BMW K bikes (Bricks)

You are not connected. Please login or register

View previous topic View next topic Go down  Message [Page 1 of 1]


touchwoodsden

touchwoodsden
Silver member
Silver member
I have been posting various things on here about my ongoing K100/Hedingham single seat chair.
 
I enquired from Hedingham about the possibility of fitting a brake to the chair because mine is a very early one which is unbraked.
 
Evidently the very very early ones had no facilities for brakes at all. The later early ones had tapped holes in the hub for a disc. Mine has no such holes.
 
I can see no problem in making suitable bracketry to attach a master cylinder and pedal to the chair frame.
 
I can also see little problem in making a floating plate to hold the caliper and bush in exactly the same way as happens on the Wasp front forks. It would need a torque arm with rod end bearings attached to a bracket on the chassis but that wouldn’t be a problem.
 
I’m wondering what the best way of attaching a disc to the hub would be bearing in mind that the hub has no spigot to locate the disc centre. It would also need a disc with a relatively small centre hole because the hub itself is not huge.
 
I know it’s relatively difficult for people just stabbing in the dark but any suggestions and/or photos  would be extremely well received.  


Whilst the reply from Hedingham was extremely helpful, the cost is going to be prohibitive at about 700 quid.
 
I don’t particularly want the brakes linked to the bike as I prefer the chair be braked separately.
 

On the other hand, should I really worry about a chair brake at all?


J

    

92KK 84WW Olaf

avatar
Life time member
Life time member
I might be wrong but I struggle to get my head around not having any brakes on the sidecar wheel. The combined car and passenger weight combined with what I will call offset or one sided braking would scare me on corners in the manner of a car pulling to one side when you hit the brakes.

Sidecar Paul might have some good comments there.

I found this on line too... Australian and seems over there sidecar wheel brake is not compulsory.

www.mrasa.asn.au/pdf/MR808_Fact_Sheet_Motorcycles_and_Sidecars.pdf


__________________________________________________
1992 K100LT 0193214 Bertha Blue 101,000 miles
1984 K100RT 0022575 Brutus Baja Red 578 bought 36,000 now 89,150 miles
1997 K1100LT 0188024 Wotan Mystic Red 689 58,645 now 106,950 miles Deceased.
1983 K100RS 0011171 Fricka 606 Alaska Blue 29,495 miles Damn K Pox Its a Bat outta Hell Now 40,490 miles. 
1996 K1100LT 0233004 Lohengrin Mystic Red 38,000 miles currently 42,640 miles.

Past:
1968 Yamaha 80 YG1
1971 Yamaha 125 YAS-1
1968 Honda 125 SS
1970 Honda CD 175
1973 Honda CB500-4
Honda CX 500
    

touchwoodsden

touchwoodsden
Silver member
Silver member
92KK 84WW Olaf wrote:I might be wrong but I struggle to get my head around not having any brakes on the sidecar wheel. The combined car and passenger weight combined with what I will call offset or one sided braking would scare me on corners in the manner of a car pulling to one side when you hit the brakes.

Sidecar Paul might have some good comments there.

I found this on line too... Australian and seems over there sidecar wheel brake is not compulsory.

www.mrasa.asn.au/pdf/MR808_Fact_Sheet_Motorcycles_and_Sidecars.pdf
 True but it pulls the other way when you accelerate! Lots of lightweight chairs have no brake. This isnt lightweight though but it certainly didnt have one from new

    

RicK G

RicK G
admin
admin
Surprising as it is you don't really need to have the disc centred very well at all. I have done it by eye and it has worked quite well.  It can be done by eye so it is within 10 thousandths, any more and depending on the weight and outer diameter you might get a bit of out of balance. So this means that having a centre spigot is desirable it is not really essential.
However you do need to have it running true so as there is no wobble.


__________________________________________________
"Man sacrifices his health in order to make money.
Then he sacrifices money to recuperate his health.
And then he is so anxious about the future that he does not enjoy the present; the result being that he does not live in the present or the future; he lives as if he is never going to die, and then dies having never really lived."   Dalai Lama


Bikes 2004 K1200GT 1998 K1100 LT, 1993 K75 RT, 1996 K75RT, 1986 K75 GS, 1979 Z1300 Kawasaki
    

5Back to top Go down   Chair brakes. To have or not to have? Empty wobbly wobbler Mon Mar 30, 2015 8:45 am

touchwoodsden

touchwoodsden
Silver member
Silver member
RicK G wrote:Surprising as it is you don't really need to have the disc centred very well at all. I have done it by eye and it has worked quite well.  It can be done by eye so it is within 10 thousandths, any more and depending on the weight and outer diameter you might get a bit of out of balance. So this means that having a centre spigot is desirable it is not really essential.
However you do need to have it running true so as there is no wobble.
 
Thanks for the reply. Provided it’s a new disc I think it could actually run out by 3 or 4 mm or even more provided the pads are always in contact with the braking surface and don’t run over the outside edge and subject to balance of course. It’s not the concentricity that is going to be the problem of course it’s going to be side run out. Regardless, that can all be resolved on the lathe.
 
If I go ahead with this I think it’s going to need some kind of spacer to space the disc out from the hub and then bolt through the whole lot disc and spacer and into the hub….or pick up a new wheel!

    

sidecar paul

sidecar paul
Life time member
Life time member
I've never had a sidecar brake in 50 years.........and never not stopped!

Towed trials bikes, racing bikes, model traction engine and transported my lathe (5" Harrison) and Milling machine, when I moved house, all behind various outfits, but mostly behind the K. 

So, is a sidecar brake necessary? No, but if you want to fit one then go ahead.

Paul.


__________________________________________________
'84 K100RS (0014643) (owned since '85), 86 K100RS (0018891) with Martello sidecar (built as an outfit in '88),
'51 Vincent (since '67),'72 Montesa Cota (from new), '87 Honda RS125R NF4 (bought 2015) 
....No CARS never ever!
    

charlie99

charlie99
VIP
VIP
I wonder if a rear pressure release - distributor from a car system could be helpful

these restrictors provide some form of balance front to rear on a car (most braking power to the front and some percentage to the rear )

my thoughts are, it could be helpful ,,,in as much as you want some braking to the chair ....but maybe not all the same force as the fronts ? 
I just wonder, could this be helpful ?


__________________________________________________
cheezy grin whilst riding, kinda bloke ....oh the joy !!!! ...... ( brick aviator )

'86 K100 RT..#0090401 ..."Gerty" ( Gertrude Von Clickandshift ) --------O%OChair brakes. To have or not to have? Au-log10

'86 k100 rs.. #######..  "Fred " (f(rame) red ) ( Fredrick leichtundschnell ) - -
bits and pieces from many kind friends across the k100 world ...with many thanks ..
    

AL-58

AL-58
Life time member
Life time member
sidecar paul wrote:I've never had a sidecar brake in 50 years.........and never not stopped!

Towed trials bikes, racing bikes, model traction engine and transported my lathe (5" Harrison) and Milling machine, when I moved house, all behind various outfits, but mostly behind the K. 

So, is a sidecar brake necessary? No, but if you want to fit one then go ahead.

Paul.

What he ^^^ said 100%

Al


__________________________________________________
'87 K100RS/HRD sidecar (1100 motor)  sc25 

'87 K100RT with Paralever backend

"When I'm too old and too foolish to handle a sidecar I'll buy a Sportsbike"

Chair brakes. To have or not to have? K-dogs10
    

92KK 84WW Olaf

avatar
Life time member
Life time member
I think Sidecar Paul has answered the question.....

The earlier units on cars were attached to the rear axle or other suspension component and if the rear became light then braking was reduced. Load proportioning valve was the term applied to some, lots of weight on the rear increased the braking pressure to the rear, little weight and the pressure at the rear was reduced. I recall fitting one to a Ford Transit van. But in such vehicles generally rear wheels are much the same, with a sidecar I imagine a significant difference.

From what I can see a sidecar brake doesn't seem to be a legal requirement...! Lighting rules and positions, brake lights, number plate lighting etc do seem to be legal requirements but no mention of brakes.


__________________________________________________
1992 K100LT 0193214 Bertha Blue 101,000 miles
1984 K100RT 0022575 Brutus Baja Red 578 bought 36,000 now 89,150 miles
1997 K1100LT 0188024 Wotan Mystic Red 689 58,645 now 106,950 miles Deceased.
1983 K100RS 0011171 Fricka 606 Alaska Blue 29,495 miles Damn K Pox Its a Bat outta Hell Now 40,490 miles. 
1996 K1100LT 0233004 Lohengrin Mystic Red 38,000 miles currently 42,640 miles.

Past:
1968 Yamaha 80 YG1
1971 Yamaha 125 YAS-1
1968 Honda 125 SS
1970 Honda CD 175
1973 Honda CB500-4
Honda CX 500
    

10Back to top Go down   Chair brakes. To have or not to have? Empty Relief Tue Mar 31, 2015 7:19 am

touchwoodsden

touchwoodsden
Silver member
Silver member
Thanks everyone for the replies. I feel a lot better now.

I’m going to have a little play when everything is together and if I can fit one, I will but if I  can’t, I’m not going to worry about it.

    

View previous topic View next topic Back to top  Message [Page 1 of 1]

Permissions in this forum:
You cannot reply to topics in this forum