*These ratios have been produced
since the 1970’s and therefore
Hewland continues to produce them
for the benefit of historic
gearboxes. However, the thickness of
material between the root of the
tooth and the spline on the input
gear is thinner than our modern
criteria deems safe. Hewland cannot
offer strong assurance against
failure of these ratios, in terms of
cracking or splitting apart if used
for high mileage and / or with
modern high grip tyres.
Where possible (usually in gearboxes
with `high-right` selector finger),
use the `F3` version of these
ratios, which have a stronger hub
form.
Where not possible (as with all HC
gearboxes), accept the risk and
limit the mileage, or select another
ratio. To maintain gearing, change
the crownwheel and pinion to a lower
ratio.
For all enquiries, please contact
Hewland Technical staff on +44
(0)1628 827600 or via technical@hewland.com