Trek Allant 9.9s chain question

[misteracng]

Anyone know about the correct chain length to buy? I see shimano chains are usually sold as 126 link length but there is a 138 link as well which I think this bike might need. I bought an XTR chain as a replacement at 126 link length and it was not long enough and shorter than the original XT chain which I did not expect. I think the 138 link is the way to go, but I don't really see any online shops that are selling that length, they almost always list 126 link.

 

[Nova Haibike]

You need to buy a so-called e-bike chain, which are longer than standard chains. I am not seeing any USA sellers of XTR chains in the 138 link length; they do seen to be sold in Europe. For a more readily available chain, I would recommend the KMC E12.

 

[Stefan Mikes]

I cannot understand the problem. Trek uses the Shimano SLX CN-M7100 12-speed 126 link chain for the drive-train of the 9.9s.

Did you unlock the "Shadow" clutch for the chain replacement? (The clutch is the small gray tab in the derailleur that needs to be pushed forward to unlock).

 

[misteracng]

It’s not an issue with the shadow clutch, it’s that the replacements chains don’t have enough links. Most online stores seem to stock a 126 link version, which I purchased, but actually it seems with the large front chainring, 126 link is too short, we need the 138 link version and to size down as needed. It just seems hard to find replacement chains in that length to buy. They are listed on shimano documents that they sell different lengths

 

[Alaskan]

Shimano Deore XT CNM8100 12 Speed 138 Links MTB Chain SILTEC W/ Quick link

This one is perfect for me right out off the box. I have the 10-51 tooth cassette though. the stock cassette is a 10-45 if you have that one, just shorten by 6 links to 132 links.

Shimano Deore XT CN-M8100 12 Speed 138 Links MTB Chain SIL-TEC W/ Quick link | eBay

Series: DEORE XT M8100 Series. - Easy connection (SM-CN910-12). Qty: 1pc (with Quick Link). Roller link plate: Chromizing.

ebay.us

 

[misteracng]

Shimano Deore XT CNM8100 12 Speed 138 Links MTB Chain SILTEC W/ Quick link

This one is perfect for me right out off the box. I have the 10-51 tooth cassette though. the stock cassette is a 10-45 if you have that one, just shorten by 6 links to 132 links.

Shimano Deore XT CN-M8100 12 Speed 138 Links MTB Chain SIL-TEC W/ Quick link | eBay

Series: DEORE XT M8100 Series. - Easy connection (SM-CN910-12). Qty: 1pc (with Quick Link). Roller link plate: Chromizing.

ebay.us

Thanks for the info, I need to order that to have a spare. My bike came with the XT 10-51 cassette as standard even though the spec says slx 10-45T. Even there website pictures show an XT cassette. They must have made a change in production. It seems like the touring style e-bikes with the larger tooth front chainrings need 138 link chains to size down, compared to e-mtb bikes.