Cycling and bicycle discussion forums. 
   Click here to join our community Log in to access your Control Panel  


Go Back   > >

Bicycle Mechanics Broken bottom bracket? Tacoed wheel? If you're having problems with your bicycle, or just need help fixing a flat, drop in here for the latest on bicycle mechanics & bicycle maintenance.

User Tag List

Reply
 
Thread Tools Search this Thread
Old 06-28-07, 07:17 PM   #1
pgoat
BatŁwŁ Griekgriek
Thread Starter
 
pgoat's Avatar
 
Join Date: May 2005
Location: NYC - for the moment...
Bikes: 1985 Trek 500, 1986 Trek 500 Tri Series, 2002 Orbea Team Euskaltel, 2005 Cannondale R1000
Posts: 2,900
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 10 Post(s)
Drilling out rear brake boss for countersunk calipers

Is this nuts?

I know it's covered on Sheldon Brown's site. The problem is you can't get a drill between the seat post and the underside of the brake boss.

I do have a hand boring tool. I beleive I can get it in there and might be able to hack away enough steel to stuff a new DP caliper in ( I currentky have cheap single pivot sidepulls; after switching the front to a DP I am really hating the lousy non-centering rear sp).

fwiw it is an 86 Trek road bike, Tange straight gauge cro mo seat stays.


My main concerns are will this weaken the stability and stiffness of the rear brake and will it make a difference if the hole I bore out is a bit out of true round?

Some folks advocate using the front brake on the rear and using the rear in front by simply sticking the recessed nut inside the bottom fork opening (tighten it inside the steerer tube by putting the allen wrench through the back of the fork). Is this a safer bet?

If these are both ill-advised can someone PLEASE help me center this %#*%^() SP brake?????

Merci
__________________
Quote:
Originally Posted by jsharr View Post
People whose sig line does not include a jsharr quote annoy me.
pgoat is offline   Reply With Quote
Old 06-28-07, 07:35 PM   #2
vpiuva
*
 
vpiuva's Avatar
 
Join Date: Jan 2007
Bikes:
Posts: 3,458
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Do you already have the new recessed mount rear? If not, just buy another front and put a nut on it. If you do, see if you can swap it somehow, or sell your rear on eBay and buy a front.

It won't weaken the bridge too much, so that shouldn't be a worry if you do decide to drill. Keep in mind the rear doesn't do much braking, anyhow
vpiuva is offline   Reply With Quote
Old 06-28-07, 08:22 PM   #3
pgoat
BatŁwŁ Griekgriek
Thread Starter
 
pgoat's Avatar
 
Join Date: May 2005
Location: NYC - for the moment...
Bikes: 1985 Trek 500, 1986 Trek 500 Tri Series, 2002 Orbea Team Euskaltel, 2005 Cannondale R1000
Posts: 2,900
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 10 Post(s)
I do have a rear already.

The trouble is it takes long reach calipers and I don't want to shell out any more big Bucks on this bike to buy a new front long reach, especially for the rear, since as you say the front matters most. I just hate the centering/rubbing issues with the SPs. I've only owned one set of sps (Modolo speedy) that worked well.

If I sold my old set of SPs and the new DP rear I might get a little bread to cover it..... but they are not big $ on ebay alas.....Sheldon Brown has nice Ultegras in long reach for $90 and Tiagra for $40. Any thoughts on the quality difference?

http://sheldonbrown.com/harris/brake...ers.html#47-57

My big question is - doesn't anyone (Black and decker? Makita? DeWalt?) make a small drill with a right angle head for tight spots like this?
__________________
Quote:
Originally Posted by jsharr View Post
People whose sig line does not include a jsharr quote annoy me.

Last edited by pgoat; 06-28-07 at 08:28 PM.
pgoat is offline   Reply With Quote
Old 06-28-07, 08:30 PM   #4
well biked 
biked well
 
well biked's Avatar
 
Join Date: Jul 2005
Bikes:
Posts: 7,123
Mentioned: 1 Post(s)
Tagged: 0 Thread(s)
Quoted: 38 Post(s)
Quote:
Originally Posted by pgoat
I do have a rear already.

The trouble is it takes long reach calipers and I don't want to shell out any more big Bucks on this bike. Sheldon has nice Ultegras in long reach.

My big question is - doesn't anyone (Black and decker? Makita? DeWalt?) make a small drill with a right angle head for tight spots like this?
Drill from the backside (not the seat tube side), enlarge both holes in the seatstay bridge.
well biked is online now   Reply With Quote
Old 06-28-07, 08:43 PM   #5
DannoXYZ 
Senior Member
 
DannoXYZ's Avatar
 
Join Date: Jul 2005
Location: Saratoga, CA
Bikes:
Posts: 11,606
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 3 Post(s)
right-angle drill-bit attachment
DannoXYZ is offline   Reply With Quote
Old 06-28-07, 08:44 PM   #6
pgoat
BatŁwŁ Griekgriek
Thread Starter
 
pgoat's Avatar
 
Join Date: May 2005
Location: NYC - for the moment...
Bikes: 1985 Trek 500, 1986 Trek 500 Tri Series, 2002 Orbea Team Euskaltel, 2005 Cannondale R1000
Posts: 2,900
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 10 Post(s)
Drill from the backside (not the seat tube side), enlarge both holes in the seatstay bridge.


I was thinking that too......

assuming I only need a drill bit just large enough to allow the nut to get in from the back, and that i may need a washer in front (between the caliper and the boss) if the hole i dril is too big.

Have u actually done this?
__________________
Quote:
Originally Posted by jsharr View Post
People whose sig line does not include a jsharr quote annoy me.
pgoat is offline   Reply With Quote
Old 06-28-07, 08:46 PM   #7
pgoat
BatŁwŁ Griekgriek
Thread Starter
 
pgoat's Avatar
 
Join Date: May 2005
Location: NYC - for the moment...
Bikes: 1985 Trek 500, 1986 Trek 500 Tri Series, 2002 Orbea Team Euskaltel, 2005 Cannondale R1000
Posts: 2,900
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 10 Post(s)
Quote:
Originally Posted by DannoXYZ
right-angle drill-bit attachment
I apologize I am a non-handyman . Can u pls post a link or pic showing exactly what you mean? Thanks!
__________________
Quote:
Originally Posted by jsharr View Post
People whose sig line does not include a jsharr quote annoy me.
pgoat is offline   Reply With Quote
Old 06-28-07, 08:53 PM   #8
cuda2k
Unique Vintage Steel
 
cuda2k's Avatar
 
Join Date: May 2005
Location: Allen, TX
Bikes: Kirk Frameworks JKS-C, Serotta Nova, Gazelle AB-Frame, Fuji Team Issue, Schwinn Crosscut, All-City Space Horse
Posts: 11,486
Mentioned: 2 Post(s)
Tagged: 0 Thread(s)
Quoted: 2 Post(s)
I drilled mine from the backside as mentioned above. I had a washer laying around from another bike that was cut to fit the curved brake bridge. This provides plenty of support for the brake against the brake bridge.
cuda2k is offline   Reply With Quote
Old 06-28-07, 08:58 PM   #9
vpiuva
*
 
vpiuva's Avatar
 
Join Date: Jan 2007
Bikes:
Posts: 3,458
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
I think I would just drill thru from the outside. That little extra hole diameter's not going to hurt on the rear, especially if you have a radius washer against the bridge.
vpiuva is offline   Reply With Quote
Old 06-28-07, 08:59 PM   #10
well biked 
biked well
 
well biked's Avatar
 
Join Date: Jul 2005
Bikes:
Posts: 7,123
Mentioned: 1 Post(s)
Tagged: 0 Thread(s)
Quoted: 38 Post(s)
Quote:
Originally Posted by pgoat
have u actually done this?
Yes.
well biked is online now   Reply With Quote
Old 06-29-07, 05:24 AM   #11
pgoat
BatŁwŁ Griekgriek
Thread Starter
 
pgoat's Avatar
 
Join Date: May 2005
Location: NYC - for the moment...
Bikes: 1985 Trek 500, 1986 Trek 500 Tri Series, 2002 Orbea Team Euskaltel, 2005 Cannondale R1000
Posts: 2,900
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 10 Post(s)
Thanks folks

Unless I can find this right angle drill attachment I will probably go with the drill from the outside (rear of bike).

The part of the boss to which the caliper actually rests on is actually squared off - like a little steel box in the center of the round crossbar connecting the seat stays. So even a regular flat washer should work. I am pretty sure I have some of those concave washers laying around just in case (I imagine I am like most on this board who keep all these little parts from many many old bikes ago - never know when they will save the day! )
__________________
Quote:
Originally Posted by jsharr View Post
People whose sig line does not include a jsharr quote annoy me.
pgoat is offline   Reply With Quote
Old 06-29-07, 08:18 AM   #12
vpiuva
*
 
vpiuva's Avatar
 
Join Date: Jan 2007
Bikes:
Posts: 3,458
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Quote:
Originally Posted by pgoat
Thanks folks

Unless I can find this right angle drill attachment I will probably go with the drill from the outside (rear of bike).

The part of the boss to which the caliper actually rests on is actually squared off - like a little steel box in the center of the round crossbar connecting the seat stays. So even a regular flat washer should work. I am pretty sure I have some of those concave washers laying around just in case (I imagine I am like most on this board who keep all these little parts from many many old bikes ago - never know when they will save the day! )
Look for one of your old knurled or serrated washers to place next to the frame
vpiuva is offline   Reply With Quote
Old 06-29-07, 08:53 AM   #13
pgoat
BatŁwŁ Griekgriek
Thread Starter
 
pgoat's Avatar
 
Join Date: May 2005
Location: NYC - for the moment...
Bikes: 1985 Trek 500, 1986 Trek 500 Tri Series, 2002 Orbea Team Euskaltel, 2005 Cannondale R1000
Posts: 2,900
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 10 Post(s)
I will - thanks!
__________________
Quote:
Originally Posted by jsharr View Post
People whose sig line does not include a jsharr quote annoy me.
pgoat is offline   Reply With Quote
Old 06-29-07, 09:08 AM   #14
DannoXYZ 
Senior Member
 
DannoXYZ's Avatar
 
Join Date: Jul 2005
Location: Saratoga, CA
Bikes:
Posts: 11,606
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 3 Post(s)
Here's what I'm talking about, a right-angle drill attachment. Might need to chop down a drill-bit as well.



Although if you have a flat surface where the brake-bolt goes, then you shouldn't have any problems with drilling it straight through from the outside and enlarging the outer hole as well. Just make sure it's the exact diameter as the shank of the allen-nut for the brake-bolt. The tight fit with the nut will provide the centering function.

Last edited by DannoXYZ; 06-29-07 at 01:11 PM.
DannoXYZ is offline   Reply With Quote
Old 06-29-07, 09:17 AM   #15
pgoat
BatŁwŁ Griekgriek
Thread Starter
 
pgoat's Avatar
 
Join Date: May 2005
Location: NYC - for the moment...
Bikes: 1985 Trek 500, 1986 Trek 500 Tri Series, 2002 Orbea Team Euskaltel, 2005 Cannondale R1000
Posts: 2,900
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 10 Post(s)
Thanks that sounds good.

I also found this http://www.makita.com/menu.php?pg=pr...t&tag=DA312DWD but not sure of cost - it'd prolly be cheaper to buy an ultegra front from Harris!!
__________________
Quote:
Originally Posted by jsharr View Post
People whose sig line does not include a jsharr quote annoy me.
pgoat is offline   Reply With Quote
Old 06-29-07, 06:17 PM   #16
HillRider 
Senior Member
 
Join Date: Aug 2005
Location: Pittsburgh, PA
Bikes: '''96 Litespeed Catalyst, '05 Litespeed Firenze, '06 Litespeed Tuscany, '12 Surly Pacer, All are 3x8,9 or 10. It is hilly around here!
Posts: 29,115
Mentioned: 4 Post(s)
Tagged: 0 Thread(s)
Quoted: 178 Post(s)
You need to use a 5/16" or 8 mm drill bit. Do NOT drill completely through the brake bridge.

I did the same job by taking a short, sharp 5/16" drill bit and clamping it at 90į into a pair of Vise-Grips. I was able to turn it about 1/4 turn at a time using the Vise-Grips as a handle and kept at it until I opened the front side of the brake bridge hole to the drill bit's diameter. It was a little slow but not too bad and it worked well.

There was no way to get a drill motor, even with a 90į attachment, between the brake bridge and the seat tube so my manual approach was the only alternative.
HillRider is offline   Reply With Quote
Old 07-01-07, 09:32 PM   #17
pgoat
BatŁwŁ Griekgriek
Thread Starter
 
pgoat's Avatar
 
Join Date: May 2005
Location: NYC - for the moment...
Bikes: 1985 Trek 500, 1986 Trek 500 Tri Series, 2002 Orbea Team Euskaltel, 2005 Cannondale R1000
Posts: 2,900
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 10 Post(s)
oy vey...........

First I only had a drill bit one size too small.

then I found an extra box of bits in the bottom of my old tool box. One was the right size but turned out to be a wood bit.

The next morning I grumpily reattached my old sp sidepull to go get breakfast, and - in a moment of mad desperation, after reading every repair manual I had one more time, I actually centered the old brake!!

Now why couldn't I have just figured it out before I drilled?

I guess I was motivated by hunger.....or maybe my mech skills improve when I'm not awake yet.

The brake seems a bit more flexy than before but still stops fine. I will eventually pick up an 8mm steel bit and slap on the DP caliper. But nice to know my brake is finally centered....
__________________
Quote:
Originally Posted by jsharr View Post
People whose sig line does not include a jsharr quote annoy me.
pgoat is offline   Reply With Quote
Old 07-01-07, 10:02 PM   #18
operator
cab horn
 
Join Date: Jun 2004
Location: Toronto
Bikes: 1987 Bianchi Campione
Posts: 28,306
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Or you can just install the brake reversed.
operator is offline   Reply With Quote
Old 07-02-07, 07:11 AM   #19
pgoat
BatŁwŁ Griekgriek
Thread Starter
 
pgoat's Avatar
 
Join Date: May 2005
Location: NYC - for the moment...
Bikes: 1985 Trek 500, 1986 Trek 500 Tri Series, 2002 Orbea Team Euskaltel, 2005 Cannondale R1000
Posts: 2,900
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 10 Post(s)
U mean on the underside of the seatstays? (between the seat tube and seat stays?)

I still need to widen the hols from either side to get the allen nut in there - it's long enough where it would need to clear the front (outer) side of the brake boss too.
__________________
Quote:
Originally Posted by jsharr View Post
People whose sig line does not include a jsharr quote annoy me.
pgoat is offline   Reply With Quote
Old 07-02-07, 07:15 AM   #20
vpiuva
*
 
vpiuva's Avatar
 
Join Date: Jan 2007
Bikes:
Posts: 3,458
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Quote:
Originally Posted by pgoat
U mean on the underside of the seatstays? (between the seat tube and seat stays?)

I still need to widen the hols from either side to get the allen nut in there - it's long enough where it would need to clear the front (outer) side of the brake boss too.
Then you need a shorter recessed nut in any case
vpiuva is offline   Reply With Quote
Old 07-02-07, 07:26 AM   #21
pgoat
BatŁwŁ Griekgriek
Thread Starter
 
pgoat's Avatar
 
Join Date: May 2005
Location: NYC - for the moment...
Bikes: 1985 Trek 500, 1986 Trek 500 Tri Series, 2002 Orbea Team Euskaltel, 2005 Cannondale R1000
Posts: 2,900
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 10 Post(s)
Quote:
Originally Posted by vpiuva
Then you need a shorter recessed nut in any case

I was thinking that too. Third hand/loose spokes carry those??? Or is it a LBS thing?
__________________
Quote:
Originally Posted by jsharr View Post
People whose sig line does not include a jsharr quote annoy me.
pgoat is offline   Reply With Quote
Old 07-02-07, 07:31 AM   #22
vpiuva
*
 
vpiuva's Avatar
 
Join Date: Jan 2007
Bikes:
Posts: 3,458
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Quote:
Originally Posted by pgoat
I was thinking that too. Third hand/loose spokes carry those??? Or is it a LBS thing?
Either should have it.
vpiuva is offline   Reply With Quote
Old 07-02-07, 09:43 AM   #23
pgoat
BatŁwŁ Griekgriek
Thread Starter
 
pgoat's Avatar
 
Join Date: May 2005
Location: NYC - for the moment...
Bikes: 1985 Trek 500, 1986 Trek 500 Tri Series, 2002 Orbea Team Euskaltel, 2005 Cannondale R1000
Posts: 2,900
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 10 Post(s)
Thanks!!
__________________
Quote:
Originally Posted by jsharr View Post
People whose sig line does not include a jsharr quote annoy me.
pgoat is offline   Reply With Quote
Reply


Thread Tools Search this Thread
Search this Thread:

Advanced Search

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off



All times are GMT -6. The time now is 09:47 AM.