[slowclimb]

My son has just started road racing this year, and has actually done really well.
All had been going well until Saturday when we ran into a slightly overzealous comm…he said he was overgeared, he wasnt, we’d checked it over and over again and he’s been fine at every other race he’s done. ( I think the issue was they were getting the kids to do their own rollouts)
Anyways…he wasnt allowed to start on his bike, high limit screw plate snapped…long story. So I’m now thinking of getting him a youth cassette but looking at ratios I’m slightly bamboozled, he’s youth a just now so 6.93 metres but will go up to junior at the start of nexr year so 7.93 metres then.
Hes on a 50 tooth at the front which ideally I diont want to change but I cant work out what cassette to get to get as close to those ratios as possible…
Any advice or experience from parents who I’m sure have gone through this would be much appreciated!

 

Topic

[slowclimb]

Yeah it’s not simple eh?!

Yeah it’s not simple eh?!

And as any of you who’ve been involved in kids racing will know it was all my fault too….certainly according to my son! 

[ChasP]

It used to be easy when 39/53

It used to be easy when 39/53 chainsets were standard as you just locked off the big ring and maybe a sprocket or 2 depending on age/cassette. With 5 arm compacts a 46t chainring was cheap and useful but now the cost of outer 4 arm chainrings is silly. Not something I need to do anymore but I wonder if a 39t inner would be a good solution nowadays (much cheaper than an outer) although as you say bigger tyres have also messed up the old standard calculations.

[slowclimb]

Yeah it was the 50 x 16 he

Yeah it was the 50 x 16 he was in, been the same gear all season, same tyres too which I know affect it,  and it’s been checked every race and been fine, I think the problem was they were getting the kids to do the rollouts themselves, and as you’ll all know, it’s not actually that easy! a good few failed.

it went from bad to worse too, when I tried to limit it into the 17 the plate the high limit screw pushes against snapped…. we’ve had better days!

50 x 16 does come out a good 30cm short too which I think does make a difference over a whole race, good for their cadence anyways!

think I’ll try and get closer to the maximum length next year some way, the youth/junior  cassettes seem the best plan.

[Simon E]

Was the commissaire /

Was the commissaire / scrutineer over-zealous or just applying the rules properly? Not that it matters, you just need to ensure the gearing will in comply in future. Sheldon’s gear calculator agrees with a table I found showing that 16t is the smallest cog you can use with a 50t front chainring on 700c wheels for Youth A.  42×13, 46×14, 48×15 or 52×16 are alternative combinations.

https://heanorclarion.org.uk/go-ride-for-youngsters/gear-restrictions-for-youth-and-junior-riders/

https://kidsracing.co.uk/blogs/bikes/british-cycling-triathlon-youth-gear-restrictions

In the end no-one wins or loses a youth race because of 0.1m difference in gearing so don’t fret over it.

[kil0ran]

I’m not familiar with the

I’m not familiar with the regs but as always, isn’t the answer just “Sheldon knows”?

https://www.sheldonbrown.com/bicycleGears.html

 

https://www.sheldonbrown.com/gear-calc.html

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