The BSA A7-A10 Forum
Technical (Descriptive Topic Titles - Stay on Topic) => Gearbox, Clutch, Primary => Topic started by: RichardL on 10.09. 2010 15:30
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Gents,
There is a long tale of woe and mistakes that has led up to the questions I have right now. I promise to share that tale as True Confessions at another time but, for now, I don't want you to be bored before I get to the point. (Hey, you may already be there!)
I have purchased a used kickstart spindle and quadrant gear for my S/A scrambles gearbox. These parts are almost like NOS. The assembly is two-piece and original. I have also purchased a new ratchet pinion. My question is about the shape of the teeth. The teeth on the new quadrant are flat-topped and the teeth on the new ratchet are pointy. I am guessing that they are different so that flat quadrant teeth don't bang against and jam on flat ratchet teeth. Is this about right? Actually, I was expecting that the ratchet teeth would also be flat-topped and that my existing part was pointy from wear.
A second question relating to the same issue has to do with the new quadrant teeth sliding over and klunking with the teeth of the old ratchet (leading me to buy the new ratchet). I was expecting the teeth of the new ratchet to be significantly taller than those on the old part, but, by looking, there doesn't seem to be enough additional height to overcome the problem. However, the points of the old ratchet teeth have been somewhat rounded over. Does anyone have experince with this type of kickstart problem?
Thanks, in advance for your advice and ideas.
Richard L.
P.S. Sorry, but I denied you a laugh by proof reading and discovering I had left the "h" off of one of my uses of the word "teeth".
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Probably no problem since both parts are new. Assemble the mechanism and see. The forms of the teeth are as you describe.
David
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I have one of those flat toothed quadrants, it will never mesh properly with the ratchet pinion as the teeth are too fat due to the flat end and can't engage far enough into the ratchet pinion, I'm convinced it's from another model - I'm sure some one on here will confirm. ( plunger maybe, M20 or even more medern than our A's).
Like you I bought it as new (which I think it is ) - chalk another down to the learning curve Richard
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I have just had this exact same problem. You need to ensure you have the ratchet pinion for the flat top quadrant. They are different, although people say the pointy pinion should work with both. Mine didn't it just mashed together and the kick start would not return. With the proper pinion its like a swiss watch. The flat top pinions are available from ~JB Restorations british made for around £20. Ring Paul on 01229 465635 in the UK.
Stu
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I had the same problem on the A7, the (flat top) quadrant simply wouldn't engage properly with the new ratchet pinion, the kickstart simply wouldn't move a bit.
Good to know where to source a properly fitting one, back then I ended up narrowing the bases of all teeth on the pinion with the file until it would work.
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Wow, three reports of the same problem. That's pretty convincing.
Stu's description of the mashing and sticking is quite accurate. I had not seen Stu's and Markus' comments before going to work on the bike this morning. I decided that my situation sounded a lot like Bill's and could not see any reason why having a new ratchet pinion was going to correct the mashing issue, so I went with a pointy quadrant rather than risk the nice new teeth on the ratchet. Everything went great and I was actually able to go an a nice ride today, after losing most of the summer to a broken gearbox cover.
I can't say to a certainty the the flat-topped quadrant would not have worked with the new ratchet, but the pointy-pointy combination seemed the highest percentage chance of success. Like Markus said. it's good to know you can get the right ratchet for the flat-topped quadrant, thus preventing the quadrant from becoming an eternal paperweight.
Richard L.
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I now believe the flat top is A50/65, didn't know you could get a pinion to match but if it is A50.65 then of course you should be able to.
I wonder if it is a better combination, most of the A10s I know stick sometimes when being kicked over - worth a bit more investigation
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I have just had this exact same problem. You need to ensure you have the ratchet pinion for the flat top quadrant. They are different, although people say the pointy pinion should work with both. Mine didn't it just mashed together and the kick start would not return. With the proper pinion its like a swiss watch. The flat top pinions are available from ~JB Restorations british made for around £20. Ring Paul on 01229 465635 in the UK.
Stu
I have used Paul from JB restorations unfortunately I cannot remember the price but the gearbox I gave him to do was something like one of those presses for crushing cars and noise was very similar as well any way he gave me a fixed price and assured me it would be completely stripped all bushes checked and only parts that would withstand his 2 year warranty would be used when I got it back from him I was truly astounded the main case and middle case had been blasted with a media that made it look like new the outer case was highly polished and the operation was like that of a rolex watch I could not reccomend him highly enough and he was a pleasant helpful man to talk to see pic of bike it had to be good Chris
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To Chrisf1,
Do you have a link to Paul @ JB Restorations?
Thanks,
Steve
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Lovely bike Chrisf1. I keep getting the urge to put on clipons and headlamp bra - it will happen............. I cant resist much longer.