The Scoop on Radius
What crank lengths are available?
We offer 165mm, 170mm, and 175mm as standard. We can do custom lengths from 150mm to 180mm for $65 additional.
We know what you're thinking! Another spline standard...
Radius has its own spline standard based on BB30. The spline allows the cranks to interface to our direct mount chainrings, SRAM 8 bolt, a spider in 94, 110, 130, or 104mm bolt circle, or use our revolutionary Adapt-R that can convert our spline to many spline conventions out there.
How does the Adapt-R system work?
These Adapt-R's are laser cut pieces of aerospace grade titanium plate that slide over the threaded spline of the Radius cranks. These can be pressed into the spline of your chainring. Both get locked down with our retainer ring that threads onto the outside of our spline. It takes a common Park BBT-59.2 tool to tighten the retainer ring. Those tools can be found at most bike shops or on Amazon. We also have a preload adjuster for the left crank and spacer kit on the right to help you fine adjust your chainline.
The Adapt-R will allow Radius to interoperate with many existing chainrings such as RaceFace, SRAM, HollowGram, FSA, E Thirteen, Absolute Black, Easton, Wolf Tooth, Hope, and others. They can be made relatively easily for quickly adapting to changes in standards, new standards, or even lesser known standards. Don't see the spline you want offered? Let us know, and we can see about making it. Once we've made the first one, we've got the machine code to cut however many more we want. Super simple!
Can I change out Adapt-R's?
Yes! That is the other great thing about our new system. You can grab multiple Adapt-R's and easily swap them out so that your new favorite pair of cranks can work with ALL of your favorite chainrings. Go From Mountain to Road and back. Mix and match in the future by ordering more as you need them!
What is the spindle?
The spindle we use is considered a BB-30 spindle. It has a 30mm bearing surface and has 8 tapered splines that mesh with the crank. The most common one we supply is 119mm, and it will work with most mountain bikes. It can be replaced with a longer or shorter one for different bike setups. We also offer a 125mm one, and RaceFace and SI spindles work as well. Our titanium spindle version is integrated to the left crank and can have a custom-made length.
How is the clearance?
The low form factor allows about a quarter inch more ankle clearance than a popular titanium tubular crank on the market. This while having more chainring clearance as well!
Spacing can vary with bike geometry and bottom bracket hardware. Use the drawing below to help dial it in. You can use our provided spindle spacers and preloader as necessary to get the chainline you want.
I made a handy Radius Crank Measuring Gage that works like calipers to more easily measure your bike for the correct spindle length. I make physical chipboard versions as well as have a DXF version for you to laser or print, an SVG, and a PDF version.
You can also send your cranks with spacers as they came off your bike and we can measure stuff here if you like.
How do I remove the cranks?
Radius cranks come with a bolt cover that has a 5/8" hex hole through it. It is screwed down tight to the crank by way of threads inside the machined cup. The cover traps a crank bolt with an 8mm hex under it. If the bolt cover is left in place and an 8mm Allen wrench is used to unscrew the bolt through the larger opening of the bolt cover, it will act as a jackscrew and pull the crank off the spindle. This means that it's not necessary to carry a bulky 5/8" wrench on the bike, as an 8mm will be sufficient to tighten the cranks during a ride if necessary.
What are the Torque recommendations?
Spindle bolts are 25-30 Ft Lbs (34-41 Nm) and retainer rings are 40-52 Ft Lbs (50-70Nm) The preload adjuster is just finger tight.