Why do handbrakes stop the back wheels only?

idunnoshur

Why do handbrakes stop the back wheels only? Is it because it's easier to run the cable to the back wheels than the front?

What are the advantages? So far I can only think of one disadvantage (it's not a very big one either) and that's young fellas flying around pulling the handbrake, if they stopped the front wheels they wouldn't bother with them.

Thanks
ids

AugustusMinimus

Because there is no need for 4 wheels to be locked to keep the car stationary ?

idunnoshur

AugustusMinimus wrote: »

Because there is no need for 4 wheels to be locked to keep the car stationary ?

I'm aware of that but why are the back wheels stopped opposed to the front?

Matt Simis

idunnoshur wrote: »

I'm aware of that but why are the back wheels stopped opposed to the front?

Some cars have the hand/parking brake at the front..

... some citroens hand brake locked the fronts.

andyseadog

probably because the front wheels have to have the ability to steer left and right so there would have to be much more slack in the handbrake cable for it to work before it would bite.

that and they are already the driving and steering wheels, there is already enough going on up the front in most cars.

Plug

The caliper would have to be very big in the front if that was the case.

Bruthal

Handbrakes only apply a small amount of braking power relative to the main brakes. Not much is needed to hold the car stationary, again compared to the braking power required in the main braking system.

So keeping it simple, and on the non steering wheels is all that is required, and is the simplest for a cable braking setup.

CiniO

idunnoshur wrote: »

So far I can only think of one disadvantage (it's not a very big one either) and that's young fellas flying around pulling the handbrake, if they stopped the front wheels they wouldn't bother with them.

I find handbrake very useful for doing u-turns so this is actually an advantage.


I can think of another one.
As most cars are front wheel drive, so by parking with your gearbox on 1st (or reverse) gear you prevent front wheels from moving, and with handbrake you prevent rear ones from moving, resulting in all 4 wheels stopped.


Few more reasons (rather technical) for brake on rear is that for many years cars had disc brakes in the front and drum brakes on the back. Drum brake is more suitable to be operated by cable.
Beside front wheels are steering wheels, and therefore using cables to operate brakes on them would be very difficult to be engineered properly.

Quietman

handbrake used to be called the emergency brake. If the footbrake failed the handbrake could be applied gradually so it was safer to connect to the rear wheels

idunnoshur

CiniO wrote: »

I find handbrake very useful for doing u-turns so this is actually an advantage.


I can think of another one.
As most cars are front wheel drive, so by parking with your gearbox on 1st (or reverse) gear you prevent front wheels from moving, and with handbrake you prevent rear ones from moving, resulting in all 4 wheels stopped.


Few more reasons (rather technical) for brake on rear is that for many years cars had disc brakes in the front and drum brakes on the back. Drum brake is more suitable to be operated by cable.
Beside front wheels are steering wheels, and therefore using cables to operate brakes on them would be very difficult to be engineered properly.

I don't think you should use the handbrake for u-turns, I had a tyre come off the rim when I was 17 and immature.

I was actually just going to post that about leaving the car in gear to effectively stop all wheels.

I wasn't aware that drums were easier to operate by cable than discs.

vectra

idunnoshur wrote: »

Why do handbrakes stop the back wheels only? Is it because it's easier to run the cable to the back wheels than the front?

What are the advantages? So far I can only think of one disadvantage (it's not a very big one either) and that's young fellas flying around pulling the handbrake, if they stopped the front wheels they wouldn't bother with them.

Thanks
ids

I witnessed that happening with the first of the Renault 4 PO vans
Stupid clown thought he knew everything and smacked it off a wall :pac:

CiniO

idunnoshur wrote: »

I don't think you should use the handbrake for u-turns, I had a tyre come off the rim when I was 17 and immature.

I can do such thing and I consider myself good at it. (I never made tyre to come off)
I also don't think about it as immature, as I'm almost 30 and it's still great fun for me.
However don't worry. You most won't see me doing such things on a road where there are any other people.

I was actually just going to post that about leaving the car in gear to effectively stop all wheels.

I wasn't aware that drums were easier to operate by cable than discs.

I'm not sure it they were acutally easier to operate, but they are definitely more efficient for handbrake.
All cars with disc brakes on the rear had way weaker handbrake than nearly any car with drums which I've seen.

DanWall

Its bad practice to apply the front brakes only, the car could slew around

Mycroft H

My xantia handbrake operates on the front. Its "failed" the NCT twice as the rear ones didn't "work" during the test.

Firewalkwithme

One practical reason I can think of would be if the car needed to be towed away for some reason (illegally parked, causing an obstruction, abandoned...).

If the handbrake had lock all four wheels, towing the car would be quite difficult, not impossible but it could possibly flat spot the tyres if it were applied very hard.

With only two wheels locked, the rear of the car (or the front if it's an eccentric Citroen) can be raised and the car towed away.

idunnoshur

BX 19 wrote: »

My xantia handbrake operates on the front. Its "failed" the NCT twice as the rear ones didn't "work" during the test.

Those testers must have been cute hoors, out of interest did you ever whip up the handbrake while moving? If yes how did the car react?

Bruthal

Cartoon_Head wrote: »

One practical reason I can think of would be if the car needed to be towed away for some reason (illegally parked, causing an obstruction, abandoned...).

If the handbrake had lock all four wheels, towing the car would be quite difficult, not impossible but it could possibly flat spot the tyres if it were applied very hard.

With only two wheels locked, the rear of the car (or the front if it's an eccentric Citroen) can be raised and the car towed away.

If the handbrake is on and the car is in a low gear on a fwd, it would not be practical to tow it anyway.

Although if only one of the front drive wheels was on the ground, it will freely spin, with the opposite one spinning in the opposite direction:D

Our man in Havana

Is the handbrake designed to stop the car if it is in motion?

andyseadog

Cartoon_Head wrote: »

With only two wheels locked, the rear of the car (or the front if it's an eccentric Citroen) can be raised and the car towed away.

with the rear wheels locked, and the front wheels raised for towing, i can imagine the car being rather difficult to tow because you will essentially be dragging the car with the wheels not turning.

jimmyw

RoverJames wrote: »

... some citroens hand brake locked the fronts.

Old Saab's as well.

Guy:Incognito

BX 19 wrote: »

My xantia handbrake operates on the front. Its "failed" the NCT twice as the rear ones didn't "work" during the test.

I've to put my new caliper on the front then get mine retested so after the last time I'll be putting a post it on the steering wheel about the handbrake. I was watching them and it took a couple of goes with the car bouncing up off the rollers before the 2 of them got their heads together and copped it.

Presumably the make and model of car is on the computer as they are doing the tests? Any things like this that would affect the test really should pop up on screen for them.

idunnoshur wrote: »

Those testers must have been cute hoors, out of interest did you ever whip up the handbrake while moving? If yes how did the car react?

Its not a good idea. Havnt done it but I'm sure its caught out the odd joyrider.

Firewalkwithme

andyseadog wrote: »

with the rear wheels locked, and the front wheels raised for towing, i can imagine the car being rather difficult to tow because you will essentially be dragging the car with the wheels not turning.

Re-read my post.

I was saying that whatever set of wheels were locked could be raised leaving the unlocked wheels free to rotate and not drag.

Mycroft H

Guy:Incognito wrote: »

I've to put my new caliper on the front then get mine retested so after the last time I'll be putting a post it on the steering wheel about the handbrake. I was watching them and it took a couple of goes with the car bouncing up off the rollers before the 2 of them got their heads together and copped it.

Presumably the make and model of car is on the computer as they are doing the tests? Any things like this that would affect the test really should pop up on screen for them.



Its not a good idea. Havnt done it but I'm sure its caught out the odd joyrider.

The first time I didn't tell them, I completely forgot about it until I was told it failed it. The put it back on the lane and retested it for free. The second time I told the person at the desk about the handbrake and they didn't tell the testers. Fools the lot of them.

I've seen starlets/corrollas failing too due to them having a mechanical airbag which is perfectly legal.

I've never used the handbrake at anything more then a couple of miles an hour. I wouldn't trust any handbrake at speed.

Nissan doctor

Our man in Havana wrote: »

Is the handbrake designed to stop the car if it is in motion?

Its supposed to be a mechanical back up to the main hydraulic brake system.
Its classed as the emergency brake in most countries.

CiniO

Our man in Havana wrote: »

Is the handbrake designed to stop the car if it is in motion?

In emergency situation when your service brake is not working - definitely.

creedp

CiniO wrote: »

In emergency situation when your service brake is not working - definitely.

It wouldn't stop an s-max unless you were just trundling along .. once you bring to a hold it would just about hold it on a hill. Will need to be nct'd shortly .. hopefully won't be problem

Bruthal

They would actually have a lot more stopping power if on the front wheels, if they were able to apply good braking force on the discs.

corglass

Plug wrote: »

The caliper would have to be very big in the front if that was the case.

Not true at all, the handbrake disk area can be significantly smaller then the active brakes.

corglass

robbie7730 wrote: »

They would actually have a lot more stopping power if on the front wheels, if they were able to apply good braking force on the discs.

Where's that logic coming from robbie?

CJhaughey

On vehicles with permanent 4wd like TLCs the handbrake effectively operates on all 4 wheels when applied.

Cartoon_Head

Cartoon_Head wrote: »

One practical reason I can think of would be if the car needed to be towed away for some reason (illegally parked, causing an obstruction, abandoned...).

If the handbrake had lock all four wheels, towing the car would be quite difficult, not impossible but it could possibly flat spot the tyres if it were applied very hard.

With only two wheels locked, the rear of the car (or the front if it's an eccentric Citroen) can be raised and the car towed away.

Cartoon_Head wrote: »

Re-read my post.

I was saying that whatever set of wheels were locked could be raised leaving the unlocked wheels free to rotate and not drag.

...most folks leave manual cars in gear when parked, automatics are left in park, neither condusive to being towed away.

Bruthal

corglass wrote: »

Where's that logic coming from robbie?

Any car has more braking traction on the front wheels when going forward and the brakes are applied. Look at the discs front and back on cars with alloy wheels (so you can see the discs), you might notice the front ones are bigger, simply because the front wheels do most of the braking.

A car braking, and more weight actually goes down onto the front wheels, and possibly reduces on the back ones if heavy breaking and no back seat passengers, engine is also at the front, giving more traction.

robbie7730

robbie7730 wrote: »

They would actually have a lot more stopping power if on the front wheels, if they were able to apply good braking force on the discs.

..... only if they were servo assisted like the service brake, a mechanical brake system like most parking brakes wouldn't apply the required force give actual stopping power to the front.

Bruthal

RoverJames wrote: »

robbie7730 wrote: »

They would actually have a lot more stopping power if on the front wheels, if they were able to apply good braking force on the discs.

..... only if they were servo assisted like the service brake, a mechanical brake system like most parking brakes wouldn't apply the required force give actual stopping power to the front.

Very true, as i said, if they were able to apply good braking force, which they wont with a cable setup like you say.

Although if they are able to lock up the back wheels on a car while in motion, so are not getting their full braking potential used there. It would be harder to lock the front ones in the same situation, so more of the braking power would be used, if they were used as emergency brakes.

Dilbert75

Remember hearing before about a front-wheel handbraked car (must have been a Xantia) which, if driven in a "spirited" fashion, would heat its front brakes causing them to expand quite a bit. However, the expansion was such that, when parked, its brakes would cool & contract, releasing the handbrake...

Dunno how true (or legible) that is.

Mycroft H

I also forgot that things like Defenders have transmission brakes which would be disasterous if applied when moving.

Anan1

CJhaughey wrote: »

On vehicles with permanent 4wd like TLCs the handbrake effectively operates on all 4 wheels when applied.

Only with fully locked differentials.

mcwhirter

idunnoshur wrote: »

Why do handbrakes stop the back wheels only? Is it because it's easier to run the cable to the back wheels than the front?

What are the advantages? So far I can only think of one disadvantage (it's not a very big one either) and that's young fellas flying around pulling the handbrake, if they stopped the front wheels they wouldn't bother with them.

Thanks
ids

On the old alfasud, handbrake was on front discs.Some of the saabs as well I think.

si_guru

Subarus had front wheel hand brakes too.

Also many cars used to have cable operated main brakes.

Land Rovers - the parking brake operates on the propshaft.

alfastud

The alfasud/sprint had their hand brake at the front also.

lomb

Cable at front could get stressed though and could snap from all the twisting while steering etc.
Also the handbrake being on the transmission tunnel is probably easier/ cheaper to engineer going backwards being less cluttered than going forward to both wheels through the engine bay.

si_guru

lomb wrote: »

Cable at front could get stressed though and could snap from all the twisting while steering etc..

The Alfasud had in-board discs so this wasn't an issue.

johnayo

I done a lot of work on these back in the day. A customer of mine at the time used to rally an alfasud sprint and he always complained that he couldn't do any handbrake turns with it.:mad: