Tandem cranks
The Tandem cranks are RS7 cranks specially machined for tandem use.
The Middleburn tandem cranks are sold in pairs so you can mix lengths between front and rear to get the right configuration for your tandem.
The cranks are HOT-FORGED from high quality 7075 T6 aluminium. The cranks then go through a CNC machining process that finely sculptures each crank arm into the unmistakable Middleburn shape.
When building a set of Tandem cranks you will need:
-Front cranks
-Rear cranks
-Crossover spiders
-Final drive spider
-Lock rings X3
And your choice of final drive rings.
The Tandem front cranks are available in square taper.
Silver 170, 175 and 180mm
Black 170 and 175mm
The Tandem rear cranks are available in square taper.
Silver 160, 165, 170 and 175
Black 170 and 175mm
The crank configuration is:
Front right crankarm- RH pedal thread, no spider.
Front left crankarm - LH pedal thread with spline for front crossover spider.
Rear left crankarm- LH pedal thread with spline for rear crossover spider.
Rear right crankarm - RH pedal thread and spline for final drive spider
Crossover spiders
Crossover is the link between the front and rear cranks this is done on the left side of a tandem.
With the Middleburn Sweat torque spline on the crank arm you can fit 4-ARM, Compact Drive or ATB spiders depending on the size of rings required.
We recommend the Dual spiders for the cross over as they do not have any inner ring bolts. Many riders now use the UNO chainrings on the cross over drive.
Final Drive Spider
For the final drive spider most riders use the XC spiders as these fit three rings.
Spiders are available in 4-ARM, Compact Drive or ATB depending on the size of rings required.
If you are using a Rohloff hub then the Dual spider is the one to use.
Middleburn cranks are machined with a JIS taper