Youth Cycling 11 speed allowed?

Brian2011

Nephew is looking to upgrade his bike as he wants to get into racing. He is 14 years old. Are 11 speed bikes allowed for youths his age looking to race?. He is looking at various carbon bikes with either shimano 105 or shimano ultegra and all of these ones are 11 speed drivetrain. The only 10 speed I can find are Shimano Tiagra.

Any other rules to be aware of before buying?, thanks.

stecleary

Brian2011 wrote: »

Nephew is looking to upgrade his bike as he wants to get into racing. He is 14 years old. Are 11 speed bikes allowed for youths his age looking to race?. He is looking at various carbon bikes with either shimano 105 or shimano ultegra and all of these ones are 11 speed drivetrain. The only 10 speed I can find are Shimano Tiagra.

Any other rules to be aware of before buying?, thanks.

It's not about the number of gears it's about the ratio.
www.cyclingireland.ie/page/disciplines/junior

Taxuser1

its not about the number of gears, its restricted from the point of view of having a maximum gear

someone with youths will probably know more about the better ratios to have but once it doesn't go beyond the following distances on a measuring stick, you're fine

6.94m = 16 sprocket x 52 chain wheel
6.54m = 16 sprocket x 49 chain wheel
6.14m = 16 sprocket x 46 chain wheel

Brian2011

Can someone explain below?

"The maximum gear ratio authorised is that which gives a distance covered per pedal revolution of 7.93 metres."

Taxuser1

yeah, from my underage days, you'll have a measuring stick on the ground and you throw the bike into the biggest gear. lift the front wheel up and bring the bike backwards, the crank will start turning. One backwards pedal revolution for a 52 x 14 should give you this approx

further explanations on here

http://www.sheldonbrown.com/gears/

http://cyclingtips.com.au/2014/08/beyond-the-big-ring-understanding-gear-ratios-and-why-they-matter/

Taxuser1

http://www.wiggle.co.uk/shimano-ultegra-6600-10-speed-cassette/

nice ratio combo for any youth/beginner

Brian2011

Taxuser1 wrote: »

http://www.wiggle.co.uk/shimano-ultegra-6600-10-speed-cassette/

nice ratio combo for any youth/beginner

So he can still get an 11 speed bike, but just put something like the 10 speed cassette above onto it? He was also on about blocking a gear on the 11 speed? How does that work?

Lumen

Brian2011 wrote: »

Can someone explain below?

"The maximum gear ratio authorised is that which gives a distance covered per pedal revolution of 7.93 metres."

Use this and select "meters development".

http://www.sheldonbrown.com/gears/

Taxuser1

Brian2011 wrote: »

So he can still get an 11 speed bike, but just put something like the 10 speed cassette above onto it? He was also on about blocking a gear on the 11 speed? How does that work?

there's 11 clicks in the gear shifter. count them out. you can move the tiny rear derailleur screws so that the shifting doesn't go past a certain gear. So it'll go 10 clicks and no further. there's a high limit (first gear) and then down to 10th gear low limit where it won't go any further once you make your changes

plenty of videos on youtube as to how to adjust your gears.

10 speed cassettes work fine with 11 speed shifting. have it set myself for my training wheels.

wav1

Brian2011 wrote: »

Can someone explain below?

"The maximum gear ratio authorised is that which gives a distance covered per pedal revolution of 7.93 metres."

7.93 mtrs is the max gear allowed for junior riders which is u18
depending on what category your son is in u14 or u16 the max is 6.54 or 6.94.this is the distance the bike travels for one full 360 deg rotation of the cranks.you can restrict the the gears at the back up off some of the sprockets but best to get a youth cassette 16/25 and work from there.not sure if there is a 16/26 11 speed youth cassette available yet but I think that BBB do them.one thing to note is that a lot of bikes come with a 53 or 50 front ring.the exact roll out is achieved with either a 52 or 49 depending on category but it can be got around someway so not much of problem

NiallBoo

Brian2011 wrote: »

Can someone explain below?
"The maximum gear ratio authorised is that which gives a distance covered per pedal revolution of 7.93 metres."

Maybe I'm wrong here, but shouldn't this mean that the maximum gear ratio that you can use is one that results in 7.93m per time a pedal goes all the way around?

ie. 7.93 /(.668*pi) - if using a .668m (700x23)wheel (
= 3.7787 to 1

So the number of teeth on the biggest front gear can't be more than about 3.6 times the number of the smallest gear on the back.

If the wheel diameter is smaller then a higher gear ratio will be allowed.

eg.
11 teeth back, 50 teeth front = 4.55 to 1 ratio - not allowed
11 back, 41 front = 3.55:1 - allowed
12 back, 50 front = 4.17 - not allowed
12 back, 45 front = 3.58:1 - allowed
13 back, 49 teeth = 3.769:1 - allowed
14 back, 52 teeth = 3.7 - allowed
14 back, 50 front = 3.57:1 - allowed


This seems a bit restrictive to me, so maybe I took something up wrong?

If it's right, it sounds tricky to buy off-the-shelf.

You might want to ask if these rules are actually enforced?

(note: I corrected an error from earlier where I had made an incorrect error re: wheel diameter - I suppose this underlines the importance of checking how things work in real life.
For example, although the theoretical diameter of a 700x23c tyre is 668mm, I found mine were a couple of mm off)

Taxuser1

NiallBoo wrote: »

Maybe I'm wrong here, but shouldn't this mean that the maximum gear ratio that you can use is one that results in 7.93m per time a pedal goes all the way around?

ie. 7.93 /(.700*pi) - if using a .7m wheel
= 3.605 to 1

So the number of teeth on the biggest front gear can't be more than about 3.6 times the number of the smallest gear on the back.

If the wheel diameter is smaller then a higher gear ratio will be allowed.

eg.
11 teeth back, 50 teeth front = 4.55 to 1 ratio - not allowed
11 back, 39 front = 3.55:1 - allowed
12 back, 50 front = 4.17 - not allowed
12 back, 43 front = 3.58:1 - allowed
14 back, 52 teeth = 3.7 - not allowed
14 back, 50 front = 3.57:1 - allowed


This seems a bit restrictive to me, so maybe I took something up wrong?

If it's right, it sounds tricky to buy off-the-shelf.

You might want to ask if these rules are actually enforced?

you can be quite creative.

I remember losing an under 12 race to a guy who was around 4 foot because his bike and bike wheels were tiny and he rode a 12. the distance his gearing was closer to the mark but within the restiction.

wav1

NiallBoo wrote: »

Maybe I'm wrong here, but shouldn't this mean that the maximum gear ratio that you can use is one that results in 7.93m per time a pedal goes all the way around?

ie. 7.93 /(.700*pi) - if using a .7m wheel
= 3.605 to 1

So the number of teeth on the biggest front gear can't be more than about 3.6 times the number of the smallest gear on the back.

If the wheel diameter is smaller then a higher gear ratio will be allowed.

eg.
11 teeth back, 50 teeth front = 4.55 to 1 ratio - not allowed
11 back, 39 front = 3.55:1 - allowed
12 back, 50 front = 4.17 - not allowed
12 back, 43 front = 3.58:1 - allowed
14 back, 52 teeth = 3.7 - not allowed
14 back, 50 front = 3.57:1 - allowed


This seems a bit restrictive to me, so maybe I took something up wrong?

If it's right, it sounds tricky to buy off-the-shelf.

You might want to ask if these rules are actually enforced?

52x14= 7.93 metres exactly on a 700cc wheel so not really very odd at all.
Any yes it is enforced[for the young riders own sake]

NiallBoo

wav1 wrote: »

52x14= 7.93 metres exactly on a 700cc wheel so not really very odd at all.
Any yes it is enforced[for the young riders own sake]

Fair enough.

For my own curiosity, can you tell me what I've not taken into account/where I've done the maths wrong? by my reckoning, 52:14 should've worked out to 8.17 travelled?

wav1

NiallBoo wrote: »

Fair enough.

For my own curiosity, can you tell me what I've not taken into account/where I've done the maths wrong? by my reckoning, 52:14 should've worked out to 8.17 travelled?

No idea mate..im no maths genius.but 7.93 for junior u18 riders is international regulation.just seen video of bikes being checked[roll out]prior to worlds TT

NiallBoo

wav1 wrote: »

No idea mate..im no maths genius.but 7.93 for junior u18 riders is international regulation.just seen video of bikes being checked[roll out]prior to worlds TT

Cheers, found that I had made the wrong assumption with wheel diameter. It was kind of bugging me so both bike and tape-measure got a run-out.

dermabrasion

My lad raced U12. To set him up he is restricted to the small ring (39) and a 14 at the back using the limit screw. Simple. Will change the big ring to a 46 next year for U14.
Kids do roll up with full standard gears. Thankfully they have not placed in the races Ive been at, as I think it would be terrible for a kid to be DQ'd having won in front of everyone.

joxerjohn

Wheel Diameter (outside) D = 622mm+(2X23)=668mm
Wheel Circumference D x PI = 668 x PI = 2098.6mm
Gear Ratio 52/14 = 3.7143
Rollout = 3.7143 x 2098.6 = 7794.8mm or 7.8m approx.
The UCI limit max 7.93m for Juniors as per Wav 1 above so this 52 X 14 gearing is allowable.

The sum above is with 23mm tyres the diameter will be different for other tyre widths but the calculation can easily be amended.

Interesting to note that 53 X 14 gearing gives a result just above the limit at 7.944m and will result in a Junior rider being disqualified if tested. A junior rider with a 50t front chain is at a dis advantage as they also can only use a max 14t on the rear as 50 X 13 is over the limit.

To convert from metres to ft. you can multiply by a factor of 3.28084 = UCI Max of 26.01 Ft, this is often rounded to 26ft and is commonly taken as the UCI limit for the rollout test for Juniors. It is as near as makes no practical difference.

So to simplify

52 x 14 for Juniors (U18)
52 X 16 for youths (U16).

A youth rider can up just change the block at the back when they progress to Junior. The fact that they are used to the 52t front chain ring makes the change quite straight forward.

slow

BBB and Miche Primato make an 11 speed cassette from 16 up. www.bike24.com sells the Miche Primato.