SpecialKev

I am putting together a single speed MTB commuter and I want to know it I can rely on just a disc brake in the front. My sense is that I will have plenty of stopping power. What do you think?

Kevin

LóFarkas

Stopping power is not the issue. Any decent front brake has enough stopping power. The issue is whether you are confident enough in that brake to rely on it as your only stopping method. If the brake fails at 30mph on a downhill for whatever reason, you're screwed.

slvoid

This will stop him.

lyledriver

I've run only a front brake on the street before. Its no big deal.

You just have to remember to brake BEFORE the corners. And check your brakes every ride.

Oh.. and learning to control a nose manual helps too.

CBBaron

I run front brake only but with a fixed gear. If I'm going to ride at any kind of speed I want to have two independent braking systems incase one fails. Cables break, bolts come loose and chains snap. All have a high mean time between failure so the chance of two systems failing at the same time is very very small but the chance of one failing is high enough to have me concerned.
Plus on wet, loose or slippery surfaces you want to be very careful with a front brake. Skidding the rear tire is easy to control but skidding the front will put you on the ground quick.
Craig

max-a-mill

yeah, front brakes are good at stopping you but once you lock up your front wheel, it is OVER!!!!

my advice: put a v-brake on the back or try fixed gear.

catatonic

For a commuter bike, I would say ALWAYS have a functional second brake, whether it be using both disc and v-brakes on the front wheel, or a rear and front wheel brake, coaster and front wheel, fixie and front wheel, erc.

Last thing you would want is to be late for work because your brake screwed up, and you had to go slow enough to use the old "shoe brake" to stop.

I say just put some basic v-brakes on the back.

squeakywheel

I've been doing this for a couple months, but I consider it a temporary situation. I have a V-brake on the front and no brake on the rear of my SS. I've been riding slowly and braking conservatively. For winter riding, a rear brake is a good thing for reasons CBBaron already mentioned.

I'm planning on building a new front wheel with a drum hub and moving the V-brake to the rear.

ItsJustMe

I really only use the front brake, but I want both brakes there. Both as a backup, and because if you're on a treacherous surface (ice, gravel, sand) you don't want to risk locking/sliding your front wheel.

In addition, it's probably illegal. It is in Michigan.

DCCommuter

In normal riding you should only use the front brake. See https://sheldonbrown.com/brakturn.html for the complete story.

It is a good idea to have a rear brake in case of a mechanical failure of the front brake.

huhenio

Great minds think alike.

In case of brake faliure, with care, a fixed gear will take you home. Providing that you have no fenders, the carefully wedging of a shoe on the rear triangle might help you brake too . I ran "shoe brake" without incident all through 1980's

royalflash

I would definitely go with two brakes- for all the reasons above and if you touch that front brake in winter when cornering you will quickly find yourself sliding down the road on your face

max-a-mill

do you think if sheldon over cooks it into a downhill s-turn he is grabbing the front brake only??? i know i would never.... in fact there are tons of places (usually going too fast with a maneuver needed ASAP) that i would NEVER use the front brake more heavily than the back.

reasoning: the back slides, cool dukes of hazard style skid, at least sometimes recoverable; the front slides, BOOM - dental work.

SpecialKev

Thanks for all the replies.

doktoravalanche

That sheldon guy is insane*. What planet does he ride on?! Don't tell, me, long straight flat roads with intersections as the only proper bends? My day to day commute route looks a lot like a Super-G ski course made of concrete, battered old tarmac and mud with cars racing each other to see how many they can fit in one lane side-by-side. If i relied on my front brake only i'd die. I don't have time for gently slowing down, i need to STOP, and i need to turn through 90 degrees at 20mph. My back tyre shows how much i use my back brake. Don't even THINK about losing it. I don't know about where you are, but in the UK your bike wouldn;t be road legal. If you were in an accident with a car, you could forget about getting anything from their insurers, and if you hit a ped, i hope you have a good lawyer...

* Yes i know, burn the heretic. But c'mon, 'Sheldon'? Is he reporting live from the 1920's?

bikebuddha 

Bingo! Backslides can be handled with practice. Front slide=ouch!

DataJunkie

Only use the front brake? I've had numerous rear wheel issues that have resulted in me riding with only my front brake for quite a few commutes. Dang cantilever brakes.
My latest issue was a shredded rear brake cable. 2 commutes of riding with only a front brake had me frazzled. At least today's commute didn't have a 3" mixture of snow, slush, and ice. That was amusing to ride with one brake.
Things should improve with the new cable I installed today.

ghettocruiser

Since I've put off buying a disc front hub, I've been running only a BACK brake most of the winter since the old front one got screwed up.

This does not mean it's a good idea, it just means I'm an idiot.

Run brakes front and rear, at least most of the time. I just bought the wheel, so starting tomorrow I will be too.

MMACH 5

I hardly ever touch my rear brake. I'm on all sorts of crappy roads. Rear brakes are worthless for actually stopping. They can help you throw off speed but the laws of physics dictate that rear brakes will skid easier and take you a heck of a lot longer to stop than front brakes.

The only reason the law requires a rear brake and not a front is because some idiots can't make an emergency stop without flying over the handlebars.

And slamming Sheldon? Dude...

Eggplant Jeff

No, the laws of physics dictate that the wheel with greater traction will support a greater amount of braking.

Secondly they state that the wheel bearing more weight will have more traction (this is because a rolling wheel is fighting static friction, a skidding wheel is fighting dynamic friction which is a different story... but static friction is a factor of weight and area).

On a light road bike, yeah the rear wheel won't stand much braking force. On my 50-lb commuter? With a bunch of stuff in my rear panniers? Hell yeah I can use the rear brake all day. It probably provides 40% of my braking force. If I only use the front it takes quite a bit longer to stop. That's with discs front and rear.

ghettocruiser

I just read Sheldon's fine print. He goes on to mention that the rear brake is valuable when it's slippery (due to water on the road, snow, or gravel) when the road is bumpy, and when the rims are wet.

In other words, pretty much all the time on my rides.

I use the front brake (when I have one installed!) for fast stops, but I admit to lazily applying the rear only drifting up to a red light. It's not at all hard to break the front end loose on some of the 'roads' I commute on.

MMACH 5

When I say the laws of physics, I mean that when you slow down, mementum shifts your weight and that of your bike forward putting more pressure on the front tire. There is no way around that. (more weight on the front tire = less on the rear = higher chance of skidding).

A motorcycle weighs a hole lot more than you and your bike and your loaded down panniers. Trying to stop a motorcycle with only a rear brake would be a nightmare. Due to the weight and momentum of the vehicle shifting forward, the rear wheel loses traction, causing it to skid.

doktoravalanche

Granted, a rear brake alone won't stop you. One thing it will do is allow controlled braking, and increased control under braking, especially at speed, by spreading the drag across the bike frame. Using the back brake keeps the back wheel down (one thing he mentions), and spreads the mass of you+bike+mph along the bike frame instead of piling it all up on the fork & headset & making the whole shebang judder like the metz man...

And what's wrong with skidding? Can get you round very tight bends if its done right, and anyway, properly setup brakes have increments of braking, not just on or off.

Perhaps the drag created by that beard means he never goes over 15mph... :-D

zoridog

I built a bike using only spare parts last summer. I only had one front brake for a while and it was OK for local treks with small hills. On a commuting bike I use the rear brake for speed control on steep hills.

Also Sheldon Brown is sane. People with questionable sanity have higher paying jobs running FEMA, lobbying in DC, running Enron ....

JASON R. TOMSIC

Keep the front v-brake, spend your money on a fixed hub.