The BSA A7-A10 Forum
Technical (Descriptive Topic Titles - Stay on Topic) => Frame => Topic started by: Dean on 04.12. 2013 15:05
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I am planning to convert the rear brake to rod operation, inspired by the description of such conversions on this forum. My wife has offered to buy the bits for Xmas (I like to make her gift shopping as easy as possible ;)). So, before I can sit her down and show her how to use her new paypal account I need some help from you guys. So, two questions:
1. Does anyone know exactly the part I should be obtaining for the brake drum end operating arm? I am prepared to mig weld and recut by hand if necessary but would obviously prefer to minimise the work.
2. Has anyone got any detailed dimensions and further information on completing the job?
cheers guys
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Deabn a very helpful guy on the forum documented the conversion and when I asked a cou[le of questions ckindly sent me a link which I'll look for now. Another way would be to speak to Brian in Lightning spares has he documented his similar conversion on the BSAOC website and I seem to remember him offering the spares ,in one go ,so to speak from his shop, hope thats of some help regards BobH.
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Hi All,
On My 61 SR which has the brake cable anchor on with the torque arm and downwards pointing drum lever,
on these models the brake cable length does not alter with wheel movement, as the brake plate rotates when the wheel is adjusted.
This is different to the earlier wheel where the cable anchor is cast onto the brake plate
I reworked the cam lever angle by adding steel wrap arounds to the brake shoes, this brought the arm to work at
as near + - 90 deg to the cable
Then I shortened the cable inner and outer to get it as near straight as possible
while ensuring the crossover lever was working at its most efficient angle, + & - 90 deg
The brake now works and will even squeal the rear tyre if needed *smile* *smile*
HTH
John
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Thanks Bob, very helpful tip. I'll speak to Brian at Lightning Spares.
John, your advice on cables is very informative and helpful. On my original Super Rocket the rear cable brake is acceptable for now. On my bitsa A10 (same brake arrangment) I bought several rear cables: one too long, another too thick (nylon lined!) and ridiculously spongy. As this bike was a project for trying out new developments I fancied trying out the rod conversion.
I still have some outstanding issues with the project bike such as the clutch and fuel tank ...........
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Nice one John, think I've just given up with mine hence the interest in the conversion. |Mine is spongy like Deans but I'm sure if I could be has accurate as yourself I could improve it but not by much . My front is pretty good so I rely on that plus dropping a couple of gears but undoughtably I better rear would be helpful and poss safer , regards BobH.
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A couple of issues ago there was an article in I think CBG about a rod conversion to a swingarm.
I seem to have mislaid the issue though, as I can't find it anymore.
It was an interesting set up with a short rod from the front lever to some kind of linkage, in order to eliminate the movement of the swingarm, and then a longer rod from the link to the brake lever.
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Hi All,
Theres an article on an A10 in the October Classic Motorcycle magazine
If you want to see a really Badly *ex* *ex* set up rear brake have a look at it *eek* *eek*
Just goes to show that bikes are thrown together with little knowledge and flogged off with the "comment"
"they'r all like that sir"
On that particular example it looks as if the brake cam is fitted 180deg out or the brake linings are utterly shot!!!
(for a start!!!)
Thanks for the kind words *smiley4*
Cheers
John
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This might be of interest:
http://www.a7a10.net/forum/index.php?topic=1163.msg29156#msg29156
Didn't realise how big this forum had got until I started looking for this thread!
Iain
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This might be of interest:
http://www.a7a10.net/forum/index.php?topic=1163.msg29156#msg29156
Didn't realise how big this forum had got until I started looking for this thread!
Iain
Cheers Ian.
Yes this forum is a mine if information. The search facility seems to work very well as I was able to find all the posts on the rod conversion topic. Still don't know exact brake arm to get tho *sad2*
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HI
ref. the link to Nicks description of his conversion -
when the topic was new, he offered to send a step to step detailed description if anybody was interested - I was, and I got a word document with step by step instructions and even a parts list from him, maybe he will still do this god service ? *???*
I haven't got around to doing it yet but it is still a hot topic on my wishing list - as I have now got the A10 together afte a total engine job.
regards
Joergen
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I don't know the protocol of this sort of stuff, but he sent me the same word doc. I could Email it to you, if it is ethical. What do you think Admin?
gav
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Hi Everyone
I produced the word document with help from forum members, as far as I am concerned it belongs to the forum so please pass it on, the forum is all about helping each other.
If any one requires a copy please contact me.
Regards
Nick
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Just to update you.
Nick has kindly emailed me his detailed instructions so I feel pretty confident in this being a relatively painless task.
I have spoken to Brian Pollitt (Lightning Spares) who says he does not currently do a kit, but following a very helpful chat is looking out the components for me to do it.
Whilst I was primarily motivated to do this mod by the lack of feel and excessive pedal travel (on one of my A10s) there is probably a more important reason for doing it: cables can break unexpectedly and mostly likely to do so when you are applying most effort, i.e. when you really need it *eek*.
I have not had a rod brake break.
cheers
Dean
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I agree Dean, I had one snap going into stop corner at Amaroo Park (race track) at warp speed, took the corner speedway style, returned to the pits and changed underwear.
As mentioned earlier the early A50/65 has a twin rod set up to get the rod onto the inside of the swingarm without a bend.
Cheers.
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Hi Chaterlea, I have a '61 SR also, with a pathetic rear brake, I've "arched" the shoes to the drum, had softer linings installed and all the other adjustments and ideas that have been posted on this forum and other forums but nothing ever really improves it. I was curious as to what you mean't by this statement,
"I reworked the cam lever angle by adding steel wrap arounds to the brake shoes, this brought the arm to work at
as near + - 90 deg to the cable
Then I shortened the cable inner and outer to get it as near straight as possible
while ensuring the crossover lever was working at its most efficient angle, + & - 90 deg" ,
I was wondering if you could elaborate on the Steel wraps bit.
thanks
Clive
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HI Clive,
On my SR the lever on the brake cam was past the 90 degree to the cable before the newly lined shoes would touch the drum, so I cut some steel strip 60 thou thick and folded it around the ends of the shoes where the cam rubs, they cannot move out of place when fitted,
If the cam is fitted turned 180 degrees, the available arm fitting positions changes relative to the cable as the square on the end of the cam spindle is not square/ parallel with the cam
An alternative would be to make a new lever with the square hole oriented differently so as the brake would start to work at the correct angle to the cable
Another point often forgotten is to centre the shoes , by loosening the shoe pivot pin nut, applying the brake, then retighten the nut while the brake is still applied
What does "arching" the shoes mean?
I have machined oversize linings to suit the brake drum diamater on other brakes with excellent results
I will try and to take a couple of photos of my over the weekend
HTH
John
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Thanks John, I look forward to the photos,. "Arching" is basicly the same as machining the shoes to fit the drum in order to get the maximum contact to the brake drum.
Clive
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HI Clive and All,
Attached photos of my bikes rear cable setup, difficult to get at it tonite as its wrapped up for the Winter
The pics show the levers with the brake applied
The cable bellied out when the adjuster was set, I rekon theres room for further tweaking , maybe shortening the inner some more to back off the adjuster a bit
Regards
John
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Thanks for the photos John. I like the custom oil tank drain plug, it beats a my method of a sucking out the last bit with a turkey baster and paper towels.
Clive
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Hooray
and Happy New Year.
Just a couple of days in the garage and I now have a rod operated rear brake, which I finished this morning *smile*
Not tested on the road yet but test in garage and brake feels infinitely better and seems to stop very well.
Striped down for painting now but will report back when I have road tested.
I need to check it works when travelling in reverse. The Slopers doesn't and gets me in a right pickle if the engine stalls when reversing out of garage due to very steep downhill drive!
So, many thanks for all your help fellow forumistas.
Special thanks to NickSR. I virtualyy just followed the very clear instructuons in your dcouments and the great photos.
Also thanks to Brian Pollitt (Lightening Spares) for his patience and parts, and Draganfly for parts.
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Another happy chappie, well done.
Drum brakes never work as well in reverse. All to do with the angle of the dangle, twin leaders are worse.
Cheers
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Hi Dean
I am pleased to see that my notes were a help to you, look forwards to photos and road test.
Regards
Nick
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Great thread
Nick, thanks for sending the details *beer*
Scotty
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After waiting week for the paint to harden I have fully installed the parts. I have yet to road test but it feels so beautifully free of unwanted slack and freeplay I will have to watch I don't rest my toe on the pedal while riding. But if I do sense a reduction on power I know the first place to look! I should really find a replacement pedal sometime as the current one is a tad short (the joy oy basket cases ;).
In the meantime here are the pics of the finished job...
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nicely done Dean, that's it I've got to get mine sorted first job after it thaws a bit, well done , BobH
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Hi Dean, You have made a great job of the conversion, look forward to your test run.
Keep safe
Nick
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Hi Dean
Looks great - where did you source the parts? Lightning Spares? *????*
regards
Joergen
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Nice job Dean, what brake arm did you use? I'm working on a slightly different conversion, but can't find a brake arm that fits the square on the end of the operating brake shoe cam. All the ones I've tried have a too large a hole to fit the square end.
Clive
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Hi Joergen and Clive
Lightning Spares are your source for the brake rod and all its ancilliaries and the rear brake arm.
The brake arm that goes on the drum 40-6041 does not fit directly. You will need to fill with weld the star hole and redrill and file to fit the square brake cam spindle end. I did not find this a hard job if you take your time to be accurate.
Lightning Spares did not have the replacement brake arm that goes on the crossover shaft (68-7020) but Draganfly have several nos.
The easiest way for me to get some tube was to pop to the local B&Q (diy store) and find the nearest size in the rack of 1m lengths. I ended up with a slightly smaller diameter tube with a thinner wall thickness than Nick states but it will be fine given the short length. After grinding down the brake arm and slipping the tube over it I found that slightly squashing it in the vice got an almost perfect all-round contact between the end of the tube and the arm so the weld could be pretty neat.
The brake rod comes with a clevis and rather large headed bolt and nut for the space available between the frame and oil pipe. To iprove clearance I was able to bend the oil pipe tube by careful use of a G clamp between it and the upper gearbox plate (another advantage of junking the silly ski jump ;))
Have fun but as I have not tried out the brake on the road yet I make no assertions as to its effectiveness (can tell I married a lawyer can't you *smiley4*).
I tried to attach a pdf of Nick's instructions before realising this is not possible on this forum. If Nick is OK I am happy to PM these to you.
Dean
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Nick's instructions are here.
BSA A7 & A10 1959 Onwards
Converting Cable Operated Rear Brake to Rod Operation
(Down Wards Rear Brake Arm & Full Width Cast Iron Hub))
Introduction:
This is a guide for those of us that have limit resources and who have basic hand skills will be able to produce this conversion very simply and with only one trip for welding.
The guidance is for A7 & A10 I can see no reason why that it will not work on B31 & B33 and also A7 & A10 with the brake arm upwards.
Items Required: Item Description Comments
1 Rear Brake Arm 40 – 6041 1962 A50/65 & C15 Draganfly Spares 01986 - 894798 & Lightning Spares
2 Crossover Shaft Arm 68-7020 1962 A50/65 (Clevis Cable End) Draganfly Spares www.draganfly.co.uk
3 Steel Pipe Dia 21.32mm Wall Thickness 2.62mm Internal 16mm Length 4.7/8’’ (130mm)
4 Brake Rod Connection Bracket 1 ¾’’ x 7/8’’ x 3/16’’ – 40 x 22 x 4.5mm
5 S/Steel Brake Rod ¼’’ X 24’’ Long Screwed BSF for 6’’ Lightning Spares 0161- 9693850
6 S/Steel Brake Rod Trunnion 7/16’’ www.lightning-spares.co.uk
7 S/Steel Brake Rod Adjuster Knurled Thread ¼’’ BSF As above
8 S/Steel 1 x ¼’’ BSF Nut & Washer As above
9 S/Steel ¼’’ Compression Spring 3’’ As above
10 S/Steel 1 x Split Pin & 1 x ¼’’ Washer As above
11 S/Steel Bolt 1.1/4’’ x ¼’’ plus Washer for Shaft Arm As above
(https://www.a7a10.net/forum/proxy.php?request=http%3A%2F%2Fi55.servimg.com%2Fu%2Ff55%2F18%2F24%2F87%2F84%2F111.jpg&hash=ea76d4096b1e00eb16cc9c61f7dbbead73ab08df) (http://www.servimg.com/image_preview.php?i=44&u=18248784) (https://www.a7a10.net/forum/proxy.php?request=http%3A%2F%2Fi55.servimg.com%2Fu%2Ff55%2F18%2F24%2F87%2F84%2F211.jpg&hash=1143e66e9da911aa0a0d10902e1b252c5f6d6f9a) (http://www.servimg.com/image_preview.php?i=45&u=18248784)
Crossover Shaft Z Arm :
1. Cut square one end of pipe, file and remove burrs inside.
2. Now cut to length 4.7/8’’ (123mm) again file and remove burrs inside.
3. From one end measure 2.1/2’’(63mm) this fits on to the arm and cut at 450
4. The shorter piece 2.3/8’’ (60mm) form the right angle (top).
Crossover Shaft Z Arm End Connection Plate:
1. Cut to dimension 1 ¾’’ x 7/8’’ x 3/16’’ – (40mm x 22mm x 4.5mm)
2. Mark centre line through plate and come in 3/8’’ 10mm and drill 5mm hole.
3. Cut and file plate into shape that is required to fit on the end of the pipe.
(https://www.a7a10.net/forum/proxy.php?request=http%3A%2F%2Fi55.servimg.com%2Fu%2Ff55%2F18%2F24%2F87%2F84%2F311.jpg&hash=7ed0b089ae515cafc31ecb4fc1d28efed7e4f8c5) (http://www.servimg.com/image_preview.php?i=46&u=18248784) (https://www.a7a10.net/forum/proxy.php?request=http%3A%2F%2Fi55.servimg.com%2Fu%2Ff55%2F18%2F24%2F87%2F84%2F411.jpg&hash=a15a05567d3be7060ca7a753c9d39c3e5ddddc71) (http://www.servimg.com/image_preview.php?i=47&u=18248784)
Crossover Shaft Arm:
1. If possible grind cable end round so it will push fit into the pipe, if not it’s a file.
2. By doing this it will keep in the right position when being welded and also when its on the crossover shaft for checking for fit.
(https://www.a7a10.net/forum/proxy.php?request=http%3A%2F%2Fi55.servimg.com%2Fu%2Ff55%2F18%2F24%2F87%2F84%2F511.jpg&hash=c3a6cae06d0d5d6f1c29019c11c4af1da8fe14a2) (http://www.servimg.com/image_preview.php?i=48&u=18248784) (https://www.a7a10.net/forum/proxy.php?request=http%3A%2F%2Fi55.servimg.com%2Fu%2Ff55%2F18%2F24%2F87%2F84%2F611.jpg&hash=016bf01cb53fe0997d850f705b532d505f4bfa2d) (http://www.servimg.com/image_preview.php?i=49&u=18248784)
Assembly of Z Arm Ready for Welding
1. Check arm on the shaft that you have clearance to oil tank and pipes, use marker pen or tipex (correction fluid) to make sure that every thing is in the right directions.
2. Rod connection bracket if the welder puts the Z arm in the vice with the pinch bolt parallel to the jaw the arm will be slightly towards the right, connection bracket now needs to be horizontal.
(https://www.a7a10.net/forum/proxy.php?request=http%3A%2F%2Fi55.servimg.com%2Fu%2Ff55%2F18%2F24%2F87%2F84%2F711.jpg&hash=69f55636b4010814b1c605627b3d074aa78155ac) (http://www.servimg.com/image_preview.php?i=50&u=18248784)
Rear Brake Arm:
1. The only brake arm that I could find that would suit was from a BSA A65, which can be purchased new, the only problem is that the stepped hole is to large.
2. Fill weld the hole and then drill 9mm hole in the centre.
3. When the hole has been drilled the boss area needs to be a 3/16’’
(4.5mm) thickness, as same as the original brake arm.
(https://www.a7a10.net/forum/proxy.php?request=http%3A%2F%2Fi55.servimg.com%2Fu%2Ff55%2F18%2F24%2F87%2F84%2F811.jpg&hash=5de29afe8c1c335d44d9a831d6935ec010d60d7d) (http://www.servimg.com/image_preview.php?i=51&u=18248784) (https://www.a7a10.net/forum/proxy.php?request=http%3A%2F%2Fi55.servimg.com%2Fu%2Ff55%2F18%2F24%2F87%2F84%2F911.jpg&hash=df64e05c4998686a3261dc1d9ba675d1a8c20129) (http://www.servimg.com/image_preview.php?i=52&u=18248784)
4. Reducing of the boss area will enable a full nut to be fitted.
5. With the brake arm in the vice with the offset facing you it needs to be at about 10/11 O’clock position so when the brake is applied the arm does not go past vertical, file square to vice jaws this will give a good guide.
(https://www.a7a10.net/forum/proxy.php?request=http%3A%2F%2Fi55.servimg.com%2Fu%2Ff55%2F18%2F24%2F87%2F84%2F1011.jpg&hash=1a211d55041abf236aa804aeef624fbb52257a30) (http://www.servimg.com/image_preview.php?i=53&u=18248784)
6. With a tapered 3/8’’ (10mm) square file (fig 7) carefully file the hole square.
Note: The original brake arm is a tight fit, there is a very small shoulder on the spindle that the arm butts up against, if you make the hole to big the arm will then butt up against the brake plate.
Continued next page
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Well, that was interesting.
Despite the ice I was itching to road test the the brake rod conversion this morning. I used to have to commute in worse weather but my bones don't bend like they used to so I'm more hesistant these days *sad2*
Anyway, I got out and on flat flat ice free bit of road, tested the rear stopper. It was not as I expected.
With the adjuster being set up so the wheel was just free to rotate the pedal had felt much better when trying it in the garage: little slack and the brake bit. But, get on the bike and ride and there was noticeably more pedal travel, although not as much as there was with the cable. So I am guessing the geometry is such that the end of the operating arm is far enough from the centre of the swing arm spindle that the effective length of the rod changes as the swing arm moves.
Fortunately its in the right direction, I wouldn't fancy the brakes being applied as I hit a bump!
As for the braking performance, I have to say I have not noticed much difference but this may reflect on the need to sort out other elements of the brake now I've eliminated the spongy cable.
I'll have a look sometime but to be honest, the brake does work and while there is room for improvement, I would not want it better than the front brake.
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Gentlemen, I have been working on a rear rod brake conversion too for my '61 super rocket, I've been sourcing only BSA parts to do this, with minimal modifications. I've been carefully photographing each stage and logging the time spent, in order to come up with this awesome conversion with a list of BSA part numbers, so other forum members, could just source these parts and enjoy the wonderful new effective rear brake. Well today I finished the job and took her out for a test ride and...................... no difference. Absolutely the same feel and effectiveness as the cable operated brake, possibly a little less spongy, but frankly it's pathetic.
Years ago some old BSA A10 expert told be "if you set up those cable brakes right, they work fine" unfortunately he's passed on now taking those brake secrets with him. I've done all the geometry corrections, changed linings, arm lengths etc. and come to the conclusion it's just a crappy brake. So now I'll be looking for QD rear wheel and brake. I hope some of the other versions I've read about turned out better than my disappointing attempt.
Clive
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Hi Clive,
Unless the new linings were machined accurately to the drum size, it will take a fair few miles to get the linings to bed in to the drum,
Its possible to assist in the bedding in process by repeated dismantling and sanding down the rubbing spots till the shoes touch all round
Have you centered the shoes by loosening the shoe pivot pin applying the brake, retighten while the brake is applied
Some shoes are a "floating" type with the linings offset, these must be fitted the correct way around
Another consideration is the lining material used, a lot of modern linings are useless being too hard
HTH
John
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Thanks John, didn't know about loosening the pivot to center the shoes. I'll give that a try next, then look into linings although I have the same linings on my '54 GF and they work fine
Clive
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Brakr Rod Conversion continued.
Brake Rod:
1. The brake rod in stainless steel can be purchased from Lightning Spares.
2. Assemble the brake and Z Arm into position, measure the length of rod that is required to the connection point on the Z Arm.
3. Grip the brake rod in the vice protecting it with wood and then form the elbow with a hammer.
4. Cut off the excess rod of the elbow and drill for split pin.
Note: If you file a very small flat where you want to centre punch it will make it easier to centre punch in the middle of the rod.
(https://www.a7a10.net/forum/proxy.php?request=http%3A%2F%2Fi55.servimg.com%2Fu%2Ff55%2F18%2F24%2F87%2F84%2F1111.jpg&hash=f51313bf6f8720f30371fd94e86f65a1063f079c) (http://www.servimg.com/image_preview.php?i=54&u=18248784)
Hints:
1. Check dimensions, from centre of the crossover shaft to the top of Z Arm 3.1/4’’ (83mm). Overall length of top part including rod bracket 2.1/2’’ (63mm), again this for a 1962 Super Rocket, could start off with pipe to long and cut to length as required, but make the arm as short as possible the longer it is then the more travel on brake pedal.
2. Check before painting on the Z Arm you may needs to remove some of the pipe as it may foul the swing arm main nut.
3. I used Hammerite Smooth Spray 4 coats gave it a nice deep shine.
4. Main problem I had when I took the crossover shaft arm off, the brake pedal spring slip come off its mount, I struggled to get in place when reassembling.
5. There is also a modification to the rear brake pedal that you may wish to consider while do this work, my Super Rocket come with this mod done.
(https://www.a7a10.net/forum/proxy.php?request=http%3A%2F%2Fi55.servimg.com%2Fu%2Ff55%2F18%2F24%2F87%2F84%2F1211.jpg&hash=27e50f3181a11c98de4da2f0b0492e01b2fb0beb) (http://www.servimg.com/image_preview.php?i=55&u=18248784) (https://www.a7a10.net/forum/proxy.php?request=http%3A%2F%2Fi55.servimg.com%2Fu%2Ff55%2F18%2F24%2F87%2F84%2F1311.jpg&hash=1fc4e2950529d6e8abf9fa31d8634769b87a6ebe) (http://www.servimg.com/image_preview.php?i=56&u=18248784)
(https://www.a7a10.net/forum/proxy.php?request=http%3A%2F%2Fi55.servimg.com%2Fu%2Ff55%2F18%2F24%2F87%2F84%2F1411.jpg&hash=a47436719331bde3709a6aa3de88b2b58dc86b82) (http://www.servimg.com/image_preview.php?i=57&u=18248784) (https://www.a7a10.net/forum/proxy.php?request=http%3A%2F%2Fi55.servimg.com%2Fu%2Ff55%2F18%2F24%2F87%2F84%2F1511.jpg&hash=72790bf2ab91f8bc1a54c9c7bdba4adfa45ab5ca) (http://www.servimg.com/image_preview.php?i=58&u=18248784)
Acknowledgment:
BSA A7 & A10 Forum
Christopher Fenoulhet & Seamus Molone who had already completed the conversion,
With out their help I would not have been able provide this guidance.
Ride Safely
Nick Gallop
March 2013 update:
Photo: Showing Z arm with clevis fitting by A7 – A10 Forum Member
(https://www.a7a10.net/forum/proxy.php?request=http%3A%2F%2Fi55.servimg.com%2Fu%2Ff55%2F18%2F24%2F87%2F84%2F1611.jpg&hash=d0c00fe5321338e9efac21eef6944758e659f69f) (http://www.servimg.com/image_preview.php?i=59&u=18248784)
As you will see in this photo a clevis has been used to connect to the Z arm.
Clearances to the oil tank and pipes would need to be checked if using this
method.
Also one of the Forum Members has used a the ring part of a combination spanner to make the brake arm, this method will give more adjustment which is a very good ideal.