Disc Brakes are the Bomb, But Don't Forget the Maintenance
Cargo bikes put extra demands on a braking system. With heavier bikes, heavier loads, valuable cargo (aka kids), or the extra momentum from an e-assist system, it's important to have a capable and reliable system. That's why were pretty adamant that cargo bikes need disc brakes, even hydraulic disc brakes. Disc brakes generally stop a bike more quickly and easily than other systems, especially in the rain. So, they definitely meet the "capable" requirement. Maintenance of your brakes will assure the "reliable" requirement is met. All systems eventually need brake pads replaced, and cables or hoses maintained. We see hydraulic disc brakes generally requiring less maintenance than mechanical brakes. We love the sealed hydraulic system in our rainy, mucky urban cycling habitat. Performance on mechanical (cable activated) brakes, disc or otherwise, can decline over a season of riding here. As you log the miles, road grime works its way into the cable housing clogging the cables and decreasing performance. Not so with hydraulic disc brakes, the sealed system keeps road grime at bay. Moreover, a hydraulic disc brake will self compensate for brake pad wear-unlike the mechanical disc brake which will require cable tension adjustment from time to time. BUT, they aren't maintenance free. "Of course not," you say.
So, why mention that disc brakes require maintenance? Well, because on a fairly regular basis we see disc brake pads worn beyond appropriate. I'm here to tell you the problems with that:
1. Safety. No brake system stops reliably with worn pads. It doesn't matter what the system or the vehicle. If your brake pads are worn, you can't rely on your bike stopping when you most need it to stop: like in an emergency situation where it matters most. All the parents out there need little reminder that your cargo both appreciates and is safer, when you have a bike that will stop when you need it to stop.
2. Expense. When pads wear beyond an appropriate level and you fail to replace them, you WILL pay more for repairs. Go too long with worn disc brake pads and you will damage your rotor. Your repair expense just doubled. For those with hydraulic systems, go a little longer and we'll need to re-bleed your brake line. Now your repair has tripled. Choose to keep going and damage to the brake calipers is possible. Now it's become a very expensive oversight!
The photo above shows three different pads. The one on the far left, is obviously worn, as is the one in the center. Both of these pads have worn down to the metal plate that holds the pad. That means this rider's rotor was damaged and requires replacement, and his brakes will need to be rebled. The pad on the far left, with its sharp edges, has also damaged the brake caliper. We will likely need to replace the caliper. Sadly, this rider did have plenty of warning. A pad this worn makes a terrible grinding noise.
The pad on the right was just replaced for a customer and shows appropriate wear. This rider's attention to maintenance means that only the cost of pads is on her repair bill.
Admittedly, it is harder to estimate brake pad wear on disc brakes than on other bike brakes. It can be especially challenging on longtail bikes where cargo bags hide the brakes (and rear tire tread - but that's another post) from sight.
On top of that, a disc brake pad is narrow (see brand new pad to the left) and an untrained eye may have a hard time determining when replacement is required. That's why we invite any of our local customers to cruise by for a free pad wear assessment any time we're open. Besides it being nice to see you, we are happy to help you keep your repair bills to a minimum.
So, to summarize today's post: when in doubt, check your brake pads for wear, don't ignore ANY noise your bike is making, especially if it didn't make that noise when new, and don't hesitate to ask us, or your favorite bike mechanic if your disc brake pads need replacing.