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

What's the most I can safely space out a hub?

Notices
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.

What's the most I can safely space out a hub?

Old 11-04-14, 07:02 PM
  #1  
Senior Member
Thread Starter
 
Join Date: Dec 2013
Posts: 78
Mentioned: 2 Post(s)
Tagged: 0 Thread(s)
Quoted: 28 Post(s)
Liked 3 Times in 3 Posts
What's the most I can safely space out a hub?

If I have a hub (say, in this case, a 110mm coaster brake hub) and I want to throw a few spacers on there to increase the spacing (to put it on a 120mm or 130mm frame), how many more millimeters of spacers can I add on until the hub is no longer safe?
mornview is offline  
Old 11-04-14, 07:32 PM
  #2  
Senior Member
 
Join Date: Dec 2010
Location: Above ground, Walnut Creek, Ca
Posts: 6,681

Bikes: 8 ss bikes, 1 5-speed touring bike

Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 86 Post(s)
Likes: 0
Liked 4 Times in 4 Posts
I don't have any idea what would or wouldn't be safe for you, but one problem, among many, with over spacing a hub is that the length of the axle between the bearings and the attachment points on the frame can become too long to support the rider and bike weight without causing a bent or broken axle. an example is the demise (and recent resurrection by Sun) of the 8 speed freewheel/hub.

all in all i believe that putting a 120mm hub on a 130mm frame is less likely to be hazardous to my health than the 30 mile ride around the suburbs/urban area that i take on a daily basis.

and i'm pretty sure that the two coaster brake hubs that i have used over the past few years were originally designed for 120mm spacing. and that neither has be re-engineered for at least 50 years.

BTW both are now are sold with spacing for 130mm's and have solid steel axles, i'm guessin mostly to withstand the abuse caused by the coaster brake.

Last edited by hueyhoolihan; 11-04-14 at 07:38 PM.
hueyhoolihan is offline  
Old 11-04-14, 07:48 PM
  #3  
Senior Member
Thread Starter
 
Join Date: Dec 2013
Posts: 78
Mentioned: 2 Post(s)
Tagged: 0 Thread(s)
Quoted: 28 Post(s)
Liked 3 Times in 3 Posts
Yeah, I'm guessing you're referring to the Velosteel coaster hubs. I'm glad that they're available as a ready-made option, but I have quite a few 110mm coaster hubs just sitting around, so I'd prefer to put them to work if possible.

And yeah, it is primarily that stress on the axle that I'm concerned about. I'm not a big guy by any means at 5'8, 180lbs., but you never know when I might find the perfect cargo-hauling frame, and what it might be spaced at .
mornview is offline  
Old 11-04-14, 11:14 PM
  #4  
Senior Member
 
Join Date: Apr 2009
Location: New Rochelle, NY
Posts: 38,350

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

Mentioned: 138 Post(s)
Tagged: 1 Thread(s)
Quoted: 5599 Post(s)
Liked 2,218 Times in 1,244 Posts
There's no real limit, but you'll run out of axle so don;t forget to allow for the thickness of the dropouts, and leave enough room for 10mm of nut plus a washer.

Also keep in mind that you want to preserve some semblance of chain line.
__________________
FB
Chain-L site

An ounce of diagnosis is worth a pound of cure.

Just because I'm tired of arguing, doesn't mean you're right.

“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  
Old 11-05-14, 09:44 AM
  #5  
Senior Member
 
Andrew R Stewart's Avatar
 
Join Date: Feb 2012
Location: Rochester, NY
Posts: 17,907

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: 4126 Post(s)
Liked 3,697 Times in 2,217 Posts
Originally Posted by FBinNY
There's no real limit, but you'll run out of axle so don;t forget to allow for the thickness of the dropouts, and leave enough room for 10mm of nut plus a washer.

Also keep in mind that you want to preserve some semblance of chain line.
+1 I'll add that having the frame fit the hub/axle width well is more important the wider everything gets. There's more leverage acting on the axle the longer it gets so if you also have to spread the frame and the drop outs aren't parallel you'll end up with some axle bowing. While this isn't the focus that the OP seemed to have I thought it is worth mentioning.

I've respaced a tandem frame from 120mm to 140mm then built up two rear wheels for it. One was a 120 double threaded steel one that allowed me to use a Shimano disk brake (this was in the mid 1970s, the hub and brake came off a JC Penneys bike). the other was a Normandy Sport hub, also originally a 120 width. Both wheels/hubs preformed well w/o issues. I wish I could say the same for that version of my tandem riding life. Not having a steady partner proved to be a real problem. Andy.
Andrew R Stewart is offline  
Old 11-05-14, 01:19 PM
  #6  
Senior Member
Thread Starter
 
Join Date: Dec 2013
Posts: 78
Mentioned: 2 Post(s)
Tagged: 0 Thread(s)
Quoted: 28 Post(s)
Liked 3 Times in 3 Posts
Thanks guys; chain line was an element I was totally overlooking.
mornview is offline  
Old 11-05-14, 02:16 PM
  #7  
Banned
 
Join Date: Jun 2010
Location: NW,Oregon Coast
Posts: 43,598

Bikes: 8

Mentioned: 197 Post(s)
Tagged: 0 Thread(s)
Quoted: 7607 Post(s)
Liked 1,352 Times in 859 Posts
IDK how much bending you are willing to do to the coaster brake arm so it is still able to be under the left chainstay when you finish the job.
fietsbob is offline  
Related Topics
Thread
Thread Starter
Forum
Replies
Last Post
savvas
Bicycle Mechanics
2
08-29-13 06:13 PM
okane
Bicycle Mechanics
4
12-01-12 07:42 PM
mbhudson
Singlespeed & Fixed Gear
3
01-20-12 10:25 AM
lostarchitect
Classic & Vintage
7
09-06-11 07:42 AM

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
Trackbacks are Off
Pingbacks are Off
Refbacks are Off


Thread Tools
Search this Thread

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

Copyright © 2024 MH Sub I, LLC dba Internet Brands. All rights reserved. Use of this site indicates your consent to the Terms of Use.