FAQ
As of this writing, SRAM's transmission drivetrain is new to the market, so we have not yet exhaustively tested the new T-Type® chain with e*thirteen chainrings.
Still, we have been able to perform some preliminary fit-up and testing, and here's what we know so far!
Rule of Thumb
e*thirteen chainrings with our latest M4 tooth shape are compatible with T-Type chains. This includes Helix Race Direct mount, Helix Race 3-bolt, Helix Race e*spec, Helix Core e*spec, and Helix Race 107mm BCD chainrings.
Helix Plus and Helix Steel direct mount rings are not compatible. Older rings with M3 tooth profiles are also not compatible.
Note: Flattop™️ chains have rollers which are slightly larger OD than Eagle™️ chains. It is possible that these larger rollers may result in slightly accelerated wear of drivetrain components which have not explicitly been designed for the larger OD rollers. While we have not quantified this in lab testing, we have seen varying reports of this in the field. Drivetrain wear rate is an extremely complicated topic due to the large number of variables and you can read a bit more about that here.
e*thirteen Helix Race direct mount, 3-bolt, e*spec, and 107mm BCD chainrings: Compatible ✅
e*thirteen Helix Plus or Core direct mount chainrings: Not Compatible ❌
e*thirteen UL direct mount chainrings: Not Compatible ❌
e*thirteen SL Guidering direct mount chainrings: Not Compatible ❌
e*thirteen e*spec direct mount chainrings (Forged, 5 arm model): Not Compatible❌
(Bosch ring shown for example)
Answer: Yes, but additional spacers are required at the mounting location. Alloy Helix rings require an additional 1mm spacer and steel Helix rings require an additional 2mm of spacers.
Details: e*thirteen UL and SL chainrings were designed for use with XCX, TRS, and LG1 Cranksets. Helix chainrings were deigned for use with Helix cranksets. UL and SL rings are 1mm thicker than Helix chairings at the mounting location. Each Helix Direct Mount ring is supplied with a 1mm spacer which should be used when mounting Helix Direct Mount rings to XCX, TRS, and LG1.
The following spacer assemblies should be used with Helix Direct Mount rings on e*thirteen cranks:
XCX Cranks:
- Helix Direct mount ring + 1mm spacer included w/ Helix direct mount ring.
- Spacer should be installed first, then chainring.
TRS/LG1 Cranks:
- Helix Direct Mount Ring + 1mm spacer included w/ Helix direct mount ring + 3mm of chainline spacers included with and already installed on crankset (Generally 1 x 2mm and 1 x 1mm).
- See charts below for ring/spacer configurations.
Helix Cranks:
- Helix Direct Mount Ring only.
Chainring / Spacer configurations for alloy Helix Plus and Helix Race rings when used with e*thirteen TRS and LG1 cranks with adjustable chainline*:
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*For steel Helix ring install, add an additional 1mm spacer between the crank and chainring.
Answer: All current e*thirteen chainring designs (Helix, Guidering SL, Guidering UL, and E*spec) are compatible with all* 12s mountain bike chains on the market.
*Exceptions:
- SRAM® FlatTop™️ chain, including T-Type - See this article.
- Campagnolo® Ekar™️ 13-speed chains. Campy's 13 speed chains are too narrow to fit on any current e*thirteen chainrings.
Helix Chainrings can achieve the 56mm Super-Boost chainline when installed on any of our 73mm spindle TRS or LG1 cranks with adjustable chainline or on our Helix Cranks.
You can find ring installation configurations in this how-to guide.
The telltale sound of a worn front ring is often a grinding noise which in some cases can be felt at the pedals under load while climbing in easier gears. So, how long should a ring last? That's not a really easy question to answer. Read below for more.
There are a large number of variables that go into how long a chainring will last. This makes it difficult to give a specific number of hours or miles before needing replacement. Some of those variables include riding conditions, chainring size, and drivetrain maintenance.
With the advent of modern 1x drivetrains, chainrings do need to be replaced more regularly than when 3x or 2x systems were the norm. This is due to wear occurring only on 1 ring rather than being spread out over 2 or 3 rings. Additionally, smaller 1x chainring sizes are also common which also increases wear speed - a 28T ring will wear about 15% faster than a 32t.
Also keep in mind that with smaller front chainrings, there may be cases where you will need to replace your ring due to wear before your chain is worn to a point requiring replacement.
The best thing you can do is keep your drivetrain clean & well lubed and regularly check the chain for wear.
We recommend removing/not using the o-ring which sits between chainring and the lockring when assembled with our direct mount ring.
BOSCH G4 motor assemblies come with BOSCH Supplied lockrings and o-rings for assembly with their spider. When using e*thirteen e*spec direct mount rings, the lockring should be used and installed per BOSCH Specification; however e*thirteen does not recommend the use of the O-ring. We have found it can bunch and interfere with proper torque of the lockring, and flatness of the chainring. This assembly variance has BOSCH Internal approval.