absoluteBLACK Premium Oval chainrings for FSA ABS (asymmetric bolt spacing) cranks like Gossamer, SL-K, K-Force. This model fits all 4 and 5 bolt design 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. 10/11/12spd compatible. Di2 Compatible. Made in EU
Size (Mass +/-1g):
34T (32g), 36T (33g), 38T (38g), 39T (41g), 50T (115g), 52T (132g), 53T(134g)
All FSA ABS (asymmetric bolt spacing) cranks like Gossamer, SL-K, K-Force, K-Force Light. Both 4 and 5 bolt versions. One model fits them all. Di2 Compatible. 10 / 11 / 12spd compatible. ABS cranks only.
- For Gossamer - use original FSA bolts and spacers
- For SL-K - use original FSA Bolt Covers and bolts
- For K-Force - purchase absoluteBLACK bolt covers (necessary!)
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 K-Force - purchase additionally absoluteBLACK bolt covers. This is Absolutely necessary as you will not be able to mount these chainrings to K-Force otherwise.
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.
Advantages of Absolute Black Road Oval chainrings:
*One of a kind special oval shape that helps you climb easier and faster (Patent Pending)
*Over 15% stiffer than Rotor Qrings due to thicker, 5mm construction
*Bespoke Absolute Black 6 point ramp and recess shifting design shifts better than any other brand and model of oval chainring
*Finest design that provides excellent strength to weight ratio
*You will not "feel" the oval shape while pedaling
*Your pedaling action will feel smoother
*Helps reduce stress on knees and helping your legs remain fresher for longer
*You will be able to maintain better cadence while climbing
*Reduces possibility of leg cramps
*You will reduce chainring/cog shifts by at least 15%
What size should I choose?
* 34T inner chainring should be used with 50T outer ring. It has 3.5% ovality. Use a 34T to help with spinning higher cadence and hilly terrain.
* 36T inner chainring can be used with 50 or 52T outer ring. It has 11.4% ovality. Use a 36T if you’re a strong rider or for rolling terrain.
* 38T inner chainring should be used with 52T outer ring. It has 11.4% ovality. Use a 38T if you’re a very strong rider or for flat terrain.
* 39T inner chainring should be used with 53T outer ring. It has 11% ovality. Use a 39T if you’re a very strong rider or for flat terrain.
* 50T outer chainring – Choose this size if you ride for pleasure or sportive events. This is the most versatile and comfortable size.
* 52T outer chainring - if you race and feel strong, it's the classic outer chainring size and a great option for experienced riders.
* 53T outer chainring - if you race and feel very strong, it's the classic outer chainring size and a great option for powerful riders.
Remember when selecting your chainring sizes - it's not about what others use, but about ensuring YOUR ability to maintain a comfortable and effective cadence across the terrain you ride most often. If you ride chainrings that are too large (round or oval), your cadence will be lower. This can affect your performance by prematurely tiring your legs and possibly lead to stress injury in your knee joints.
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
For K-Force Light- place the big ring first on the outer position of the spider, then place small chainring on the inside of the spider. Use absoluteBLACK bolt covers and place them from the front on big ring. Tighten with provided bolts while holding the bolt covers by hand from the other side (this is important to not to damage the bolt covers).
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.
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