Children chainrings for road bikes

[Small Frye]

Does anyone know a good size chainring and cassette for a 10 year old child? I was going to buy my son a 42 or 46 cm Fuji Newest 4.0 24 speed road bike. A friend said that the stock gearing setup may create damage in his undeveloped muscles. http://www.fujibikes.com/bike/details/newest-403

Thanks for the help in advance!

 

[An old Guy]

Junior racing has gear restrictions for juniors. Your friend might be thinking about that.

Shimano makes a 16-27 cassette. I would use that unless the 27 is not enough to get up hills.

16, 17, 18, 19, 20, 21, 22, 23, 25, 27

http://www.excelsports.com/main.asp?page=8&description=Ultegra+CS-6600B+10+Speed+Cassette&vendorCode=SHIM&major=1&minor=10

and a 12-30 cassette (you can do a search for that. It is a lower level cassette.)

I mixed them and came up with a 16-30 that I use. But I don't know what type of terrain you have to deal with.

16, 17, 18, 19, 20, 21, 22, 24, 27, 30

 

[Small Frye]

Thanks to an old Guy, the friend did mention jr. gear racing as well. The bike was going to be assembled this weekend so I just thought to switch the cassette/chainwheel at that time.

 

[Small Frye]

Oh, and we will probably be doing mostly riverbed riding since the bike path is so convenient. If he decides to compete at some point, I'm not sure how courses are usually set up.

 

[dabac]

With kids, it's usually more of an issue to get them to use the gears they have rather than than setting up the bike that's the problem.

At 10 the kid is just about old to begin to get the hang of it, but he's likely to forget himself ever so often and just churn along on whatever gear he's in.

What I like to do when considering gear ratios is to look at the speed range. The stock gearing of that bike would let him hit about 33 MPH / 53 KMH, which seems kinda excessive.

If you're concerned, the easiest thing is just to dial out the biggest chainring. Even the middle would let him hit 26 MPH / 42 KMH which is plenty for bike path use.

Switching to a 16-27 cassette would give the same top speed as staying on the middle ring, but would give a bit more oomph uphill. For riverbed riding I can't see that being particularly important.

 

[nycbikerental]

At the age 10 is the correct to begin to get the road bike.