Machine shop that can cut fork tubes | GTAMotorcycle.com

Machine shop that can cut fork tubes

j2

Well-known member
I've been restoring a KZ650 and now I'm getting to the hard part.

The forks are quite badly pitted so I've been on the lookout for a good set but have not been able to find anything.

I think I have a few other options.

I can get aftermarket tubes, but the consensus on the KZ board is that most come from Taiwan or China and quality is not great.

I could also try to have them re-chromed but they may be too far gone

There is also a third option. A friend of a friend gave me a set for an SR650 that are in pristine condition and identical to the KZ except they are 3 inches longer. The SR was the cruiser version of the KZ. Does anyone know of a machine shop that could cut three inches off and recut the o-ring seat and threads like this?

[video=youtube;HNiblp32Qq0]https://www.youtube.com/watch?v=HNiblp32Qq0[/video]

TIA
 
Check the household hints sites or do a Google search from removing rust from stainless steel.
It won't do anything about the pitting, but it can probably make them look presentable.
This is not an area where I have any expertise, but it looks to me that the cost re-tooling the new ones to make them fit would probably be prohibitive.
Take all possible steps to restore the existing ones is my advice.

In my experience the tubes are usually stainless steel, not chrome.
If yours are chrome use an SOS pad with warm water to remove the rust.
Apply two or three coats of chrome polish afterwards.
 
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The first thing I would do is talk to Steve Darlington, he's a regular on www.vrra.ca/board. He probably has a set to sell you. He has tons of KZ stuff for sale. If you're into KZs he is a good guy to know.
If that doesn't work try Frank's http://www.frankmain.qpg.com/

If all else fails... if you HAVE to get a local machinist to cut your forks down... look at the other end.
I just shortened a pair of GSXR forks, and they were too big to mount in my lathe, so I took the inch off the bottom with a mill, and then peened in the collar. I was done in less time than it would have taken to set up the threading

If you need a machinist try N A Yorke at 30th and Horner. (416) 255-2032


... and just so statsman knows fork tube are made from stainless then hard chromed. Stainless is way too soft, the chrome not only gives a nice hard bearing and seal surface but it also makes the fork stiffer.
 
I will grant that my experience is limited to BMW, but I have never owned a bike where the tubes are chromed.
They have always been stainless on every bike I have owned.
I would hardly describe stainless steel as soft.
In the military there is another term for stainless steel. They call it armour plate.
 
I will grant that my experience is limited to BMW, but I have never owned a bike where the tubes are chromed.
They have always been stainless on every bike I have owned.
I would hardly describe stainless steel as soft.
In the military there is another term for stainless steel. They call it armour plate.
I've never heard of Stainless steel fork tubes. Hard chromed steel is the norm including BMW's. Unless you go to a 400 series heat treatable st st most Stainless is too soft and will wear in the seal area too easily. Hard chroming is different to regular chroming and must be precision ground to size after plating.
 
Thanks. Some good ideas here

TK4, I wouldn't mind them sticking through the the clamps about an inch but they are so long I wouldn't be able to get the bars on.

Statesman. The issue with pitting is that it's not a cosmetic problem. The pits ride over the oil seals and bushings causing wear, oil leaks and seal failure. The forks are definitely hard chromed steel. I wish I could just clean them up
 
These are the tubes on my 40 yr old Yamaha.They were rusted and pitted.Redone by NA Hardchrome.Wish i had a before pic.
P7020052_zpsasg36eia.jpg
 
Thanks. Some good ideas here

TK4, I wouldn't mind them sticking through the the clamps about an inch but they are so long I wouldn't be able to get the bars on.

What about using top clamp extenders to move the bars back and up for clearance and/or using a clamp-on style handlebar (think CBR 250 or EX300) ?
It wouldn't be period authentic, but might solve the immediate problem ?
 
I've never heard of Stainless steel fork tubes. Hard chromed steel is the norm including BMW's. Unless you go to a 400 series heat treatable st st most Stainless is too soft and will wear in the seal area too easily. Hard chroming is different to regular chroming and must be precision ground to size after plating.

I did a little research and I stand corrected.
Sorry if my earlier posts sent you down a blind alley.
 
My friend had the same problem with this 89 Gold Wing. I took the forks to Bent Bikes, he had them re-plated.
They looked like brand new. And worked like brand new.

Good price too.
 
I have a KZ650 for sale, its a '78" or so.
The owner purchased it a few years ago, I've gotten into its too much work / cost involved to fix it up to the condition he wants it in. So its for sale now.

The bike is still plated.

The forks are MINT! most of the bike is mint, just need a lot of TLC and adjusting to make it all work. Motors been rebuilt already but needs a starter shaft installed (replacement part in hand)

send me a pm with your name and number and I will contac tou.
 
here is a pic to the condition of the bike...

the forks have just been dropped in the triples.

12010688_1043444035700430_5085972764711314993_o.jpg
 
I will grant that my experience is limited to BMW, but I have never owned a bike where the tubes are chromed.
They have always been stainless on every bike I have owned.
I would hardly describe stainless steel as soft.
In the military there is another term for stainless steel. They call it armour plate.

Not to nitpick and there are dozens (at least) of steel types but isn't stainless a steel alloyed chromium and armour a steel alloyed with nickel? IIRC Sudbury's nickel deposits were discovered before the invention of armour plate and weren't considered very valuable until that point.
 
adding for those that may not know, hard chrome is different from "show" chrome. Places like NA that Wingboy suggested dont do car and boat parts that need to look nice, they do hydraulic rams and forks and industrial fittings that will be exposed to weather or chemicals and need to fit against Orings and seals.
I have had some hydraulic parts done by NA in oakville, its not cheap but good work seldom is.
 

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