Youth gearing - workarounds

martyc5674

Hi there my young lad is racing the weekend in his first u12 race where gearing is considered(46/16 is the max allowable but he has a compact 50/34 11-28)
Do they count teeth or just select the highest gear selectable and do the rollout?
I’m thinking of removing front derailleur ((leaving just the 34) and limiting it to the 12 on the block which if my calcs are right are just under max allowable.
Really I’m wondering if mechanical limitation is acceptable or not?(I’ll do my own rollout aswell to be sure)
Marty.

wav1

martyc5674 wrote: »

Hi there my young lad is racing the weekend in his first u12 race where gearing is considered(46/16 is the max allowable but he has a compact 50/34 11-28)
Do they count teeth or just select the highest gear selectable and do the rollout?
I’m thinking of removing front derailleur ((leaving just the 34) and limiting it to the 12 on the block which if my calcs are right are just under max allowable.
Really I’m wondering if mechanical limitation is acceptable or not?(I’ll do my own rollout aswell to be sure)
Marty.

They just do a rollout
Its acceptable to just use the limit screws both front and rear retailers.. many combinations give the same end result as 46 x 16 or just under it..no need to remove front derailed just use the screws
FYI the rollout distance for u12 is 6.14 mtrs for 1 x complete 360 degrees turn of the cranks

wav1

martyc5674 wrote: »

Hi there my young lad is racing the weekend in his first u12 race where gearing is considered(46/16 is the max allowable but he has a compact 50/34 11-28)
Do they count teeth or just select the highest gear selectable and do the rollout?
I’m thinking of removing front derailleur ((leaving just the 34) and limiting it to the 12 on the block which if my calcs are right are just under max allowable.
Really I’m wondering if mechanical limitation is acceptable or not?(I’ll do my own rollout aswell to be sure)
Marty.

They just do a rollout
Its acceptable to just use the limit screws both front and rear retailers.. many combinations give the same end result as 46 x 16 or just under it..no need to remove front derailed just use the screws
FYI the rollout distance for u12 is 6.14 mtrs for 1 x complete 360 degrees turn of the cranks

martyc5674

wav1 wrote: »

They just do a rollout
Its acceptable to just use the limit screws both front and rear retailers.. many combinations give the same end result as 46 x 16 or just under it..no need to remove front derailed just use the screws
FYI the rollout distance for u12 is 6.14 mtrs for 1 x complete 360 degrees turn of the cranks

Perfect- I think the 34/12 as highest will work quite well then as it’s just under. He will have 10 gears then to choose from and not have to worry about FD at all.
Essentially the highest allowable gear is achievable on the small ring- prob not the best chain line though!

Euppy

martyc5674 wrote: »

Hi there my young lad is racing the weekend in his first u12 race where gearing is considered(46/16 is the max allowable but he has a compact 50/34 11-28)
Do they count teeth or just select the highest gear selectable and do the rollout?
I’m thinking of removing front derailleur ((leaving just the 34) and limiting it to the 12 on the block which if my calcs are right are just under max allowable.
Really I’m wondering if mechanical limitation is acceptable or not?(I’ll do my own rollout aswell to be sure)
Marty.

You say 46x16 is max allowable. I'm guessing that is for 700c wheels. If your son's bike has smaller wheel size you'll have to compensate for that.


Do the rollout test that Wav1 mentioned your self to make sure all is good.

martyc5674

Euppy wrote: »

You say 46x16 is max allowable. I'm guessing that is for 700c wheels. If your son's bike has smaller wheel size you'll have to compensate for that.


Do the rollout test that Wav1 mentioned your self to make sure all is good.

Yeah it’s based on 700s 25mm which is what he has - but yeah will do the rollout to confirm. 34/12 is just under 46/16 but will check.
Thanks all

Edit: just did the rollout- bang on 6.0 metres so 140mm under the max allowable. Should be good