Premium OVAL chainrings for all FSA ABS cranks 4 & 5 bolt

Color : Black
Variant : 50Size Guide

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absoluteBLACK Premium Oval chainrings for FSA ABS (asymmetric bolt spacing) cranks like Gossamer, SL-K. This model fits 4 and 5 bolt design FSA cranks. 4&5 bolt cranks are identical except the one hidden bolt behind the crank arm in 5 bolt design which is not needed. These are finest FSA compatible chainrings on the market in terms of shifting, stiffness, smoothness of pedaling and manufacturing quality. 10/11spd compatible. Di2 Compatible. Made in EU

Just 3 hours in and I love it

" After 3 hours of riding I think I'll never change for round chainring. I'm not faster but i can feel much comfortable riding and linear effort. "


"Initially, reluctant. However, after month of riding I am very impressed with the power distribution and no knee pain. AB undoubtable got it nailed. You won't even know your are riding an OVAL after 15 minutes time."

I love how well they shifting

" I'm absolutely impressed how well they shift, which was my biggest fear."

Smooth ride and easy on the knees

" I’ll never go back to round and will order one for each of my bikes. Super smooth, eased my knee pain, and has helped my climbs ten fold"

Skeptical at first but a complete convert now

" I was quite skeptical until a friend of mine got AB oval rings. He was blown away with how good they were so I got some too and have to say I’m absolutely delighted."

Improved my ride

"I particularly notice the difference climbing. Just seems to be easier and I feel like I’m turning circles rather than ‘mashing’."

Size (Mass +/-1g):

34T (32g), 36T (33g), 38T (38g), 39T (41g), 50T (115g), 52T (132g), 53T(134g)


Black only


FSA ABS (asymmetric bolt spacing) cranks like Gossamer, SL-K. Both 4 and 5 bolt versions. One model fits them all. Di2 Compatible. 10 / 11spd compatible. ABS cranks only.


For Gossamer - use original FSA bolts and spacers

For SL-K - use original FSA Bolt Covers and bolts

Material & Finish

cnc machined 7075 Txxx Aluminum. Long-lasting construction. Type II anodizing


Optimized to each size separately. 34T- 3.5% ; 36T, 38T, 39T- 11.4%, 50/52/53T - 10-11.2% ; Timing of 108 -110.5° after TDC (top dead center) - Ideal for road climbing. Patent Pending


*For Gossamer cranks - use original FSA bolts and spacers. There is nothing else needed to mount these rings

*For SL-K - use original FSA Bolt Covers and bolts that will fit perfectly. There is nothing else needed to mount these rigns

*Ramps on big rings are specially configured for combinations: 50/34, 52/36, 52/38, 53/39T

* If you wish to use other configuration it will also work, but shifting will be slower and may require more "adjustments" of front dérailleur to be acceptable. Also remember that front dérailleur can only accept max 16T difference between 2 chainrings - this is how Shimano and Sram designed them.

How to mount absoluteBLACK Oval chainrings to FSA ABS cranks

First, you need to remove your crank from your bike. Once removed, unscrew the 4 bolts that hold two chainrings together with a T-30 torx key. Remove both original rings. Asymmetric bolt design will prevent mounting the rings with the wrong orientation. The bolt holes on the small chainring are recessed – so the bolt heads will sit flush with the surface of the chainring - these recesses should face you when mounting the bolts

*For Gossamer - place the big ring first on the spider, then place 4 FSA spacers and then small chainring. Tighten with original FSA bolts

*For SL-K- place the big ring first on the outer position of the spider, then place small chainring on the inside of the spider. Use the FSA bolt covers and place them from the front on big ring (they are all identical). Tighten with original FSA bolts

Tighten all four bolts with force of about 5-7Nm. Mount your crank back to the bike. You may also need to adjust the front derailleur slightly.

Absolute Black always recommends using a new chain when fitting new chainrings.

When mounting absoluteBLACK 4 bolt chainring on 5 bolt crank, leave the hidden bolt hole empty or patch it with waterproof grease. This hole is not important hence FSA removed it with new version of cranks.

How to adjust front derailleur with absluteBLACK Road Oval chainrings

To proceed with the adjustment you will need 2mm and 5mm allen keys.

Trouble shooting:

*If your derailleur overshifts the chain when moving from small ring to the big ring, it means your "gap" is greater than 2mm when chain is on big chainring (see video). You may need to reduce the gap. Your front derailleur may also be too high compared to what is advised on the video. Last thing to check is if your cage is parallel to the big chainring face.

*If your front derailleur is hesitating to shift from small to the big ring then two issues may be present. The "gap" may be too small (It has to be 2mm - see video) or your cage is not parallel to the big chainring face.

All Absolute Black products are designed in UK and manufactured in Poland (EU) to the highest standards of quality.

Cranks visible on the photos are not included to the purchased chainrings.

The World's finest oval (elliptical) road chainring. Non circular chainrings, Non-round chainrings. Asymmetrical chainrings.