WO R D S A N D IMAGES : CHRIS HERRON
There was a time not too long ago that 11 speed drivetrains were all us mountain bikers needed to shred our local trails and climb and descend the big mountains. 11 gears, good range and reliable shifting. I even thought that any more gears would be wasted and reliability and durability would go out the window.
That was until the ‘Eagle’ had landed. SRAM dropped 12 speed Eagle drivetrains on us and it was bye-bye forever to 11 speed. I know most people who haven’t had the chance to ride Eagle could argue that it was only one more gear, but it is really is more than just that.
So, what do you do as a rider that has a perfectly good, expensive 11 speed SRAM XX1, X01, X1 or even GX drivetrain on their bike but want to upgrade to 12 speed? Well, don’t contribute to landfill is what e*thirteen were thinking when they came up with their 12 speed upgrade kit for SRAM.
The TRS+ 12 Speed Upgrade is e*thirteens answer to any SRAM 11 speed owner with that itch to upgrade to 12 Speed without dropping more than a weeks pay on a shiny new Eagle drivetrain. The entire conversion kit comes in at a reasonable $499, not too bad considering what you get in the box. Plus, you get an even larger gear range thanks to e*thirteen’s 511% 9-46T cassette outdoing SRAM’s 500%.
When I first heard about this upgrade, I was pretty keen to get my hands on a sample to see exactly how they have achieved this feat whilst keeping most of your existing 11 speed parts on your bike, or at least replace some of your already worn drivetrain.
Opening the box for the first time revealed a 12 speed cassette, 12 speed YBN silver chain, some shift housing and cable, 12 speed ratchet spool, spacers and bolts and lastly a bag of tools and grease. Everything you need to get the job done at home. That’s right, I said at home, as this is what e*thirteen were intending when they thought up this conversion.
The ‘genius’ behind their conversion… change your 11 speed shifter to a 12 speed shifter. Pretty simple idea, executed by a rather simple upgrade to your shifter. It sounds daunting, pulling apart something most bike mechanics
would tell you never to tinker with, but this is what they want you to do.
For something as difficult as replacing your shifter’s 11 speed spool to 12 speed, it only took 20 minutes to complete that task (not including the 10 minutes watching the YouTube video) This was really only made possible by a very useful little tool included in the box called the “Claw”. Looking like something that sits in your take-away pizza box, the claw basically becomes a 3rd hand when pulling apart your shifter, holding the shifters internal assembly in place whilst you swap out the shifting spool. After inserting a cable into the shifter and confirming that there were indeed 11 clicks, it was time to get the other parts swapped out to complete the conversion.
As the e*thirteen cassette is XD driver compatible, a simple swapping out the old and in with the new, I had a fresh, lightweight 12 speed cassette ready to roll.
The only other major conversion necessary in this 12 speed upgrade is to re-space the jockey or pulley wheels on the derailleur with the supplied spacers and longer bolts. It is a 5 minute job and it’s ready to shift all the way up to the 46T cog without any hassles.
Once the new chain was on and shortened to the required length, I needed to adjust the rear derailleur’s B-Tension screw to allow for that larger cog and double check the high and low limits. Now it was time for a test ride.
ON THE TRAIL
There is one point to add here before going any further which is I was originally running SRAM XX1 Eagle on this bike before switching back to an 11 speed setup for this test. So I do have a good baseline for shifting performance and reliability and comparison between 11 and 12 speed drivetrains.
That said, a quick roll around the streets going through the gears I didn’t notice anything really that different compared to the original 11 speed setup. Shifting was nice and crisp, thanks to the ever reliable SRAM X01 shifter. The cassette is slightly noisier than the stock SRAM cassettes, likely due to the hollow construction of the e*thirteen cassette. The only fault I found with the drivetrain in my initial test ride was the performance of the upshifts and downshifts from the 9 and 10 tooth cogs. It was a little slow and sometimes took a few revolutions before the gear would change. A lot of this has to do with the amount of B-Tension added to the derailleur to clear the 46T cog when shifting down from the 39T. It is really not a major issue as I knew I wouldn’t be using the 9T that often.
But this is a mountain bike after all, so I really needed to get the bike out in the dirt and mud and give it a thrashing to really put the conversion kit to the test.
I put almost 12 hours on this drivetrain in varying conditions and I have to say I am quite amazed as to how well the shifting performance was throughout the test. I rode some quite technical trails that required a few last second down shifts on steep and rocky climbs and the shifting was pretty flawless. I might have thought a few times the down shift to the 46T cog was not as rapid as the new Eagle XX1 cassettes, but I am nit picking just a bit.
I did, however, never get the shifting between the 9 and 10T cogs to be as smooth and rapid as the shifting between the 10 and 11T cogs on the SRAM 11 and 12 speed cassettes but this really didn’t annoy me too much as I only got up to those gears on a couple of fire road sections.
Only time would tell how reliable the shifting on the 12 speed e*thirteen cassette would be, as past experience with the 11 speed versions is the shifting performance diminished quite quickly as the cassette wore.
After all, the 12 speed is a very light cassette, tipping the scales at 338 grams compared to the Eagle XX1 cassette at 360 grams. As the cassette is broken into 2 parts, the 9-33T and 39-46T, you can purchase the individual parts so if the lowest gears are worn out, you can replace just that section, saving quite a few dollars.
SO WHO IS THIS CONVERSION KIT R E A L LY F O R ?
In my experience, as a mechanic replacing countless 11 speed drivetrain parts at quite considerable costs, it would be fair to say that any rider who has worn drivetrain parts, namely cassette and chain, and was thinking of a costly Eagle upgrade, then this could be the solution. I know with the latest and cheapest SRAM NX Eagle hitting the market, there will be people who would argue that e*thirteen is too late to market with this product. But in reality, with NX Eagle’s 11-50T cassette you just don’t get the huge gear range of the 9-46T. And the weight alone would be a turn off for me!