ETZ 250 Rear Brake

[alexxx]

I am new to MZ's, when I first rode my ETZ251 recently I thought the back brake was totally lacking in feel and not sharp at all.
I can lock up the back wheel but it takes a bit more effort that any other bike I have used, the rear brake feels useless, it feels like not slowing down the bike, press harder and it can lock up (talking about less than 30 mph in testing)
I have not opened it to check the shoes etc but no grinding so I assume there is enough brake material there.
I would hate to rely on the rear brake alone

[Andy_C]

I am new to MZ's, when I first rode my ETZ251 recently I thought the back brake was totally lacking in feel and not sharp at all.
I can lock up the back wheel but it takes a bit more effort that any other bike I have used, the rear brake feels useless, it feels like not slowing down the bike, press harder and it can lock up (talking about less than 30 mph in testing)
I have not opened it to check the shoes etc but no grinding so I assume there is enough brake material there.
I would hate to rely on the rear brake alone

Pretty much like mine - as you say not sharp just lacking in power, and I cannot even lock mine up.

New rear tyre going on soon so I'll take a look, I plan on fitting new shoes in any case given that they are pretty cheap.

Font disk has plenty of power and works very well, even if the action is a little "wooden"

[DAVID THOMPSON]

on the stopping problem they used to cut a BIG square block of WOOD and store it in the rumble seat of the cars

the kids would toss it out tied on the bumper ...when dad needed to slow down coming down the mountain
then leave it in town for fire wood

[DerekR]

ETZ rear brake? Can't say - never ridden one.

But for what it's worth, I have ridden bikes since 1963 more or less continuously. For over twenty years I rode despatch with various companies from 1976 through 2004, and at one time went out with a Class 1 Police instructor on a 200 mile blast around North Wales. Interesting - yes, informative - not so much.

Emergency braking is a bit of a misnomer in as much as it's more likely to be panic braking to avoid a collision which still may occur when the unexpected happens. In such situations you simply grab a fistful and stamp on the pedal - how much and which first doesn't enter the equation, when it's "Ooops" time and your world is looking to end, straws are grasped with all strength, although frequent practicing of a chosen technique helps to get acquainted with how a specific machine will react in said situation.

An emergency brake test is something that is fore-planned, and the techniques used may aid in understanding the dynamics and forces involved, however, there are many factors which will affect which brakes to use for the best results in stopping as quickly as possible within the space/time available. Some of those are surface friction from varying grades of dressing; water on the road surface; ice and snow, and then there's the machine itself - and there is a great difference between how a moped will brake compared to a race replica. My old 750 Harley WL45 had an atrocious brake at the front, but a really good one at the rear, and it was the rear brake that did most of the retarding in normal riding. It worked so well because the weight of the machine was high, along with a long wheelbase and low centre of gravity that the back brake was 'master'. Not so on something like a CX500. There the c of g was higher, wheelbase shorter, and with twin discs up front a very different technique was needed. Likewise with the CB72 with its twin leading shoe set up at the front. I got caught out on that when a London bus turned across my path on a wet road - grabbed a handful and lost the front, ending up on the deck - a panic situation. An emergency - yes, but the natural reaction in panic mode prevents any calculated action. The BSA C15 had a poor front brake and a goodish back one, and the only time I got out of shape in that was accelerating away from lights on the N. Circular. I got sideways on the greasy road - so much power!

Going back to that 45, despite its all up weight, it was the only bike I could ride on snow with confidence. So much so that it could be ridden speedway style around a hairpin bend, on a steep hill, on packed snow. The road was The Twist (an apt name), it runs between Wigginton, Herts. down to the A41 just South of Tring. On any other bike I would have been on my ear.

As to which technique is best (and I've heard contradictory ones), the bike that stopped the quickest for me is the Guzzi with linked brakes. Stamp on the rear brake and the whole bike squats down on the road in complete control - and that's with a fairly crude system without any balancing valves involved. During my early years riding, I learned from manuals that the front should be applied slightly ahead of the rear. It works a lot of the time, but not all. And at a certain point in time, the USA banned front brakes on motorcycles, because they caused accidents. And for many years after most cars had disc brakes, the London Black Cab continued with drums, because the authorities deemed disc brakes stopped so quicky, passengers would be injured!

Driving well is a skill, and riding bikes more so than driving cars. In all my years despatching, my four 'offs' were at low speed and caused by other vehicles being driven into me through carelessness or plain ignorance. Most of my skill was learned from London Transport driving school, and the defensive, and observance techniques learned there have saved me from prangs – so maybe I’m out of practice as emergency braking has been something I have seldom needed. Road safety is essentially an attitude of mind, and knowing your vehicles capabilities - which can be many and varied. Watch grand prix racing, most of the braking is done with the front, even engine braking alone can make the back end squirm. It's horses for courses, and learning how each one reacts as individuals is all part of increasing a skill base.

The Dutch site is OK, but some meanings may be lost, or misunderstood in translation.

[Blurredman]

I do tend to use my rear brake quite a lot. The front can seem to powerful for the size of bike so therefore i do make sure there is a nice balance between the two, and the rear tends to go on first. It definately stops the front diving quite so much which due to the soft suspension I find it does regardless as to how leisurely you stop. Not least because I am afraid of the over-braking ability of the front disc.

I'm not sure what shoes are in the rear of my current daily user MZ, but I can admit it isn't particularly feely. Perhaps because there is so much leverage on the brake pedal itself? It is an interestingly simple design.

As the CX500 has been discussed, I must mention I have one and often find the rear a lot better a brake on that too. I have good pads and lines on the front but it's extremely ineffective. Considering it is double disc it is quite underpowered. The rear however does bind on- That is however due to lack of maintenance.. Or at least, lack of caring to get it sorted. It has 80k miles on it now and it is a very bad frame now. I have had to weld up 10 holes on the frame and two on the swingarm. Poor poor bike. I have mis-used it.

I've had the rear slide once in the MZ around town in a somewhat freak occasion. It was a slight corner but off centre cambre. The road was covered with that stupid red paint they insist on making loads look 'pretty' with these days. Most of it has come off though.. And the light turned red. I braked.. Not much effect, braked more and i found myself skidding. Released it when I realised what was occuring. Though I didn't actually feel it that much, it was the audio confirmation which put my mind into the 'lets release the brake now' mode. Re-applied and everything fine.

I'm afraid of the front brake. However, I have been putting my mind at ease by practicing in quiet areas various speeds and the bike takes (ie Lock or not lock, dive, etc) when braking pretty hard. I have found that my front wheel doesn't easily lock, but still.. That bite..

[DerekR]

On that CX: Sounds like something is amiss. I could lock the front wheel and drive forward at walking pace using throttle and front brake lever. Bit of a daft thing to do, but I was just seeing how much hand co-ordination I could muster keeping the feet on the pegs. There are better brakes around, but the twin discs on my old BMW R80/7 weren't up to the above trick. They were pretty naff.

Sorry guys - straying a bit.

[AlanJ]

Hi,
By the cringe Andy, that brought some good stuff out of the woodwork.
Take care All Alan.

[alexxx]

Hi Andy,

A strange thing I noticed with my MZ ETZ was that the rear brake felt good and worked great...after the bike had sat outside in the rain for a few days.
For the first couple of applications, it was good... then faded later, so maybe a better friction material could give better brake feel all the time?

[DerekR]

Left standing, a thin layer of rust will form on the inside of the drum. That will increase the friction and the brake will feel good, until the rust wears off and you are back to shiny metal again.

[Blurredman]

I've found the opposit with rust in the drum..

I have a Suzuki TS185ER that had incredible amount inside the drums.

When using it, I had to periodically adjust the brake biting point as it was coming closer and closer to the bar, and was fairly poor. After all the rust has gone and the drum is shiny, the brake is pretty much the same actually. I suppose it's a good thing that on this particular bike the shoes/drums are the same size front and back..


I want to come back with the braking breifly. I have just come back from riding my MZ to Turkey, in all a total of 5,000 miles in 14 travel days. I had one off which involved the braking. It had been raining, and a corner approached me fast (back roads of Poland in the dark- 40w bulb- need to upgrade..! ) and I was braking with the front and a little with the rear. I saw a dog suddenly walking towards the centre of the road from my left. I unconsciously must have squeezed a bit more front brake as I ended up sliding on my arse watching the bike making pretty sparks down the road. The MZ's have quite a dive on them at the front and before now I have put half an inch of pre-load on them- this one didn't. The resistence in the suspention also has a lot to do with how weight is allowed to transfer throughout the bike. Perhaps if I had used more back brake instead.. Perhaps if I had stiffer front suspension.. Perhaps.. Never mind.. As, Derek says, sometimes no matter the training or experience, freak occasions can occur which can make your mind react in a way that you can't seem to stop.

As for the bike.. One broken original 251 indicator lense (replaced with an awful reproduction one), and a bent footrest, which has been since bent back and angle ground to remove the jagged melted edge.

[Andy_C]

Hi Andy,

A strange thing I noticed with my MZ ETZ was that the rear brake felt good and worked great...after the bike had sat outside in the rain for a few days.
For the first couple of applications, it was good... then faded later, so maybe a better friction material could give better brake feel all the time?

You may be right about better firction material - took teh rear wheel out of mine at the weekend to fit a new tyre, found that the shoes were very glazed, but worse than that they are marked "Made in Taiwan" so I have my doubts about the friction material.

As I needed the bike pronto I de glazed the shoes and put it all back together - a bit of an improvement, but I will get some more reputable shoes on order and fitted.