New tech and racing go hand in hand. In the same vein, cost-cutting and keeping those credit card bills at bay also plays a very important part in most privateers plans. So when it comes to new technologies and racing advancements, it's often prudent to find a work-around and to make best use of your existing kit; that is until the trickle down effect hits more affordable levels. Our tech guru took a look at the increasing trend toward the 1x11 drivetrain and discovered this nice little fix for those wanting to convert their 10 speed cassette and run a 1x10 setup with a 40/42T expander, but have been struggling with gearing issues.

Tech Tip - One Up RAD cage


There is an ever growing view that the front derailleur is dead. A lot of riders already run 1x10 and the emergence of narrow-wide rings and clutch rear mechs has replaced the clumsy chain guides of old. The weight savings of a single ring set up can be significant and then there is the simplicity and reliability of one less thing to go wrong.

The only snag is big hills. You can fight your way up on a traditional 11-36 cassette, or you can splash out on a 1x11 rig, but that is expensive. So, the availability of expander gears which can take your rear cassette up to 40T or 42T is a very attractive, low cost 1x10 set up that can conquer pretty much anything. Great, sorted.

But. Yes, there is always a but. Anyone who has been running an expander gear knows that the set up is frustrating. Yes, they work, yes the installation is easy, but can you eliminate all the grinding, can you preserve the pristine, crisp shifting of an XTR groupset?

To get the derailleur to move across to the monster expansion cogs, the B-limit screw has to be right out, or extended. To most riders the B-limit screw is a mystery anyway. It's the tweak of last resort when nothing else seems to be getting rid of slipping gears, just before your relent and purchase new jockey wheels, new cassette, new chain etc. So adding the complication of the expansion ring into the B-limit dilemma and you just end up living with imperfect shifting and putting music on to drown out the noise.

How do 11 speed systems avoid this problem? It's not just a narrower chain, there are differences in the distance between the jockey wheels and the cassette built into 11 speed systems. Jockey wheels and the position of those wheels is way more important than most people appreciate, and you only really appreciate it when they are wrong.

Jockey wheel placement and the B-limit adjustment is a problem that One Up Components RAD (Radial Appositioned Derailleur) cage have set out to solve. Their expander ring specific cage for the Shimano range looks pointless and puzzling for it's $35 price tag, but without a doubt, it works!


Delivery was courtesy of a UK distributor and what you get for your money is one half of a derailleur cage and a new fixing bolt. That's it! Fitting instructions are provided on-line and are within the limits of any half competent home mechanic. If you are able to strip an axle or fit a group set, you could handle the challenge. It's only a 30 minute job and it is not until you reassemble the rear mech that you realise what a clever solution the One Up cage is.

Rad Cage

The standard 10 speed derailleur cage fixes the top jockey wheel into the centre of the bolt which also holds the cage in place. What the One Up cage does is shift the top jockey wheel off that central axis by about 5mm. That has the same effect of winding out the B-limit screw all the way but without affecting the bottom jockey wheel position.

The end results? Well, we have been running one of these cages for a few weeks and a 10 speed XTR groupset with a Hope 40 T-Rex now shifts as crisply and noiselessly as without the expansion ring. There is no slippage at all, and all-in-all it inspires confidence and the ability to exploit the full potential of the expanded 1x10 arrangement.

If you are buying a new groupset, adding up the expansion ring and the replacement cage starts to push the price up to the point where you might as well go for a 11 speed system. But if you are wanting to extend and get the most out of a perfectly good existing set up, then a One Up cage - to go along with your expansion ring - makes a lot of sense and is well worth the effort.

Si, @transalpuk

You can find more details on the One Up Components RAD Cage here -