Royal Enfield Standard 350 Crankshaft: Is It Heavier Than Classic and Electra 350?
The Royal Enfield Standard 350 is often singled out for its heavier crankshaft compared to its counterparts, the Classic 350 and the Electra 350. This difference in crank weight is not just a marketing point, it is a design choice that significantly impacts the bike's performance and riding experience.
Heavy Crankshaft Design
The Royal Enfield Standard 350 is equipped with a heavier crankshaft, which contributes to a more stable and smoother power delivery, especially at lower RPMs. This is due to its intended use and design philosophy, which focuses on providing a comfortable and stable ride.
In contrast, the Classic and Electra models feature lighter crankshafts that are optimized for quick revving and a more responsive feel. These differences reflect the different criteria Royal Enfield uses to design each of its models.
Part Numbers and Crankshaft Designations
As highlighted in the image, the difference in crankshaft weight is clearly marked. In row 40, the part numbers for the crankshaft assembly for 350 Kick Start Standard, Electra, and Classic 350 and Classic 500 models are distinct. The numbers '70' and '72' stand for light and heavy crankshafts, respectively. The crankshaft of the Bullet 350 KS, although heavy, has a slightly different design than the ones used in 500cc models. The heavier crank in the Bullet 500 and Thunderbird 500 also uses the part number '571172/C'.
For the Cast Iron Engine-based Standard 350 and Electra 350 models from 2006 onward, the crankshaft is heavy and marked with the part number '72'. This was confirmed in a personal experience where the author overhauled the engine of a 2008 Standard 350, finding it had a heavy 10.4 kg crankshaft.
Heavier Crankshaft in the Bullet 350 STD
The Bullet 350 STD model also has a heavier crankshaft, about 10.5 kg, according to the information available. This was done to counter the practice of local mechanics who would modify the crankshaft for a "heavy flywheel" effect. This modification led to unbalanced engines and frequent failures. As a result, Royal Enfield introduced a basic model with the Standard Bullet’s design, including a 19-inch wheel, 1950s rear lights, a heavier crankshaft, and larger bearings.
The larger bearings in the Standard 350 are allegedly German-made, although this detail is not confirmed. These modifications aimed to provide a more stable and reliable ride, which was particularly important considering the open and varied terrain where these bikes are often used.
User Experience and Performance
Owner experience with the heavier crankshaft in the Standard 350 is positive. The heavy crankshaft provides low end torque, making the bike very easy to drive in higher gears at lower speeds. In the city, it runs smoothly up to about 60 kph without any vibration. The sound is described as more mellow, similar to the original Bullet.
However, at higher speeds, around 60 kph and above, the Electra and Classic models are superior. They provide a smoother and more responsive ride. The Standard 350 is more suited for a more relaxed, slower riding style, and might feel heavy and clunky when pushed harder.
The mileage of the Standard 350, driven slowly, is excellent. An owner reports achieving 45-48 km/L in heavy traffic in Chennai. It is considered easier to drive than many modern Indian and Japanese bikes due to its superb balance and handling.
However, the Standard 350 is not recommended for regular high-speed riding. It was designed for a more leisurely pace, best enjoyed when "seeing life pass by, take it as it comes."
In conclusion, the heavier crankshaft in the Royal Enfield Standard 350 is a design feature that distinguishes it from other models, providing a unique riding experience that is best suited for slower, more relaxed journeys.