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Bent Forks (where?)

PostPosted: Thu Jul 07, 2022 9:55 pm
by Lord-Spanner
Hiya folks

Quick question as I'm trying to find out if my forks are straight before spraying them (AGAIN :evil: ) So far I've used 2 long M12 bolts and 3 long extended nuts and basically pushed them through the bottom arm bolt holes and joined them up so I'm quite confident those are square and straight, and is it possible to check the straightness of the single upright tube with a straight edge?

Now for the question.....if your forks are bent do they bend inside the frame tube or can they bend in other places too??

cheers peeps :mrgreen:

Re: Bent Forks (where?)

PostPosted: Fri Jul 08, 2022 6:57 am
by Storkfoot
Holding a steel rule against the stem (move it around the circumference) will give you a pretty good idea. Watch for differing distances above the “crumple zone” in particular. If they were really badly out, you may well be able to see witness marks around the bottom of the stem.

I have a set at the moment that are ever so slightly out. I am going to take them to a jig to check properly.

Re: Bent Forks (where?)

PostPosted: Fri Jul 08, 2022 7:38 am
by Lord-Spanner
Storkfoot wrote:Holding a steel rule against the stem (move it around the circumference) will give you a pretty good idea. Watch for differing distances above the “crumple zone” in particular. If they were really badly out, you may well be able to see witness marks around the bottom of the stem.

I have a set at the moment that are ever so slightly out. I am going to take them to a jig to check properly.


I have a spirit level with a small V cut out which the stem sits nicely into, I've chased it around the stem with a feeler gauge where the stem narrows slightly and all seems to be the same, when you say the crumple zone I'm guessing you mean the very bottom of the stem? (seen that in stickies bible)

Re: Bent Forks (where?)

PostPosted: Fri Jul 08, 2022 10:55 am
by Storkfoot
The crumple zone, well that’s what I call it, as about 6” up the stem. It is where the stem is at its narrowest ;) :)

Re: Bent Forks (where?)

PostPosted: Sat Jul 09, 2022 5:53 am
by Lord-Spanner
Storkfoot wrote:The crumple zone, well that’s what I call it, as about 6” up the stem. It is where the stem is at its narrowest ;) :)


I see, that would be the weakest point I guess that would bend in a fender bender :roll:

Re: Bent Forks (where?)

PostPosted: Sat Jul 09, 2022 8:34 am
by HxPaul
Go to Mike Phoenix they do fork straitening. They have a jig.Its in Manchester.

Re: Bent Forks (where?)

PostPosted: Sat Jul 09, 2022 8:32 pm
by Lord-Spanner
HxPaul wrote:Go to Mike Phoenix they do fork straitening. They have a jig.Its in Manchester.


I've asked the question :mrgreen: