Want to replace centering adjustment screws on Dura Ace BR-7403 brakes
11-29-20, 12:53 PM
#1
Full Member
Thread Starter
Want to replace centering adjustment screws on Dura Ace BR-7403 brakes
The attached pdf files shows the centering adjustment screws on Dura Ace BR-7403 brakes as Phillips head, but mine are straight. The screws in both the front and rear brakes are tight and the screwdriver tends to slip out of the slot, damaging it. I'd like to replace the centering adjustment screws with Phillips head screws or, even better, with socket head cap screws. One of the attached pdf files says the screws are M4 x 11.7. Is there any reason why the screws at https://www.ebay.com/itm/Genuine-Shi...EAAOSwZ2tcLH41 wouldn't work as replacements?
11-29-20, 01:01 PM
#2
aged to perfection
Join Date: Jun 2009
Location: PacNW
Posts: 1,817
Bikes: Dinucci Allez 2.0, Richard Sachs, Alex Singer, Serotta, Masi GC, Raleigh Pro Mk.1, Hetchins, etc
Mentioned: 24 Post(s)
Tagged: 0 Thread(s)
Quoted: 839 Post(s)
Liked 1,258 Times
in
663 Posts
might work. all you can do is try them.
if you have problems with "phillips head screws slipping" consider going to 1/4 hex bits with accurately shaped Phillips drivers. I like the Wera items available on ebay. you can get hex and Torx drivers as well.
A really good Phillips screwdriver, like a Snap On, is OK when new. The one you pull out of the bargain bin at ace hardware will destroy fasteners from the start.
The shimano screws in particular seem very soft. A good "bit" fits correctly and will not slip and round out the screw head.
Mark Petry
Bainbridge Island, WA
if you have problems with "phillips head screws slipping" consider going to 1/4 hex bits with accurately shaped Phillips drivers. I like the Wera items available on ebay. you can get hex and Torx drivers as well.
A really good Phillips screwdriver, like a Snap On, is OK when new. The one you pull out of the bargain bin at ace hardware will destroy fasteners from the start.
The shimano screws in particular seem very soft. A good "bit" fits correctly and will not slip and round out the screw head.
Mark Petry
Bainbridge Island, WA
Last edited by mpetry912; 11-29-20 at 01:05 PM.
11-29-20, 01:06 PM
#3
Really Old Senior Member
A genuine JIS screwdriver fits much better-
https://www.parktool.com/product/der...ewdriver-dsd-2
https://www.parktool.com/product/der...ewdriver-dsd-2
11-29-20, 01:08 PM
#4
Senior Member
Join Date: Sep 2010
Location: Roswell, GA
Posts: 8,319
Bikes: '93 Trek 750, '92 Schwinn Crisscross, '93 Mongoose Alta
Mentioned: 30 Post(s)
Tagged: 0 Thread(s)
Quoted: 1438 Post(s)
Liked 1,092 Times
in
723 Posts
Shimano screws are likely JIS drive, not Phillips. JIS drivers will probably fit the recesses properly. Having said that I prefer socket drive over Phillips. M4 x 12 should fit OK, if not it would be easy to grind off the slight extra length.
https://en.wikipedia.org/wiki/List_o...rives#Phillips
https://en.wikipedia.org/wiki/List_o...ves#JIS_B_1012
https://en.wikipedia.org/wiki/List_o...rives#Phillips
https://en.wikipedia.org/wiki/List_o...ves#JIS_B_1012
11-29-20, 01:14 PM
#5
SE Wis
Join Date: Apr 2005
Location: Milwaukee, WI
Posts: 10,516
Bikes: '68 Raleigh Sprite, '02 Raleigh C500, '84 Raleigh Gran Prix, '91 Trek 400, 2013 Novara Randonee, 1990 Trek 970
Mentioned: 40 Post(s)
Tagged: 0 Thread(s)
Quoted: 2747 Post(s)
Liked 3,401 Times
in
2,058 Posts
I personally would just run down to my Ace or Tru Value hardware store with one of them and match it up with a SS socket head they have for like $1
Likes For dedhed:
11-29-20, 01:34 PM
#6
Newbie
Join Date: Mar 2020
Location: Mid Atlantic, Nawf Cackalaky, Rawlywood
Posts: 68
Bikes: 3 road steelys, 3 alu, 1 mtb, 1cx
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 20 Post(s)
Likes: 0
Liked 22 Times
in
15 Posts
Try using a 2.5 or 3mm hex wrench in the existing bolts on your brake adjuster bolts.
Some of the dura ace brakes used a combination JIS and hex bolt. Assuming the bolt
is not seized in place, it should turn with a hex wrench.
Some of the dura ace brakes used a combination JIS and hex bolt. Assuming the bolt
is not seized in place, it should turn with a hex wrench.
11-29-20, 01:39 PM
#7
Full Member
Thread Starter
I think these will work, although I'd rather have a socket head as long as the screw was stainless steel. I just bought the 2-pack which cost me $1.25.
https://www.homedepot.com/p/M4-0-7-x...1058/204225839
https://www.homedepot.com/p/M4-0-7-x...1058/204225839
Last edited by johnlink; 11-29-20 at 01:54 PM.
11-29-20, 01:40 PM
#8
Full Member
Thread Starter
Neither the front nor the rear bolt is seized but no hex driver works.
11-29-20, 03:25 PM
#9
Senior Member
Join Date: Feb 2012
Location: Rochester, NY
Posts: 18,095
Bikes: Stewart S&S coupled sport tourer, Stewart Sunday light, Stewart Commuting, Stewart Touring, Co Motion Tandem, Stewart 3-Spd, Stewart Track, Fuji Finest, Mongoose Tomac ATB, GT Bravado ATB, JCP Folder, Stewart 650B ATB
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 4210 Post(s)
Liked 3,875 Times
in
2,315 Posts
On the vast majority of the dual pivot calipers I see I don't touch these "centering" screws at all, unless the caliper is already set up really off center. Then I generally just set the screw so that the two sides/arms/pads are symmetrical. To center the caliper/pads I just turn the caliper backing plate (and the mounting bolt) on the frame. Andy
__________________
AndrewRStewart
AndrewRStewart
11-29-20, 03:50 PM
#10
Full Member
Thread Starter
On the vast majority of the dual pivot calipers I see I don't touch these "centering" screws at all, unless the caliper is already set up really off center. Then I generally just set the screw so that the two sides/arms/pads are symmetrical. To center the caliper/pads I just turn the caliper backing plate (and the mounting bolt) on the frame. Andy
11-30-20, 03:13 AM
#11
Droid on a mission
Join Date: May 2018
Location: Palm Coast, FL
Posts: 1,005
Bikes: Diamondback Wildwood Classic
Mentioned: 4 Post(s)
Tagged: 0 Thread(s)
Quoted: 317 Post(s)
Liked 280 Times
in
195 Posts
I think these will work, although I'd rather have a socket head as long as the screw was stainless steel. I just bought the 2-pack which cost me $1.25.
https://www.homedepot.com/p/M4-0-7-x...1058/204225839
https://www.homedepot.com/p/M4-0-7-x...1058/204225839
Hex Head cap Screws Metric
Or this Metric set screw with internal hex
Set Screw Metric M4
__________________
JoeTBM (The Bike Man) - I'm a black & white type of guy, the only gray in my life is the hair on my head
www.TheBikeMenOfFlaglerCounty.com
JoeTBM (The Bike Man) - I'm a black & white type of guy, the only gray in my life is the hair on my head
www.TheBikeMenOfFlaglerCounty.com Last edited by JoeTBM; 11-30-20 at 03:17 AM.
11-30-20, 10:03 AM
#12
Senior Member
Join Date: Aug 2005
Location: Pittsburgh, PA
Posts: 33,656
Bikes: '96 Litespeed Catalyst, '05 Litespeed Firenze, '06 Litespeed Tuscany, '20 Surly Midnight Special, All are 3x10. It is hilly around here!
Mentioned: 39 Post(s)
Tagged: 0 Thread(s)
Quoted: 2026 Post(s)
Likes: 0
Liked 1,096 Times
in
742 Posts
On the vast majority of the dual pivot calipers I see I don't touch these "centering" screws at all, unless the caliper is already set up really off center. Then I generally just set the screw so that the two sides/arms/pads are symmetrical. To center the caliper/pads I just turn the caliper backing plate (and the mounting bolt) on the frame. Andy
