Disc brakes on folding bikes: do they make sense?

Posted by Dr. Yan Lyansky on Nov 11th 2017

Folding bikes are more improved than they were a decade ago. In the retail market today, it is very difficult to purchase a ‘bad’ folding bicycle. For the purpose and intention of this article, we will make the assumption that everybody has a nice folding bicycle. We will talk about upgrading disc brakes and when they are sensible to have on folding bikes. We will also make a comparison on the most inexpensive, fully disc-ready folding bike in the United States, the Downtube 9FS (MSRP $549). 

Disc brakes are considered very popular and trendy upgrades. Still, they are not for everybody, buyers will have to get disc hubs to use disc brakes. The standard discs are fitted with six bolts. Additionally, buyers need to make certain the frame and fork has disc tabs. Not many folding bikes below $1,000 are fitted with disc tabs on their frames and forks. Even fewer of them are built with disc hubs. However, one bike, the Downtube 9FS folding bike, is fully disc ready and fitted with all of these: the tabs on the frame and fork, the disc hubs as well as cable routing for the hubs.

Folding bikes that do not feature disc hubs will need to be upgraded with a wheel that cost about $250, an upgrade of the fork that may run you more than $100 and disc brakes for roughly a hundred bucks per wheel. For that reason, the economical cost to install a disc brake is usually more than $550 in comparison to the Downtube 9FS, which doesn’t need any upgrades to its components. It is already fully disc ready and for only a low price of $549.

Many riders don’t require disc brakes. Bikes will stop very quickly with rim brakes on machined-sidewall rims. However, for bikes with non-machined rims, the brakes won’t stop that quickly. The machined-sidewall feature on the brake pads, gives it a jagged surface to grip, resulting in more efficiency on the brakes. Furthermore, there are risks associated with disc brakes. Once there is a bend in the rotors, the bakes are going to squeak loudly. This can be extremely irritating. More than likely, rotors will bend on a portable folding bicycle because there are increased risks every time you fold the bike. Consequently, many customers should continue with the more inexpensive V-brakes with its machined-sidewall rims. Never accept non-machined sidewall rims since they do not engage the brakes.

Bike riders living in mountainous terrain will need disc brakes. On a zigzag mountainous descent, you will find that rim brakes are going to melt generated from the heat. They don’t have time to cool. Once the V brakes melt, there will no longer be brakes on your bike. Therefore, you can do two things: engage the brakes while making the descent and allow them to melt at the bottom of the descent or you can take the risk of not using them while on the descent so that they will work when you get to the base of the mountain. Disc brakes cool even when engaged, so they are best for the mountains.