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 09-06-11, 10:48 AM   #1
DCB0
Banned.
Thread Starter
 
Join Date: Apr 2011
Bikes: CCM Torino 76
Posts: 937
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Thread Size on Older Bike's Rack/Fender Mount

Hey, all!

I am coming around the final bend in my race to build my CCM Torino 76 into a sturdy all weather Afline 8 equipped commuter, and all that needs to be done now is to mount fenders and a rack. There are braze-ons aove the rear and behind the front dropouts, but they are obviously a larger diameter than the modern standard (M4?) for mounting racks, fenders, and water bottles.

I have found in the past that some BSOs have larger holes that are threaded, but don't know what thread size and pattern they were. Does anyone know what size(s) of bolt are likely to thread into an old frame like this? It is a Made in Canada CCM Torino '10 speed' from , I think, 1976.

I am going to try a few different sizes tonight, and I may just wind up going with an M4 or M5 with a nut, but if there is a more elegant solution I will be happy as a clam at high tide!

Thanks,
LASF
DCB0 is offline   Reply With Quote
Old 09-06-11, 10:52 AM   #2
FBinNY 
Senior Member
 
Join Date: Apr 2009
Location: New Rochelle, NY
Bikes: too many bikes from 1967 10s (5x2)Frejus to a Sumitomo Ti/Chorus aluminum 10s (10x2), plus one non-susp mtn bike I use as my commuter
Posts: 29,404
Mentioned: 2 Post(s)
Tagged: 0 Thread(s)
Quoted: 79 Post(s)
Close to 100% of threaded fender/rack mount eyes are 5x.8mm, the same as the water bottle screw.

If you have brazed on WB mount, you might borrow that screw and confirm.
__________________
FB
Chain-L site

An ounce of diagnosis is worth a pound of cure.

“Never argue with an idiot. He will only bring you down to his level and beat you with experience.”, George Carlin

“One accurate measurement is worth a thousand expert opinions” - Adm Grace Murray Hopper - USN

WARNING, I'm from New York. Thin skinned people should maintain safe distance.
FBinNY is offline   Reply With Quote
Old 09-06-11, 11:19 AM   #3
DCB0
Banned.
Thread Starter
 
Join Date: Apr 2011
Bikes: CCM Torino 76
Posts: 937
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Quote:
Originally Posted by FBinNY View Post
Close to 100% of threaded fender/rack mount eyes are 5x.8mm, the same as the water bottle screw.

If you have brazed on WB mount, you might borrow that screw and confirm.
I will certainly try am M5 to confirm but I am pretty sure the hole is too big for that.
Many older and cheaper bikes (mine included) have a larger hole that M5 passes right through. In the past I have sometimes been lucky and had the correct bolt to fit customers' bikes when they had these holes. Perhaps it was the same bolt size as the long bolt normally included with fenders to mount to the crown of the fork. M5? M6? 1/4-20? 10-32?
DCB0 is offline   Reply With Quote
Old 09-06-11, 11:25 AM   #4
FBinNY 
Senior Member
 
Join Date: Apr 2009
Location: New Rochelle, NY
Bikes: too many bikes from 1967 10s (5x2)Frejus to a Sumitomo Ti/Chorus aluminum 10s (10x2), plus one non-susp mtn bike I use as my commuter
Posts: 29,404
Mentioned: 2 Post(s)
Tagged: 0 Thread(s)
Quoted: 79 Post(s)
Quote:
Originally Posted by DCB0 View Post
I will certainly try am M5 to confirm but I am pretty sure the hole is too big for that.
Many older and cheaper bikes (mine included) have a larger hole that M5 passes right through. In the past I have sometimes been lucky and had the correct bolt to fit customers' bikes when they had these holes. Perhaps it was the same bolt size as the long bolt normally included with fenders to mount to the crown of the fork. M5? M6? 1/4-20? 10-32?
As I said, most threaded eyes are M5. Unthreaded eyes are usually bigger to accept an M5 screw (or bigger) and nut. M5 is fairly standard threaded eye or not, because most fenders and racks have a 5mm unthreaded hole, so that's going to be the screw of choice either way.

Of course, there are always exceptions, so confirmation by measurement or trial and error is still the best course, which is why I suggested it.
__________________
FB
Chain-L site

An ounce of diagnosis is worth a pound of cure.

“Never argue with an idiot. He will only bring you down to his level and beat you with experience.”, George Carlin

“One accurate measurement is worth a thousand expert opinions” - Adm Grace Murray Hopper - USN

WARNING, I'm from New York. Thin skinned people should maintain safe distance.
FBinNY is offline   Reply With Quote
Old 09-06-11, 11:26 AM   #5
DCB0
Banned.
Thread Starter
 
Join Date: Apr 2011
Bikes: CCM Torino 76
Posts: 937
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Quote:
Originally Posted by FBinNY View Post
As I said, most threaded eyes are M5. Unthreaded eyes are usually bigger to accept an M5 screw (or bigger) and nut. M5 is fairly standard threaded eye or not, because most fenders and racks have a 5mm unthreaded hole, so that's going to be the screw of choice either way.

Of course, there are always exceptions, so confirmation by measurement or trial and error is still the best course, which is why I suggested it.

Excellent. Thanks for the advice!
DCB0 is offline   Reply With Quote
Old 09-06-11, 11:38 AM   #6
cyccommute 
Mad bike riding scientist
 
cyccommute's Avatar
 
Join Date: Nov 2004
Location: Denver, CO
Bikes: Some silver ones, a black one, a red one, an orange one and a couple of titanium ones
Posts: 17,818
Mentioned: 3 Post(s)
Tagged: 0 Thread(s)
Quoted: 77 Post(s)
Quote:
Originally Posted by FBinNY View Post
Close to 100% of threaded fender/rack mount eyes are 5x.8mm, the same as the water bottle screw.

If you have brazed on WB mount, you might borrow that screw and confirm.
Close to 100% of modern rack mount eyes are M5 threads (a 10-32 will also work). However, older bikes may not have the same size rack mounts. I've had bicycles in the distant past that required drilling out the rack itself so that it would fit. Those are M6 bolts. Given the age of this bike, it may be one of those rare (for today) larger bolts.
__________________
Stuart Black
New! Pokin' around the Poconos A cold ride around Lake Erie
New! Dinosaurs in Colorado A mountain bike guide to the Purgatory Canyon dinosaur trackway
Solo Without Pie. The search for pie in the Midwest.
Picking the Scablands. Washington and Oregon, 2005. Pie and spiders on the Columbia River!
Days of Wineless Roads. Bed and Breakfasting along the KATY
Twisting Down the Alley. Misadventures in tornado alley.
An Good Ol' Fashion Appalachian Butt Whoopin'.
cyccommute is offline   Reply With Quote
Old 09-06-11, 11:54 AM   #7
DCB0
Banned.
Thread Starter
 
Join Date: Apr 2011
Bikes: CCM Torino 76
Posts: 937
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Quote:
Originally Posted by cyccommute View Post
Close to 100% of modern rack mount eyes are M5 threads (a 10-32 will also work). However, older bikes may not have the same size rack mounts. I've had bicycles in the distant past that required drilling out the rack itself so that it would fit. Those are M6 bolts. Given the age of this bike, it may be one of those rare (for today) larger bolts.
OK, 100% probability that it is M5, unless it is M6. Got it! TrialAndErrorVille, here I come!

Last edited by DCB0; 09-06-11 at 12:08 PM.
DCB0 is offline   Reply With Quote
Old 09-06-11, 12:02 PM   #8
dsbrantjr
Senior Member
 
dsbrantjr's Avatar
 
Join Date: Sep 2010
Location: Roswell, GA
Bikes: '93 Trek 750, '92 Schwinn Crisscross, '93 Mongoose Alta
Posts: 4,487
Mentioned: 1 Post(s)
Tagged: 0 Thread(s)
Quoted: 27 Post(s)
DCBO: I rebuilt an old Schwinn Collegiate which was tapped for M6X1 rack and fender hardware.
dsbrantjr is offline   Reply With Quote
Old 09-06-11, 12:09 PM   #9
DCB0
Banned.
Thread Starter
 
Join Date: Apr 2011
Bikes: CCM Torino 76
Posts: 937
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Quote:
Originally Posted by dsbrantjr View Post
DCBO: I rebuilt an old Schwinn Collegiate which was tapped for M6X1 rack and fender hardware.
Good to know. M6 is starting to sound like a possibility, too!
DCB0 is offline   Reply With Quote
Old 09-06-11, 12:15 PM   #10
Dan Burkhart 
Senior member
 
Dan Burkhart's Avatar
 
Join Date: Oct 2004
Location: Oakville Ontario
Bikes:
Posts: 5,923
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 12 Post(s)
I just did a frame up build on an old CCM and here is what I found. Front fork fender stay mounts were m5x.8, two holes on either side on the rear dropouts, one for fender stays had an unthreaded hole that an m5 bolt would pass through, and a rack mount hole that an m6 bolt passed through.
I ran an m6x1 tap through the fender stay hole, and it worked out great.
Dan Burkhart is offline   Reply With Quote
Old 09-06-11, 12:24 PM   #11
DCB0
Banned.
Thread Starter
 
Join Date: Apr 2011
Bikes: CCM Torino 76
Posts: 937
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Quote:
Originally Posted by Dan Burkhart View Post
I just did a frame up build on an old CCM and here is what I found. Front fork fender stay mounts were m5x.8, two holes on either side on the rear dropouts, one for fender stays had an unthreaded hole that an m5 bolt would pass through, and a rack mount hole that an m6 bolt passed through.
I ran an m6x1 tap through the fender stay hole, and it worked out great.
Good to know. However, the rear dropouts look kinda thin, so if they aren't already threaded I think I will just use a nut... there is plenty of room with the IGH - not like a 10 speed cassette where a nut on the inside would interfere with the chain.

Thanks for the info!
DCB0 is offline   Reply With Quote
Old 09-06-11, 01:08 PM   #12
dsbrantjr
Senior Member
 
dsbrantjr's Avatar
 
Join Date: Sep 2010
Location: Roswell, GA
Bikes: '93 Trek 750, '92 Schwinn Crisscross, '93 Mongoose Alta
Posts: 4,487
Mentioned: 1 Post(s)
Tagged: 0 Thread(s)
Quoted: 27 Post(s)
DCBO: If you end up using a nut, an elastic stop nut will resist loosening due to vibration if there is no room for a lock washer. Blue Loctite is another possibility.
dsbrantjr is offline   Reply With Quote
Old 09-06-11, 01:30 PM   #13
bikeman715
Senior Member
 
bikeman715's Avatar
 
Join Date: Mar 2008
Location: Salinas , Ca.
Bikes: Bike Nashbar AL-1 ,Raligh M50 , Schwinn Traveler , and others
Posts: 2,402
Mentioned: 1 Post(s)
Tagged: 0 Thread(s)
Quoted: 4 Post(s)
You can also put the bolt in backward (the head of the bolt inside the frame ) so there will be clearance for the chain . Just put the nut on the outside of the rack or fender .
bikeman715 is offline   Reply With Quote
Old 09-06-11, 01:58 PM   #14
JohnDThompson 
Old fart
 
JohnDThompson's Avatar
 
Join Date: Nov 2004
Location: Appleton WI
Bikes: Several, mostly not name brands.
Posts: 16,361
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 58 Post(s)
Quote:
Originally Posted by DCB0 View Post
I will certainly try am M5 to confirm but I am pretty sure the hole is too big for that.
Many older and cheaper bikes (mine included) have a larger hole that M5 passes right through. In the past I have sometimes been lucky and had the correct bolt to fit customers' bikes when they had these holes. Perhaps it was the same bolt size as the long bolt normally included with fenders to mount to the crown of the fork. M5? M6? 1/4-20? 10-32?
The vast majority will be M5, a small number are unthreaded or M6.
JohnDThompson is offline   Reply With Quote
Old 09-06-11, 02:02 PM   #15
DCB0
Banned.
Thread Starter
 
Join Date: Apr 2011
Bikes: CCM Torino 76
Posts: 937
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Quote:
Originally Posted by bikeman715 View Post
You can also put the bolt in backward (the head of the bolt inside the frame ) so there will be clearance for the chain . Just put the nut on the outside of the rack or fender .

If I had limited clearance I could certainly use button head bolts on the inside of the stay, however there is a tonne of clearance between the dropout and the cog on the IGH so this shouldn't be an issue.

Quote:
Originally Posted by dsbrantjr
DCBO: If you end up using a nut, an elastic stop nut will resist loosening due to vibration if there is no room for a lock washer. Blue Loctite is another possibility.
I don't think I will be able to get 'elastic stop' nuts (do you mean nylon insert nuts or something else?) I will be using simple stainless hardware that is lying around. But I do have blue locktite to I will probably use that. I find is is effective as a threadlocker and as an antisieze.

Thanks, lads!
DCB0 is offline   Reply With Quote
Old 09-06-11, 02:03 PM   #16
DCB0
Banned.
Thread Starter
 
Join Date: Apr 2011
Bikes: CCM Torino 76
Posts: 937
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Quote:
Originally Posted by JohnDThompson View Post
The vast majority will be M5, a small number are unthreaded or M6.
Excellent. I will make sure I have a selection of both and I will fill you chaps in later!
DCB0 is offline   Reply With Quote
Old 09-06-11, 03:56 PM   #17
dsbrantjr
Senior Member
 
dsbrantjr's Avatar
 
Join Date: Sep 2010
Location: Roswell, GA
Bikes: '93 Trek 750, '92 Schwinn Crisscross, '93 Mongoose Alta
Posts: 4,487
Mentioned: 1 Post(s)
Tagged: 0 Thread(s)
Quoted: 27 Post(s)
DCBO: An advantage to your suggestion to put the bolt heads on the inside is that if you should happen to shear off one of the bolts you will be able to easily drive out the remaining piece of the bolt.
dsbrantjr is offline   Reply With Quote
Old 09-06-11, 07:09 PM   #18
LarDasse74
Guest
 
Join Date: Jul 2008
Location: Grid Reference, SK
Bikes: I never learned to ride a bike. It is my deepest shame.
Posts: 3,769
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
So I (I am also DCB0) got a selection of bolts and checked the frame and fork... all the holes are just big enough to accept an M5, but they are not threaded. I could not scrounge up any M5 nuts so I will have to wait until I do to mount the rack and fenders. Luckily, the Torino 76 is replacing a perfectly functional bike that I have on long term loan from my young sons, so there is no urgency to the repair. Thanks to all who replied!
LarDasse74 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 12:24 PM.