Horrible caliper brakes on cheap kids' bike

[MCsT]

Hi, everyone,

My 6¾-year-old son was due for a new bike. Without consulting, his grandfather bought him one from a box store. My son loves it. Honestly, it's mostly an OK bike from what I can tell (with all the caveats about serviceability, etc., that come with a cheap bike). However, the brakes are dangerously bad. From running speed, the stopping distance is on the order of 40 feet (12 m) (my eyeball estimate, not measured). I've tried it myself: even with my adult grip strength, it still brakes very poorly.

My question: How can I remedy this? If money were no object, I could completely replace all of the components with quality ones. (Then again, if money were no object, I could just buy him a higher-end kids' bike.) Which component will give the most improvement if replaced? Pads? Calipers and pads? Levers?

There's also a BMX-style untangler, a part that I've never had on a bike before; it initially struck me as something that would decrease the efficiency of the cable system except that, from what I've read, BMXers don't seem to have any complaints about untanglers.

I look forward to your advice.

Thanks in advance.

[Jesper]

(06-30-2021, 08:49 PM)MCsT Wrote:  Hi, everyone,

My 6¾-year-old son was due for a new bike. Without consulting, his grandfather bought him one from a box store. My son loves it. Honestly, it's mostly an OK bike from what I can tell (with all the caveats about serviceability, etc., that come with a cheap bike). However, the brakes are dangerously bad. From running speed, the stopping distance is on the order of 40 feet (12 m) (my eyeball estimate, not measured). I've tried it myself: even with my adult grip strength, it still brakes very poorly.

My question: How can I remedy this? If money were no object, I could completely replace all of the components with quality ones. (Then again, if money were no object, I could just buy him a higher-end kids' bike.) Which component will give the most improvement if replaced? Pads? Calipers and pads? Levers?

There's also a BMX-style untangler, a part that I've never had on a bike before; it initially struck me as something that would decrease the efficiency of the cable system except that, from what I've read, BMXers don't seem to have any complaints about untanglers.

I look forward to your advice.

Thanks in advance.

I would first clean the brake pad and braking surfaces with some rubbing alcohol to remove any possible surface contaminants. Ensure that the brake pads are making maximum contact on the rim or brake rotor (I am assuming rim caliper brakes). You can certainly add better pads at a very reasonable cost, but it does seem odd that the bike doesn't stop in short order with new brakes on it. I use KoolStop pads on many bikes as upgrades to smaller and less efficient brake pads. If you have disc brakes I might take it to a shop; I am not overly familiar with that type of braking system except on cars. You can also check the cable adjustment; set pads a little closer to the rim surface and see if that helps some, but I don't think that's the solution.

As far a "untanglers" go (I think they call them detanglers), I am again unfamiliar with them except that I know what they are and why they are used. I am sure someone out there would know exactly what to check for regarding that type of set-up.

[ReapThaWhirlwind]

That sounds incredibly odd.

Caliper brakes when adjusted properly, even the cheap ones, have very close-range, strong braking power.

Possibly, you didn't adjust them right.

The proper way to do this is to undo the brake line bolt and free up the brake line. Then squeeze the calipers into the rim and press them there with your one hand. Tug the line down as far as you can with your other hand, keeping the caliper arms squeezed to the rim. Now tighten the bolt (very carefully), keeping the caliper arms squeezed into the rim. Once the bolt has been torqued, let go of the caliper arms, give the brake a little tilt left and right.

You should have a properly adjusted caliper brake—with quick engagement and strong braking power.

Notice that it is very close to the rim, but should not have any rim rub, despite the method it was adjusted.

If you have rim rub, then you have another problem, and we can go from there.

[ChaseCal]

my best guess, based on the fact that it is a cheaper bike, a lot of the ones I see come into my shop have painted rims. knowing that, quite honestly, there is no remedy for it aside from getting new wheels. you could try and sand down the surface and rough it up, but it might not look very good. you could also pull the cable pretty tight to the brakes and true up the wheel so it doesn't rub and hopefully, that added little bit might help.

or even investing in getting newer, better brakes altogether that have better stopping power but you would need to make sure they are the right kind.