I can't find it now, but I 'm sure someone has posted the difference between the sizes of the metric and imperial rear wheel bearings and the thickness of their respective spacer rings. Can anyone help please. Ron
email (option): ronpier@talk21.com
Hi Ron,
My understanding is as follows.
I don't know the thicknesses of the spacers/thrust washers.
Regards
Pat
"The front bearings are expensive. I do not know of a cheap metric solution.
Be careful on the rears. I just made the mistake of trying to fit a 30204 metric bearing which ended up being a fraction too wide. On the rears I put in 05079 cones and 05185 cups (they come in a pair so if you quote 05079 you will get the correct cups.
On the rears I guess that it depends on what someone may have done in the past to make a metric bearing fit. 30204 is 15.25mm wide, whereas a 05079 is 14.38mm wide (the o/d and i/d are virtually the same).
I guess the answer on the rears is to read the number on the cups and cones and use those. The metric bearings are much cheaper, but not much good if you have to machine the spacers to make them fit."
email (option): sacombsashtrees@hotmail.com
OK Patrick thanks for the input. I've just measured an original cup, (all be it still in the hub) and it's about 11+mm (7/16") so subtracting that from your 05079 would make a difference of about 3mm, which would have to be removed from the size of each of the spacer rings. Does the comply with other's findings? Ron
email (option): ronpier@talk21.com
Hi Ron
I am not sure we are talking about the same spacer. Do you mean the one that goes on before the bearings are fitted?
If so, I doubt they are 3mm thick (though I cannot remember as it was a few months since I fitted new bearings). My guess is that you have to take around 0.87mm off each spacer (15.25mm less 14.38mm).
Also, I think that you can only measure taper bearing widths when the cups and cones are together.
I haven't done the conversion, it was quicker for me to fit imperial bearings, so I would be interested in the conversion measurements too.
The other thing to mention is that I swapped like for like i.e. the imperial bearings that were fitted before. I wasn't able to cross reference the BSA part number with a bearing number. As they were imperial and a good fit I presumed that they were to original spec.
Regards
Pat
email (option): sacombsashtrees@hotmail.com
OK Patrick I thought your measurements were just for the cup. I was in a situation yesterday where the bearings were too wide, but I didn't have a vernier to hand to make any measurements.
So the overall difference between the fitted metric and imperial bearings is less than 2mm? I'm sure someone has posted the entire measurements, but just can't find it. Cheers Ron
email (option): ronpier@talk21.com
Hi Ron,
Fitted, one metric bearing will be too wide by 0.87mm.
So, 0.87mm off each spacer.
Regards
Pat
email (option): sacombsashtrees@hotmail.com
Thanks Patrick. Just waiting for the guy to confirm the measurements of the bearings he has. He said he bought them at Netley a year or two ago and they're in SKF boxes?? Ron
email (option): ronpier@talk21.com
Try these guys if you can't get any:
https://simplybearings.co.uk/shop/advanced_search_result.php?search_in_description=1&keywords=05079
Also, below are the Timken dimensions:
https://cad.timken.com/item/all-product-types/tapered-roller-bearings-ts-tapered-single-imperi-2/item-27298
Regards
Pat
email (option): sacombsashtrees@hotmail.com
Thanks again Patrick. I guess these SKF Swedish bearings must be the larger metric size. Ron
email (option): ronpier@talk21.com
Fitted, one metric bearing will be too wide by 0.87mm.
So, 0.87mm off each spacer.
Regards
Pat
email (option): m.wijbenga@hotmail.com
I fitted the wider bearings and just trimmed the inside of the nut, 15-7049, down. If you trim it down an extra few thou than needed it allows the lock nut to go on a bit further.
Well the hub that I was looking at on Saturday, seemed to have the wider bearings which in turn caused the floating brake drum axle 66-6104 to balk against the bearing and brake drum, which is why I raised this query. In my opinion the only way to prepare the hub with the wider bearings is to do what has been suggested which is to fit narrower spacers which in turn will then put the outside edge of the bearings in their original position? Ron
email (option): ronpier@talk21.com
Hi Michael
When you are putting the rear wheel back on, make sure you inspect the condition of the threads on the brake torque arm bolt (BSA 24-209) and the torque arm nut (BSA 15-1166 castle nut/split pin locking). Mine had a plain torque arm nut on it.
If the nut comes off on braking, the rear brake will lock on, bend the brake rod and smash your pannier racking to pieces and bend the rear frame section. Been there, seen it, done it.
Funny how old BSA brakes only work extremely well when you don't want them to!
Regards
Pat
email (option): sacombsashtrees@hotmail.com
Yes, I also used to adapt the 'spindle"-side, but that is a bit tricky as you have to take care the spindle stays in the same axial position as it also affects the position of the brakeplate to the drum,
When material taken from the large spacers in the hub you don't have these thinkabouts and you keep all the parts on the spindle original.
It is also a very easy operation on the lathe as you can clamp the spacer on the inside and only have to take very little material of from the outside edge of the spacer, not along the whole side.
In this way the process is even is reversable to the narrow bearings again if you turn the spacers.:relaxed:
email (option): m.wijbenga@hotmail.com
Going through the many posts on this subject, I have noticed from the parts I have here that the numbers can't be trusted.
I measure the original Timken bearings as 14.70mm + - 0.05mm The measurement is using a spacer under the bearing to allow for the cage protrusion.
As for the 30204 I measure them at 15.4mm despite the claims of them being 15.25mm by the suppliers.
One thing I don't think has been mentioned is that the 30204 is a higher capacity bearing, so if you don't over grease or tighten it, it should last a lifetime.
It might be wise to measure rather than trust quoted numbers.
email (option): pes.sales@btconnect.com
Mark since this thread was started some time ago, I've collated the differences. The modern metric bearings are about 1.25mm (0.050") thicker than the originals, So for the metric bearings, new spacers need to be made that are 50 thou thinner than the originals. A few thousandths either way won't matter as that can be adjusted out. Ron
email (option): ronpier@talk21.com
I just read this post. I had all the same issues with my own wheel bearings and have all of the dimensions including replacement bearing sizes written down somewhere.
I had new spacers made which are 0.050" thinner to accommodate the slightly wider bearings mentioned.
I also fitted ballrace type bearings in the other wheel with a spacer tube machined up to fit between them as in most modern bikes. This arrangement was much cheaper and if you know some-one who can make the spacers it is an easy option.
Let me know if you need details and I will dig out my paperwork.
Regards
Tony.
email (option): tony-wilkinson@sky.com