While conducting our big E-MOUNTAINBIKE group test in Finale Ligure, we ran into Robert Schwenk, founder and CEO of FRAEZEN. When we told him we’d accidentally wrecked a SRAM Transmission derailleur cage, he didn’t hesitate and immediately handed us his very own version: the so-called KAEFIG.
FRAEZEN specialise in high-end CNC-machined components, offering everything from chainrings and stems to pedals and derailleur cages – all crafted from aluminium. What sets the KAEFIG apart is that it’s machined from a single block of 7075 aluminium. According to the manufacturer, this minimises weight while maximising torsional stiffness, which should improve shifting precision – the FRAEZEN cage tips the scales at 96 g. For comparison, the SRAM XX Transmission cage weighs in at 94 g, whereas the X0 Transmission cage weighs 100 g.
The matching pulley wheels are also machined from 7075 aluminium and spin on high-quality ceramic bearings, designed to be extra smooth and durable. On top of that, they feature a narrow-wide tooth profile with alternating widths to keep the chain securely in place. The number of teeth matches SRAM’s original spec exactly with 14 on the upper and 16 on the lower pulley.
So there’s nothing new in the design, whereas the original SRAM XX and XX SL cages feature a clever little twist: the spokes of the lower pulley are designed to rotate independently of the teeth, preventing damage caused by sticks or debris getting in the way, called the Magic Pulley. FRAEZEN’s aluminium jockey wheels are rigid and replacements are only available as a set for around € 150. Unfortunately, FRAEZEN’s cage isn’t compatible with the more affordable SRAM alternatives. On the plus side, FRAEZEN’s jockeys feature 18 skinny spokes, making them less likely to pack up with mud.
The FRAEZEN KAEFIG is available for the following groupsets:
- SRAM Eagle Transmission
- SRAM Eagle AXS (12-speed electronic)
- SRAM Eagle mechanical (11- and 12-speed)
- Shimano 12-fach: XTR (M9100), XT (M8100), SLX (M7100)
Regarding looks, the German-made cage is available in two colours – black or silver. You can colour-match the pulley wheels or go with a contrasting black or silver, allowing you to integrate the FRAEZEN KAEFIG into your bike’s design or tailor it to suit your taste.
For a hefty € 419, you’ll receive the premium derailleur cage along with a cotton tote bag, stickers, and a 3 mm hex bit for installation. As the intended use cases, FRAEZEN list XC, enduro and eMTB. Naturally, we put that claim to the test, not just mounting the KAEFIG to full-power e-mountainbikes, but also on a few analogue trail bikes for good measure.
One more thing: before replacing your stock cage with the FRAEZEN KAEFIG, be aware that doing so will void the warranty on your SRAM Transmission.
The FRAEZEN KAEFIG Derailleur Cage on Test – Or Should We Say, in the Ring?
No doubt, holding the KAEFIG in your hands, it feels like a precision-crafted piece of engineering. High-quality, solid, and flawlessly finished. The FRAEZEN cage doesn’t just look the part on the bike, the small FRAEZEN logo at the bottom also blends seamlessly into the overall design.
Installing the cage takes around five minutes and is straightforward using the included 3 mm hex bit and FRAEZEN’s how-to video. Once installed, it’s essential to fine-tune the Transmission – for detailed instructions, check out the dedicated article in our sister magazine ENDURO.
In terms of shifting performance, the FRAEZEN KAEFIG is on par with SRAM’s original. Despite its rugged build and ceramic bearings, we didn’t notice any tangible improvement during testing. Whether mounted on the Specialized Turbo Levo 4 or the YT JEFFSY, shifting was consistently smooth and precise.
That said, the KAEFIG can’t quite compete in the featherweight division – at 96 g, it’s about 2 g heavier than the XX Transmission cage and 4 g lighter than the X0 version. You won’t notice the difference in weight, but the benefits of the added durability and impact resistance are undeniable. If your derailleur kisses a rock or trail feature, chances are the rock will come off worse. It’s only upon closer inspection that you’ll find any damage. The black cage on test showed a few scratches but didn’t bend or suffer reduced shifting performance in the slightest – nice!
So, if you like to ride hard and want one less thing to worry about on the trail, the FRAEZEN KAEFIG is a solid choice.
Conclusion on the FRAEZEN KAEFIG
With FRAEZEN’s derailleur cage, € 420 gets you a rugged and stylish upgrade. The CNC-machined aluminium cage offers noticeably more peace of mind when your derailleur takes an unexpected knock from rocks or branches – much more so than SRAM’s standard model. That said, we didn’t experience any tangible improvement in shifting performance. Note: installing the FRAEZEN cage voids the warranty on your SRAM Transmission. If you’re looking for one more way to pimp your dream build, this exclusive upgrade might just fit the bill. Everyone else may be better off sticking with SRAM’s more affordable original, and keeping their warranty intact.
Tops
- Rugged and durable
- Premium machining quality
- Stylish looks
Flops
- Expensive
For more information, head to FRAEZEN.com
Words: Robin Ulbrich Photos: Robin Ulbrich, Benedikt Schmidt
