Changing Chain-ring on One-Piece Crank?
 

My 10 year old son is a bit of a daredevil so I just picked up a SE Bronco Freestyle for him. It is a strong (cheap) entry-level bike but we are finding that he prefers riding slower, doing tricks riding rather than faster like in racing.

The question is where can I get parts to change out the chain-ring from the one piece crank to a smaller one that is more suited to his style of riding? Will I have to change the whole crankset?

http://bikeforums.net/attachment.php...hmentid=278021http://bikeforums.net/attachment.php...hmentid=278022

Have worked on our mountain bikes for a few years (all have three-piece cranks) but never played with one-piece cranks. And no, I don't want to spend too much money on a beginner bike.
Thanks in advance!

You can buy the rings by themselves and you don't need any special tools to do it. They come in handy, but not a necessity. Remove the left pedal, loosen and remove the lock nut on the crank, then the washer and finally the bearing race. It has a slot in it so you can use a screwdriver. It won't be that tight. All these parts will have left hand threads so turn everything the opposite way then normal.

Now remove the crank out through the other side. There will be the race on the other side holding chain ring on. A spanner wrench is used to remove it but channel lock pliers will work too. This side has right hand threads. Now just switch rings and reassemble. Only tricky part is adjusting the bearing tension with the race and lock nut.

Now I am betting he wants a smaller one like a 25 tooth. That is not going to work because it will be way to easy to pedal. You can put a smaller freewheel on the back, but probably limited to a 16 tooth. To do it right, you would need a new rear wheel with a 9 tooth driver.

If all you are doing is trying to make it easier to pedal, go down 4 teeth or so on the front. Most shops should have them, around $12.

My son wants it much easier to pedal. He is really wanting to do trials, not bmx but those bikes are MUCH more expensive.
Thanks michaelscycles. I will hit our local Bike shop to see what they have.
John

If he wants to ride Trials, he should really be on a bike built for it. BMX will be a good starting block in the way you need to move, and bike handling, but he should really be riding the correct bike to do whatever it is that he wants to do.


One good way to at least get a feel for the proper riding would be to get some disc brakes on there somehow. That would give him the proper braking-feel. And if his bike has a freewheel, theres a chance that you could get something down to 13 teeth. But that really depends on the hub.

They make freewheels at least as large as 20t. That should do it, and you don't have to take the BB apart. He won't have the bb clearance, but when he's at that point, it's probably time for a new bike anyway.

22t!

Thanks guys. A lot of ideas to ponder. Much of what was said here was also said by the guy at the bike shop today.
One surprising thing he said was trials is all but "dead". Said they had three bikes in the back that they can't sell. Suggested my son was probably wanting to do BMX freestyle. And BMX bikes were much easier to sell so if we find out it is not what he wants to do, we would not be stuck with an unsellable bike.

Trials isn't very big right now. Hasn't been in years. Danny Mcaskill is still keeping it alive, but thats one guy.

Exactly. My son wants to do what "Danny does"... not sure what you call it.

Yea, he's a trials rider. Dude is nuts.

Any BMX bike with front and rear brakes- 990s would be ideal- would last him through his progression until he outgrows it, THEN you can think about a trials specific bike.