Riding Baby Bear's bike* home from work I met a bloke on a shiny black, beautifully restored 1972 Norton Commando 750. It looked a lot like this; what a gorgeous machine: http://www.jerrydoe.com/commandoslideshow/timingsidefull.jpg There's something about vintage Brit bikes that stirs a fond yearning in my neocortex or archipallium or whatever it is that resonates. Maybe Columbanus of Bobbio will smile on me and put one in my future. ps. This short history of the Commando says some of the 750cc models had proved to be unreliable with main bearing and head gasket problems -- I wonder which ones. Gotta do some research I guess. http://website.lineone.net/~alan.shaw/nortonhist.htm Sean_Q_ BC, Canada * Virago 250
Nice looking bikes, but that website is a fucking eyesore. Kiddies with crayons appear to have unleashed.
Yes the 750 Commando crankshaft flexed sufficiently to ruin it's main bearings. The solution is "barrel roller" bearings. I quote: "These are well-known in the Norton community. In 1972, Norton introduced its Combat engine, which unfortunately lived up to its name by turning itself into shrapnel before the warranty period was even half over. Chief among the problems was the crank bearings; up to this point, Norton had used a ball bearing on the drive side and a roller bearing on the timing side of its twins, but the Combat was capable of power levels that were pushing a standard ball bearing's ability to cope. So Norton went with a roller bearing on both ends of the crank. Now, a roller can cope with more load than a ball bearing, all things being equal, but it has one drawback; it is less forgiving of misalignment and crankshaft flex than is a ball bearing. And the Combat engine would flex its crank, especially at high rpm, leading to embrittlement of the rollers and scoring of the bearing races with resulting nastiness of a rotating kind. It was a financial and public-relations nightmare for Norton, and was only cured when they went to the so-called Superblend bearing, which have rollers that are the tiniest bit barrel-shaped, allowing for some normal crank flex while still retaining their superior load-bearing qualities" HTH
