Underage Gearing question

Mugser

Apologies if this has been covered before but have a quick question with regards to gearing restrictions for under 14s:
According to the CI technical rules the gear/distance restrictions state a distance of 6.54m and suggests achieving it by the following formula: "6.54m = 16 sprocket x 49 chain wheel"

My son's bike has a 50t big chain wheel on the front and the cassette is a 16-24.
Is it acceptable to mechanically restrict the rear derailler using the adjustment screw so that the chain doesn't go onto the smallest rear sprocket? And does a 50-17 ratio meet the requirements?

Chips Lovell

50-17 is 6.2 metres, so OK for competition.

Mugser

Vladimir Kurtains wrote: »

50-17 is 6.2 metres, so OK for competition.

Fantastic, that's a very handy little tool there. Thanks a million!!:)

morana

Mugser wrote: »

Apologies if this has been covered before but have a quick question with regards to gearing restrictions for under 14s:
According to the CI technical rules the gear/distance restrictions state a distance of 6.54m and suggests achieving it by the following formula: "6.54m = 16 sprocket x 49 chain wheel"

My son's bike has a 50t big chain wheel on the front and the cassette is a 16-24.
Is it acceptable to mechanically restrict the rear derailler using the adjustment screw so that the chain doesn't go onto the smallest rear sprocket? And does a 50-17 ratio meet the requirements?

if the bike can go into the 16 the rider will be disqualified.youmust ensure it cant go into 16.

bikenut74

It's a daft combination, who sells 49 tooth chainrings. A 50x17 is a much smaller gear than a 49x16 , 6.17m versus 6.43. The rule says U14's are allowed 6.54 which neither of these gears are, however 50x16 is 6.56m a mere 2cm over the limit. Surely sense should prevail and allow riders to use 50x16 and drop the nonsense of a 49 chainring. The majority of bikes are sold in Ireland are sold with a 50 tooth chainring.

Seaneh

bikenut74 wrote: »

It's a daft combination, who sells 49 tooth chainrings. A 50x17 is a much smaller gear than a 49x16 , 6.17m versus 6.43. The rule says U14's are allowed 6.54 which neither of these gears are, however 50x16 is 6.56m a mere 2cm over the limit. Surely sense should prevail and allow riders to use 50x16 and drop the nonsense of a 49 chainring. The majority of bikes are sold in Ireland are sold with a 50 tooth chainring.

This is a very valid observation.