The BSA A7-A10 Forum

Technical => A7 & A10 Engine => Topic started by: terryk on 27.07. 2010 14:26

Title: A10 main bearing quality
Post by: terryk on 27.07. 2010 14:26
Hi I purchased a main bearing on UK ebay but when I got it the quality seems poor. I have another one I got from Draganfly a few years ago that seems much better quality. Are the Indians making these too? It has the same numbers as the Draganfly one. Here is the ebay link whats your thoughts has anybody tried them.


http://cgi.ebay.co.uk/BSA-A7-A10-drive-side-main-bearing-/250672086417?cmd=ViewItem&pt=UK_Motorcycle_Parts&hash=item3a5d387d91

Title: Re: A10 main bearing quality
Post by: terryk on 27.07. 2010 14:28
The one on the left is the Draganfly one it came in the blue box. The one on the right is the ebay one it came in a cheap looking box.
Title: Re: A10 main bearing quality
Post by: MG on 27.07. 2010 14:32
I never heard of Indian roller or ball bearings, but who knows.
There definitely are cheap bearings from Taiwanese manufacturers around.

The original Hoffmann bearing would have been a C3 version btw (increased bearing play), which is good practice when both races are an interference fit in their seats.

I've ordered one from SRM recently (advertised as "heavy duty"), but not yet received the parcel. If you're interested, I'll report back when it is here.

Cheers, Markus
Title: Re: A10 main bearing quality
Post by: terryk on 27.07. 2010 15:19
Yes Markus let me know how you go, thanks
Title: Re: A10 main bearing quality
Post by: bonny on 27.07. 2010 15:23
always buy branded bearings , skf , fag , rhp, timkin etc , better off buying off a proper bearing factor rather than mail order or ebay. that way you have some come back if they turn out to be wrong.
Title: Re: A10 main bearing quality
Post by: A10Boy on 27.07. 2010 15:28
I agree. Buy good branded ones, its worth always buying the best you can afford. If I don't spend it, she will.......  *smile*
Title: Re: A10 main bearing quality
Post by: BSA_54A10 on 28.07. 2010 12:03

Again are you trying to find the absolute cheapest bearing in the world instead of ordering one from a reputable bearing supplier ?

Next rule of thumb.
If the maker, distributor or retailer are either too cheap or too ashamed to put their name on the product and packaging then it should be considered as CRAP.

So I have never had pistons grow & sieze in the bores or split around the oil groves or bearing collapse or head bolts that won't tension.
This means that i don't do each repair 4 times, get to spend more time on the road & less in the shop.

99.99999999999999999999999999999999999999999999999999999999999999999 % of what is on ebay is rubbish.
Even NOS is often stuff that was retrieved from the scrap bin.
And finally if you buy every thing off ebay then there will be no shops left to sell quality parts.
Title: Re: A10 main bearing quality
Post by: bsa-bill on 28.07. 2010 12:36
Don't think it's just quite that black and white BSA_54A10
Fair number of our better suppliers sell on Ebay, some are quite easy to spot by the stock and address, most don't sell under their known trade name.
your correct that there is some crap on there, most of us will have been caught out at some point, but there is also some good stuff also some over priced good stuff in  as much as if you know the price a trader is charging for bits you can spot the same bits on Ebay with the price hyped up by the inclusion of RGS in the description and people who don't know better will pay up.
It is an auction after all, unless you know what your after and what it is worth - don't bid
If you do bid - know and stick to your valuation, don't bid over
Look to see who is bidding, Ebay will mark with a question mark anybody who has  a history of bidding with the seller, ( some sellers help each other out by bidding for each other, sometimes they have more than one identity (recent court case)).
Also if you indicate an interest ( question to seller ) and there is little interest you might find a bid all of a sudden toward the end to umph the price up - don't bid

Nothing your going to buy on Ebay is likely to be life threatening if you don't win it - if it's suspect in quality or price , don't bid
 
Title: Re: A10 main bearing quality
Post by: terryk on 28.07. 2010 12:46
Its a bit hard to tell quality until someone buys it and lets everyone know. Unfortunately this time its me I wasnt aware of cheap bearings I thought buying on UK ebay would land me some English made ones. Just goes to show you have to ask the questions.
Title: Re: A10 main bearing quality
Post by: Goldy on 28.07. 2010 14:20
BSA_54A10 is correct regarding bearings. If the bearing is marked "SKF" then you know it will be ok but if it's marked, No Chance Bearing Co"   then expect trouble. The real problem is with other parts. I purchased a kick start ratchet for my A10 from what I thought was a reputable supplier. I only kicked the bike over about 5 times when it disintegrated. I am not a metallurgist, but the material was a grey colour as cast iron which is completely unsuitable. The problem is that these parts do not arrive in a little box marked BSA made in Birmingham. It's not so bad with a kick start ratchet, it just means you cannot kick start the machine, but what if it's a brake lever or brake pedal. If someone gets killed because a part which was not fit for purpose fails, do the authorities prosecute the back street manufacturer..... of course not.
Keep safe.
Title: Re: A10 main bearing quality
Post by: Goldseeker on 28.07. 2010 16:51
I am sure there are plenty of people that have bought off Ebay and not been disappointed but I'm not one of them. Except for one item my experience of Ebay has not been good and consequently I don't.

As for bearings, for me there is only one place to buy from and that is a local supplier where you can go and ask them for good quality stuff. In my last job I used to get good quality English/American/Japanese/Western European bearings at huge discounts, anything up to 80% off. Admittedly I worked for an OEM but even as an individual needing a single bearing you are likely to get a reasonable discount if you ask.

Finally, I recently bought a Goldstar rear brake drum/sprocket, Ebay price under £40. Due to past Ebay experiences I called a well known and respected dealer and was quoted £75  *eek*. Hearing by sharp intake of breath he answered "Well if you want Chinese/Indian at half the price its your decision, but mine are made in England, I use them myself for restorations and they are guaranteed not to wear out in six months or fall apart".
I paid up and looked big.
Title: Re: A10 main bearing quality
Post by: Brian on 29.07. 2010 01:31
I saw those bearings on evil-bay myself but when I went down to my local bearing supplier I bought a "Nachi" bearing cheaper. Being metric bearings even the top brand ones are not expensive.

As for the pros and cons of buying on evil-bay, nobody knowns more than me how big a bunch or mongrels they can be. But it is still a very good place to buy parts, you just have to be very careful. I have bought lots of stuff on evil-bay and lots of stuff from reputable shops over the years and have had just as much junk sent to me from the shops. You might say the advantage with the shops is that you can send it back but thats not the case, if you buy a part from even the most reputable bike shop and it fails they will not take it back once it is damaged.

This is a subject I could go on about for hours as pattern or repo parts are my pet hate and have caused me lots of grief over the years but if you use your bike and wear out parts then you have to source replacements from wherever you can and so called "quality" stuff is not always available.
Title: Re: A10 main bearing quality
Post by: terryk on 29.07. 2010 10:53
I thank this forum for lots of information and look forward everyday to checking the new post and comments. I think it would be a good idea if we all just keep letting one another know on this forum about good and bad products whether on ebay or wherever. Then at least we have an opportunity to buy something that we know others have found to be ok. I understand there will be differences in opinion and thats great because its good to hear both sides of the story so we can make our decisions. It costs enough to restore these bikes without getting ripped off with parts that will just sit on our shelves because we arent game to use them.
I've learnt my lesson about bearings. What else can you tell me that is not worth buying? The kick starter story was good advice I would expect they would be of good quality metal but it goes to show you.
Title: Re: A10 main bearing quality
Post by: Goldy on 29.07. 2010 11:31
bsa-bill If you contact JJ Cables in Warwick tel 01926 651470, they make the cables on site. Tell them the length and they make it up for you.
Title: Re: A10 main bearing quality
Post by: MG on 29.07. 2010 11:35
Err, we've got a "Known good suppliers and workmanship" thread that could be used.  *smile*
Title: Re: A10 main bearing quality
Post by: bsa-bill on 29.07. 2010 12:56
Thanks for the Tel No Goldy, I did know there was someone who made cables up (think I read about them in a mag) but did not have a contact, I do need a spare back and front brake cable.
Your right MG, I'll see if I can shift it tonight
Title: Re: A10 main bearing quality
Post by: MG on 29.07. 2010 13:35
That would be great, Bill.
If we collect all the good sources in the thread, we'll hopefully end up with a great database for quality suppliers.
Title: Re: A10 main bearing quality
Post by: A10Boy on 29.07. 2010 14:03
With ebay, you just need to use common sense.

If you want some pistons and see a set of a10 Hepolite pistons, new old stock in original packaging, that the seller has had in his workshop for 30 years, and hes got good feedback you can be pretty sure they are pukka. I've bought and sold stuff like that with no problems.

However, the problems do arise with new made stuff, I ordered a [cheap] front brake cable from a well known supplier, when it turned up I was shocked to see it had "cast on" nipples made of some alloy sh1te. It went in the bin and I ordered one from JJ - lesson learnt.

As far as bearings and suchlike are concerned, i dont think it's worth the risk of buying cheap unbranded stuff when the consequences of failure could be disasterous.

I know of someone who bought a brilliant LJ Crankshaft from ebay - although the seller was a gentleman of the highest moral fiber and character.  *smile*
Title: Re: A10 main bearing quality
Post by: MG on 29.07. 2010 14:13
Quote
I know of someone who bought a brilliant LJ Crankshaft from ebay - although the seller was a gentleman of the highest moral fiber and character.  

Yep. You think I should I add his data to the "good suppliers" thread?  *lol*
Title: Re: A10 main bearing quality
Post by: bsa-bill on 29.07. 2010 14:38
Look out there's a nod and a wink about
Title: Re: A10 main bearing quality
Post by: A10Boy on 29.07. 2010 16:06
 Modesty forbids...  *red*

Ohh and there was a nice camshaft that went to a gent in scotland recently........
Title: Re: A10 main bearing quality
Post by: MG on 06.08. 2010 10:11
I received my parts from SRM today (well, everything except the con-rods, but at least I can start work on the bottom end now).

The roller bearing they sent me is a Japanese NTN NF206E. The suffix E makes it a high load capacity version with increased roller diameter.
So far so good, but what I'm not completely happy with is the resin roller cage. The picture on the SRM website to me clearly looks like a brass cage, but judge for yourself:
http://www.srmclassicbikes.com/catalogue/index.php?target=products&product_id=138 (http://www.srmclassicbikes.com/catalogue/index.php?target=products&product_id=138)

I am not saying that a plastic cage is not going to work, assuming it is temperature-stable and oil-resistant, but just thought I'd mention it, as I think a picture is part of an item's description and you should get what you see in the end.
Title: Re: A10 main bearing quality
Post by: bsa-bill on 06.08. 2010 10:50
Also says USA if I'm not mistaken MG, but most are plastic these days and they seem ok, they would probably take it back but then you would just be adding return postage to the cost of the item.

Andy - sorry I meant to reply, item as described, positive feedback left and now residing in it's new home
Title: Re: A10 main bearing quality
Post by: orabanda on 06.08. 2010 13:45
A very nice feature of the resin (plastic?) roller retainer cage, is that it makes the task of setting the crankshaft end float very easy.

This is because the rollers can be popped out from the retaining cage one by one, leaving the inner bearing race on the crankshaft. In the next step, a standard split bearing puller can be placed around the inner race, and it can be pulled off easily, without any damage.

Finally, the bearing can be re-assembled by putting the cage back in position, and popping the rollers back in place.

I have just set up an A10 bottom end this week, using the SRM bearing;a sometimes difficult task has never been easier!

I also had the crankcase halves set up in a lathe  for the line boring of the bronze outer / white metal inner timing bush, (after making a supporting fixture from an aluminium bellhousing) and am rapt in the final result; bottom end is perfectly aligned and spins like a top, with 0.0015 " clearance between journal and bush.

Other point of note is that I could measure a bit of ovality in the bore for the bushing, in RH crankcase half. I checked the bore because the old bush would slide in from one side, but had an interference fit on the other.

I asked the machinist to bore out the crankcase half, until it cleaned up; it took 0.012" to clean up (concentricity!).
In the future I will adopt this practice always, as clearly ovality is likely to be an issue in old crank case halves.

I then machined up a timing bush from phosphor bronze (had a billet lying around) and sized it to give 0.002" interference on the crankcase. Then I poured babbit (white)  metal on the inside, left a couple of mm undersize on the bore, and shrunk into the crankcase.

The bronze is a better choice than steel, because the co-efficents of expansion are much closer between aluminium and bronze, than for Al and mild steel.
Therefore, it is more likely to maintain an intereference fit (and consequently maximum oil pressure!) when the engine is hot.

By machining in the lathe, we were able to clock perfectly on the primary drive bearing recess, then bolt up the RH half, and machine the timing bush in line.

Richard
Title: Re: A10 main bearing quality
Post by: muskrat on 06.08. 2010 13:59
G'day Richard,
                        I'll give you your 1st karma for that.
I remember using a bearing like that years ago and did the same.
But I've never checked for ovality in the case/bush bore. I will in future.
Cheers
Title: Re: A10 main bearing quality
Post by: orabanda on 06.08. 2010 14:32
Muskrat,
Your'e sweet!
A few pics to complement explanation above:

(http://i302.photobucket.com/albums/nn82/orabanda/P1030196.jpg)

LH crankcase bolted to bellhousing. This was then clocked in lathe, to priary drive bearing

(http://i302.photobucket.com/albums/nn82/orabanda/P1030234.jpg)

Once aligned, RH half bolted on and then line bored

Prior to this, original bore machined until it was round again. Here it is with the new bush installed.

(http://i302.photobucket.com/albums/nn82/orabanda/P1030194.jpg)

Here is new bush (pb outside, white metal inside), machined to be oversize on re-bored crancase

(http://i302.photobucket.com/albums/nn82/orabanda/P1030191.jpg)

Another pic of installed bush

(http://i302.photobucket.com/albums/nn82/orabanda/P1030193.jpg)

Richard

Title: Re: A10 main bearing quality
Post by: MG on 06.08. 2010 17:15
Richard, great idea to remove the rollers for pulling the race off, and nice work with your crankcases!  wink2
Title: Re: A10 main bearing quality
Post by: iansoady on 06.08. 2010 17:26
Nice job.

I might struggle to do that on my 3.5" Granville.......
Title: Re: A10 main bearing quality
Post by: RichardL on 06.08. 2010 17:30
Richard,

A quick question: What assures the poured-in babbit adheres to the phosphor bronze?
Title: Re: A10 main bearing quality
Post by: MG on 06.08. 2010 17:48
Usually you would tin the inside of the bush prior to casting the babbit into the pre-heated bush. This makes sure it will adhere properly.
Of course I don't know how Richard (orabanda) did it, but from what I've seen of his work so far, I'm sure he did it properly  *smile*.
Title: Re: A10 main bearing quality
Post by: orabanda on 07.08. 2010 01:00
As usual, MG knows his stuff!
With the bronze properly tinned, the white metal will make a permanent bond.

What I didn't mention previously was that I had to remove the bush after line boring, remove the white metal and re pour it, because the crankshaft was tight to turn in places.

So, the first time the machining was done in a vertical borer. The LH crankcase half was bolted to my fixture, and the machinint clocked OFF THE CRANKCASE JOINTING FACE. After machining, the alignment was not perfect, because rotation was not easy.

I removed and repoured the bearing (as mentioned above), and insisted that the machinist set up off the LH (roller) bearing surface.

He then did the machining in a lathe, as mentioned at the strt, with perfect results.

This confirms what I have suspected for a long time; that the factory line boring of the crank case halves is not always at 90 degrees to the mating surfaces.
Richard
Title: Re: A10 main bearing quality
Post by: RichardL on 07.08. 2010 01:29
Richard,

Extremely interesting stuff. From the first story I took it that concentcity and angle-on-axis were both taken off the bearing outer ring in the left side. However, with this newly revealed story, I get it that he sought angle-on-axis from the mating surface but wonder what he tried for concentricity? I hope this question makes sense. Very convenient to have have a bell housing with a circular flange.

Richard L.
Title: Re: A10 main bearing quality
Post by: orabanda on 07.08. 2010 02:50
Richard L,
For the first set-up, the machinist used the roller bearing housing for concentricity, but the crankcase jointing face for parallel. This is where it all turned to poo, because the bearing housing had been factory machined at a slight angle to the jointing face.

When set up in the lathe, it was easy to get it right. Concentricity was checked with a dial indicator, and the indicator was also used to check paralell ALONG the bearing housing. The angle was adjusted by shimming the base of the bellhousing in the 4 jaw chuck (and the usual judicious taps with the hammer!).

I used an old hydraulic pump - electric motor bellhousing for the crank case mount as there was one lying around, otherwise I would have made something similar, but probably half the length (not that it matters).

Dick from Oz
Title: Re: A10 main bearing quality
Post by: RichardL on 07.08. 2010 02:58
Richard,

Thanks for that explanation. I like having a clear understanding when the solution is brilliant.

Richard L.
Title: Re: A10 main bearing quality
Post by: BSA_54A10 on 07.08. 2010 11:20
Quote
A quick question: What assures the poured-in babbit adheres to the phosphor bronze?

Provided that you warm the outer first to prevent instant chill grains forming on the bronze then the Beta phase actually alloys with the copper and penetrates into the atomic lattice of the outer case.
As such it dose not adhere but , for want of a simpler term , melts into the case.
If you cut it in half there would be no clear sharp line that was yellow on one side and white on the other.

If done cold then you can get a suitation where the Beta phase solidifies out on the bronze case which starts to expand due to the heat from the molten metal which starts to contract due to its solidification and a mechanical tear occurs in the weaker material, namely the babbit but normally this only happens when you have a big lump of metal like pouring a babbit into the con rod on a long stroke A 7.
Title: Re: A10 main bearing quality
Post by: bonny on 07.08. 2010 13:54
hi orabanda

couple of questions , where do you get the babbit metal ? did you make it yourself ? and do you have any pictures of the cases in the lathe ? it would be good to see. i was thinking about something similar making a jig for the milling machine and aligning everything off the roller bearing housing and using a boring head to bore the bush to size .
Title: Re: A10 main bearing quality
Post by: BSA_54A10 on 07.08. 2010 15:04
You can buy castable babbit ( in about 200 grades) from most engineering supply stores, usually in break offs.
It is not hard to make but use plenty of Potassium nitrate flux on top or you will burn off the lower melting point metals.
Ideally you would use a mix of 2 parts Potassium nitrate , 1 part ammonium nitrate & 1 part sodium nitrate but if you go and buy those 3 chemicals together expect a visit from the "hut, hut, hut" boys at about 2 am and they won't be riding their A10's.
Title: Re: A10 main bearing quality
Post by: orabanda on 07.08. 2010 17:19
Hi Bonnie,
As Trevor pointed out, white metal is readily available.
I am using "OTL C.I.E., which is a tin base alloy, containing Cadmium.
It's application is " Compression Ignition Engines (Diesel) and all other types of internal combustion engines.

My machinist found it easier to set in the lathe rather than the mill, when it came to aligning along the length of the LH bearing bore. Setting concentricity is easy in either machine.
Richard
Title: Re: A10 main bearing quality
Post by: bsa-bill on 07.08. 2010 20:40
You know I was chuffed the other day at my ability to machine ( grind with stone in my bench drill ) a head bolt so I could get a longer one to get past stripped threads in the head, then I read the above mails, boy oh boy the depth of expertise in here is something else.
Respect Richard  *yeah*