FF: Forks Straighten Bent Top Fork Link

[Chris.R]

Maughan`s have looked at my fork links both of which were bent as seen when dismantled and laid on a sheet of marble the distortion was not so bad and they have straightened the bottom link which will be returned in fine fettle, however they say they as professionals will not try to straighten the top link, the link however is only bent in one direction and they suggest that I might like to have a go at straightening the link myself how would I go about this. the difference on a flush surface was a matter of at most 1.5mm.

 

[greg brillus]

I've done them before no problem.......The links are difficult to straighten as the bends are not on one arm only but both, and they can twist as well. Use a pair of steel rulers as straight edges to check the alignment of the sides to get equal distances. You need to end up so that you can pass the spindle through with little or no binding. You should straighten it cold........ Good luck.

 

[Chris.R]

Thanks for the up on that Greg mine appears to be out of alignment in only one direction the up/down I am told there is no twisting side to side which makes things easier. Maughan`s have overhauled the bottom link straightening it, there was similar movement, they have a jig that does that one. They did say I would need a strong vice and iron bars and that the movement needs to be beyond what is actually required as there is a tendency to spring back. I will have the links back with me in a week or so which is a pretty quick turnround.

As I work on the bike I am finding more of the history it was dropped at some time the evidence is of the off side riders foot peg bent and on cutting the pedal rubber off the front end of the peg is ground away, The edge of the number plate is grazed but not badly. The underside of the silencer now I have it off has a graze on the end of the tail pipe while underneath there is a foot long nasty graze and flattening of the silencer. Curiously neither the saddle or the tank show any signs of damage. The seat I have remade with new board squab and cover, the tank I have only to redo the gold lining. most of the eight owners before me did not have her for that long but there was one owner from 1968 until 1991 when sold to the fellow whose dad had the museum the Comet ended up in until four years ago I bought the bike from it`s last owner a classic bike and car dealer last June as a project to restore and ride. If you have not seen it my last Comet a 1952 is with Ken Phelps.

 

[greg brillus]

Not too many old bikes that have survived unscathed in some way or other. I've had bikes where if you tighten up the fork spindles to the correct amount, the forks lock solid. I had a Shadow where in the boxes of old spare parts that came with it, there was a 5 inch speedo where the very top of it was folded over and ground away quite a bit (I still have that one.........) The worst damage apart from bent links (generally always the lower one) and bent blades, is if the headstock bearing pockets are oval from the impact trying to rip the bearing races out of their pockets....... That is not a nice thing to repair.........

 

[Chris.R]

Fortunately Greg my links are not so bad they cannot have been as Maughan`s have fixed them pretty quick. I should have them back in a week.
Just now have got to strike up the courage to get the bearing cup refitted in the rear hub, it has been nickel plated a thou and has been in the freezer for a week, I am told to heat the hub with a blowlamp and it should drop in after cooling a few drops of locktite will do the rest then reverse the hub as it was likely an overtight chain that caused the bearing cup to come loose in the first place. I cannot believe that this is the way workshops would have done the same job surely a press would be used. I can probably achieve that with an oversized G-Clamp what do you think.

 

[greg brillus]

I straightened a bent lower link the other day, took me about an hour............they are quite strong. The tight chain theory sounds possible, I have always thought it to be from incorrectly shimmed bearings, generally too tight. But I had one the other day on the back of a Comet that was flogged enough that the bearing housing has split. I think that he housing is quite a weak design, given the original ones made pre war were actually made of steel. So now i am of the opinion that it is generally caused by a lot of use and age. It is pretty rare to carry out a full restoration on these bikes and not have to replace one or both hubs. Like old cylinder barrel assemblies, I don't try and repair them, as the effort to fully strip a wheel to change the hub is far more than the cost of new replacements. Measure the outer OD of the bearing and the hub to see how much interference you have. if the bearing will press in without to much effort, I would lightly coat the bearing and hub inner wall with a light coat of bearing fit loctite, and press it in cold. If the interference is more than about 0.0015" heat the hub and simply drop the race in. I have never bothered to freeze the bearing, even with 0.003" interference with a hot hub the bearing will still drop in ok. Do not overheat the hub, the small area to be heated is not large, and thin walled. I mostly use an electric heat gun on smaller items like these. Good luck with it all.............. Greg.

 

[chankly bore]

If you're lucky enough to have metric hubs they don't flog out as easily because there is more "meat" around the cups. If you're staring from scratch go metric as well, for this reason and because the bearings are cheaper and more readily available nowadays. Bearing retailers fill the price of Imperial bearings with helium in Australia to discourage customers who talk steam-age measurements. Quite a few bikes came to Australia with metric wheel bearings originally.

 

[Chris.R]

I have metric bearings in the 54 Comet.