Go Back  Bike Forums > Bike Forums > Bicycle Mechanics
Reload this Page >

70-80mm O.L.D. wheel hub with break disc

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.

70-80mm O.L.D. wheel hub with break disc

Old 10-01-18, 09:54 AM
  #1  
Huxster
Newbie
Thread Starter
 
Join Date: Oct 2018
Posts: 3
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 1 Post(s)
Likes: 0
Liked 0 Times in 0 Posts
70-80mm O.L.D. wheel hub with break disc

Hi there,

I'm new to bikes and was just wondering if it was possible to find a wheel hub with an over lock distance between 70-80mm with a break disc attachment. I know Bromptons have hubs that fall in this range but none of them have brake discs and I haven't been able to find any.

If anything I'd love to know why these don't exist, e.g. is it something to do with torque?

Any help would be greatly appreciated!
Huxster is offline  
Old 10-01-18, 03:25 PM
  #2  
cpach
Senior Member
 
Join Date: Oct 2009
Location: Santa Cruz, CA
Posts: 1,144

Bikes: Too many. Cannondale SuperSix, Trek Remedy 8, Trek Crossrip+ get the most ride time.

Mentioned: 12 Post(s)
Tagged: 0 Thread(s)
Quoted: 222 Post(s)
Likes: 0
Liked 4 Times in 4 Posts
What fork do you have with a very small OLD?

A smaller OLD is fine for smaller wheel sizes but there's not a lot of advantage in most cases, and having a nonstandard part is to avoided when possible, so I'm not aware of anything with a short OLD and a disc mount.

Also, there's a non-trivial chance that you simply have a fork that's been damaged.
cpach is offline  
Old 10-01-18, 03:35 PM
  #3  
dsbrantjr
Senior Member
 
dsbrantjr's Avatar
 
Join Date: Sep 2010
Location: Roswell, GA
Posts: 6,225

Bikes: '93 Trek 750, '92 Schwinn Crisscross, '93 Mongoose Alta

Mentioned: 13 Post(s)
Tagged: 0 Thread(s)
Quoted: 649 Post(s)
Likes: 0
Liked 44 Times in 41 Posts
I would venture a guess that at 20-30mm narrower than the standard 100mm dimension there is not a lot of room for a disc.
dsbrantjr is offline  
Old 10-02-18, 02:41 AM
  #4  
Huxster
Newbie
Thread Starter
 
Join Date: Oct 2018
Posts: 3
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 1 Post(s)
Likes: 0
Liked 0 Times in 0 Posts
Okay,

I know Bromptons have a small O.L.D. and utilise paddle brakes. We're working on a custom bike with the aim of taking up as little space as possible without compromising wheel size (we're using 20" wheels). The forks we're using are a custom design that don't taper and we want to use brake discs for styling and performance reasons.

The goal:
- 20" wheels
- Less than 80mm O.L.D.
- Brake discs

Does anyone know if it's possible to have a smaller O.L.D. with this wheel size or would it create problems?

Thanks for the help chaps!

Last edited by Huxster; 10-02-18 at 02:42 AM. Reason: Manners
Huxster is offline  
Old 10-02-18, 03:23 AM
  #5  
Huxster
Newbie
Thread Starter
 
Join Date: Oct 2018
Posts: 3
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 1 Post(s)
Likes: 0
Liked 0 Times in 0 Posts
I've just googled it and the Brompton front hubs have a 74mm O.L.D. Would this hub size work with a larger wheel?
Huxster is offline  
Old 10-02-18, 10:21 PM
  #6  
Andrew R Stewart 
Senior Member
 
Andrew R Stewart's Avatar
 
Join Date: Feb 2012
Location: Rochester, NY
Posts: 11,653

Bikes: Stewart S&S coupled sport tourer, Stewart Sunday light, Stewart Commuting, Stewart Touring, Co Motion Tandem, Stewart 3-Spd, Stewart Track, Fuji Finest, Raleigh Pro, Trek Cycle Cross, Mongoose tomac ATB, GT Bravado ATB, JCP Folder

Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 1729 Post(s)
Likes: 0
Liked 45 Times in 32 Posts
It's always possible to custom fab a wheel/hub/fork and then find out why no one else does that Wheels like an amount of spoke bracing angle for the side forces to be dealt with. Front wheel collapse is a bad thing when riding... Smaller diameter rims will have better bracing angles all else being the same.

I suggest you mock up the spoke bracing angles on a Brompton front wheel and a 26/559 wheel and see how they compare. I'll add that for a two wheeled bike one leans into the cornering. But if you're designing a three+ wheeled machine those cornering forces will be greater due to the inability to lean in. (Reading of more then one fork...) Andy
__________________
AndrewRStewart
Andrew R Stewart is offline  
Old 10-03-18, 12:53 AM
  #7  
cpach
Senior Member
 
Join Date: Oct 2009
Location: Santa Cruz, CA
Posts: 1,144

Bikes: Too many. Cannondale SuperSix, Trek Remedy 8, Trek Crossrip+ get the most ride time.

Mentioned: 12 Post(s)
Tagged: 0 Thread(s)
Quoted: 222 Post(s)
Likes: 0
Liked 4 Times in 4 Posts
I suspect the bracing angles on a 20" wheel would be acceptable, but I definitely guess you'd have to have the hub custom fabricated.
cpach is offline  
Old 10-03-18, 03:20 AM
  #8  
dabac
Senior Member
 
Join Date: Mar 2008
Posts: 7,947
Mentioned: 36 Post(s)
Tagged: 0 Thread(s)
Quoted: 813 Post(s)
Likes: 0
Liked 1 Time in 1 Post
If you have a lathe, reducing OLD is no big deal - as long as the axle threads continue far enough inwards.
Find a hub with a cylindrical mid section. Remove axle.
Stick hub in lathe, cut in half. Remove desired portion of mid section.
Remove hub from lathe.
Cut a sleeve from appropriate tubular stock to go over center section. You may choose to extend in all the way to the flanges for minimum visibility.
Rejoin hub halves in your preferred method. I like a press fit aided by heating the sleeve before assembly.
Pay attention to how spoke holes line up.
Now, for a disc brake hub, I'd probably want to to research my options a bit.
If the brake side bearing seat can be recessed further, I'd do that, then trim the disc brake mounting flange accordingly. Then cut a section out of the center.
W/o drawing it out, I'm somewhat concerned about what bracing angle you'll get.
Maybe do a heads-in radial lace on the brake side. Or a heads-in 1X.
dabac is offline  
Old 10-03-18, 11:13 AM
  #9  
cpach
Senior Member
 
Join Date: Oct 2009
Location: Santa Cruz, CA
Posts: 1,144

Bikes: Too many. Cannondale SuperSix, Trek Remedy 8, Trek Crossrip+ get the most ride time.

Mentioned: 12 Post(s)
Tagged: 0 Thread(s)
Quoted: 222 Post(s)
Likes: 0
Liked 4 Times in 4 Posts
Originally Posted by dabac View Post
If you have a lathe, reducing OLD is no big deal - as long as the axle threads continue far enough inwards.
Find a hub with a cylindrical mid section. Remove axle.
Stick hub in lathe, cut in half. Remove desired portion of mid section.
Remove hub from lathe.
Cut a sleeve from appropriate tubular stock to go over center section. You may choose to extend in all the way to the flanges for minimum visibility.
Rejoin hub halves in your preferred method. I like a press fit aided by heating the sleeve before assembly.
Pay attention to how spoke holes line up.
Now, for a disc brake hub, I'd probably want to to research my options a bit.
If the brake side bearing seat can be recessed further, I'd do that, then trim the disc brake mounting flange accordingly. Then cut a section out of the center.
W/o drawing it out, I'm somewhat concerned about what bracing angle you'll get.
Maybe do a heads-in radial lace on the brake side. Or a heads-in 1X.
A press fit together, sawed in half hub shell with radial lacing on the brake side sounds like an amazingly bad idea. With radial lacing on the brake side all braking torque will have to be transmitted through the hub shell to the right side.
cpach is offline  
Old 10-03-18, 11:49 AM
  #10  
nfmisso
Nigel
 
nfmisso's Avatar
 
Join Date: Mar 2011
Location: San Jose, CA
Posts: 3,010

Bikes: 1980s and 1990s steel: CyclePro, Nishiki, Schwinn, SR, Trek........

Mentioned: 12 Post(s)
Tagged: 0 Thread(s)
Quoted: 381 Post(s)
Likes: 0
Liked 1 Time in 1 Post
Originally Posted by cpach View Post
A press fit together, sawed in half hub shell with radial lacing on the brake side sounds like an amazingly bad idea. With radial lacing on the brake side all braking torque will have to be transmitted through the hub shell to the right side.
++++++

Flip it around 2X at least, preferrably 3X on the disc side, and radial on the non disc side; to minimize the torque through the sleeve.

Also use a larger number of thin spokes, to allow for more compliance (softer ride) while maintaining strength.
nfmisso is offline  
Old 10-05-18, 10:32 AM
  #11  
fietsbob 
coprolite
 
fietsbob's Avatar
 
Join Date: Jun 2010
Location: NW,Oregon Coast
Posts: 41,928

Bikes: 8

Mentioned: 188 Post(s)
Tagged: 0 Thread(s)
Quoted: 6833 Post(s)
Likes: 0
Liked 211 Times in 176 Posts
Originally Posted by Huxster View Post
I've just googled it and the Brompton front hubs have a 74mm O.L.D. Would this hub size work with a larger wheel?
You could get a custom wheel-builder to build one..
and someone to modify, of custom build a 20" wheel fork.

a folding bike reduces its folded size in several, ways ,
small wheel size is one, narrow hubs and fork, another..

a 20" wheel folding bike is less likely to use a 74, more likely a 10cm wide hub ,
then you may have a greater likelihood of finding one made around having disc brakes..

For the 74mm wide Brompton , an Australian company, Greenspeed ,
remachines S-A front drum brake hubs to go in an unmodified fork,
Drum brakes are not disc brakes but they are not rim brakes either..

A Glasgow Scotland frame builder/Brompton dealer makes a 10cm wide fork
to use disc brake wheels custom built, with rims from Brompton...

Bike Friday in Oregon, makes 20" wheel disc brake bikes , I own one.

Precisely Why you want this, remains a question..





...

Last edited by fietsbob; 10-05-18 at 10:42 AM.
fietsbob is offline  
Related Topics
Thread
Thread Starter
Forum
Replies
Last Post
Thadcorn
General Cycling Discussion
2
06-27-16 09:48 AM
joe englert
Classic & Vintage
22
07-04-12 10:14 PM
cwhale27
Electronics, Lighting, & Gadgets
7
04-01-10 05:44 AM
KDC1956
Bicycle Mechanics
2
12-03-09 10:18 PM

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


Thread Tools
Search this Thread

Contact Us - Archive - Advertising - Cookie Policy - Privacy Statement - Terms of Service

Copyright 2018 MH Sub I, LLC dba Internet Brands. All rights reserved. Use of this site indicates your consent to the Terms of Use.