Royal Enfield is on a winner with its 650cc twins as American engine giant S&S Cycle has now added 750cc and 865cc big-bore kits.
This follows the recent announcement that premium Swedish suspension manufacturer Ohlins has developed suspension grades for the twins and the Himalayan.
S&S also have other performance parts for the new Interceptor 650 and Continental GT 650.
They include clutch kits ($US399.95), mufflers ($US474.95) and handlebar adjuster kits ($US69.95).
But the biggest news is the 750cc big-bore kit at $US630.95 (about $A900) and 865cc kit ($US634.95).
S&S usually only make big-bore kits and performance gear for Harley-Davidson and Indian V-twins.
This is the first time the Wisconsin company has produced performance parts for any other specific motorcycle.
The company stress that the performance gear is for “closed-course competition use only”.
While they do not yet reveal power and torque output for the kits, they have released the following tech details.
S&S 750 Kit
Bore X Stroke
78 x 67.8mm
83.5 x 67.8mm
S&S 865 Kit
90 x 67.8mm
The kits feature comprehensive engine upgrades including larger cylinders and pistons in addition to new head gasket.
Royal Enfield’s 648cc parallel twin produces 35kW (47hp) and 52Nm of torque. Output should increase about another 17kW to around 52kW.
Here is the full list of S&S performance parts for the new Royal twins.
Price (INR – For Representation only)
Dynojet Power Commander V with Calibration
High-Flow Air Intake Eliminator Plate Kit
High-Flow Replacement Air Filter
High-Compression 11:1 Piston Kit
Stainless Muffler Set
Race only Stainless Muffler Set
Handlebar Adjuster Kit (INT 650)
Performance Clutch Kit
High-Performance Camshaft Kit with Shims