U/14 Gears

[Sammajoor]

Now before anyone shoots me a perves a funny quip, I have a foster son who has now taken up cycling.

 

Rides Campy 9 speed.  If he rides with a compact crank 36/50 what must his cassette be at the back to ride legally in races.

 

Please help as Remano would like to start competing in the U/14 licensed cat, and needs the  correct gears

 

Please help  Johan Bornmann  where are you

 

[Chrispy]

Affordable, practical options for junior gears<?: prefix = o ns = "urn:schemas-microsoft-com:office:office" />	by Owen Hannie

 

Cycling has become very expensive due to import taxes and the weakening rand, so why don't we look for cost effective ways to make it easier on our pockets? I have found a cost effective way to help up coming school boy/girl cyclists and their parents to save a lot hard earned cash when selecting clusters for restricted gear ratios. Junior cyclists are required by the national federation to cycle with restricted gear ratios according to their age groups. The reasons for these restrictions are: To create a fair playing field for all cyclists of similar ages to compete in, and To protect these young cyclists from knee or muscular injuries and To promote spinning of the gears or high cadence riding. These restricted gears are enforced at all SACF sanctioned races by official who visually check and measure out the correct gear rations. How the gear restrictions measured? There is a formulated chart with all the measurements of the different gear ratios possibly used in cycling. This measurement is calculated by rolling a bicycling backward in the selected gear and the distance of a full revolution of the crank is the measurement used in the chart. For example, if you measured out the distance of a full revolution of the crank on a bicycle in a 52-14 gear, the distance would be 7.930m. Age Group Maximum Roll-out Distance Maximum gear ratio (23CC tire) Under 10/12 6.227m 41 x 14 Under 14 6.626m 41 x 13 Under 16 6.897m 42 x 13 Junior Ladies 7.400m 42 x 12 Junior Men 7.930m 52 x 14 So where is the cost effective part in this article? The cost of clusters has become very expensive, some clusters may cost in the region of R1000 plus. It is also very rare to find a cluster that can accommodate a ratio of 16-23, 17-24 or 18-25, as required by most schoolboy age groups if they ride with a maximum 52 tooth chain blade upfront. Where as, a 13-21 or 14-23 cluster can be bought with a new bike as a standard feature and it will see you through most your schoolboy racing career. The cost of replacing a 52 tooth chain blade for a 41 or 42 tooth chain blades is only R300-R400. So do the math, would you like to spend R1500 or R350? On a personal note I would suggest that if parents would like their children have a long prosperous cycling future that they encourage that their kids ride restricted gears during races as well as in training. Restricted gears are only there for the benefit of our up and coming future of South African cyclists and that they have a healthy injury free cycle to the top.

[Chrispy]

Sammajoor I know you have knowledge of cycling for kids, but please keep the training to a max of  2 hours (roughly) 60km . They need nothing more at that age. Shorter harder rides are much better for their development. Good luck!!

[The Guy in Pink]

With a 50 front ring the smallest is a 16 rear.

[Chrispy]

With a 50 front ring the smallest is a 16 rear.

 

That gives you a 84.375 inch gear and the max must be 82.8.

 

But it is the roll-in distance of 6.626m that is important.<?: PREFIX = O />

 

[The Guy in Pink]

With a 50 front ring the smallest is a 16 rear.

 

That gives you a 84.375 inch gear and the max must be 82.8.

 

But it is the roll-in distance of 6.626m that is important.<?: PREFIX = O />

 

From The chart above  the 41x 13 is a 85.153 inch

Using a 2.076m circumfence  6.626m rollout = 86.176 inch.

[Witrot]

Just a correction on the chart. The junior ladies is also roll in distance of 7.9300

[Jean-Jay]

Give them 55x11

 

case closed

 

 

 

[Witrot]

Give them 55x11

case closed

 

Wonder if there is 10 year old kiddies that can turn this big gear???

[martelpypie]

I have also just upgraded my u14 son's racing bike with 50x16. Must still roll it in. Hope it will!