ATTEMPTED TO MAKE A FEW UNOBTAINABLE PARTS FOR THE B175 BANTAM INCLUDING A NEW 2 PART CLUTCH BUSH AND A PAIR OF STUFFER PLATES FOR THE CRANK. FOR MORE BANTAM CONTENT CLINK LINK BELOW • BSA BANTAM B175
Really nice to see someone who knows what they are doing doing a good job with a pragmatic approach. Far too many annoying You-tube channels full of restorers who think a quick clean, sandblast, a load of shiny paint and re-assembly is restoration.
And now for the bad news.... 8 -) Not familiar with the D14 but there is a ton of extra room in the D7 cases, so you can put in much thicker stuffing plates. A small, but noticable, performance boost. I made them out of alloy, to lessen the increase in rotating mass, and they were complete replacements, fitting in the location for the originals but extending to the edge of the flywheels. I also sealed them. And, as mentioned by others, the centre punching goes in the slot of the screwhead, not anywhere but. The D7's clutch bearing was solid bronze. I suspect the later, two-part piece was simple cost saving.
probably right about the cost saving, the earlier bush was quite a chunk of phosphor bronze . Room is a bit tighter in the B175 as the scars left by the escaping rivets bare witness.
Cock up? No. Modification! Enjoyed that, Mr. Tweed. And now I know what I want for Christmas. A Stuffing Plate. (A plate piled high with stuffing. Paxo, obviously. Only the best)... 👍
I've had homemade, posh stuffing, with walnuts and apricots etc ....but you are quite right Bill, you can't beat plain Jane, sage and onion Paxo floor sweepings stuffing .........I'm even partial to a cold slice of it the next day 😋
Nice job of making that bushing. As just a thought, I myself would have probably left the turning of the final outer and inner diameters until after pressing the steel into the bronze. That way you know that they are concentric. But still, well done. And the Oil grove is as you know not a problem, it just insures a more effective lubrication path. Call it a design feature. As a quick thought, another way to mount the stuffing plate stock would be to run over to the flea market and find a plastic dinner plate that is bigger than the part. That can be turned flat on one side and then have the sheet metal glued onto it. Then you have a nice thick stable thing to turn. Again, a random thought while watching.This is useful for those of us without a mill with a DRO.
Thanks, I´ll take the double scroll as a win ;-) and thanks for the thoughts, that's the nice thing about engineering there's many ways too approach a problem and many solutions which is what makes it so enjoyable.......there´s many ways to skin a cat as the old saying goes. If you ever think about a DRO on your mill I would highly recommend it, they save so much time in setting up, marking out etc and always being able to return to your start position. I really didn't need to mark out the plates as it could have all been done from zeroing the X and Y at the centre of the plate and running all the coordinates and PCD program from that point.
Good progress Senor Tweed. The oiling scroll wasn't really a balls up, as long as it has one it will be fine. The main thing is to eliminate the headache from a worn bush, as this causes clutch drag and in extremis, the clutch drum starts chomping through the outer casing. Which is nice. Best wishes, Dean.
Hi Allan, just found you and am enjoying your videos. The usual way to remove / re-fit bearings in motorcycle crankcases is to put them in an oven, the bearings drop out and in with no mechanical assistance. Done quite a few Bantam re-builds as well as various other Brit bikes this way. Colin
Hi Mr Tweed I remember seeing an article in the motorcycle weekly in the 60s or later about bantam tuning where this fellow glued or bolted thick dural discs to the flywheel to increase crankcase compression , I don't know if this gave a bubbling increase in power or not I'm not an engineer just an old retired sparky but your opinion on this would be interesting cheers loving your videos can't wait to see much more of them
Hi Frank, it not my area of expertise but the way i see it is you are reducing the volume of the crank case so the air fuel mixture has less room to loiter around in so makes it's way quicker to the cylinder to do the work it is intended to do . Sort of like the having a wide corridor in a school with lots of nooks and crannies like doorways and lockers for itinerant teenagers to hang around in compared to a narrow corridor with no features allowing an unhindered flow of little darlings from A to B.....
Been watching progress, as it needs a rebore with that scoring maybe some easily sourced modern pistons and rings might be an alternative ( as the small end bushes have gone a custom pair could be turned up for metric gudgeon pins) , might reduce the cash outlay.
@@TweedsGarage The LE club has pistons and use modern (Honda I think?) rings. Apparently the bored need to be machined to a finer clearance than normal. I need to start making a list/spreadsheet of all the things I need.
Nice work Mr Tweed, that Bantam should run very sweetly when it's back together. I doubt it's seen much love in the past. They were cheap transport and ridden into the ground in the day. Are we ever going to see your troublesome apprentice on screen? Thanks for the video.
Judging by futher damage repairs I've uncovered under all the crud someone must of loved it a bit ( or it was their only form of transport ). Unfortunately Jenkins has as they say in the trade " a face fit for radio" so he's best not seen 😉
I haven't seen a Bantam in pieces for more than 50 years, same problem, crank stuffer plates 'fell out'. (D14-4) 'Ours' were only staked in around edge of flywheel, are the screws standard BSA or did someone modify it (Bantam isn't something I bothered to learn about so only 'been inside' one) Seven or eight year old Honda' 50'ss were cheap at the time, you could pick up a running C110 for less than ten quid (and straighten the push-rods with two bricks after you bent them by over revving it, the 1965 OHC motors would take even more abuse I would probably have made the bronze piece a shrink fit onto the steel, think that's how the original was made? Looks like you have the same cheap centre drills as me, they need sharpening before they work properly. Crank pin. I had a friend bring a new Zeus book over around 2010, the one I bought in 1978 was a bit out of date but I still have it and use it. (mainly tapping drills for metric thread) I also have those little aluminium containers (30:20, two o'clock, right side) damn handy and quite heavy duty.
originally the stuffer plates were riveted to the crank, but used to come off ( this is what happened to the missing plate, BSA then screwed them to the crank but these also came loose so BSA finally welded them on, the screws had been added to mine I suspect after the other plate came loose. Those little containers are really handy, a customer gave me them, they contained some sort of medical stuff that he has. Every workshop should have a Zeus book, I use mine every day :-)
Very enjoyable Allan! I wonder why the original stuffing plates were punched in every place other than by the screw slot? No wonder the screws came undone, I would think the mangling they got when they came loose destroyed one of them, so they threw it back together without it, that is a very nice little parting tool you have, I had one similar but it self destructed while parting stainless steel! Stay safe! Chris B.
Hi Chris, Originally the plates were riveted in ( hence why one came out ) the other side they've tapped the rivet holes and upgraded to screws but having the other side let go they've probably punched everywhere around the screws just to be safe . The parting tool is a Greenwood's parting tool made for the model engineering world but its pretty indestructible ( unfortunately the chap has retired so the tips are difficult to source )
He's cactus from Mexico so his English isn't very good......he said.. "i can make a cup of tea" " i can clean the lathe" " i can sweep the floor " " at last my plan for world domination begins" "Hello and welcome to Tweed's Garage " "No no put me down" Hope that clears it up
They were welded eventually but i dont want too risk distorting the crank webs, so screwing the plate down gets it tight against the crank and welding the screws/plates keeps the heat localised with the option to drill the heads out to remove the plates.
what a stupid design my cz175 crank is so mush better a solid crank no freaking about with plates what a silly design your better off making a new solid crank will be so much better.
