Front wheel centralisation

Information relating to the Matchless G3 or AJS Model 16 350cc Heavyweight
sno335
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Front wheel centralisation

Post by sno335 »

Hi, I put the front wheel back in my 54 G3 forks but it is closer to the left-hand fork leg(brake plate) side.It is a single side hub fro nt wheel c.1952.The bike is allegedly 1954 but I haven't had it dated yet.
With the wheel in this position the torque arm doesn't sit right and is at an angle.
I've checked the parts lists and workshop manuals and the hub is assembled correctly.
The only way to centralis e the wheel is to put a 5mm spacer between the outer brake plate nut and the fork leg.Highly unsatisfactory as the axle is not clamped across it's full width and not enough thread engaged on the spindle nut.
Anyone had this dilemma or theories please?
John
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Rob Harknett
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Re: Front wheel centralisation

Post by Rob Harknett »

???? The axle is clamped.
Ashampoo_Snap_17 June 2021_10h33m43s_001_.jpg
This is 1952 wheel. Do not add a 5 mm spacer. Place the wheel in the forks brake on the left hand side. Loosely fit the 2 fork end caps/ 4 washers & nuts, which clamp the spindle. Position the wheel so the brake plate non threaded end of the spindle is almost flush with the forks. Just the rounded end of the spindle proud of the forks. Fit the brake anchor bolt. Now fully tighten the 4 clamp nuts. Next fit spindle washer, nut and tighten. If when tightening the spindle nut the opposite end of the spindle starts to pull through, you have not tightened the 4 clamp nuts enough. You may have the wrong brake anchor arm.
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clive
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Re: Front wheel centralisation

Post by clive »

Hmm I have always tightened up the spindle nut, then fully tightened the endcap on that side but left the endcap just off tight on the other side, Then pumped the forks up and down a couple of times before tightening the other end cap. This ensures the forks are lined up correctly and will be free for full movement. As advised by Les at Russell's in 1979!
If the wheel is not centralised when the spindle nut is done up the problem may be the length of the nut holding the brake plate on, there were different lengths over the years, but if there is not then enough thread on the spindle nut if it moves across I wonder if the wheel has been rebuilt and the offset is wrong.
clive
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Rob Harknett
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Re: Front wheel centralisation

Post by Rob Harknett »

Tell Les end caps should be tightened first Clive, having got the spindle in the correct position on the right hand side, r/hand end cap tight enough to grip the spindle in position. ( I have seen bikes where the spindle had pulled up to half way through the fork leg through tighten the spindle nut before fully tightening end cap nuts.) The l/hand cap nuts can be left a little loose, pump the forks to centralise which should result in no stiffness pumping forks. Fully tighten all end cap nuts, then fully tighten the spindle nut.
When I was 16 I went by how I read it in the book.
Ashampoo_Snap_18 June 2021_10h26m10s_001_.jpg
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Last edited by Rob Harknett on Fri Jun 18, 2021 11:09 am, edited 1 time in total.
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ajscomboman
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Re: Front wheel centralisation

Post by ajscomboman »

If you think about it logically, tightening the spindle nut first clamps both the cap and the slider. By doing do it that way means that there is no way of then being certain on tightening the end cap nuts on the brake plate side that the cap clamps around the spindle correctly. I always assemble everything loose, pull the spindle over to the alloy slider using the spindle nut so the brake plate lock nut just touches the slider and end cap, tighten the end cap nuts and then lock the assembly with the spindle nut. Leaving the off side cap slightly loose I take the bike off the stand and pump up and down with the brake on, then I nip up the off side clamp.
g80csp11
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Re: Front wheel centralisation

Post by g80csp11 »

Have you had the wheel re-laced new rim /spokes ? if so its likely that the offset is incorrect and the Tyre sits in the wrong position by 5 mm
Back in the late 70's I had my 46 G80L re-laced after stove enameling the rim (black in 46) at a local motorcycle shop , I had the same problem so took the opportunity to re-lace with stainless spokes myself and set up correctly
It was clear that being a professional motorcycle mechanic , does not actual prove you have any idea about old bikes

God , back in the day , that makes me feel old , what happened to the last 46 years!
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clive
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Re: Front wheel centralisation

Post by clive »

ajscomboman wrote: Fri Jun 18, 2021 11:03 am If you think about it logically, tightening the spindle nut first clamps both the cap and the slider. By doing do it that way means that there is no way of then being certain on tightening the end cap nuts on the brake plate side that the cap clamps around the spindle correctly. I always assemble everything loose, pull the spindle over to the alloy slider using the spindle nut so the brake plate lock nut just touches the slider and end cap, tighten the end cap nuts and then lock the assembly with the spindle nut. Leaving the off side cap slightly loose I take the bike off the stand and pump up and down with the brake on, then I nip up the off side clamp.
I think that is what I tried to describe too and have no intention of correcting Les! I don't understand Rob H how if you do not use the spindle nut to pull the spindle right across how machines with a brake plate that is bolted to the left hand slider (40 to 49) is bolted up without twisting the brake plate or at least putting stress on it.
clive
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sno335
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Re: Front wheel centralisation

Post by sno335 »

Thanks everyone for their input.Much appreciated. As the wheel is fairly rusty I would think it's original and hasn't been rebuilt.
I think torque arms are similar apart from front or rear brake adjuster position.I need to try bouncing the forks before tightening but have yet to try it.Unfortunately I failed to notice how the wheel was positioned before I took it off to check the bearings.I bought the bike as a bitsa so I don't know the age of the various components.I'll post when I've tried bouncing the forks .
John
sno335
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Re: Front wheel centralisation

Post by sno335 »

Well I tried bouncing the forks but no improvement.
I checked fork alignment by clamping a bar in the fork ends and it was fine.I then put a straight edge across both sides of the wheel rim using steel parallels as spacers.I marked the wheel spindle both sides onto masking tape previously attached.
The result is that the wheel needs a 5mm spacer to centralise it.
So I must assume the wheel is incorrectly laced! I'll be on the lookout for a full width hub wheel.
Just one other query? Are the fork ends identical or different?
The parts list has left and right but also 2 the same?
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clive
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Re: Front wheel centralisation

Post by clive »

I thought the fork end caps were identical.
clive
if it ain't broke don't fix
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