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View Full Version : Advice please....Brake-doubling.



DannyC
02-05-2015, 10:18 AM
Hi Folks,

Could I pick the "community brains" please?
For my new trike I purchased Sturmey Archer Brake Levers that are specifically recommended for use with Drum Brakes and V-Brakes.
As you only have 2 hands it is reasonable to assume that you would want to have one hand do the front wheels and the other to do the rear wheel.
These brake levers are not "dual-pull" so I am trying to think of elegant ways to achieve the activation of both front brakes from the one brake lever.

One idea I have is to have the front brakes directly linked to each other with a single cable (single point of failure I agree, but I have never experienced a cable failure on a properly maintained bike) with 2 cable guides (one each side to effect a 90-degree turn to each wheel) and a central "saddle" in the middle that is being pulled by the brake lever (like a centre-pull brake).

I don't know what the cable guides would be called (other than "cable-guides") or if you can buy them readily.

I did think of those "cable-noodles" or some pulley-guides like you see on older gear change bikes, or, 3 cable stops (2 up, one down and a cable-clamp joining all 3 cables at one point.

Still at the planning stage so my options are open, and any practical and elegant ideas that folks may be willing to share would be very welcome.

Thanks in advance.

bambuko
02-05-2015, 11:47 AM
The usual advice (often rubbished here, but making perfect sense to me) is to use rear brake as handbrake/parking brake only.
Having said so, I would still do as you say i.e. double front brakes to one lever.
Cable guides (and many other goodies) are easily available http://www.ceeway.com/ but it will be expensive to buy just few bits?

DuncanM23
02-05-2015, 11:48 AM
BMX bikes have brake splitters that allow you to have a rotatable headtube (I think I'm going to try the one I got from a scrap bike).
Or you can buy a little kit from SJS cycles for a few quid that has a bar you pop through your brake lever and another you bolt to the fixed part and allows you to run dual cables from 1 lever (I have this on my bike polo bike).
The most elegant solution is just to buy a dual cable pull brake lever setup - I think they are about a tenner on eBay, but that might not be as zombie as you like - that's up to you. :)
Cheers
Duncan

DannyC
02-05-2015, 12:24 PM
Hi Chris,

Yes, I've used Ceeway before, they are nice folks (I might even buy some new headset-tubes at the same time).

The levers I have are a matched pair both with parking-brake buttons, and I want to make this bike look as professionally built (don't laugh) as I can; so "ugly" solutions will not do.
I think I could (at a pinch) rescue some brake-cable stops and buy a small MAP-GAS kit and try brazing them on and use some "noodles" to support the 90-degree turns required.



Hi Duncan,

I will take a look at the SJS adapter and I have used a double-pull brake lever (current trike) but I rather wanted to keep the common look of matched SA Brake-Levers.

Thanks to you both for your responses, it is much appreciated.

Twinkle
02-05-2015, 12:25 PM
Hi Danny

SJS have sold out of the brake doublers when I rang them a couple of months ago . They did work well especially on electric cutoff brake levers , There are a couple of dormant threads on 1 into 2 splitters . I have started to manufacture my own similar to the old SJS ones and they do work well . Alternatively there are some dual brake levers out there but these are expensive , Neil B uses one and I have one on the Mkll trike . The problem arises once electrification happens , The EAPC regs state all 3 wheels on an e-trike must be braked . so without 3 hands a dual lever is a must BUT this must also be fitted with a kill switch .

regards emma

DannyC
02-05-2015, 12:46 PM
Thanks Emma :-)

LongRider
02-05-2015, 12:58 PM
I am using the Pyramid dual cable brake lever on my round tube chromo warriors -- works great, easy to set up, inexpensive and after I had the lever powder coated black it looks unobtrusively professional. Does the trick for me.

Also -- brake noodles are your friend...

Doc.
02-06-2015, 12:30 PM
Depends on your fabrication skills really, how you overcome this.

I always recommend copying/modifying what Yamaha did on their GP Race Bikes in the late sixties.
They had double-sided drums on the front.
They used a brake lever with a simple pulley mounted to it, where the cable would normally connect.

One single-piece (inner) cable ran from one brake arm, up to the lever, around the pulley, then down to the other brake arm, but through two separate outers, which terminated at the brake lever mounting.
I expect other factories did the same, but I've only ever seen photos of it on Yamahas.

Result is perfectly balanced brakes.

The pulley doesn't need to be on the lever, you could have it anywhere that's practical, and have a single (heavier-duty) 'link' cable running to it from the lever.
That would keep your levers the same, and 'standard' looking.
Obviously you'll need to make cables to suit, the 'main' one with a single inner, but two separate outers, and the short link cable from the lever (and some way to locate the ends), but it's all doable with a bit of work (and head-scratching).

Plenty of choice for donor pulleys . . .
http://www.ebay.co.uk/sch/Cycling-/7294/i.html?_from=R40&_nkw=cable+pulley

DannyC
02-06-2015, 12:42 PM
Thanks Doc'

That is essentially what I was considering, a simple balanced solution. :-)

LongRider
02-06-2015, 01:20 PM
Kind of like the Pyramid dual cable brake levers...

DannyC
02-06-2015, 01:32 PM
Kind of like the Pyramid dual cable brake levers...
I have one of those on the current trike and while it is "OK" It is not as aesthetically pleasing as the SA "pair" I have purchased and its ability to even out the pulling is a bit limited I have found (but that might be maladjustment on my part).

Doc.
02-07-2015, 02:22 AM
Kind of like the Pyramid dual cable brake levers...
Sort of, but that's not an option if you want to use a single-cable lever.
You could use a 'balance bar' type arrangement instead of the pulley idea, but then you'll have two more nipples in the system, so more potential failure points.

LongRider
02-07-2015, 12:51 PM
Very True ; )

DuncanM23
02-08-2015, 01:54 PM
This is what the SJS kit looks like when fitted:
https://farm8.staticflickr.com/7390/15852236584_492a3047ae_z.jpg (https://flic.kr/p/q9NRDS)20150208_161217 (https://flic.kr/p/q9NRDS) by duncancmartin (https://www.flickr.com/people/90461577@N00/), on Flickr

DannyC
02-08-2015, 02:15 PM
Oh dear....

How can one put it?
in a single word..."Fugly" springs to mind; I shall try to do something pleasing to the eye, thanks for letting me see the example though Duncan.

DuncanM23
02-08-2015, 03:04 PM
in a single word..."Fugly" springs to mind; I shall try to do something pleasing to the eye, thanks for letting me see the example though Duncan.

Yeah, elegant it is not. :)
Something like this (though maybe not in red) looks quite cool to my eyes though: http://www.winstanleysbmx.com/product/17052/Blank_Upper_Gyro_Cable

Cheers
Duncan

darnthedog
02-08-2015, 03:35 PM
Danny
I found this to be much more pleasing to the eye. Example from Ebay:http://www.ebay.com/itm/Sunlite-Alloy-Double-Pull-MTB-Bike-Brake-Lever-for-Caliper-or-Cantilever-/321651888859?pt=US_Brake_Levers&hash=item4ae3f252db

LongRider
02-08-2015, 06:20 PM
Also marketed as the Pyramid dual brake cable lever...
Great minds think alike!

DannyC
02-09-2015, 12:36 PM
Thanks Bruce,

That's the very one I have on the current Trike today.

I reckon I can do something outside of brake-levers that will be effective & elegant. If not, then I can use one of these for sure.

darnthedog
02-09-2015, 01:06 PM
Danny
If you have that type of doubler- Why the question? Does it not work for you? Or does it not work with the drum brakes? Or are you just thinking ahead?

I would like to know as I just placed 2 SA Drums on order and looking for rims to build up the wheel set with. And the plan is to use this doubler. Got the 90mm set with Quick release.

DannyC
02-09-2015, 06:23 PM
Hi Bruce,

No, they work "adequately" I believe.
They are not so good on my current trike, but that is because the brakes on the trike are not "matched" due to a build error.

The reason that I am looking for an alternative "doubling" method is that I already have a brand-new pair of SA brake levers specifically made for Hub/V-Brake usage rather than Cantilever etc. that incorporate a "parking-button" also (all in the brake lever(s)).
As I have only 2 hands I wanted to double-up the 2 SA hub-brakes on the one hand and have the rear V-Brake on the other hand while keeping the smart SA style & motif throughout.
It is more vanity than need (I am sure), but I want to make the bike look as good as I can.

It is as simple as that, I am looking to get the best I can with what I have already have.

Twinkle
02-09-2015, 07:19 PM
Remember this thread
http://forum.atomiczombie.com/showthread.php/8325-1-into-2-cable-splitter?highlight=brake+doubler

regards emma

Doc.
02-10-2015, 01:14 AM
This is part of the Braking system I designed and made for my (Disabled) Daughter's little KMX Trike.
All three Brakes are activated by back-pedalling.
It also puts the brakes on if the Trike rolls backwards more than a few inches.
You could use something similar to the front brake pulley/cable set-up . . .

http://img.photobucket.com/albums/v93/docv400/Brakeunit_zps80e77e23.jpg (http://smg.photobucket.com/user/docv400/media/Brakeunit_zps80e77e23.jpg.html)

MrIdaho
02-11-2015, 12:23 PM
yes but need more info
http://forum.atomiczombie.com/showthread.php/9400-Advice-please-Brake-doubling?p=95362#post95362
on this picture

Doc.
02-11-2015, 01:40 PM
What do you need to know Mr I?
The return run of the chain passes under (and meshes with) a sprocket that is mounted on a toothless ratchet mechanism ('Roller Clutch' from a 3/8" ratchet handle).
The shaft of the mechanism is fixed to a bell-crank arrangement, which has the brake actuating cable attached.
http://img.photobucket.com/albums/v93/docv400/SANY0005_zpscc6fbd5e.jpg (http://smg.photobucket.com/user/docv400/media/SANY0005_zpscc6fbd5e.jpg.html)
When you pedal forwards, the sprocket free-wheels, when the pedals are rotated backwards, the ratchet grips and rotates the bell-crank, which pulls the cable.
The cable (left end of the pivoting arm in the original picture) rotates the brake arm on the Cross-beam, pulling on the rear and front brake cables.

MrIdaho
02-12-2015, 09:01 AM
sounds complicated wile reading so I need to print pics then assemliate how it works. A drawing would help.