Rail 9.7 chainring rubbing

[dannypr]

Hey peep anybod you have this issue

 

[dannypr]

Bought bike Jan 9

 

[BrentD]

I've had a very slight issue (enough to just touch the top layer of paint) but I put that down to a stick or something getting sucked through there at some stage. Nothing as serious as what you show in your pictures though.

 

[Doug Stampfer]

Wow. New bike time. There's a thread about a motor being out of line on a carbon bike if you have a look further down the page

 

[coregrind]

There's a thread about a motor being out of line on a carbon bike if you have a look further down the page

Did that thread get removed? It seems to have disappeared.

 

[Hamina]

Is the chainring nut tightened?

 

[Rob Rides EMTB]

Did that thread get removed? It seems to have disappeared.

Yes. The poster of that thread requested removal.

 

[bluewater87]

Yes. The poster of that thread requested removal.

Yes as Rob said, I had the thread removed. Feel free to pm me with any questions.

 

[Mr_Price]

I got my stunning new bike February 17th. Noticed this exact thing yesterday after a ride. Bike is booked back in on Monday @ my LBS. Hope they can offer me a satisfactory solution ASAP. I’m already feeling lonely. ?

 

[coregrind]

Is the chainring nut tightened?

I was surprised to find how easy it was to remove the nut on the new bike, fresh out of the box. It didn’t feel like it was anywhere near the torque amount recommended by the brand for the ring I installed in place of the stock unit. Make sure to check your nuts, folks!

 

[dannypr]

I was surprised to find how easy it was to remove the nut on the new bike, fresh out of the box. It didn’t feel like it was anywhere near the torque amount recommended by the brand for the ring I installed in place of the stock unit. Make sure to check your nuts, folks!

little update shop made warranty claim Just waiting for Trek to send warranty

 

[dannypr]

little update shop made warranty claim Just waiting for Trek to send warranty

I was surprised to find how easy it was to remove the nut on the new bike, fresh out of the box. It didn’t feel like it was anywhere near the torque amount recommended by the brand for the ring I installed in place of the stock unit. Make sure to check your nuts, folks!

Yeah i keep rechecking my bolts before each ride they tend to be get loose after every ride

 

[Mikerb]

If it is a 4 bolt chainring the bolts and threads should be clean and threadlocked.

 

[Philly G]

If it is a 4 bolt chainring the bolts and threads should be clean and threadlocked.

No bolts, the chainring is held on with a reverse thread lockring

 

[Mikerb]

So the lock ring is reverse thread and torqued to c 30nm?
The mating faces of the lockring and chainwheel and the threads must be clean/degreased and the thread treated with loctite......and left to set for 24 hours before use.

The reverse thread will be self tightening under normal pedalling forces, BUT the reverse will be the case when freewheeling downhill on rough terrain due to suspension kick back on the chain. Clean mating surfaces will delier higher friction to movement and blue loctite will further help to ensure the lock ring does not loosen. Personally I would also remove any glossy paint finish on the mating surface of the chainring.
You essentially want a raw metal contact surface on both lock ring and chainwheel.

 

[Mr_Price]

A mini update from Trek. They believe the rear triangle has too much play in it and are sending a new chain stay to see if that stiffens it up.

 

[Philly G]

So the lock ring is reverse thread and torqued to c 30nm?
The mating faces of the lockring and chainwheel and the threads must be clean/degreased and the thread treated with loctite......and left to set for 24 hours before use.

The reverse thread will be self tightening under normal pedalling forces, BUT the reverse will be the case when freewheeling downhill on rough terrain due to suspension kick back on the chain. Clean mating surfaces will delier higher friction to movement and blue loctite will further help to ensure the lock ring does not loosen. Personally I would also remove any glossy paint finish on the mating surface of the chainring.
You essentially want a raw metal contact surface on both lock ring and chainwheel.

I used red loctite on mine, torqued to c 30nm, it's remained nice and tight

 

[Mikerb]

I used red loctite on mine, torqued to c 30nm, it's remained nice and tight

good luck getting it off again!!

 

[Philly G]

good luck getting it off again!!

I suppose that could be an issue, I thought red loctite was appropriate given the lockring is not tightened to especially high torque, and the fact that, as you say, it self-loosens due to suspension kick back. Guess I'll find out when its time for s new chain ring lol

 

[Mikerb]

Red loctite is designed for permanent fixings. It can take quite a bit of heat to soften it for removal and a specific solvent to get it off the threads. Blue loctite which is medium strength should do the job because the chain kick back force is not great. Assuming your lock ring is ally you may be lucky in being able to break it off in 2 pieces.

 

[Philly G]

Red loctite is designed for permanent fixings. It can take quite a bit of heat to soften it for removal and a specific solvent to get it off the threads. Blue loctite which is medium strength should do the job because the chain kick back force is not great. Assuming your lock ring is ally you may be lucky in being able to break it off in 2 pieces.

Oops! I might have f**ked up then ?

 

[Mr_Price]

I got my bike back from my LBS yesterday. The owner is convinced it's fixed and believes it's "basically because flouro paint needs to go really thick" so it's that's why there is reduced clearance between the chain stay and the chain ring. The owner forgot to update his head mechanic on his theory, the mechanic almost had coffee come out of his nose when I recounted the story.

They have replaced the yellow chain stay with a new black chain stay, and whilst the clearance has increased by <1.0mm it's nowhere near as much as a gap as on the three other Rail X that they have in stock.

The mechanics have asked me to go ride it as hard as I can for a few days and see if the contact still occurs. At least I feel like the mechanics have got my back even if the shop owner needs to get his head around the situation.

I'll post a picture of the current clearance next week. Riding on Tuesday.

 

[Sean0711]

i was just scrolling though trying to find out if this was a common problem. I was out today for about my 6/7th ride on the bike (its only covered 250 miles) I have the same markings on my chain stay, thought i must have got something stuck in there. but looks like it might be a bigger problem than I first thought.

 

[Mr_Price]

This thread indexes very well on google when you search for Rail Chain Ring Rub, it's how I found the forums.

I am not a carbon fibre engineer, bike designer or multi-millionaire (I'd just buy a new bike) but I'm pretty unhappy about the scenario I have. Riding the bike this week to see what's up but I think you need to contact your LBS pretty quick.

 

[Paul Mac]

Not sure if the actual chainring may have something to do with it.
I have the 9.8 and it came stock with the sram eagle chainring.
As no one seems to have them in stock, I bought the e13 one that comes on the 9.9 models.
It is definitely closer to the swing arm than the sram version. ?

 

[Mikerb]

Is this a case of using a standard chainring...normally 6mm offset.........rather than a boost chainring which is 3mm offset? Assuming the rear hub is 148 it should be a boost chain ring which will be 3mm further away from the chainstay than a standard non boost chainring. The offset should be stamped somewhere on the chainring.

 

[Paul Mac]

Is this a case of using a standard chainring...normally 6mm offset.........rather than a boost chainring which is 3mm offset? Assuming the rear hub is 148 it should be a boost chain ring which will be 3mm further away from the chainstay than a standard non boost chainring. The offset should be stamped somewhere on the chainring.

I think e13 only make the one size for the bosch motor, which is meant to be the boost version.
I'll look at my one see if it has any markings on it?

 

[Paul Mac]

Is this a case of using a standard chainring...normally 6mm offset.........rather than a boost chainring which is 3mm offset? Assuming the rear hub is 148 it should be a boost chain ring which will be 3mm further away from the chainstay than a standard non boost chainring. The offset should be stamped somewhere on the chainring.

Just checked mine has 52mm boost written on it.
Has anyone got the e thirteen chainring that came standard on the bike?
Is this what you have written on yours?

 

[Hamina]

Just checked mine has 52mm boost written on it.
Has anyone got the e thirteen chainring that came standard on the bike?
Is this what you have written on yours?

I just bought and installed e13 34t chainring. On Rail 5 you have to remove the shimplate under the oem SRAM chainring. Otherwise there’s not much thread for the nut.

 

[Sean0711]

Just checked mine has 52mm boost written on it.
Has anyone got the e thirteen chainring that came standard on the bike?
Is this what you have written on yours?

Just stripped mine down and that’s the same as my chainring.