are 125cc allowed to run c class in acu events

Not to My knowledge.

the limit for c class is 80cc

Copied from 2016 ACU Handbook  https://www.acu.org.uk/Uploaded/1/Documents/2016%20Handbook/Trials.pdf

 

ENGINE CAPACITY /WHEEL SIZE FOR ABOVE AGE GROUPS:

The maximum permitted for machines used in the Age Groups set out in this Regulation are as follows:

A Class 125cc Mono or 250cc Twinshock** combustion engine, and Electric up to 10bhp measured at the rear wheel.

B Class 125cc Mono or 250cc Twinshock** combustion engine, and Electric up to 10bhp measured at the rear wheel. ** Twinshock machines over 125cc must have twin rear suspension units and drum brakes as at the time of manufacture.

C Class 80cc combustion engine, and Electric up to 7bhp measured at the rear wheel.

D Class 80cc combustion engine, Maximum Medium wheel. and Electric up to 7bhp measured at the rear wheel.

E Class Small wheel Electric powered machines up to 2bhp measured at the rear wheel.

The C and D Classes may be split by wheel size. C Class Standard Wheel. Medium Wheel. D Class Medium Wheel. Small Wheel.

yes i seen that in handbook,reason i asked i noticed in my club results from weekend there was 125cc bikes marked in youth c

So from reading that if my son is 9years old born march 2007, then regardless of ability or size he can only ride up to D class up to 80cc?

 

 

I thought they can be ridden on a no award basis at the Clerk of Course discretion - Although that maybe as in a child at the correct age for a 125cc riding below his class