I'll start from the beginning, a few years ago I purchased a rigid B31 frame complete with telescopic forks off a genuine enthusiast, the forks had never been off the bike for years if ever at all, I returned home and took note of the frame number, and had it checked through the club, it is a 1949 frame. I took the forks off the machine noting what went where as I hadn't had a BSA for years.
I removed the fork legs firstly, then I removed the top yolk (after some struggle with that castellated sleeve) I put all the headrace bearings into a cup and saved them, fast forward 1 year !!! Once I had the rebuilt motor in the frame together with the gearbox, I moved onto the forks, having had all black parts painted by a friend in 2 pack stoved, so I unwrapped the bottom yolk and the top one, grabbed the boxes with parts in and began building it up ( I must add I had a new castellated sleeve) I put plenty of grease on and tightened it all up, however, I wasn't happy, it felt a bit threepenny bit when I rotated the yolks lock to lock, so I took it all apart again, thinking maybe a ball had slipped out, anyway I assembled it all and carried on regardless, 18 months later I was lifting the bike off the workbench when I detected movement in the head? Jesus it had to all be stripped, headlight bars the lot, once in bits I measured the balls 5/32" dia. I rang Draganfly and asked what they should be, they said 3/16", so I purchased a full set of balls and 2x cups that fit in the headstock (they have none of the ones that slip on the steering stem, so this morning I decided to get the yolks back on, but to my dread, nothing fits, with the 3/16 balls in the top and bottom cups the other cones will not go in it seems the balls are too big (and before you do, I don't want anyone saying fit taper rollers, so shut it buster) so I tried the 5/32 balls, but found that they actually wander about in the cones. Has anyone got a decent suggestion, the 1948/49 stuff is a bit weird I know such as the lightweight gearbox, but head bearings?? HELP OH I HAVE PICTURES
The 1949 ZB31 prefix frames should take 1/4 inch steering bearing balls.
1946-48 XB31 and YB31 frames should take 3/16 inch balls and different cups and cones.
Julian
It still doesn't work out 1/4 is larger than the 3/16 that are too big, so surely they won't work, Draganfly don't seem to be able to come up with what I need, to be honest, I really am lost with it all.
Regards
Phil
two things.
firstly, presumably you were supplied with the correct cups?
secondly have you checked the cones? if they are worn you may get thruppeny bit feeling and if not matched wont ever fit right.
not pushing them, but, according to SRM's web site, they say taper bearings fit :
Fits Rigid , Plunger and Swingarm models , M21 B31 B33 Gold Star , A7 , A10, A50 and A65 models up to 1970 , please see technical information for Rigid and Plunger models.
could you find an option for one of those models to find alternative
With a 1949 frame the cups should be part 66 4149 - these are 2 1/8 inch outside diameter and take 1/4 inch balls. The cones 65 5126 and 65 5127.
These parts are the same the A pre unit twins and I would expect them to be easily available from most reliable suppliers and usually offered as a complete set.
The 1946-48 cups are 65 4465 - these are 1 7/8 inch outside diameter and take 3/16 inch balls.
The new cups and original cones may not be compatible with each other.
What part numbers did Draganfly supply?
Julian S
My mistake (it's the stress) my frame is a 1947 number XB31 9949 from your old books just which size should this frame use, the bike is at my workshop and I cannot get the cups out, I don't think there is a tread for the BSA tool, and there is no ledge to knock against (they recess in the frame) I have been told to run a weld around the cup, but I didn't want to burn the paint at this stage, but the frame of mind I'm in the bloody gas welder will be coming out.
Phil
Answering my own questions I think, OK I got the books out for a 1947 frame the Bottom cone is 65-5320 top 56-5319 both top and bottom cups are 65-4465 with 3/16 balls, Draganfly have none because I went over this on the phone a while ago, so I'm sorry to ask but Julian s what should I do ? which flippin taper roller bearings fit and is the O/D 1 7/8"
I know it's a typo, but the part no. for the top cone is 65-5319. Is the whole setup damaged? The balls and cups are readily available on ebay. I think the cones may be the same as a D1 bantam - at least some of them are anyway from memory. When removing mine I just tack welded a flat piece of metal across the cup and tapped it out with a drift from the bottom/top. All the best, Glenn
1946-48 "B" steering bearings are the same as Bantam model D5.
The cups are the same 65 4465 for D1-D14.
The D1-d3 takes 2 x cones 65 5319.
The D7-D14 takes 65 5319 as top cone. But completely different bottom.
If it was my bike I would leave the cups in for the moment until a full set was obtained.
I would try C and D Autos and Burton Bike Bits.
Bournemouth Bantams had some earlier this year also worth trying.
http://bournemouthbantams.co.uk/?s=steering+bearings
Dont know about taper conversion.
Ive come across many bikes where there is no thread for cup removal, Im guessing they came that way for a few batches from the factory. The B40 Ive just done was a case of getting a screwdriver under (between the cup and frame ) and levering it out. You said you cant spark weld and a flame weld will burn paint. The other option I have heard of is drill a couple of smallish holes through the headstock at an angle so you can drive the bottom of the cup out.
the taper rollers are available but normally expensive . Ive picked up a pair for £5 but going to cost £40 for grinding the o/dia of the cup down.
Couldn't sleep for thinking about these cups, the bottom cup feels a bit rough, that's why I purchased new, I couldn't get the old ones out so I thought I will leave them as they are, however, something didn't feel right and I stripped the lot, I may have been the culprit quoting my frame as 1949 and it isn't, so Draganfly sent me what I thought were 3/16 balls, with these in the whole thing will not fit together, and with the original balls in it feels rotten. OK guys this morning I went to the workshop determined to sort it all out, for the first time I decided to measure the bloody balls, Draganfly sent me 1/4" which are too big for the cups/cones, I examined the lower cup still in the frame, and it is knackered, I started having a scrape around with a small sharp screwdriver, and bugger me there is a thread on the cups, only about 2-3 threads, but that will do me, so now I need that 61-3060 tool.
Sorry, fella's it's these Blonde moments again, thanks julianS always there with the true facts.
Phil
Well done Sideways. Problems like that can be a real headache. Hope your latest detective work proves fruitful.
Can't get a tool number 61-3060 anywhere, however on an old thread this site someone named JACKSON had made himself one on his lathe, could anyone direct me to him, maybe I could borrow for a small fee.
Well lost my rag with these cups, arrived at my workshop in a foul mood, firstly I tried warming the cups up, I could smell the paint on my lovely frame burning ( my fault leaving this problem) and there is about 1/8" of the cups showing at the bottom, so to get a purchase with a chisel is near impossible. then I put a cutting disc on the hand grinder, but the disc is nearly the thickness of what is showing of the cup, so all it does is remove that 1/8" so that was useless, the effing started about this point, so the last resort, as many have said weld a piece of steel across, then belt it down through the tube, all I have is a gas welding set, and I am not that good with it due to being a blind bugger, I found some bit of plate and wedged it up under that horrible cup, then struggled with the flippin goggles over my dodgy £1 glasses, eventually I lit the torch and got a decent blue zone flame, I managed to tack the plate onto the 1/8" it wasn't brilliant but here goes, I got a bar down through the headstock and gave it a gentle tap, then another, then a...the weld gave way, more effing, however when I shone my torch on the cup, the bugger had moved, I got a tiny sharp cold cisel and knocked the hell out of it, going around equally and it fell out, I felt like slinginging it through the window, but wanted to check the O/D, my new one is now fitted and the yolks are back on and free as anything. Just thought you all might enjoy my agony. Thanks for all help.
Wow,
Not the best frame of mind to tackle a task but your determination got you through it - eventually. Time for a few beers and to relax.
Like most of us you learn the hard way. Bur learn you do.
I have not had to replace these on my 1948 B33 but I seem to remember hearing that the cones etc are the same as on a bantam and it might be easier asking for these. The same numbers as for the 46-48 B series but dealers might be more familiar with the Bantam items. (do please check for yourself though!)
cheers
Pete
HI THERE SOMETIMES WHAT I DO IS AFTER OLD CUPS REMOVED IS TO GRIND 2 LITTLE SLOTS OPPOSITE EACH OTHER INSIDE THE FRAME NECK TO ALLOW A PUNCH IN TO REMOVE FUTURE CUPS > JUST A LITTLE TIP FOR NEXT TIME YOU NEED TO REMOVE THEM . REGARDS JOHNBOY .