight line, but i do not use the first gear a lot so i am happy. by the way, since i use narrow wide chainrings on all of my 1x bikes i never had to refit the chain
hello would you be able to send me a direct link to the exact chain ring i need please,i have a rail 5 and im quite new to bikes.
thank you
 
thank you very much,did you have to lengthen the chain much.
also will this fit a gen 3
 
thank you very much,did you have to lengthen the chain much.
also will this fit a gen 3
No a gen3 has another fit, the chain is just long enough on my bike but it is better to use a longer one if possible
 
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