Mk3 front wheel on pre-Mk3? (2007)

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So, I've been working on the 850 project bike. It turns out that what I have is basically a 750 rolling chassis with a 1974 850 engine and a Mk3 front wheel (as evidenced by a circlip instead of a threaded retainer ring on the non-disk side).

I'm not familiar with the Mk3 parts, so this raises some questions:

Will this wheel work with my pre-Mk3 front end, or will there be alignment issues due to the wheel being flipped around backwards?

If it will work, what exactly do I need for spacers and seals outboard of the bearings? I bought it as a parts bike and most of the spacers were missing (it was just loosely assembled for sale). I don't have a Mk3 parts book and I'm having a hard time figuring out what parts are supposed to go on each side.

thanks,
Debby
 
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Deb,

I have a MKIII wheel parts list with drawing that I could pdf and email to you tomorrow. Or, if I can figure it out, perhaps I could post the info on this website.
 

L.A.B.

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The Mk3 front wheel/hub can be used either way around without any problems (don't forget to change the tyre round so that any rotation arrows are the correct way), as it has the circlip for bearing location, unlike the pre-Mk3 disc wheel hub that has the screwed sleeve which can become loose if used the reverse (Mk3) way around.

However, the Mk3 wheel uses a different spoke pattern as the disc would normally be on the left side, so the wheel is built with the disc-side inner spokes being the ones under tension during braking, turning the wheel around then places the disc side outers under tension, but I'm not sure if the change really makes any real difference?

Unfortunately the BSA Regal Commando parts lists are off-line at present due to the change of ownership.

The parts you should need are:

Hub circlip side:
From the circlip-

06-2448 Dust cover (inc. spacer)


Disc side:

06-2071 Washer
06-7614 Seal
06-3012 Retaining washer
06-6034 Dust cover

The wheel spindle/axle is the same as the earlier wheel.
 

Ron L

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Debby,

There should be no alignment issues as the disc determines the hub position regardless of left side or right side. Essentially the forks are just flipped (the drain plugs wind up at the front on the Mk3!). The circlip was used to eliminate the possibility of the bearing retainer unscrewing with wheel rotation.

The spacers you need are:

disc side 062448 (same as pre mkII)
non disc side dust cover 066034 (same as 063918?)

I am not sure if there is any difference in 066034 and the non-mk3 063918.
 

L.A.B.

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Ron L said:
non disc side dust cover 066034 (same as 063918?)

I am not sure if there is any difference in 066034 and the non-mk3 063918.

I think there would be a difference, as there is no threaded sleeve, spacer and separate seal on the Mk3 hub, circlip side, as the bearing on that side should be a sealed (RS) type?
 
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L.A.B. said:
Ron L said:
non disc side dust cover 066034 (same as 063918?)

I am not sure if there is any difference in 066034 and the non-mk3 063918.

I think there would be a difference, as there is no threaded sleeve, spacer and separate seal on the Mk3 hub, circlip side, as the bearing on that side should be a sealed (RS) type?

My wheel had unshielded bearings on both sides, but I don't know if it was original. I put in a new sealed single-row bearing, but retained the unsealed double-row bearing for now (they're expensive).

Anyway, this is starting to make sense, and I think it will actually work :D
I have a 062448 spacer as well as a new felt seal and associated washers, so I think I'm covered on the disk side.

For the non-disk side it sounds like I'll need the 066034 dust cover (in spite of an apparent typo in the parts lists that refers to this as "dust cover, disk side"). I should be able to fit the wheel without the dust cover though, as the axle has a shoulder. The axle will slide in a little further than normal but that shouldn't be a problem. Eventually I will want the dust cover as it should provide some additional protection for the bearing.

I'll report back after I have a chance to test-fit the wheel. Fun stuff! I love it when a new bike starts to emerge from the piles of parts.
8)

Jason - sent you a PM. I would like to see that pdf.

Debby
 

L.A.B.

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debby said:
The axle will slide in a little further than normal but that shouldn't be a problem.

It could be a problem, as there may not be enough thread length on the end of the axle to enable the nut to be tightened if you do that?

Better to find a correct length spacer to put between the axle shoulder and the bearing I would have thought?
 
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L.A.B. said:
debby said:
The axle will slide in a little further than normal but that shouldn't be a problem.

It could be a problem, as there may not be enough thread length on the end of the axle to enable the nut to be tightened if you do that?

Now that I think about it, I believe you are correct, Les. When I received the bike there were no spacers on the non-disk side and the nut was indeed bottomed on the threads. I didn't know why at the time.

I guess I'll be ordering the correct spacer!

Debby
 

Ron L

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My wheel had unshielded bearings on both sides, but I don't know if it was original. I put in a new sealed single-row bearing, but retained the unsealed double-row bearing for now (they're expensive).
I think most of us are familiar with the double row bearing replacement using the sealed version in 17X40X17.42 requiring machining of the bearing spacer. However, when ordering new bearings for a set of wheels I'm lacing, my bearing supplier shows a double sealed double row bearing in 17X40X16 (2203E-2RS1TN9 SKF). This bearing is about the same cost as the stock bearing and since I don't have a lathe to cut down the spacer, the extra cost is a wash with what I would have to pay a machinist to cut down the spacer. It also simplifies the the rear wheel fitment.

I'm sure this bearing has been around awhile. Any good reason why to do the machining rather than use this stock dimension sealed bearing?
 

L.A.B.

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Ron L said:
However, when ordering new bearings for a set of wheels I'm lacing, my bearing supplier shows a double sealed double row bearing in 17X40X16 (2203E-2RS1TN9 SKF). This bearing is about the same cost as the stock bearing and since I don't have a lathe to cut down the spacer, the extra cost is a wash with what I would have to pay a machinist to cut down the spacer. It also simplifies the the rear wheel fitment.

I'm sure this bearing has been around awhile. Any good reason why to do the machining rather than use this stock dimension sealed bearing?


A 2203 bearing has a much lighter load range than a 4203.

4203
http://www.skf.com/skf/productcatalogue ... =104004203


2203E
http://www.skf.com/skf/productcatalogue ... 1140312203

So I don't think I'd want to use them, -personally.
 
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I have 4 off 4203 2RS's on order awaiting delivery from Wyko UK, will post info when I see them, European manfacturers do not list them but Japanese do so they are a special order.
 
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Hey Ron,

I hear those Harbor Freight lathes are actually pretty good, but you have to treat them as pre-assembled kits. Kind of like a Royal Enfield Bullet :wink:

Debby
 
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L.A.B. said:
The Mk3 front wheel/hub can be used either way around without any problems (don't forget to change the tyre round so that any rotation arrows are the correct way), as it has the circlip for bearing location, unlike the pre-Mk3 disc wheel hub that has the screwed sleeve which can become loose if used the reverse (Mk3) way around.

However, the Mk3 wheel uses a different spoke pattern as the disc would normally be on the left side, so the wheel is built with the disc-side inner spokes being the ones under tension during braking, turning the wheel around then places the disc side outers under tension, but I'm not sure if the change really makes any real difference?

That is a god point since when I had Buchanan build my wheels I had to specify wheter Iw as running the disc stock or to the right side which I am doing now.
 
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As a young chap I had the double race fail through water ingress. The replacement was expensive and unavailable locally. I had noticed most Jap bikes of the era only used single races both sides and were of a similar size to the Norton. Desperate times need desperate actions, and as I had a spare single race I made up a spacer and stuck it in. It never failed and was still in the hub years later.
Since then I've always fitted a single race sealed bearing to each side and never ever had a problem. My current 850 has had this setup for near 14years and is still on the same bearings. Clearly this is at my risk I just thought I'd let you know.

Cash
 
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Picked up the bearings today, they are 4203 2RS but no maker markings, were £11 plus VAT.
 

Jdub

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Did not want to start a new thread to ask a question this thread seems to answer. That question is this: Is there any reason a Mk3 front hub cannot replace a Mk2 front hub for use in a 1974 Mk2 project bike? I do note the different lacing of Mk2 vs. Mk3 front wheels, but that would not apply here - I simply have a Mk3 hub and cannot seem to find a Mk2 hub at a reasonable cost. So, I am thinking of just applying the Mk3 hub to this project bike.
 

L.A.B.

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Is there any reason a Mk3 front hub cannot replace a Mk2 front hub for use in a 1974 Mk2 project bike?

The Mk3 hub can be safely used for either left or right-hand or pre-Mk3 disc applications as it has a circlip bearing retainer.
 

RoadScholar

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Given the level of speculation and LAB's remark about spoke pattern I suggest that you make a call to Buchanan's and see if they have any wisdom to add about re-purposing the Mk3 wheel assembly to your project.

Best
 

L.A.B.

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Given the level of speculation and LAB's remark about spoke pattern I suggest that you make a call to Buchanan's and see if they have any wisdom to add about re-purposing the Mk3 wheel assembly to your project.

I understood Jdub's question to be about the Mk3 hub not wheel*, so it can be laced as required.

*(That was 2007)
 
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