Yamiya Fork Stanchions

[ashimotok0]

Anyone used Yamiya early CB750 fork stanchions ? I fitted mine but noticed the bottom piston and valve ring was a sloppy fit on the stanchions.

The attached pic  is what I found when I measured them.

I am going to take this up with Yamiya but they are hard to get a reply from as far as I know plus  I bought them a couple of years ago via Saisei in the UK but only got round to using them recently.

[ashimotok0]

This is the hopeless reply I got back from Shimpei at Yamiya

Dear Sir,

Thank you for your inquiry.
We checked the picture you attached, but some errors will occur as it becomes a rebuilt item and there is no such thing that we can not install it until now.
We would appreciate your understanding.
Thank you.

Best Regards,
Motorcycle YAMIYA

[4pots1969]

It's a shitty answer... It's not good but you can ride it anyway...  
That's why I do not like copies Yamiya, because when it reproduces parts, it's always approximate...
I sometimes wonder if they do not do it on purpose ...

I bought tubes from EMGO, and it was the opposite of yours... Impossible to put the pistons and the rings because the tubes had been completely chromed, and I had to soak the bottom in the hydrochloric acid to remove the thickness of chromium... And after I could put the pistons and rings without any excessive play...
And if you have to choose, I prefer that it's like that...

[vnz00]

There was a recent thread on Facebook about the quality of their double cut guards. At first I thought the poster was bringing the quality of the Vietnam copies into question, but no, they were talking about the $1500usd version.  It’s a shame because these parts are not living up to the quality we’ve come to expect of them.

I recently returned one of their white ABS 3 hole airboxes because they’re basically the 2 hole version with an extra hole, so the top isn’t right.  The bottom isn’t quite there either where the winged bolts sit.  

It’s a shame because someone has spent money to develop the parts, only to get them not quite right.

[kp]

This is the company I've bought replacement tubes from. They fit, are/were cheaper than Yamiya and, as I understand, are the first choice for fork replacements in the US. Mr Swan and others may know more.(Don't hold your breath though) Forking Frank has you by the forks 
http://franksforks.com

[Steve Swan]

franks forks or "forking by frank" as it used to be called in the 1960's is the way to go. i've used their forks on a number of different makes over the decades.  Frank died a few years ago, his son took over the business.

[ashimotok0]

Thanks for the replies guys.

I sent this reply copied below to Yamiya,so they might refuse to sell to me in future   as they get tetchy when you question the quality of a part.

I guess I am stuck with them now !

Two thoughts:-

1) Try to get somebody in the UK to build up the bottom area with hard chrome and grind back to the correct size.
2) Bush the bottom piston with 0.1 mm shim and make some new undersize I.D. damper rings at work. Not sure what the damper rings are made of though and how hard the material is.

What do you guys think please ... I really appreciate your help.

David Silvers stanchions are made in Italy, fully chromed and the diameter is too large to fit the pistons and valve rings. I find it incredible that nobody in 2018 can manage to copy a part faithfully to the original.  It makes you question what the actual metal the stanchions are made from

Ashley Derrick <ashimoto750@gmail.com>
09:03 (8 hours ago)
to shimpei, order

Dear Sir,

Thank you for your reply but I cannot understand why the dimensions of the pipe are not a faithful reproduction of the Honda original part. In my opinion these pipes have not been made to the correct dimensions. Can you check your stock to see if they are the same dimensions as mine please.

Kind regards and best wishes ...Ashley

[Steve Swan]

unfortunately as much as i have been a Yamiya supporter in the past, especially 15 years ago when they started reproducing hard (near impossible) to find parts like the LR's, my position on their parts and service is changing.  there seems to be report after report of some of their parts just not being right.  there is no reason steel fork tubes such as in Ash's case should not be able to be made to factory spec; these are not complex parts to reproduce.  Ash, i assume you have you taken measurements on factory tubes to compare with these Yamiya replacements?  a difference in the diameters between the two where Yamiya diameter is smaller than factory would be "damning" evidence and in that case, Yamiya needs to not only do what is right by you but also, as you asked them, check their inventory so they're not selling an incorrectly replicated part.

[ashimotok0]

unfortunately as much as i have been a Yamiya supporter in the past, especially 15 years ago when they started reproducing hard (near impossible) to find parts like the LR's, my position on their parts and service is changing.  there seems to be report after report of some of their parts just not being right.  there is no reason steel fork tubes such as in Ash's case should not be able to be made to factory spec; these are not complex parts to reproduce.  Ash, i assume you have you taken measurements on factory tubes to compare with these Yamiya replacements?  a difference in the diameters between the two where Yamiya diameter is smaller than factory would be "damning" evidence and in that case, Yamiya needs to not only do what is right by you but also, as you asked them, check their inventory so they're not selling an incorrectly replicated part.

The photo at the beginning of this post is annotated with  the diameters of both my original 10/69 stanchion and a Yamiya one Steve in the piston/valve ring unchromed area. The swept area is the correct diameter (i.e the chromed part). I included  that photo in my original email to Yamiya /Shimpei. Who is Shimpei by the way ?

[Steve Swan]

Shimpei has been there as long as i know, seems to be kind of the face of Yamiya to us round-eyes.  despite my attempts to strike a convo with him, no luck have i.

[ashimotok0]

Shimpei has been there as long as i know, seems to be kind of the face of Yamiya to us round-eyes.  despite my attempts to strike a convo with him, no luck have i.

https://www.pressreader.com/australia/old-bike-australasia/20160701/282016146593357

[42barab]

Ash,

I agree that Yamiya's response to you is unacceptable.  Of three purchases (repop LR exhausts, a one-off MC, a repop frame bolt set), two had issues, with similarly indifferent responses from Shimpei.  Sometimes companies become indifferent to legit customer issues when mgmt or internal policies change.  Or when they forget their roots.  I hope this slide is temporary.

John

[Steve Swan]

Shimpei has been there as long as i know, seems to be kind of the face of Yamiya to us round-eyes.  despite my attempts to strike a convo with him, no luck have i.

https://www.pressreader.com/australia/old-bike-australasia/20160701/282016146593357

well, here we are.  i learn more every day.  Thanks Ash!

[hondasan]

Have not dealt direct with Yamiya for many years having had a similar experience with a damaged chainguard that arrived - their response to "just" send it back for a refund did not work (better to keep the damaged item than have nothing and have paid TWO lots of international post + import duty and taxes!).

No denying they  have made many previously obsolete items available again as repros, but the quality needs to be right. Original Lotus root exhausts had a fault. Repro seats  for 69/70 bikes are based on the earliest version of the seat pan, only correct for the first 500 or so bikes, not the following 44,000 sandcast / die cast "K0"s.


Tough one Ash, and not acceptable.


Chris R.

[4pots1969]

If you look closely at the Lotus Roots, you will notice that they are very poor quality because the upper and lower welds are very poorly made and really look like lace... I think they do not control anything and they do not care... This is unacceptable