Topic: Are my bent forks minor enough to straighten?

[Thunder]

Well, i was riding her around, and the handling was was off, so i lined the forks up by eye and they looked twisted.But as i want to eventually get her into a cafe racer, looking perfect, i thought i better pull em off and get em re chromed.

After disassembly i took the two upper tubes and held them together, At their worst(when rotating them against each other) i get a gap of around 1.5 mm.

i have a place willing to straighten and hard chrome em, but i was just wondering what you guys thought... is it minor enough to straighten?

Thanks
Thor

[mlinder]

I doubt 'straightening' them and rechroming them is a reasonable proposition.

It will be cheaper, and better, to buy either a used set off of ebay or from someone her eon the forums, or a new set from someone like forks by frank. http://www.frankmain.qpg.com/

[crazypj]

They are old thick walled spring steel. (about 4mm wall thickness)
If you use shaped alloy blocks you wont damage chrome. (I used to use 1/16h sheet, curved around fork tube in 'V' blocks and on ram although I hear shaped nylon blocks are now available)
 It sounds like they are curved rather than bent, actually pretty normal, need to put them on centers or rollers to check if both are curved by 0.75mm or just one  by 1.5mm.
 You also need o figure out where the bend starts and ends (usually above the top of slider)
 As long as there is no kinking where they meet clamps your OK to straighten them, new forks are large diameter thin wall tubing (1.5~2mm) and very difficult/impossible to straighten with normal shop equipment
 It would probably be cheaper to get new ones (Forks by Frank) than to have them re-chromed as its a special 'piston' chrome as used on hydraulic rams and needs to be ground to size after plating (unless you work somewhere where they will do it 'free'?)
PJ

[fuzzybutt]

i used the new fork tubes from the cycle exchange http://www.cyclexchange.net/Front%20Ends%20Page.htm  theyre super nice quality and inexpensive too.

[Thunder]

Thanks guys

Well the place does industrial hard chrome, and they've done alot of forks,they tell me.
(re chroming and straightening it comes to about 90 dollars for both).

i didn't know that a slight bend in the forks is normal(heavy bikes i suppose.)This is from braking?
Well i reckon, i'll take em to them and ask what they think. I got new fork seals, and finding new /used forks here is going to be difficult.

Any further advice is always appreciated

thanks again
Thor

[Clyde]

Looks like the bike has been in a minor accident.
Check the triple tree around the bottom race and see if there is any buckling, as these can be damaged as well.
Even if there is no damage, it most likely will be bent also. I suggest you take it with the forks and get the whole lot straightened together.
That is a very good price for straightening and chroming.
I have had a lot of these old forks straightened and chromed. As mentioned before they are very thick and even if pitted badly can be rechromed.
Whether you get them rechromed or buy new ones is just a cost question.

[754]

That is a vey good price even if they are straight!

where are they located?....(Too far for me I think). but others might need it.

For you guys that dont know, Hard Chrome is almost forever (Honda uses it after 73), Decorative Chrome (FbyF), will last a few seasons.

I have cut down a lot of forks for a bike builders, and tolerances on aftermarket are not always the best..

When I straighten forks I have steel blocks that I made up for 1 5/8 and 1 3/8 tubes, they work xcellent.... usually get the forks to under .003 runout.

BE VERY CAREFUL using V-blocks (not best choice).. a mechanic near here smashed his thumb pretty bad when one let go..

[crazypj]

Good point, most 'V' blocks sold are cast iron, you need steel V blocks with alloy pads, no sharp edges.

PJ

[Thunder]

Well, they seem the real deal...  ;Di handed the forks over,
 and in an "authoritative voice" i stated "they are 35mm",
 the guy looks at me askance and says, nope they are 34.97 (something, i forget his exact figure), he then showed me with a gauge.

The guys seem to do alot of things (hell, they had four 3 meter lathes in just the section i went into), and the turnaround is about 4 days.

...but they are in South Africa (Cape town) so i don't know if it is feasible for you guys.

Here is their telephone  (+27) 21-5932240
 

the e-mail i'll have for you on fri, when i go to pick the stuff up.