Vintage Dirt Bike Q & A

I have a few questions about the early Showa shocks on the 73 - 75 cr's. The early cr125m had 10 mm shafts and dual rate 2 piece springs. Did the 250's have dual rate springs ? Did the 250's come with 10 mm shafts originally ? I have read that Honda changed to the 12.5 bmm shafts due to bending. Does anybody know when this happened ? Was it in 75 or mid year ? Did Honda drop the 10 mm shafts altogether for later models of the cr125m ?


Thanks,

Mark

The 73/74 CR250M had "dual rate" (two different springs in a stack) and the smaller shock shaft. The '75
CR250M was equipped with a single spring and the larger shock shafts.

Honda dropped the "360" shock shaft for the 125 in '76 along with the stacked spring in favor of a larger
shaft and single spring like they did for the 250 the year before.

I don't know if it was because of bent shock shafts. I know many riders were modifying the shock mounts
to move the shocks forward on the "green stripers" (it was all the rage at the time). This modification
yielded more travel but was very hard on the stock shocks and often exceeded the design limits resulting
in failure.

dogger

_________________
1973 CR250M
1979 CR250R
1993 CR250R
2008 CR500R
2009 CR250R

Thanks Dogger - So I guess anything with a 12.5 shaft is 1975 only ?

There was a mid-year 74.5 updated model of the green tank CR 125 that had the 12.5mm shaft shocks and the reinforced footpeg mounts. I'm not sure if it included the new fork tube caps.