Youth compliant chainsets/gearing

by kitebikeski   February 28, 2013  

I want to make the gears on my 14 yo (youth A) daughters bike more suitable.

It currently has a standard double 53/39, and a 12/27 cassette.

She is pretty strong and MOST of the time this is fine, but she really could do with some lower gears. In events she can't use the higher gears anyway.

My plan is to swop the double for a compact 42/34, this will avoid big jumps in ratios, give her the lower gears, and still use the double shifters.

Does this sound sensible - or is there another can of worms in there??

Cheers

9 user comments

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Why 42/34? I'd say a 50/34 gives a far better range - 42/12 going downhill would be horribly spinny.

posted by bashthebox [528 posts]
28th February 2013 - 17:58

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So it is compliant with the restricted gearing for Youth competitions.

If I use a 50 then she will only be able to use no smaller than the 16 on the back in competitions.

But that is a fair point I should also be thinking about when she is riding outwith competitions. The 42 would be kinda restrictive.

So - do I go for the 50 or something inbetween??

posted by kitebikeski [18 posts]
28th February 2013 - 18:54

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Ooh, my favourite topic!

IMO, its best to maximise the gears. I moved my Youth A chainrings to my winter bike., so its now a 42x13.

Obviously Youth B is that bit smaller, but it should offer the perfect range for a 14 year old.

Its one less thing to use as an excuse as well.

Big Grin

I've got ro race on restricted gears with the big boys now, and what I would give for a full double...

Sir Velo

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posted by Raleigh [1725 posts]
28th February 2013 - 19:03

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CDWM website has disappeared but their recommendation for youth gearing was: use a 46T outer ring, which gives a maximum gear of 46x16 for U12, 46x15 for U14 and 46x14 for U16 with 700c tyres (presumably 23mm, larger volume tyres could push you over the limit).

You could use a 50/34 compact and use the limit screw to run a max of 50x16, but that cuts the number of ratios available. A 46/36 double (e.g. Shimano CX50 chainset) or 42/34 may a be better idea.

Restricted gears for youth riders mean they don't try to push big gears, so why not get her used to it all the time? The youth coaches I see are always reminding the kids to keep their cadence up. And 50x16 is not exactly a small gear!

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posted by Simon E [1778 posts]
28th February 2013 - 22:50

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Thanks that's all really useful stuff. It was the limited ratios available that was concernig me with the 50/34, and the big step when changing between chainrings. Sounds like a 46 would be the one to go for. She's pretty good at keeping a high cadence.

posted by kitebikeski [18 posts]
28th February 2013 - 23:26

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Related to this how important is chainset weight - bearing in mind it is for a very keen youth, but not Rebecca Pendleton!
As it is a rotating part is is a bit like weight saving on wheels, or does it not really make much diference saving 75-100g?

Thanks

posted by kitebikeski [18 posts]
2nd March 2013 - 9:39

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I shouldn't think that inertia would come into effect.

She can probably only pedal as a maximum of about 120rpm, and even then, not for very long.

I wouldn't worry about it.

Sir Velo

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posted by Raleigh [1725 posts]
2nd March 2013 - 18:52

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kitebikeski wrote:
As it is a rotating part is is a bit like weight saving on wheels, or does it not really make much diference saving 75-100g?

It will make no difference, rotating or otherwise.

The benefit of weight reduction is exaggerated out of all proportion in order to sell lighter wheels, frames and components. The same goes for "stiffer" cranks etc.

Maximising performance depends on a vast range of factors, most of which involve the rider, not the bike. Your daughter will not ever win, lose or come 8th in a race because of the weight of her chainset.

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posted by Simon E [1778 posts]
2nd March 2013 - 21:00

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Thanks - that'll do for me - the amount of bling kit that young riders seem to have amazes me!!

posted by kitebikeski [18 posts]
3rd March 2013 - 22:15

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