- Joined
- Nov 29, 2011
- Messages
- 96
Many great engineers had a similar motto, “Simplify [or Simplicate] and add lightness.” For motorcycles there could also be a corollary, “and lower the centre of gravity.” For the first two-thirds of the twentieth century several fine motorcycle companies adhered to this rule.
Many have wondered how Norton could possibly adopt a pushrod engine in 1948 when they had already been making good OHC engines for a couple of decades. [OHC probably predates OHV but this is not completely clear. The Buick patent is for a valve-in-head design but it applied to both OHC and OHV. Whichever type came first both schemes can move valves reliably.]
Norton might have been able to build some sort of Manx Twin but it would have been very expensive to make. Cost is very important for a street bike which needs to be priced similar to competing designs. Bert Hopwood’s compact pushrod “hemi” was simple, light, and affordable, with the weight down low. It was a fine choice for one of the greatest road bikes ever made and deserves to be remembered that way.
Many have wondered how Norton could possibly adopt a pushrod engine in 1948 when they had already been making good OHC engines for a couple of decades. [OHC probably predates OHV but this is not completely clear. The Buick patent is for a valve-in-head design but it applied to both OHC and OHV. Whichever type came first both schemes can move valves reliably.]
Norton might have been able to build some sort of Manx Twin but it would have been very expensive to make. Cost is very important for a street bike which needs to be priced similar to competing designs. Bert Hopwood’s compact pushrod “hemi” was simple, light, and affordable, with the weight down low. It was a fine choice for one of the greatest road bikes ever made and deserves to be remembered that way.