TheVakman

Well, it is certainly not ideal but can be ridden safely, in my opinion.

StanSeven

A fixie stops very fast. It's easy to lock up the rear wheel. On the other hand a road bike with just a rear brake is dangerous.

BoSoxYacht

I wish the OP explained exactly why he was without a front brake.

calgarc

which is why i said i do not recommend it lol

motorthings

but that does not mean they don't exist in large numbers...i have met many of them, so convinced that even laying their motorcycle down is a safer way to avoid hitting a car than using (both) their brakes as god intended them to be used.

i agree they should not have licenses, but that covers a large swath of the motorcyling community. it's gotten a lot better over the years, but still has a long way to go.

sorry for the off-topic mini rant.

RollCNY

Equating a coaster brake to a rear caliper brake is goofy, IMO:

1) Coaster brake is unaffected by weather and road conditions, as it is sealed and internal. Rim brakes lose effectiveness in the wet.
2) A coaster brake works on metal to metal contact, based on a much higher force applied through the chain.
3) Weight distribution is on the rear foot, more toward the rear wheel, when braking. Weight is more uniformly spread when using rim brakes.
4) A road bike usually has a much smaller contact patch than older single speeds, so it is far easier to brake the rear wheel into a skid.

All that said, I would not trust having only a single rim brake on the rear.

Nachoman

Under those conditions, I would not hesitate to do it albeit cautiously and slowly.

banerjek

If it were me, I'd ride to the shop to pick up what I needed to fix the brakes and take care of things immediately.

But if I couldn't get to a shop for a couple days, I'd ride in the conditions you describe because you barely need your brakes. It's still not a great idea.

PaulRivers

It's more like 30% of the effectiveness of the front brake. Please, if you want to disagree, do a quick search before doing so.

Still though, all you have to do to get around it is to ride somewhat easier - give more distance in front of you for stopping. My old road bike lost half it's braking capacity or more in the rain - but it worked fine because I adjusted how I ride.

The one serious issue is if there's any possibility that your rear brake could stop working while riding. Take a look at it, make sure it looks ok. If you lost the rear brake while riding that would be a rear problem with only 1 brake...

DaveLeeNC

FWIW, I already have a 'second' bike which is a spinner bike that I ride as much as my Bianchi. As luck would have it the BB gave out (IOW the squealing got so loud that I literally could not stand it) last week. New parts/instructions came in over the weekend and I am now trapped in 'remove the BB hell'. It isn't a place that I recommend to anyone.

But 3 bikes - that would have worked :-)

dave

Reynolds 

+1

prathmann

The book "Bicycling Science" by Frank Whitt and David Wilson goes through a calculation in Chapter 8 ('Braking') concluding with the sentence: "Therefore, the stopping distance [for rear brake only] is about twice that for reasonably safe front-wheel braking."

Of course the exact ratio will depend on the specific geometry of the bike, the road conditions, and the skill of the rider. If the rider can move his weight back sufficiently to avoid a pitch-over then the front brake can be made more effective than usual. OTOH, poor road conditions make hard application of the front brake riskier and reduce the ratio.

prathmann

1&2) Both properly operating coaster brakes and decent rim brakes should be capable of making the rear wheel skid. However one generally has better modulation ability using good hand-operated brakes therefore allowing the user to brake at just under the level where skidding would start. Since static friction is higher than dynamic friction, this allows for faster deceleration.

3) Weight distribution is a function of how the rider's body is positioned on the bicycle - i.e. the position of his center of mass relative to the wheel contact points. That would be essentially independent of what type of brake he is operating (I can lean back to put more weight on the back tire equally well while operating a handbrake).

4) Size of contact patch has little effect on maximum braking power. The braking force is equal to the coefficient of friction of the tire rubber on the road surface times the normal force of gravity pulling down on the rider/bike and holding the rear tire in contact with the road.

DaveLeeNC

For the life of me I cannot imagine why anyone cares about this. Regardless, see post #35 and #18 in this thread.

dave

ps. I wish someone would explain to me why they care about this question.


ps.

BoSoxYacht

i wondered what was wrong with your brakes so that we might be able to help you fix the problem.

BTW neither 18 or 35 say anything about what's wrong with your brakes, but at this point I don't give a damn.

Ride safe.

I <3 Robots

I used to do that when I was a kid in the 80's. Rode with no brakes and used my right foot on the rear tire to slow me down. I stopped doing it when I realized how fast my shoe and rear tire was wearing. Lol...I had to put my rear brake back on.

The BMX kids still do that today. It would bald your tire and burn out your shoe fast.

DaveLeeNC

Now that I look back it actually doesn't state the problem. FWIW, the nut-like thingey that holds the calipers on is gone (mid 90's Campy Chorus groupset). Despite my best measurements of 6mm, a 6mmx1 nut doesn't work. And that is pretty much my experience (VERY limited) in dealing with bicycle mechanics - as I said I am roughly clueless.

dave

PaulRivers

Ah, sorry, I think I misunderstood what you were meaning. That sounds right.

hamster

Define "does not work". Too big, too small, or does not screw on because it does not mate with the thread on the bolt?

If it looks like you need a 6 mm nut but a 6 mm nut does not work, it may be that you somehow have a SAE bolt and therefore you need a 1/4" nut. Would be pretty strange to have SAE parts in an Italian groupset, but, if it went through the hands of a few American mechanics, anything is possible. Also, did you try to take the nut from the rear brake and put it in front?

DaveLeeNC

My best judgement is the right diameter and wrong thread pitch (keeping in mind that I am not all that competent).

A half-brakeless ride tomorrow morning and off to my LBS. In the meantime my 'backup' (a spinner bike where I put in many hours) finally has the (I think) defective BB assembly removed. Damnation, that was hard to do. And I have no idea how the biking Gods managed to 'break' my brake calipers and the BB on my spinner bike within days. Must be living wrong.

In the meantime I hope this thing goes back together better than it did coming apart. The BB cups were tight beyond my personal belief of what is reasonable, so I am suspicious of another lurking problem of which I am unaware.

dave

hamster

Well, there are two 6 mm metric thread standards, 1.0 and 0.75. However, M6-1.0 is by far the most common and I can't find any evidence in Google that your Campy calipers require anything different. Is it possible that the bolt is in fact M6-1.0, but the nut you're trying to put on it is SAE? A 1/4-20 nut would look very close (slightly wider than M6-1.0) but would not screw on because thread pitch is too far off.

DaveLeeNC

It came out of the M6-1.0 box in a hardware store (per the HW store guy anything else is quite unusual in that diameter). But I guess that there are no guarantees. Regardless the next stop is my LBS. All my bike repair energies at the moment are being spent on my spinner bike BB assembly replacement. Godzilla after a 4 month diet of 98 pizza's per day could have stomped on those cranks with no risk to loosening that BB assembly (which, BTW, I finally broke loose).

dave

powbob

Ha-Ha! My track bike is 11 years old. I'm in my 50's and I get the hipster jibe from time to time from friends.

DaveLeeNC

Ended up riding once (and a half - had to get home after the caliper feel off) without a front brake. LBS fixed the problem easy and I need to find just exactly what threading is required on that bolt.

But what a great way to reduce weight. Drop off a whole caliper and brifter and go to a downtube shifter (and once this catches on maybe they will build some CF dowtube shifters). Talk about a great grams reduced per dollar trade-off

I was not uncomfortable on the solo routes I rode with that single brake, but in a group or on some hills I recall riding back in the Bay Area - VERY different.

dave

RoadMike

I work in a bike shop and apparently this is a trend in BMX. All the cool kids are riding brakeless now. My coworker who has been riding BMX for 18 years thinks this is probably one of the dumbest trends he's ever seen.