Confirmation needed - forks

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Coolhands

Coolhands

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Hey Norton experts. Ham fisted day in the garage yesterday and I need to determine how I screwed up.

Rebuilding the forks on my 1972 Norton Combat Commando and my left fork was seized when I put it together with new bushings.

I’m thinking one or both of these

1. The removal of the slider cover required use of the big blue wrench. Maybe I distorted the slider heating it up?

2. Looking back at the bearing kit I bought it has the words “road holder” would this be different than stock bearings?

Any advice would be much appreciated.
 
Were the forks removed from the bike or was the work done with the forks in place?

If the forks were removed, was the fork seized immediately upon reassembly but before being reinstalled or were both OK until the reinstall and then one was seized?

Do you have a Fork brace - Hyde or whatever?

It is quite possible that the flame wrench caused some distortion...

"Roadholder" is OK BUT there were different road holder forks used on different era Nortons. It may be that you have a kit for the wrong Roadholder fork set. I have no experience at all with the earlier forks so I don't know if having the incorrect kit would cause binding/seizing or not. I'm sure there are folks here that do know!
 
MexicoMike said:
"Roadholder" is OK BUT there were different road holder forks used on different era Nortons. It may be that you have a kit for the wrong Roadholder fork set.
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The same upper and lower bushes were fitted to Roadholders (but under different part numbers so from 1949 to 850 Mk3) as far as I'm aware.

andover-norton.co.uk

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andover-norton.co.uk

Motorcycle parts and spares for Norton motorbikes - Genuine Andover Norton Spare Parts - Andover Norton Motorcycles Parts - Original Andover Norton Parts

Motorcycle parts and spares for Andover Norton motorbikes: Andover Norton manufactures and supplies all Genuine Factory Spare Parts for Norton motorcycles built before 2002.
andover-norton.co.uk
 
Forke yokes are different from the last models. The stanchion inclination is different and you canot mix up lower and top yokes. However loosen up the top stanchion nuts should not be more dificult than using a socket spanner. Before or now, take the wheel out. Pushing the stanchion out of the cone needs to be done with loose bolts on the low yokes. Best you screw in again the top nuts (without the speedo/rev cups) half the way and protecting the top of the nut with wood a hit with a hammer should do the job to loosen the stanchion. Bushes are the same in most. There are some longer top once but this is not a must. One issue is the short distance between bottom and top bush and I am working on a new version of collar with a Triumph oil seal but this is still in drawings. Also collars of aluminium with an integrated scratcher are available. (specially for the versions with the small gaiter in order preventing dirt getting to the oil seal)
 
Martin Bernert Rahm said:
Forke yokes are different from the last models. The stanchion inclination is different and you canot mix up lower and top yokes. However loosen up the top stanchion nuts should not be more dificult than using a socket spanner. Before or now, take the wheel out. Pushing the stanchion out of the cone needs to be done with loose bolts on the low yokes. Best you screw in again the top nuts (without the speedo/rev cups) half the way and protecting the top of the nut with wood a hit with a hammer should do the job to loosen the stanchion.
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The fork has already been rebuilt so none of that appears to be relevant, unfortunately.
 
Both forks were rebuilt on the bench and have not been installed to it’s not binding in the yoke.
 
Maybe just bad aftermarket parts? I ordered everything a while ago. Don’t think it’s AN. Part numbers match.
 

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Recently rebushed forks on my 74. New stanchions as well. One vendors bushes were way too tight.
Ordered another set from AN. Perfect fit. Suggest you get the stanchions and sliders etc from the same outfit .
I think RGM has said that there were varying dimensions on forks due to sourcing from various firms. True or not , no idea.
 
Coolhands said:
Both forks were rebuilt on the bench and have not been installed to it’s not binding in the yoke.
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I recently had one where it would stick when fully compressed but otherwise was OK - this was without springs. Turns out that there was a burr on the bottom edge of the fork tube. It would slide perfectly but at the bottom would catch and was a bear to get out. I never figured out what it was catching on, but I lightly filed (smoothed) the area below the circlip and it was resolved. This would never have been a problem in use since the forks would not compress that much, but it bothered me, so I corrected it.
 
It is fully compressed so who knows. That’s could be it right there. I’m going to reorder everything from AN and give it another go.

Thank you everyone for the comments!
 
When I bought and installed the new bushing in my Atlas, they were very tight. I think I used a wheel cylinder hone on the ID until I got a better fit. I had also replaced the fork stanchions at the same time, and they were aftermarket. I suspect they were slightly oversize.
 
Did you make any mods to the internals like the damper tube or cap if it is sticking it fully compressed something may be catching on the oil passage hole.
 
Thanks guys. Ya’ll probably think I’m an unfit parent of this thing. All the parts on the way to get it right.

Hopefully I’ll be posting some pretty pics and sweet sounding vids soon.
 
Coolhands said:
Thanks guys. Ya’ll probably think I’m an unfit parent of this thing. All the parts on the way to get it right.

Hopefully I’ll be posting some pretty pics and sweet sounding vids soon.
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I'm confirming that you are not unfit. Buying a used poorly maintained classic Norton in this day and age takes courage, a lot of blind faith, and a healthy toy fund.

Enjoy the journey.
 
Coolhands said:
It is fully compressed so who knows. That’s could be it right there. I’m going to reorder everything from AN and give it another go.

Thank you everyone for the comments!
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Since it only sticks at full compression, odds are that you didn't warp the lower leg. That said, in future, rather than use a "big blue" wrench, the following is safer:

#1 Wait until "she who must be obeyed" is not home.
#2 Line the bottom of the oven with aluminum foil, to catch any dripping oil. Oil will leech out of the part when heated.
#3 Heat the oven to 275 - 300 F.
#4 Place seize aluminum part in the oven to safely free it up.
#5 After successfully freeing up that part, open the windows to air out the kitchen and clean the oven to hide all the evidence of your misdeed. ;)

Heating aluminum above 300 F or uneven heating risks warping that item. [Yes, I'm aware that cylinder heads regularly operate above 300 F]
 
Thanks for the additional info. I broke the pinch side lower so I have a whole new front end on. Will use Chaz’s method for freeing up the mangled parts to see what might help someone else.

She who must be obeyed is used to my kitchen bullshit after 20 years of this stuff. I just made the comment this week that there’s been more hydraulic fluid in the turkey baster thanks whatever you are supposed to baste turkeys with.
 
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Forks are such a simple thing, just two bushes that need to slide on a machined tube, but they can be a bugger to get right. As for replacement parts, I've had poorly fitting bushes from AN that wouldn't fit brand new AN fork tubes, so no-one's immune from quality issues. I was recently building a set of Veocette forks (all new parts) and everything worked perfectly until I put the stanchions into the sliders at which point one of the two forks started to bind. I swapped bushes side to side with no change and eventually the penny dropped that one of the new legs was slightly bent. It was fractional, but with everything new and little clearance anywhere it was enough to cause binding on or close to full extension. I replaced the stanchion (again) and it all worked perfectly. Sadly the moral of the story is to trust nothing and test at each stage of the assembly process - and be prepared for new parts to be the source of the problem.
 
bsaboss said:
Forks are such a simple thing, just two bushes that need to slide on a machined tube, but they can be a bugger to get right. As for replacement parts, I've had poorly fitting bushes from AN that wouldn't fit brand new AN fork tubes, so no-one's immune from quality issues. I was recently building a set of Veocette forks (all new parts) and everything worked perfectly until I put the stanchions into the sliders at which point one of the two forks started to bind. I swapped bushes side to side with no change and eventually the penny dropped that one of the new legs was slightly bent. It was fractional, but with everything new and little clearance anywhere it was enough to cause binding on or close to full extension. I replaced the stanchion (again) and it all worked perfectly. Sadly the moral of the story is to trust nothing and test at each stage of the assembly process - and be prepared for new parts to be the source of the problem.
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+1 on this.

If you have all new parts, check that there is free movement on the stantion with the fork bushes. I had a new AN tube and bush that didnt have a good free slide, and swapping new bushes around L/R fixed that.
 
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