Brand new 9.9 1 mile riding and frames is damaged due to rear mech hanger

chrismechmaster

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Dec 7, 2020
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So I recently purchased a 2021 rail 9.9 x01 invisframe it set it all up ready for the first ride today

when out just to get a feel for the settings etc
2nd gear change then chain went slack and the rear mech was further forwards than it should be

took the rear wheel out and WOW šŸ˜® the plastic mech hanger has gone forwards but it has been forced over the frame drop out and the carbon is damage and all split

so it appears the bolt that says 20 nm wasnā€™t tight enough and the whole thing has moved forwards and damaged my frame

I have only owned the bike 19 days and never ridden it until today
I have took it back to the shop

so what should I expect ??
Would trek replace the chain stay arm ??
Or would then repair it ??
Would they even stock this frame part

What would you guys want done

I have since seen a you tube video on this bolt and it Appears a problem

many thanks chris
 

chrismechmaster

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If they donā€™t have a replace parts or another bike suitable would I be entitled to a refund

anyone else had this problem
 
Last edited:

slomtbr

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It would have been installed incorrectly or was VERY loose to rotate forward - either way, it's on the shop/Trek to make it right.

Screen Shot 2022-01-23 at 8.40.31 AM.jpg
 

chrismechmaster

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Must of been in correct as that little lump circled with number three is missing / broken off and that ridge has been broken away
 

Stihldog

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In the past 2 years both my neighbour and myself, broke and cracked, our rear triangle. Trek replaced and reinstalled both under warranty. My wait time was a little faster (1 week). His was 1 month. We both have Rail 9.7ā€™s. I never asked about a temporary replacement. Got a few spare derailer hangers though.
 

Stihldog

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Great news just what I wanted to hear as canā€™t wait to get out on the bike
There was only some question about the new upgraded rotor (220mm Magura). They thought that the new size may have attributed to the broken triangle ā€¦but they replaced it under warranty anyways. I donā€™t think the manufacturer want a reputation of breaking frames under normal use.
 

chrismechmaster

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Hi
No I did the invisframe myself
but didnā€™t touch the mech or hanger only took the wheel out the normal way didnā€™t touch the bolt that holds the hanger on

do you think they will try and blame me to get out of it I wonder ??
 

Mikerb

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May 16, 2019
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I was wondering whether you contracted the job out ,or the LBS did it...and if so did they apply invisiframe under the mounting. If you did the job and stayed clear of the hanger area there is no reason why anyone can hang the blame on you. It looks simply like a case of the hanger not being rotated properly against its stop when originally fitted. It then only took a couple of gear changes for chain tension to rotate it with force sufficient to rip the stop off etc.

That said, it does look like the design was an attempt ( failed) to prevent damage to the carbon chainstay in the event of impact. They avoided using a locating/securing grub screw and just went for fairly feeble stop instead.............well any impact causing the hanger to be rotated is hardly likely to be stopped by a small carbon stop ..........so it would get destroyed regardless. The shear point needs to be on the hanger so it breaks first!!
 
Last edited:

chrismechmaster

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I was wondering whether you contracted the job out ,or the LBS did it...and if so did they apply invisiframe under the mounting. If you did the job and stayed clear of the hanger area there is no reason why anyone can hang the blame on you. It looks simply like a case of the hanger not being rotated properly against its stop when originally fitted. It then only took a couple of gear changes for chain tension to rotate it with force sufficient to rip the stop off etc.
Thatā€™s exactly what I believe it was when I took the wheel out today to see what had happened the hanger had ridden over that little stop peg so I think it wasnā€™t sat against there properly when the bike was built , itā€™s then been force further round via the gear changing thatā€™s caused further damage to the frame

looks like the chain stay section of the bike is available on the trek parts list for Ā£430 so o guess one of these and a new hanger and hope the warranty/ shop covers this
 

slomtbr

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Its a known problem, unfortunately yours wasn't caught early
This video is about the damage caused when the derailleur hanger moves toward the back when not torqued to spec. Something caused the OP's hanger to move forward, which means incorrect installation or it was VERY loose.
 

slomtbr

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Well canā€™t fault trek warranty at all

The Bike shop called trek and they accepted the warranty no problems and parts are already on there way

they are also replacing the seat stay not sure why as this is damaged only the chainstay ??
Perhaps because the derailleur hanger goes through both stays and they want to make sure the seat stay is sound.
 

Mikerb

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May 16, 2019
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A word of caution. The Trek Rail 5 is ally not carbon and on the YBM video there is clearly no "stop" against which the hanger should be positioned as on the carbon frame version. So the arrangement appears to be different and that torque of 25nm may be excessive on the carbon framed bike.
Both systems look to be lacking good design to me! One relying on friction ( are the faces of the nut and hanger serrated even??) and the other on a carbon stop.
 

chrismechmaster

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Dec 7, 2020
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A word of caution. The Trek Rail 5 is ally not carbon and on the YBM video there is clearly no "stop" against which the hanger should be positioned as on the carbon frame version. So the arrangement appears to be different and that torque of 25nm may be excessive on the carbon framed bike.
Both systems look to be lacking good design to me! One relying on friction ( are the faces of the nut and hanger serrated even??) and the other on a carbon stop.

totally agree on the video the guy says torque to 25 nm which is to high for the carbon frame

my bike the bolt says 20 nm

it look like when mine was built the hanger was possibly sat on top of the stop peg so the hanger was at a angle which is why it moved so easy and the stop I think is completely broken off
 

Binhill1

šŸŠ Tango Man šŸŠ
Mar 7, 2019
3,265
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Scotland
So I recently purchased a 2021 rail 9.9 x01 invisframe it set it all up ready for the first ride today

when out just to get a feel for the settings etc
2nd gear change then chain went slack and the rear mech was further forwards than it should be

took the rear wheel out and WOW šŸ˜® the plastic mech hanger has gone forwards but it has been forced over the frame drop out and the carbon is damage and all split

so it appears the bolt that says 20 nm wasnā€™t tight enough and the whole thing has moved forwards and damaged my frame

I have only owned the bike 19 days and never ridden it until today
I have took it back to the shop

so what should I expect ??
Would trek replace the chain stay arm ??
Or would then repair it ??
Would they even stock this frame part

What would you guys want done

I have since seen a you tube video on this bolt and it Appears a problem

many thanks chris
Cant believe you had a bike for 19 days before you used it .
 

CJaMTB

Well-known member
May 9, 2020
402
382
Dartmoor
it look like when mine was built the hanger was possibly sat on top of the stop peg so the hanger was at a angle which is why it moved so easy and the stop I think is completely broken off
Not possible, the gears would never have been indexed and your derailleur would have been in your spokes the first time you got anywhere near your biggest cogs. Mech hangers have to be sat in perfect alignment for the gears to index, especially with 11 and 12 speed groupsets, which is why a derailleur alignment gauge is probably one of a mechanic's most used tools.
 

markloch

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May 14, 2021
188
154
NorCal
Mine was loose at purchase (rail 5) - be careful tightening it, when I did the hanger rotated as I tightened it and it cracked. Fortunately local shop had the hanger, bought two and I carry the spare n my pack.
 

Binhill1

šŸŠ Tango Man šŸŠ
Mar 7, 2019
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Not possible, the gears would never have been indexed and your derailleur would have been in your spokes the first time you got anywhere near your biggest cogs. Mech hangers have to be sat in perfect alignment for the gears to index, especially with 11 and 12 speed groupsets, which is why a derailleur alignment gauge is probably one of a mechanic's most used tools.
Broken plenty hangers and repaired but ive never needed that tool or even heard of it . Old school .
 

Stihldog

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Jun 10, 2020
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Coquitlam, BC
Why is the hanger plastic? Like @markloch said ā€œitā€™s either straight or snappedā€.
Mine is aluminum and it bends. You might have one or two chances of straightening it, after a crash, with a derailer alignment tool. Depending on the amount of misalignment, it can be realigned with the tool. A plastic hanger ā€¦probably not. I keep a couple of spares.
 

markloch

Active member
May 14, 2021
188
154
NorCal
Here's SRAM's page for the hanger, with some explanation of why it is what it is how it's supposed to operate - it is expected to rotate.

 

Binhill1

šŸŠ Tango Man šŸŠ
Mar 7, 2019
3,265
5,054
Scotland
Why is the hanger plastic? Like @markloch said ā€œitā€™s either straight or snappedā€.
Mine is aluminum and it bends. You might have one or two chances of straightening it, after a crash, with a derailer alignment tool. Depending on the amount of misalignment, it can be realigned with the tool. A plastic hanger ā€¦probably not. I keep a couple of spares.
Straightened plenty with a shifter .
 

Stihldog

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Jun 10, 2020
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Coquitlam, BC
I may have missed it but is the Sram replacement plastic?
Straightened plenty with a shifter .
So you donā€™t need/use a derailer hanger alignment tool? (If itā€™s aluminum).
Does using this method (if I understand you correctly) work for both the horizontal and/or vertical axis?
 

Binhill1

šŸŠ Tango Man šŸŠ
Mar 7, 2019
3,265
5,054
Scotland
I may have missed it but is the Sram replacement plastic?

So you donā€™t need/use a derailer hanger alignment tool? (If itā€™s aluminum).
Does using this method (if I understand you correctly) work for both the horizontal and/or vertical axis?
Yes always worked for me . Remember when was the alignment tool actually invented ? . Same as the chain measurement tool never heard of it till a year ago . Im not sure how i have managed to be honest .Old school . Not being cheeky just how it is now. Torque settings another would be engineers like to throw about.
 

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