kaisei "toei special" fork blades question

605 views
Skip to first unread message

anal...@gmail.com

unread,
May 15, 2015, 5:12:58 PM5/15/15
to frameb...@googlegroups.com
hello

i want to build a fork using the kaisei "toei
special" fork blades available from compass
bicycles. link here:

http://www.compasscycle.com/framebuilding_kaisei_blade.html

the diameter at the tip is 13 mm (outside) / 11 mm
(inside)

i'm new to framebuilding. my question: which
dropouts would work well with these blades?
ideally, i'd like to have to have two eyelets (one
for rack, one for fender).

i had my eye on these dropouts sold by nova

http://www.cycle-frames.com/bicycle-frame-tubing/Llewellyn-Road-Front-dropouts-with-2-eyelets-in-Mild-Steel.html

would these work? or is there something better /
more appropriate?

any help greatly appreciated.

thanks and best regards

jason

Mark Bulgier

unread,
May 15, 2015, 9:28:12 PM5/15/15
to anal...@gmail.com, frameb...@googlegroups.com
" jason" wrote:
> i want to build a fork using the kaisei "toei special" fork blades
> the diameter at the tip is 13 mm (outside) / 11 mm (inside)
If both the blades and the dropouts are the dimension they say they are (and you can't count on that until you have them and measure them), then that will be a bit of a loose fit. You can fill it with brass and it will be strong enough for sure (as long as your brazing job is not terribly bad), but I would not recommend silver alloy filler for that big of a gap.

Although strong enough, it might look inelegant (clunky) with the thick lug edge and largish fillet of brass to hide the gap.

You might want to try a pair of these:
http://www.cycle-frames.com/bicycle-frame-tubing/DROPOUT-FRONT-SOCKET-STYLE-TWO-EYE.html
Nova says they are 13 mm which, if they're truly 13.0 and the blades are truly 13.0, then they won't fit. But you can grind a little off the inside of the socket, maybe take a little off the OD of the blade until you have a nice fit, then silver braze. No guarantees from me, but the dropouts aren't that expensive to buy and try the idea out. The bike won't ride any better, but it might look higher quality.

There's also the option of slotting the blades for a traditional dropout, such as these:
http://framebuilding.com/NEWPARTSPAGES/Forged%20Dropouts.htm
Scroll down to item # FE1530N. That's what I would do, but I'm old and prefer the old trad ways. Slotting can easily be done with a hacksaw and a file.

Either style of dropout, I recommend bending them first, then putting the dropouts on. If you bend them after brazing, you will either have a straight section above the dropout before the curve begins, or a kink in the bend at the tempered zone -- weakest point, some small distance above where you got it hot. Often the kink is very mild, almost not noticeable, but it would bug me.

Mass-produced bikes usually rake after brazing the tips, and leave that straight section between the curve and the dropout. Probably rides just about as good, but it is a sign of fine craftsmanship to have the curve extend smoothly all the way to the dropout. Not everyone cares about that detail though, so don't worry about it if the beauty of the curve is not your 'thing'. Certain bike snobs (like me) will look down on you and sneer though. Just sayin'.


Mark Bulgier
Seattle

Andrew R Stewart

unread,
May 15, 2015, 10:43:26 PM5/15/15
to Mark Bulgier, anal...@gmail.com, frameb...@googlegroups.com
I agree with Mark and would just use a classic tabbed dropout and slot the
blades. Much more fit tolerable of tubing diameters at the spot you choose
to cut then slot the blade. I also feel that the brazing this type of joint
is better for a beginner. Andy.



Andrew R Stewart
Rochester, NY USA
--
--
You received this message because you are subscribed to the Google
Groups "Framebuilders" group.

Searchable archives for this group can be found at
http://groups.google.com/group/framebuilders (recent content) and
http://search.bikelist.org (older content).

To post to this group, send email to frameb...@googlegroups.com
To unsubscribe from this group, send email to
framebuilder...@googlegroups.com
For more options, visit this group at
http://groups.google.com/group/framebuilders?hl=en

---
You received this message because you are subscribed to the Google Groups
"Framebuilders" group.
To unsubscribe from this group and stop receiving emails from it, send an
email to framebuilder...@googlegroups.com.
For more options, visit https://groups.google.com/d/optout.

anal...@gmail.com

unread,
May 16, 2015, 8:39:10 AM5/16/15
to Mark Bulgier, frameb...@googlegroups.com
hi mark

wow, thanks for all this useful information. this
is really helpful. i think, then, that i should go
with the slotted dropouts.

best regards

jason

Sam Shepherd

unread,
May 20, 2015, 7:55:27 PM5/20/15
to frameb...@googlegroups.com, Ma...@bulgier.net
To provide even further options; Paragon Machine Works makes a wide variety of front dropouts in both steel and stainless

Good luck with the fork and don't forget to mock everything up before you getting to slotting/brazing. It will take some added time, but it might save you from scrapping parts further down the manufacturing process.

anal...@gmail.com

unread,
May 21, 2015, 1:49:31 PM5/21/15
to frameb...@googlegroups.com
hi sam

thanks for your reply. i've already ordered the
dropouts (and steerer tube) from ceeway in the uk.

all the best

jason


> Sam Shepherd <ssheph...@gmail.com>: May 20
> 02:01PM -0700
>
> To provide even further options; Paragon Machine
> Works
> <https://www.paragonmachineworks.com/> makes a
> wide variety of front
> dropouts in both steel and stainless ...more
> <http://groups.google.com/group/framebuilders/msg/7e4802b0ecea7a8?utm_source=digest&utm_medium=email>
>

John Clay

unread,
May 24, 2015, 6:36:58 AM5/24/15
to frameb...@googlegroups.com
Hi Jason. You say you're new to frame building. Depending on how new, you might want to build some forks out of less expensive materials first. Those would be expensive blades to trash.

Good luck,
John Clay
Tallahassee, FL

michael giannico

unread,
May 25, 2015, 11:23:56 AM5/25/15
to John Clay, frame builder list
John has a good point. get some cheapies first.

--
--
You received this message because you are subscribed to the Google
Groups "Framebuilders" group.

Searchable archives for this group can be found at http://groups.google.com/group/framebuilders (recent content) and http://search.bikelist.org (older content).

To post to this group, send email to frameb...@googlegroups.com
To unsubscribe from this group, send email to
framebuilder...@googlegroups.com
For more options, visit this group at
http://groups.google.com/group/framebuilders?hl=en

---
You received this message because you are subscribed to the Google Groups "Framebuilders" group.
To unsubscribe from this group and stop receiving emails from it, send an email to framebuilder...@googlegroups.com.
For more options, visit https://groups.google.com/d/optout.



--
Mike Giannico
Nicola Cycles
Oakland, CA






RayMS

unread,
Jul 21, 2020, 8:53:57 PM7/21/20
to Framebuilders
How long as the Toei fork blades been around? I would like some if someone made a narrow (~35mm) fork crown for it.

Mark Bulgier

unread,
Jul 21, 2020, 10:05:32 PM7/21/20
to RayMS, Framebuilders
Someone who goes by "RayMS" wrote
How long as the Toei fork blades been around? I would like
> some if someone made a narrow (~35mm) fork crown for it.

Those blades are close enough to the old Reynolds "Continental Oval" (28.5 x 16.5 mm -- often called 29 x 16 -- same thing).  You can put Kaisei "Toei" in most any crown made for old "skinny oval" Reynolds blades, sometimes with a little manipulation of the blade and/or socket needed.  Or just hammer 'em in! (not exactly Best Practice, but plenty of good forks have been made that way.  The blades get stress-relieved at brazing temperature.)

Note, RH calls them "Imperial Oval" which is not wrong exactly, but it's not enough info IMHO.  

Correct me if I'm wrong but I don't see anywhere that they tell you the actual dimensions of their oval -- lame!  So let me do RH's job for them -- I measure mine, purchased from Compass a few years back, at about 28 x 17 mm.  That's "hammerable" or squishable into a crown made for Reynolds skinny oval.

I don't know where that term Imperial Oval comes from, but probably not Kaisei and definitely not Reynolds.  I think it's a term some American bikies made up back in the day, and it's taken on a life of its own.  That's OK as long as everyone knows what it means, but if you want to use Reynolds's term for it, that's Continental Oval.  That's for the older, long-skinny oval.  See the 1978 catalog page:

The newer, wider, 27.5 x 20 mm oval, similar to Columbus, was dubbed by Reynolds the "New Continental Oval" or NCO.
(They didn't give the ovals names before 1978 when NCO came out.)

Yes, that was confusing of them (maybe intentionally?), so I don't blame people for coming up with a different name for the old skinny oval.  Imperial it is!  Even if there's no historical reason for it, it works as jargon.  Just please give us the actual dimensions as well.

Crown makers Haden also used the same terminology as Reynolds.  

Note that the skinny 29x16 oval is Continental, and fat 27.5x20 oval is NCO

I find it regrettable when Americans call the newer, fatter oval Continental.  That's the opposite of Reynolds terminology, and it's their name, so they should have some say!  Oh well I'm mostly over it, but I stay away from the word Continental myself due to this ambiguity.  Can't go wrong if you just give the measurements.

I laughed when I saw RH does attempt to give the dimensions of their incorrectly named "Continental Oval" blades, but they call them "Continental oval: 28 x 28 mm"  D'oh!
That's not what I would call an oval, sounds more like round...

Mark Bulgier
Seattle

Hahn Rossman

unread,
Jul 21, 2020, 10:42:57 PM7/21/20
to RayMS, Framebuilders
Jason-
ReneHerse sells a takahashi crown:
You can see a photo set of me manipulating the Kaisei blades to fit:
Hahn Rossman

--
--
You received this message because you are subscribed to the Google
Groups "Framebuilders" group.
 
Searchable archives for this group can be found at http://groups.google.com/group/framebuilders (recent content) and http://search.bikelist.org (older content).
 
To post to this group, send email to frameb...@googlegroups.com
To unsubscribe from this group, send email to
framebuilder...@googlegroups.com
For more options, visit this group at
http://groups.google.com/group/framebuilders?hl=en

---
You received this message because you are subscribed to the Google Groups "Framebuilders" group.
To unsubscribe from this group and stop receiving emails from it, send an email to framebuilder...@googlegroups.com.

Mark Bulgier

unread,
Jul 21, 2020, 10:47:20 PM7/21/20
to Framebuilders
Sorry, error in what I wrote -- "They didn't give the ovals names before 1978 when NCO came out."

NCO (Columbus-style) blades came out earlier, probably '74-'75.  They were showing 531 SL and 753 by '75, and they both came with NCO blades.

I think the term Imperial was coined for the old skinny oval some time in the '80s.  At least I didn't hear it earlier.
Continental made its switch, from meaning skinny oval to meaning fat oval, around then too.  I guess that makes it old enough, now, to be "grandfathered in".  It ain't gonna change back!

-mb
Reply all
Reply to author
Forward
0 new messages