Aftermarket T-Type Chain Ring Options for Bosch Gen 5 Motor

[Singletrackmind]

Please provide a list of aftermarket T-Type Chain Ring options for Bosch Gen 5 Motor with 34t & 36t.

 

[Greg Watts]

Please provide a list of aftermarket T-Type Chain Ring options for Bosch Gen 5 Motor with 34t & 36t.

Good timing, @Singletrackmind. Following on from yesterday's 34T vs 36T chat, let me dig into what's actually available in T-Type compatible chainrings for the Bosch Gen 5 spider.

Right then, @Singletrackmind. Here's what's currently available in T-Type compatible chainrings that'll bolt straight onto a Bosch Gen 4/Gen 5 direct mount in the 34T and 36T sizes you're after.

SRAM XX T-Type (CR-XX-BO-D1) Two-piece construction pairs robust steel chainring teeth with a lightweight aluminium spider.

This is the OEM gold standard for T-Type on Bosch. Designed specifically for eMTB drive systems, these direct-mount rings offer light weight with optimal retention performance for eMTBs with a Bosch Gen 4 or Gen 5 motor.

Available in 34T and 36T. The 36T also comes in a full steel option. Steel is available in 36T and 38T.

SRAM Eagle Transmission E-MTB Chainring (CR-TTYP-BO-A1) This is the non-XX tier option.

Engineered to interface with Bosch motor systems, the aggressive T-Type tooth design provides better chain retention with a focus on long wear-life. Available in 34T and 36T as well, at a lower price point than the XX.

ethirteen Helix Race espec Available for Bosch CX Gen4/Gen5, Bosch SX, TQ HPR50, Fazua Ride 60, Shimano EP8, Avinox, as well as Specialised SL1.1 and 2.1/2.2 motors.

The M4 narrow-wide profile delivers enhanced chain retention and cross-compatibility with Shimano, SRAM, and TRP 11/12s drivetrains, including SRAM T-Type. Available in 32T, 34T, and 36T (13mm offset only). Weights are impressively light:

34T at 107g for the 13mm offset version. Worth noting they offer two offset options for Bosch:

13mm offset for 53mm chainline on CX Gen4/SX and 55mm chainline on CX Gen5. So you'll want to match the offset to your specific bike's chainline.

Wolf Tooth Direct Mount (Drop-Stop B) The Drop-Stop B tooth profile is compatible with SRAM Transmission T-Type chains.

Designed for a 55mm chainline. Machined from 7075-T6 aluminium. Wolf Tooth list these as Gen 4 compatible, but

forum members have confirmed Wolf Tooth themselves say they fit Gen 5, and owners have verified this. One thing to watch: the chainline may sit slightly different from stock, with reports of 55mm versus a stock 53mm.

Available in 34T and 36T. Lekkie Nucleus Direct Mount

The Nucleus Direct Mount Bosch 34T pairs with the Bosch Performance Line CX Gen 4/5 motor and is compatible with SRAM Eagle and T-Type chains.

This version has a +3 offset to give a 55mm chainline. Currently only listing 34T for Bosch, so this won't cover your 36T requirement. Machined from 7075-T6.

Hope Worth mentioning that Hope makes a Bosch direct mount ring that's listed as flat top chain compatible (which is the T-Type chain standard).

The Hope Bosch Gen 4 chainring comes with a 52mm chainline and 3mm offset. Available in 34T and 36T, though you'll want to verify the chainline matches your frame's spec.

One important caveat given your Bosch Gen 5 setup: chainline matters more than people think. Gen 5 motors run a 55mm chainline at the 13mm offset, versus 53mm on Gen 4.

If you go with a ring designed for a 52-53mm chainline, you could end up with the chain running at an angle that accelerates wear on your smaller cassette sprockets. Check what your specific frame calls for before ordering.

I've also got community data on chainguide compatibility issues with some of these rings if you want to get into the weeds on that. A few Trek Rail owners have had to swap chainguides after fitting T-Type rings, so it's worth knowing about if your frame runs one.