braze-on distances index

i've added this to the framebuilding wiki at

cantilever/v-brake bosses

From: "goodrichbikes" 
Subject: Re: [Frame] Canti Boss Location - Std Dimensions Available?
Date: Mon, 20 Dec 2004 13:29:51 -0600

700C(622) = 283mm
26"(559) = 253.5mm
650B(584) = 265mm
A post center to post center measurement of 80mm works best for most canti & v brakes.

Curt Goodrich
Minneapolis, MN


Date: Wed, 26 Jan 2000 01:00:11 -0500 (EST)
From: Jeff DelPapa 
Subject: [Frame] measurements question
The last time I asked about canti spacing, the number I got was 80mm center to center,
apparently from the literature of the big S.  I expect it should depend on the rim width,
but they didn't mention a correction.  As to distance from axle, I was told 25mm less
than the bead seat diameter, which worked fine for the canti's I used. (happened to be
scott self energizing -- pre linear pull style.)


Subject: Re: [Frame] Brake Boss Location
From: "Jon_norstog AKA \"Thursday\"" 
Date: Fri, 14 Oct 2005 20:03:56 -0600

I'm working from the 1999 Shimano book.  The spacing between canti posts
depends a little on rim width.  basically it's 77-85 mm, but on a road
bike you could probably go down to 75 and be fine..

I use 80 for mountain bikes and 85 for BMXers and bikes that are gonna
run V-brakes and wide rims.

Different V-brakes will have different tire clearances.  This may not be
an issue with cantis.

Good luck


DT shifter bosses


ISO disc/disk brake mounts

From: ThomasT41(AT)
Subject: [Frame] ISO mounts and 7005 tubing source
Date: Sun, 13 Jan 2002 12:39:27 EST

For those of you interested here are the iso dimensions for disc brake--can
be found on the net but if your lazy like me.............

mounts- 6mm to 9mm thick, dimensions are plus/minus .1mm

rear ISO brake mounts for disc brake are 51mm(between centers) x79.1mmx39.9mm(axle
center to hole centers), inside flush with inside of drop out

front ISO brake mounts for disc brake are 51mm(between centers) x87.3mmx49.7mm(axle
center to hole centers), inside mount surface set 4mm outboard of the inside drop out face

TT brake cable stops/bosses

From: "Andrew R Stewart" 
Subject: Re: [Frame] TT brake cable BO location - since we're talkin' BO's And
Date: Mon, 24 Oct 2005 20:53:48 -0400

Roman- As I like to be able to run a TT pump I make sure that the stop JUST
clears the pump. Trying for as little of the stop hanging out past the side
of the TT. I like the cast bullet shaped type. The distance from the HT
center is about 10cm. My frames are small and I hate cable loops that are
really tight so I give both the brake and gear cables a bit of room for the
casing to loop away from the bars. ( I run Ergo). Another difference I have
is that I run my brakes righty/front lefty/rear so the TT forward TT stop is
on the TT's right side... the rear stop is on the left side... yes the cable
just grazes the underside of the TT. (Oh my kingdom for five Campy rear
brakes made in a mirror image, the cable on the other side). Again on the
rear stop I place it 10 cm from the ST center. Look at a lot of production
alu or carbon frames and on the smaller sizes the rear stop is so close to
the ST that the cable gets a tight loop, enough to cause friction issues.

water/H2O bottle bosses

From: "Andrew R Stewart" 
Subject: Re: [Frame] TT brake cable BO location - since we're talkin' BO's And
Date: Mon, 24 Oct 2005 20:53:48 -0400

As to water bottle bosses. The bottles overlap. The ST one is as low as
possible, straddling the ft der clamp. The DT set so it clears the ST bottle
by a small bit. About 10cm for the ST and 18.5 for the DT, lower boss to the
BB shell outside surface (add 2cm for BB center).Again small frames and also
46-50 tooth large rings. An interesting story here. Our Co-Motion tandem
also has a set of stoker ST water bottle bosses straddling the der clamp.
they didn't know of our 48 tooth large ring and the der clamp lined up
exactly on the lower boss! So I used a clamp diameter 1/8" larger and a shim
(cut down to clear the boss) and the der mounted right over the boss. Can't
attach a bottle on that tube without some kind of clamping but so far we've
not needed it. Andy S.


Subject: Re: [Frame] H20 boss placement question
Date: Wed, 19 Oct 2005 10:57:01 -0700

I have a drilling jig that I use for this.  It places the bottom hole
for the cage at 16cm above the crotch of the ST/DT.  I use it for both
DT and ST boss locations.  Unlike some, I drill and braze WB's on after
the frame is built.
Omar Khiel


From: "e-RICHIE" 
Date: Wed, 19 Oct 2005 14:44:17 GMT
Subject: Re: [Frame] H20 boss placement question

i like my two opposing sets of bosses to
be "symmetric". when the seat tube cage is
lower than the down tube cage, it bothers
my eyes. my lower cage boss is usually 19cm
from the bb centerline.


Date: Wed, 19 Oct 2005 11:39:32 -0400
Subject: Re: [Frame] H20 boss placement question
From: Doug Fattic 

My sense of proportion is the same as Richie's.  I like the seat tube bottle
to be the same distance from the bottom bracket shell as the down tube
bottle.  Sometimes this has to be altered with small frames.  How low they
can be depends on several factors (bb angle, cage, etc) so when I am
particularly fussy, I will put the actual cage with bottle in place and see
where they comfortably just miss each other and mark the spots.  Of course
they shouldn't be so close that a change in cage will make the bottles bump
each other.  I measure from the top of the bottom bracket shell and this
distance is usually between 6 3/4" and 7/8ths.

Doug Fattic
Niles, Michigan


Subject: Re: [Frame] H20 boss placement question
From: "Jon_norstog AKA \"Thursday\"" 
Date: Wed, 19 Oct 2005 23:02:47 -0600

I've got a Waterford Paramount in for some frame repairs that has the
lower boss 7.5 inches above the crotch.  On mountain bikes with short
seat tubes, I move the bosses down, 5.25" or so above the crotch, which
gives you a little more than just enough clearance for the derailleur



From: Margo Conover 
Date: Wed, 19 Oct 2005 11:41:03 -0600
Subject: [Frame] H2O boss placement

I think this "all depends."  On tiny frames I have to go really
low--like 11cm--in order for the rider to get a big bottle (sometimes
even a small one) in there, particularly if they use a top tube mounted
frame pump.  Also, if the frame uses a clamp-on front derailleur, then
you need to be very aware of where that clamp will sit on the seat tube
when placing the lower boss.

Margo Conover
Luna Cycles, LLC


Date: Wed, 19 Oct 2005 16:48:59 +0200
From: M-gineering 
Subject: Re: [Frame] H20 boss placement question

Tom Palermo wrote:
> Seems like most production bikes are hovering around 15cm.

depends on the size of the frame the angles and the cages. I like to
space them fairly symmetrical and often use 200mm (downtube) & 180 mm
seattube. (c-c). But with small frames and big bottles this won't work


over-/under-BB shifter cable guides

From: "Bill Boston" 
Subject: Re: [Frame] over BB cable guides
Date: Fri, 27 Dec 2002 15:55:02 -0500

I always liked to run the cables over the bottom bracket, but never liked
the Campy guides. I preferred to place 2 cable stops on the downtube, one on
the chain stay and one on the back of the seat tube. this provided good
shifting and it was far easier to paint the frame and was also easier to
clean the frame because toy could move the cable housings. If you go this
route, NEVER use plastic covered or lined cable housing as it will trap
water and dirt and eventually seize up. Bare Stainless cable housing is the
only way to go. Another advantage was that you could bypass the cable stop
on the back of the seat tube and run directly to the cable stop on the front
changer if necessary. This was particularly useful with some of the older
changers that needed a cable housing to function. Fortunately those are no
longer being made.

I probably have a stack of the Campy braze on guides kicking around here
someplace if anyone needs them.


----- Original Message -----
From: "tim paterek" 
To: "cliff mcleroy" 
Sent: Friday, December 27, 2002 3:13 PM
Subject: Re: [Frame] over BB cable guides

> My feeling on under or over is 50-50. They both have their advantages and both have
> their disadvantages. By all means, the simplest to install is the underneath plastic
> fitting that Shimano makes -- it only requires one tapped 5 X .8 hole in the bottom
> of the BB. The easiest to build with is the integrated underneath guides like the
> ones Henry James provides. One hint for topside guides: I have always tacked the
> tail end of the left guide to the BB shell/seat tube with silver after bending it
> in towards the seat tube. This prevents the guide from bending upward due to hard
> shifting.
> Tim Paterek

front pannier/low-rider boss

Subject: RE: [Frame] low-rider and rear rack mount locations
Date: Thu, 18 May 2006 13:17:22 -0500
From: "Dave Gray" 

We use of eyelet to center of lowrider rack boss.

Dave Gray


From: "Omar Khiel" 
Subject: Re: [Frame] low-rider and rear rack mount locations
Date: Thu, 18 May 2006 11:24:27 -0700

I use 165 also.  It works for the rigid mounted Blackburn racks.  I measure
c to c eyelet to boss.
Omar Khiel

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