Rail (750Wh) T Type Chainring and chainguard dilemma.

[ThrottleAbuse]

I have a 9.9 Gen 3 AXS that I swapped out the AXS Eagle to T Type XX. The issue I am having is with chainline and the chainguide. The new T Type chainring sram # 11.6218.059.000 is the only T Type chainring for the Bosch motor. It is marked 55mm chainline. I believe the bike came with sram # 00.6218.013.001 x sync chainring that is marked boost 148. After I installed the new T type chainring I measure the chainline at about 57mm. The Trek manual says chainline should be 52mm. The Trek T Type FAQs says 55mm chainline for all Trek T Type bikes and when my local shop reached out Trek tech said 55mm. The issue I am having is when I install the t type chainring it hits the chain guard on the outside. If I use the xsync chainring it lines up perfect with the chainguide and measures 55mm. The Trek tech said I need a 52 to 55mm chain guide spacer kit. The issue with that is if you space out the chainguide it will hit the inside of the chainring inner alloy ring and you cant actual get the chainring on.

My E thirteen chainguide has 4.5mm spacers behind it. The 52 to 55mm kit would change those to red 12mm spacers IIRC. There is no way that will fit. I tried stacking 2 of the 4.5mm spacers just as a test and I cant even install the chainring without it hitting.

Does anyone have a T Type with the chainguide on it? I am also curious to see what the chainline measures on a Rail that came the T Type.

 

[Stihldog]

Not sure if I can help but when I installed a new ethirteen chainring on my 2020 Rail the chain would rub against the chain guard. This obviously meant that the chain alignment was wrong, caused by the new ethirteen chainring. Here’s what I discovered …

The new ethirteen chainring had a raised portion which eliminated the need for a thin brass “O” ring spacer. I left the very thin plastic spacer. By doing this the alignment was perfect …no chain-rub on the chain-guard.

I applied sufficient grease to this area and kept a close eye on it for awhile. I later installed the bearing seal kit (specific Bosch grease). I’ve had no problems since.

My Fuel EXE has the T-Type derailer along with a chain guard. This bike is fairly new so I haven’t had the need to upgrade the chainring.

I do think alignment is critical for the t-type derailer. After I purchased the Fuel EXE the chain was rubbing against the lower triangle. It was found that the axle bushing was installed backwards. Also I heard that a spacer is required for the cassette alignment.

Regardless, this t-type derailer is amazing. I hope to install one on my 2020 Rail as a future upgrade.

Hopefully someone with experience in this area can add some suggestions or solutions.

 

[ThrottleAbuse]

Unless Trek changed the frame or is using a different chainring they are send out T Types at 57mm chainline.

The trek website lists this for the chainring

"SRAM Chainring XX for Bosch eMTB direct mount, 34 tooth, Transmission, SRAM part number 00.6218.036.001 "

There is no SRAM part number that matches that.

My current thought is to order a Hope chainring. They are listed as flat top chain compatible and a 52mm chainline. When mounted up that will be the same chainline as the original xsync and should measure at close to 55. Absolute Black has a chainring carrier that they say is 53mm but their supersteel chainrings are not flat top chain compatible. The combo lists for $310. Its very light though.