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Old 10-09-2008, 09:48 AM   #31
Ray of Sunshine
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[QUOTE=mymindsok]
IINM, BMW was the first manufacturer to offer disks on bikes. That was good.

BZZZZZZZZZZZZZZT! The 1969 Honda CB-750K0 in 1969 was equipped with a single front disc. This was the first production motorcycle sold with a disc brake. In 1969 BMW was still building the lovely and challenging /2 series.


It is possible that the /5 series bikes had discs, I don't remember. I am not clear. However, I dimly recall that the /6 bikes, introduced in 1975 were the first BMWs with disc brakes. But hat time, the Kawolski Z-1, KZ750, Suzuki GT750, GT550 and GT 550 had been introduced Yamaha was building the RD 250, 350 and whatever that 500 cc thing was by then.

Please consider wikipedia your friend.
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Old 10-09-2008, 10:04 AM   #32
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Sheesh! To listen to some of you guys you'd think anybody who actually rode a MC in the 60's 70's and into the 80's should be dead. While the brakes on modern bikes are vastly better than those on old bikes. The brakes on both my old 70's era (76 R90/6, 77 xs650) bikes are not all that bad. You must remember they were set up needing more force on the hand grip than we are now used too. You CAN make them work provided everything is set up properly it just takes more force to do it. The ratio of master cyl to brake cyl size is not really optimum on those older bikes.

Look at the size of the disks on some cars compared to our bikes, some car disks are amazingly small when you consider the weight difference.
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Old 10-09-2008, 04:01 PM   #33
Max Headroom
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[quote=Ray of Sunshine]
Quote:
Originally Posted by mymindsok
IINM, BMW was the first manufacturer to offer disks on bikes. That was good.

BZZZZZZZZZZZZZZT! The 1969 Honda CB-750K0 in 1969 was equipped with a single front disc. This was the first production motorcycle sold with a disc brake. In 1969 BMW was still building the lovely and challenging /2 series.


It is possible that the /5 series bikes had discs, I don't remember. I am not clear. However, I dimly recall that the /6 bikes, introduced in 1975 were the first BMWs with disc brakes. But hat time, the Kawolski Z-1, KZ750, Suzuki GT750, GT550 and GT 550 had been introduced Yamaha was building the RD 250, 350 and whatever that 500 cc thing was by then.

Please consider wikipedia your friend.
You're both kinda on the right track....

* The Honda CB750 was the first production bike with a disc brake.

* The BMW R90S was the first production bike with TWIN disc brakes.
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Old 10-09-2008, 09:33 PM   #34
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Maybe I'm just conservative or maybe I just like being on the upside of the grave but:

If you really think that your /6 brakes are up to the rigors of todays traffic situations, I truly wish you the best.

I base my opinion on the Norton that I raced in 1967 that needed more brakes, the /2 that I rode that needed more brakes, the harley's that I rode that needed more brakes and the other bikes, including the /6's, that really needed more brakes then and really really need it now.

These days we are sharing the roads with plenty of cars that'll outrun an R-90 or an R-100 but today,every car on the road today will outbrake those single disk BMW bikes.

I don't consider that safe. If you do, rock on brother. I really don't give a damn.

My bike stops.
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Old 10-09-2008, 10:05 PM   #35
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Relax, man...

Quote:
Originally Posted by mymindsok
Maybe I'm just conservative or maybe I just like being on the upside of the grave but:

If you really think that your /6 brakes are up to the rigors of todays traffic situations, I truly wish you the best.

I base my opinion on the Norton that I raced in 1967 that needed more brakes, the /2 that I rode that needed more brakes, the harley's that I rode that needed more brakes and the other bikes, including the /6's, that really needed more brakes then and really really need it now.

These days we are sharing the roads with plenty of cars that'll outrun an R-90 or an R-100 but today,every car on the road today will outbrake those single disk BMW bikes.

I don't consider that safe. If you do, rock on brother. I really don't give a damn.

My bike stops.
Peace and love and all that. I can't speak for anyone else here, but methinks the fella doth protest too much.

You want to optimize the brakes on every vehicle you've ever driven to make you feel like you are improving your safety margins, more power to you. Nobody is saying you shouldn't. If I had the money, I probably would too.

But you don't need to insist that we are knocking on deaths door who choose to ride with the original equipment, properly sorted. They are not great brakes - I get that, fer chrissakes. They weren't great then, I get that too.

No matter what the speed or situation, car meets bike means bike loses. The idea is to not meet the car at all where possible. My EMT buddy reminds me of this every time he picks up a biker, reminding me that the meat should go in the machine, not on it.

My point is simply that it is important, no matter what piece of equipment you are using, to know what its limitations are and to operate within that envelope, period. No matter how fantastic your brakes are, you can ride over your head and get into trouble. With really responsive equipment, I find myself emboldened to push the envelope.

32 tickets in 3 years with a Mustang GT, for instance. What envelope?

Staying inside the envelope is safer. With a motorcycle, that means always looking for and expecting the unexpected, and riding accordingly. Plenty or room all around, minimize exposure to risk, exit strategies where traffic is involved, plenty of room to stop or slide if necessary.

If I don't ride my 30 year old bike with brakes that weren't the best back then expecting to stop like a GSXR, or even a hyundai, then I'm being responsible, too.

I really do appreciate your concern, and your position is sound, but your condescension is a little grating.

Ride safe, no matter how fast you can stop.
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Old 10-10-2008, 06:55 AM   #36
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Quote:
Originally Posted by mymindsok
Maybe I'm just conservative or maybe I just like being on the upside of the grave but:

If you really think that your /6 brakes are up to the rigors of todays traffic situations, I truly wish you the best.

I base my opinion on the Norton that I raced in 1967 that needed more brakes, the /2 that I rode that needed more brakes, the harley's that I rode that needed more brakes and the other bikes, including the /6's, that really needed more brakes then and really really need it now.

These days we are sharing the roads with plenty of cars that'll outrun an R-90 or an R-100 but today,every car on the road today will outbrake those single disk BMW bikes.

I don't consider that safe. If you do, rock on brother. I really don't give a damn.

My bike stops.

How come guy's with the most modern bikes and/or cars with the best brakes, ABS, etc. still get in accidents and say "I couldn't stop fast enough it happened too fast"? Because the brakes were just not good enough? No, they were just "maybe" driving in a manner that was too fast for the conditions or situations. Yup it's always the poor @#*$% brakes fault.

I guess it's just a statistical oddity that I'm still alive after rideing (and still rideing) all those lousy bikes for 35 years. It's not always the bike that's unsafe, maybe just maybe once in a while its the rider. Nobody here is included in that last statement of course!

Enough of this, this subject has been beat to death. Everybody has their own opinion, and you know what they say about opinion's.
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Old 10-10-2008, 09:19 AM   #37
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Quote:
Originally Posted by mymindsok
...

Unfortunately. BMW designed and installed those brakes during a period when they were worried about being sued by owners who might have launched themselves over the bars, by using the new disk brakes. Therefore, BMW's single disk brakes ended up being less powerfull than the drum brake that they replaced. That was bad.

...
Whilst I agree that a properly setup /5 front drum brake is a significantly better performer than the single sided disk of the /6, what factual basis do you have to support your conjecture above regarding BMW's choice for making crappy brakes??

If you're theory--i.e. conjecture--were to hold true, why then did BMW keep the same system thru the /7's and not upgrade the system after the masses became accustomed to better stopping power??
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Old 10-10-2008, 09:29 AM   #38
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Quote:
Originally Posted by Ray of Sunshine
...

It is possible that the /5 series bikes had discs, I don't remember. I am not clear. However, I dimly recall that the /6 bikes, introduced in 1975 were the first BMWs with disc brakes. But hat time, the Kawolski Z-1, KZ750, Suzuki GT750, GT550 and GT 550 had been introduced Yamaha was building the RD 250, 350 and whatever that 500 cc thing was by then.

Please consider wikipedia your friend.
The /5 did NOT have a disk brake. The first BMW to have one was the R90S (which were introduced in the '74 model year, not 1975.) Also note that the R60/6 retained the front drum brake of the /5, but without the chrome hubcap.

While wikipedia might be your friend, it is often times not correct...
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Old 10-10-2008, 09:53 AM   #39
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I guess we can beat the brake thing to death.....




I ride defensively, I drive defensively.

Personally, I am old enough to not have to impress anybody. I learned to ride in the late '60's, so I presume that what braking power I have on my 60/6 and my 50/2 is IT, and that's how I ride. I would rather depend on my judgment and observation than on my brakes.

Luckily I have not had the opportunity nor the desire to scare myself silly with new power and brakes!
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Old 10-10-2008, 11:59 AM   #40
kixtand
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Quote:
Originally Posted by bpeckm
I guess we can beat the brake thing to death.....




I ride defensively, I drive defensively.

Personally, I am old enough to not have to impress anybody. I learned to ride in the late '60's, so I presume that what braking power I have on my 60/6 and my 50/2 is IT, and that's how I ride. I would rather depend on my judgment and observation than on my brakes.

Luckily I have not had the opportunity nor the desire to scare myself silly with new power and brakes!
I think this should pretty much sum it up...
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Old 10-10-2008, 12:10 PM   #41
Max Headroom
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Quote:
Originally Posted by kixtand
Whilst I agree that a properly setup /5 front drum brake is a significantly better performer than the single sided disk of the /6, what factual basis do you have to support your conjecture above regarding BMW's choice for making crappy brakes??

If you're theory--i.e. conjecture--were to hold true, why then did BMW keep the same system thru the /7's and not upgrade the system after the masses became accustomed to better stopping power??
The reason that BMW kept the same design lies in the contemporary magazine articles of the era. Compared to other bikes of the time, the ATE caliper setup was regarded as "different" but very capable and highly regarded. ATE had considerable experience in automotive brakes, and the design principle was sound.

The single disc had its limitations, but the double disc didn't. The first year criticism of wet weather braking performance was largely overcome with the drilled discs fitted for the 1975, so with the 40mm calipers fitted for 1976 onwards the double discs were considered among the best brakes then available on a production bike, with impressive stopping distances "in the day".

Consider that this was a "pioneering" phase for disc brake technology on bikes, and remember the nasty cable operated calipers on some cheaper bikes and the fully enclosed setup on early '80s Hondas and it becomes quickly apparent that the technology was still finding its feet.
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Old 10-10-2008, 01:21 PM   #42
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Quote:
Originally Posted by Max Headroom
The reason that BMW kept the same design lies in the contemporary magazine articles of the era. Compared to other bikes of the time, the ATE caliper setup was regarded as "different" but very capable and highly regarded. ATE had considerable experience in automotive brakes, and the design principle was sound.

The single disc had its limitations, but the double disc didn't. The first year criticism of wet weather braking performance was largely overcome with the drilled discs fitted for the 1975, so with the 40mm calipers fitted for 1976 onwards the double discs were considered among the best brakes then available on a production bike, with impressive stopping distances "in the day".

Consider that this was a "pioneering" phase for disc brake technology on bikes, and remember the nasty cable operated calipers on some cheaper bikes and the fully enclosed setup on early '80s Hondas and it becomes quickly apparent that the technology was still finding its feet.
Exactly my point.

BMW was using the best stuff available at the time, not worrying about a lawsuit over owners that "launched themselves over the bars".
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Old 10-11-2008, 07:09 AM   #43
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I have a speigler floating disc and EBC pads on a 75 R90/6, and although it is not as esthetically appealing as the original, it will lock em up.
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Old 10-11-2008, 08:20 AM   #44
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After about a year of ownership, I went with the dual disc upgrade on my R90.

I wouldn't say the upgrade was probitively expensive. I did end up buying a new under tank master. This was about 10 years ago, and the price was around 300$. I found a wrecked R90S locally, and used its right side slider and disc.

Probably spent 500-600$ on the whole thing, including stainless lines. I did good on the wrecked bike as I sold the motor, trans, final drive and frame, so I came out about even.

I've recently gone to the floating disc's available from Bob's, as one of my original discs developed a hard spot causing the brakes to pulse. The floaters make a nice difference as well.
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Old 01-12-2013, 07:17 PM   #45
mrc.engr
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[QUOTE ... because its impossible to ride an Old School /6 safely in todays environment. [/QUOTE]

Horses arse. Been riding /6 for three decades and lovin it. Sure.... I did some brake work to make things better. Got rid of that stupid cable operated m/c under the gas tank. What re re thought that one up. "Lets give them a disc brake and then take 50% of it back with cable operation".

Got rid of the stainless rotors because they're so soft they don't last worth a damn especially if you try some real brake pads (H or HH) on it, so what the hey..... might as well drop on some cast iron rotors and fit some Ferrodo kick ass pads on it. VIOLA !!! Damn thing stops.

No..... not as good as 4 pot Brembos w/320mm rotors.....but it's a hell of an improvement. So much so I throughly enjoy running with all the squids that come out of the DC area and want to play in West By God on the weekends.

Never ceases to amaze me that they need almost 120 hp pushing 450 lbs down the road to stay up with 68hp, 575 lb 38 yr old Airhead BMW (R90S). All to many times I've had one say they still need more hp.

Now you and I both know that's a crock and I tell 'em just start taking some track days and learn how to ride that thing instead of just pointing it down the road and get all puckered up when a corner comes up.

Like Code says..... "just tell the bike what you want it to do and relax..... it'll do it all on it's own.

Somebody here said it..... ride an old bike accordingly, but this dosen't mean you have to ride like a pussy just because it's old.
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