Double sided front brake

[Nourish]

 
Riding a bike with shitty brakes does concern me in today's traffic. So I've been thinking of improving the front brake on my build. I have just ordered a second 1947/48 front drum thinking of perhaps having a double sided brake à la Vincent. Could a pair of hubs be split and the splined halves built back to back? 

[Rex]

I know someone who owns a bitsa where the previous owner did just that. Apparently it works well enough but you'd need to be pretty handy in the workshop to do the conversion.

[Adler]

... Look here:
https://youtu.be/0SFpoixKnDg?si=j52lodVBFRFl5Ubn
 

[chaterlea25]

Hi All,
There are photos of factory racing BSA's where they have reversed the brake arm so it points forward rather than back. I know some members have done this mod.
I was building a set of forks last week and I had a thought
If the fork legs were swopped side to side and the wheel reversed the lever and action should be as desired without having to do further mods
Or am I talking sh1te

If 2 drums are fitted and trying to use the original rim the spoke angles on one side
will be incorrect

John

[Swarfcut]

No CJ, that is fine, especially with later legs full width hub and Y bracket mudguard bridge. Problem is that the lower mudguard stay mount is now at the front..... And offhand I can't think of a BSA leg that has front and rear stays and one stud above another for the bridge. Suppose homespun L brackets would work for the full valanced mudguard legs and something exotic for the torque arm on a single sided 8" Brake....... The best one for normal road use without spending a fortune.
 Swarfy.

[Nourish]

Ooh - "If 2 drums are fitted and trying to use the original rim the spoke angles on one side will be incorrect" Please explain! Cheers

[Adler]

Hello Nourish,
maybe this literature helps to better understand the topic. This book has been a good help for me restoring my motorbikes. Please check the wheel building section.

https://share.google/zqMcQ0cMq8m3EXK3P

Best regards. Manfred

ed: but before you make yourself a double sided front brake I would suggest to study the front brake threads in this Forum. Lots of discussions and tips to find to improve your front brake to a good standard.

[Swarfcut]

 The dimples for the spoke nipples are punched to match the angle at which the spoke joins the hub. Neatly explained by CB as in lacing wheels post.   

  Standard single sided brake has long and short spokes and the angle* at which they leave the rim is not the same. All part of the black art of wheel building. I'm all for planning ahead, but stopping would be a long way down my own to do list. Standard brake with modern linings will be easiest and cheapest fix.

 Swarfy.

 *Taken as the angle between the spoke and a plane across the rim,  situated on the centre line of the dimples.

[Nourish]

My idea was to use + two larger flanges of the crinkle hub back to back, the difference between the small and larger flange surely wouldn't make that much difference to the spoke angle would it? I think my concern would be getting the wheel out of the forks!

[berger]

well what can i say,   if this is a challenge fair enough good luck but if it's about a better brake stick a disc front end on it

[Nourish]

It's not compulsory that you have to reply if you're not interested!

[Rex]

if the 8" FW hub is a similar diameter to the 8" HW then problem solved. Just order a rim punched for a FW hub.

[Nourish]

Nah - the smaller hub looks period - and I like engineering!

[Adler]

Hello Nourish,
just ckecked some of your posts - you are definitely not a newbie and so my comments to your post will not be helpful for you.
Instead I would like to ask you to let us take part on your project "Double sided front brake".
Thanks in advance.
Best regards, Manfred

[chaterlea25]

Hi Nourish,
Apologies I did not remember that you are working with a crinkle hub
On those the spokes are the same length both sides as the spokes go to the hub rather than the brake drum on one side as on the later wheels..
Memory says the earlycrinkle hub front fork yokes are wider than the later type.

To see if its feasable place the drum and hub against one fork leg and measure from the leg to the spoke hole centres (average as the holes are staggered).  multiply by 2 and subtract the total from the width between the axle bosses of the forks, this will give you the width that would be between the spoke flanges.
Compare that to the existing width and please tell us?
If the spoke flanges were too close together I think the wheel will lack stability

I think you will have to re engineer the bearing and axle spacers to make it all fit ?

John