The BSA A7-A10 Forum
Technical (Descriptive Topic Titles - Stay on Topic) => Frame => Topic started by: jhg1958 on 22.11. 2021 11:33
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Just refitting my brake levers. I noticed there is a hole in each suspiciously like one for a mirror. I can not think this would on a 1961 Golden Flash. Am I barking up the wrong tree?
On a slightly different topic. I do not have a ball bearing for the end of the clutch push rod. Do I really need one and if so where can a buy on or do I just have to buy a pack?
John
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Yes, the holes are for mirrors and, no, they were not included as original stock. If you are referring to the ball bearing in the end of the clutch pushrod adjuster in the gearbox, I would say, yes, you need it. New aftermarket adjusters are available.
Richard L.
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Like this? https://draganfly.co.uk/shop/72908/clutch-pushrod-adjuster-and-nut/#65-3403
Richard L.
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Hi John,
The one GB refers to is in the gearbox outer cover. My reading of your request was - Do you need one at the other end beneath the clutch cover? My original 4-spring clutch for 1961 did not have one there, relying on GB's /BSA's gearbox adjuster ball which means that the rod rotates with the clutch. But I purchased a new clutch including the alloy outer plate from Draganfly (probably Wassell or MCA) a few years ago and it has a drilling in the cover which takes a 1/4" ball bearing snugly. The rod pushed directly onto this ball to lift the plate. I found that adjusting the 4 springs evenly was a little more difficult but worthwhile. With a ball at both ends I don't know whether the rod now rotates or not. Many members recommend cutting the clutch rod in two and fitting a 1/4" ball in the centre. Probably then both parts of the rod rotate separately?? I haven't done that because my clutch is quite good at the moment. If you need a different rod length, I used a 1/4" Silver Steel rod and hardened the ends.
With a new SRM clutch, they have a flat roller bearing fitted into the clutch outer plate instead of this ball which helps to lift the plate evenly, and may make the spring setting easier?
There are certainly many ways to improve the clutch. *countdown*
My 1961 Flash also has it's original levers, and no hole for mirrors.
Col
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These are aftermarket levers. I'm pretty sure your bike didn't have adjusters at the levers originally. Mine didn't.
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Thanks for the detailed reply on the clutch pushrod. Yes it is the ball bearing in the middle or end of the push rod. I have purchased some ball bearings and will put at least one. I bought an SRM clutch (made by NEB). They did not send the flat roller bearing. After I went back they sent a flat mushroom without roller bearings. Nor did they send a ball bearing. I have the silver steel and just waiting for the ball bearing. I will probably stick with one between the mushroom and rod.
I would love to hear from others who have had a clutch from SRM since it’s caused me such grief.
I am not surprised at the none original levers. Apart from the frame and engine I am not sure anything else is. I have not helped with this rebuild.
Reminds me of the story of my grandad’s axe, had it three generations, had 6 new shafts and 2 new heads.
Still I hope to have a good bike to ride about in the summer and almost definitely outlast me. At this rate the rebuild may outlast me!
John
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Unlike a typical car clutch, the pushrod, bearing and pressure plate do not rotate when the clutch is disengaged. Movement between the pushrod and ball/pressure plate/pushrod only takes place as the clutch is slipped to take up the drive. As my Dad used to say, "A Clutch should be In or Out" The bearing and lined plates only wear when being slipped. How many motorists used the clutch pedal as a footrest and wondered why the fuel consumption was high and the clutch life short?
Small quantities of imperial bearing balls can be sourced from Bicycle Spares suppliers, eBay has plenty of choice. Great for giving headstock bearings a makeover. Usual scheme is just one ball between the cut pushrod stubs, more often used as a cheap fix to make a non-standard pushrod fit, or an attempt to improve the design. Don't forget that little bit of slack on the cable adjustment, there should be no load on the release mechanism with the clutch engaged.
Swarfy.
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Fitted an SRM clutch about 3 years ago with no problems.
I would get back to them if they did not send the right parts.
I did not think that NEB made clutches for SRM.
Photos shows the flat thrust bearing.
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Using bearing ball in a cut clutch push rod is a good idea, and using a clutch 1/4 X 1/4 roller is even better as it gives a greater surface area to push on with less chance of the push rod ends wearing cup-shaped over time.
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Hi John,
"The one GB refers to is in the gearbox outer cover. "
Col,
Thank you, I'll take it that you meant this confusuin between myself and GB as a compliment toward me, and not an insult toward GB. *smile*
Richard L.
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SRM must have changed their suppliers. I received a 6 spring NEB clutch with a modification to my Cush drive that thought would be a good idea. See picture.
I did go back to SRM and they sent me a flat thrust mushroom with no bearing. After seeing yours it am wondering if I should try and source one of these as it is bound to better than a flat end.
John
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Hi Richard L,
Upon re-reading, it seems you and GB are one and the same. *red* He He. Sorry GB.
I am a bit intrigued about the clutch SRM have sent John - a 6-spring?? Have they got a new clutch from NEB to match John's new cush drive?
Col
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Upon re-reading, it seems you and GB are one and the same. *red* He He. Sorry GB.
😁
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Col
I suspect that the NEB Clutch is more to do with the belt drive than the Cush drive SRM modified for me. I can only think of 3 belt drives for A10s Bob Newby, Hayward and NEB. Not sure how many springs the Hayward clutch uses but the Bob Newby has 6.
There maybe more. I know most people prefer 4 springs to 6 but I trusted SRM to keep me right.
My main motivation for a belt drive was the memory of my old A10 dropping oil from the primary chaincase and that I needed a new clutch and primary chain.
John
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Hi John
There is no comparison between an original BSA six spring clutch and the NEB six spring
The NEB is a thoroughly modern affair *ex*
The spring nuts are fully tightened and the top hat pusher keeps the pressure plate evenly lifted
There is no thrust bearing as on the SRM 4 spring pressure plate, it relies on a bearing between the pusher and pushrod plus the bearing in the clutch actuating arm on the kickstart side
You will need to adjust the pushrod length to get the clutch arm and lever to work at the correct angle
the arm should be parallel to the cover joint and the inside arm inline with the pushrod when the clutch is pulled in fully
John
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Thanks John
I had not realised the the spring nuts need to be fully screwed in. I did not receive any information from SRM on fitting or adjusting the clutch. Good to have the advice on the length of the pushrod too. This is my next job.
John
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Hi John
Get a length of 1/4 or 6mm rod and do the experimenting with that
Once you have the correct length sorted, then make the silver steel rod and harden the ends
John
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Rodger,
The discussion is about an NEB clutch with belt primary drive, not the Triumph based chain drive clutch
John
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Rodger,
The discussion is about an NEB clutch with belt primary drive, not the Triumph based chain drive clutch
John
Thanks John, silly me *conf*