The screws holding the timing side outer casing on my 1965 B40F are Phillips, or something similar. Is that what they would have been originally? Seems to me that an ordinary Phillips screwdriver won't give much leverage to achieve a tight joint (of course you wouldn't want to be trying to get it too tight either.) I think it's also easy to round them off. The other side (primary chaincase) has Allen screws. Phil
Hi Phil,
They were originally Phillips.
I have changed to stainless hex head as I also have had issues 'rounding them off and damaging the plating leading to corrosion. I use a hex screwdriver to ensure I don't overtighten them.
I have loads of original BSA Phillips screws if anyone is interested.
Best wishes...
Hi Phil
Get yourself a set of stainless socket screws and use the correct size allen key. They won't round off but be careful not to exert too much force or you'll damage the casing. As long as everything's flat, there should be no problem forming a seal. Not as original but I personally think they look good.
Hi Phil,
Sorry I meant to say hex socket, I don't use an Allen key on casing screws but a screwdriver as so:
https://www.ebay.co.uk/p/2254446685?iid=383753270134
Best wishes...
Hi,
I use Allen keys but only the short side to tighten as much as I can just using finger and thumb and the long side is good for undoing as sometimes the screws can become a bit tighter during use. For the inner case screws that need to be tighter I use the long side. The screwdriver type for tightening the outer case screws is definitely a good idea to avoid over tightening.
It is also a good idea to clean out the threads really well so that the screws tighten against the case and not against compacted goo and bits of gasket in the bottom of the hole.
Dave.
I would be interested in some Phillips screws. I think they look much better than Allen type. 8)
I make sure my Phillips head fits tight and all goes well ;D
Pozidrive screws. New screws and a #3 Pozidrive tip, they'll work well and look good a long time. When we were kids we all thought they were #3 Phillips and stripped the heads out.
I notice the allen screw drivers on Bess's link (thanks, Bess) are metric sizes. Does anybody know what the threads on the screws are? I would have thought imperial, ie BSF or BSCy? (1965 B40F timing side outer cover) Phil.
Quote from: Phil C on 13 Dec, 2020, 14:47
I notice the allen screw drivers on Bess's link (thanks, Bess) are metric sizes. Does anybody know what the threads on the screws are? I would have thought imperial, ie BSF or BSCy? (1965 B40F timing side outer cover) Phil.
Going into aluminium I suspect they will be Whitworth
Makes sense. If I'd taken one out before asking I guess I'd have noticed it was a coarse thread rather than fine! Thanks, Calum.
Phil
Hi,
Bizarrely a high probability they are Phillips CEI:
https://www.draganfly.co.uk/bsa/bsa/b40/category/1187-1187-
Best wishes...
Hmmm, which I think is the same as BSCy? Phil
Hi Phil,
They are interchangeable, the thread forms are slightly different though.
Best wishes...
I've just noticed something in my BSA Instruction Manual (which is for the C15 Star, C15 Sportsman and B40 Star. Mine is a 1965 B40F. )
On p.40, under a sub-heading "Starter Pedal Spring", it says "The recessed-head screws retaining the cover require a screwdriver of a special type and a standard screwdriver must not be used." Now I've no reason to doubt Bess's assertion, above, that the screws were originally Phillips, but would BSA have described Phillips screws like that? Were Phillips screws that uncommon back in the mid-60s? I ask just out of interest. Phil
Thinking about it, I reckon the answer is probably yes. The wording in the manual sounds now a bit comically dramatic, but maybe few people back then would have known what a Phillips screw was. Phil
Hi Phil,
Phillips screws originated in the US, I guess BSA pandering to that market used that standard fixing. Bizarrely they were designed to enable more torque to be applied which may have contributed to threads being stripped.
Best wishes...
I'm starting to wonder why Pozidrive isn't being mentioned here at all. Is that something that came along later then the early 60s? Most of my English bikes are late 60s BSAs. I like the original look, so all of my case screws are posidrive. Usually when I drag a bike home all the case screwheads have been hogged out by Phillips drivers over all the years. When they're all out I get new PD screws and with the PD# driver they work great, the tip never slips.
I looked at the Draganfly site, didn't see the word Phillips. Here in the states we have british fasters.com. I never see the word Phillips there either, only posidriv. So for 20 years I've thought all the britbike phillips looking screws were PD......beginning with the change from slotted screws. I'll stay tuned, I like to know this stuff.
Hi Leon bee,
Sorry you are correct they are Pozi drive screws.
In my circle of friends in the UK, Phillips seems to be readily used as a generic term for cross head screws.
Best wishes...
Esoterica for sure. I have a bucket just like that!
Quote from: Bess on 22 Dec, 2020, 08:14
Hi Leon bee,
Sorry you are correct they are Pozi drive screws.
In my circle of friends in the UK, Phillips seems to be readily used as a generic term for cross head screws.
Best wishes...
So Bess, are you saying the screws would have been Pozidrive back in 1965? If so, I'm surprised, I thought they arrived later. Phil
Hi,
I think the extra 4 lines on the screw in Bess's bucket indicate 'Pozidrive'. I do not think that Philips have these. The Pozidrive probably came about because the Philips had a tendency to slip. I have a selection of crosshead screwdrivers and sometimes finding a good fit is not easy especially if screws have been replaced over the years. It seems even more complicated today as there are several formats for crosshead screws and none fit another well enough to use. The more non-original the screw the less likely it is to be Philips or Pozidrive.
Dave.
But to return to my original question, what would the original screws have been on my 1965 bike's timing side outer casing? Phil
Hi,
Maybe not definitive but I would say Philips rather than Pozidrive. Philips came out about 1936 but have conical flanks that can cause an 'ejection force' when being used to do things up tightly. So OK for outer covers. Pozidrive came out in 1963 and have a parallel flank so putting all the effort in to the rotation of the screw as there is no 'ejection force'.
However, it is quite feasible that with the availability of the superior Pozidrive head from 1963 that this was specified for uses where a tighter screw was needed such as inner and outer covers that bear a load.
Is there a toolkit page in the B40 workshop manual that give the type of screwdriver included?
Dave.
Hi,
Worth a look here:
https://www.bsaunitsingles.com/ItemList.wws?cpubcode=BSA&Category=Fasteners&Page=18
Best wishes...
I think that many stainless screws appear to favour Philips, which have a much smaller cross point whereas most wood screws and engineering applications appear to have Pozi drive which, as previously noted, can handle higher torque applications. All the fittings on lock mechanisms with UPVC doors seem to be Philips. (useless info I appreciate) I find that a Philips head that is tight, especially if there is any corrosion, are extremely difficult to release without damaging the head!
I don't use screwdrivers with Phillips tips any more; I use JIS (Japanese Industry Standard) tipped screwdrivers instead. They are designed not to cam out, unlike the Phillips ones, and can be used with success on both JIS and Phillips screws. But you can't use a Phillips driver on a JIS screw without damaging it; the source of all those tales of Japanese case screws being made of cheese.
I use the Vessel brand. They are fairly widely available and are of good quality. If you buy some, one peculiarity is that compared to Phillips screwdrivers, you'll seem to be using too big a size on any given screw. It doesn't matter. I've used them to undo JIS screws that were quite well mangled from being got at with a Phillips previously, and when a Phillips will no longer grip it.
The outer timing cover screws (and the 5 on the inner timing case) plus all the clutch cover screw threads are all 1/4" (UNC) unified national course.
As above, I have fitted socket head Alan screw as I find them a breeze to screw/unscrew, you just have to take care not to over tighten them as screwing into the soft aluminium case the threads can be easily striped with the extra leverage.
You can still buy the original fitment Pozidrive cheese head screws from Draganfly in the UK (Drag an Fly) if you want to keep the bike original.
https://www.draganfly.co.uk/index.php/bsa/bsa/b50/category/431-kickstart (https://www.draganfly.co.uk/index.php/bsa/bsa/b50/category/431-kickstart)
I suppose one down side to using Allen screws is that you would have to cut them down to the various lengths, given that you're unlikely to find a supplier happy to provide one of this length, one of that, etc. (I think I'm right in saying the outer casing screws are of various lengths?) Not that shortening them is a huge task, but if doing in a vice you'd ideally want a couple of nuts to hold the screws, and you'd want to be sure the end of the thread where you sawed it was nice and clean, ie no burrs etc, before fitting, in order not to damage the aluminium female. So for example you might want to run a die nut down it (but might not have one, of course.) So it is a little bit of a faff, but I guess you could say "so what, it's all part of the fun." By the way, I notice in this hobby how often it would be useful to have a little centre lathe. Phil
Hi,
For a 1965 B40, worth looking here for clarification, seems a high probability they are CEI Pozi drive.
https://www.draganfly.co.uk/bsa/bsa/b40/category/1187-1187-
https://www.bsaunitsingles.com/item.wws?cpubcode=BSA&sku=76-0546
Best wishes..
Hi Phil,
Yep, nice to have a centre lathe.
However a bench grinder or a power file is a great assist to dress and put a small chamfer on the cut end.
Best wishes...
If you want to use Allen key headed screws, they are available as sets from multiple outlets. One such on a well know auction site is attached but the page lists many others https://www.ebay.co.uk/i/402341648872?chn=ps&norover=1&mkevt=1&mkrid=710-153316-527457-8&mkcid=2&itemid=402341648872&targetid=4584826053363458&device=c&mktype=&googleloc=&poi=&campaignid=398226951&mkgroupid=1299622978767076&rlsatarget=pla-4584826053363458&abcId=2145997&merchantid=87779&msclkid=a6d77251958c1e12382c2db20ed3e64c
Getting good quality cross head screws could be more difficult and require more than 10 seconds of research.
Very useful. Thanks Pete. I guess it's just a matter of deciding.
Phil
Classicbikeshop do the full sets as well for both the distributor model and side points model. They are all defined as BSF which is the same as BCy for the pitch (26) but a slightly different thread angle. I think it is pretty well accepted that for 1/4" diameter that two threads are interchangeable.
I think that trying to get cross head screws could be problematic as the heads are like a deep cheesehead screw not just the standard cross head of today.
In the garage briefly just now, and keen to keep moving before frostbite set it, I thought I'd just see how difficult one of the screws would be to undo. Tried one which looked pretty abused, the one behind the footrest. I had the impact driver out ready, but to my surprise (see photo of its condition) it unscrewed easily, using an ordinary Phillips screwdriver. When it turned straight away I thought oh no is the thread stripped, but it came out fine. Fingers crossed, hope the female is okay.
The photo is not exactly an advertisement for Phillips screws, is it? But obviously they shouldn't be abused, as this one has been. I guess we've all seen lots of them that have been damaged like this.
Makes it tempting to get one of the allen head sets as in Pete's post.
Phil.
When I built my SS90 engine I bought stainless allen bolts for primary chaincase, inner and outer timing cases and found that they made tightening and undoing a lot easier as you get a more positive engagement of the tool into the bolt head. The thread form was cycle (CEI or BSC). The previous advise about using the short end to tighten the bolts is handy to prevent over tightening and potentially damaging the threads in the aluminium casings.
There's an outfit on line called Namrick.co.uk who do a massive range of imperial bolts and machine screws. They might do Phillips headed screws of the right size and may be worth a call. I've also noticed that ebay are selling case screw sets for T120 which have the Phillips heads - not sure what thread they are but again it could be a lead to someone who has the correct size.
But maybe one or two of quite a few different lengths would just be a pain for them. I quite like the idea of buying a set. My primary chaincase cover has cheesehead allen bolts - I wonder if the B40 would have had them originally, or have been the same as the timing side outer case. Phil
Actually it's not very easy to find a set for my 1965 B40F (sidepoints) model. Tried a number of places without success so far. Phil
Hi Phil
Have you tried Richard at 'Tradeclassicbikes'?
No, but will do now, thanks.
He's going to check and get back to me.