Good news for anyone riding an Esker or even one of the OG Advocate hardtails – your bike is now SRAM UDH compatible. You’ll have to buy a new set of dropout plates, but that was part of the plan when Advocate Cycles (now Esker Cycles) developed their Portage dropout system.
Stating that they designed the system to be “”future proof” from the start”, the Portage system uses twin dropout plates that bolt to the frame. On the initial Advocate Hayduke, it was one of the things that attracted us to the bike as it allowed you to use 135, 142, or 148mm rear spacing on the same bike for QR or Thru axle, and geared or single speed drivetrains.
Now, those dropout plates have been updated with an option to run SRAM UDH. This not only allows you to run a SRAM Transmission drivetrain, but you can run any derailleur while taking advantage of the SRAM UDH. Why would you want to do that? Finding a replacement derailleur hanger for the UDH should be much easier while riding across the globe since so many bikes are now using the system.
Currently, the SRAM UDH dropout plates are offered in a fixed position with Boost 148 x 12mm spacing. Note that the UDH requires a new Maxle that is included with the kit since the Transmission Full Mount Bolt has a different thread pitch than the original Portage dropout plate, and requires a longer axle.
Esker also has an adjustable UDH plate kit coming soon that will allow you to run single speed drivetrains or adjust your chain stay length. The sliders will work with their FAN nut system for 4-position adjustability, or an 8mm nut for infinite adjustment within the 17mm range.
The 6061-T6 plates are CNC-machined, and will be sold as a set, or as individual left/right sides f you need a replacement. One of the beautiful things about consistently using a dropout system like Portage is that the new plates are compatible with all Esker & Advocate frames dating back to 2016.
In order to get everything to fit in the frame, the UDH dropout plates have three main changes. There’s the different axle as mentioned above, but there’s also a change to a 180mm post mount disc brake standard at the rear, and the chain stay length grows by 7mm.
SRAM UDH Dropout Options & Pricing
There are a number of options here, and they are priced according to how many pieces you need.
- Individual plates – $45 each
- UDH Fixed Set: Includes Left and Right plates, SRAM UDH Hanger, and 180mm axle – $150
- Transmission Fixed Set: (no UDH hanger) Includes Left and Right Plates and 180mm Axle – $130
- UDH Adjustable Set: includes Left Plate, Right Plate, and SRAM 180mm Axle (additional hardware required depending on drivetrain) – $140 Shipping August 10th
Note that UDH plates are available for aftermarket purchase now, and Esker will begin shipping all new frames with the UDH dropouts in 2024.
How to Add SRAM Transmission to Your Bike
If you own an Advocate or Esker with the Portage dropout system, step one is purchasing the UDH dropout kit and a SRAM Transmission of your choice. I happened to have one of the new SRAM GX Transmission kits on hand, but without a frame to hang it on – until Esker announced their new Portage plates.
If you’re using the complete Transmission kit, you’ll also likely need a new bottom bracket as the SRAM Transmission cranks use their DUB 29mm spindles. The early Advocate Hayduke had a pressfit bottom bracket (which has since changed to threaded), so I had been using a Wheels Manufacturing PF92 threaded bottom bracket. The BB has been flawless for years, so I was a bit bummed that I had to swap it out – especially since the larger 29mm DUB spindle meant Wheels Manufacturing hasn’t been able to create a thread-together DUB bottom bracket for this BB86/92 shell size yet.
Wheels Manufacturing does have a BB that will fit though, and the pressfit cups pressed nicely into the frame.
After sorting out the crankset, all that’s left is to remove the existing drivetrain and rear brake, swap out the dropout plates, reinstall the rear brake, and then install the Transmission as specified by SRAM.