Go Back  Bike Forums > Bike Forums > General Cycling Discussion
Reload this Page >

bmx crank on a road bike ?

Notices
General Cycling Discussion Have a cycling related question or comment that doesn't fit in one of the other specialty forums? Drop on in and post in here! When possible, please select the forum above that most fits your post!

bmx crank on a road bike ?

Old 01-15-20, 08:31 AM
  #1  
jambon
Senior Member
Thread Starter
 
Join Date: Jul 2014
Location: Ireland
Posts: 397
Mentioned: 6 Post(s)
Tagged: 0 Thread(s)
Quoted: 104 Post(s)
Liked 1 Time in 1 Post
bmx crank on a road bike ?

Hi there,

I am looking for a 180mm single speed crankset. I have found one second hand but it is a BMX crankset ,Truativ BMX ISIS crankset 180mm with Giga Pipe ISIS bottom bracket.

Will this run on a normal road bike with 68cm BB . Will there be chainline issues , I am hoping to get close to 50mm to match the rear cogs chainline (single speed setup).

Any other things to factor in ?

Thanks

J
jambon is offline  
Old 01-15-20, 08:34 AM
  #2  
alcjphil
Senior Member
 
alcjphil's Avatar
 
Join Date: Jun 2002
Location: Montreal, Quebec
Posts: 5,869
Mentioned: 16 Post(s)
Tagged: 0 Thread(s)
Quoted: 1792 Post(s)
Liked 1,671 Times in 955 Posts
Is that crank designed to work with a 1/8" single speed chain? If so, a derailleur chain will not fit the chainring
alcjphil is offline  
Old 01-15-20, 09:33 AM
  #3  
Wilfred Laurier
Señor Member
 
Wilfred Laurier's Avatar
 
Join Date: Feb 2013
Posts: 5,065
Mentioned: 5 Post(s)
Tagged: 0 Thread(s)
Quoted: 648 Post(s)
Liked 291 Times in 215 Posts
I believe BMX refers to 68mm threaded bottom brackets as 'Euro' style. If that is the BB then it will likely fit. But as mentioned above, the BB fitting is not the only thing you need to consider.
Wilfred Laurier is offline  
Old 01-15-20, 11:38 AM
  #4  
jambon
Senior Member
Thread Starter
 
Join Date: Jul 2014
Location: Ireland
Posts: 397
Mentioned: 6 Post(s)
Tagged: 0 Thread(s)
Quoted: 104 Post(s)
Liked 1 Time in 1 Post
Well on this particular crank I can switch out the chainring so that should not be an issue
jambon is offline  
Old 01-15-20, 01:22 PM
  #5  
mihlbach
Senior Member
 
mihlbach's Avatar
 
Join Date: Dec 2005
Location: Long Island, NY
Posts: 6,643
Mentioned: 3 Post(s)
Tagged: 0 Thread(s)
Quoted: 114 Post(s)
Liked 125 Times in 67 Posts
3/32" chainrings are readily abundant, so you should be able to use a chain intended for use with a derailleur. However, BMX chainlines are among the narrowest of all bicycle drivetrains, often between 40-42 mm. They have to be narrow to accommodate the narrow spacing of the dropouts (110 mm) in the rear of the frame. I do not know the chainline of the crank you referenced, but if it is a true BMX crank, the chainline is going to be too narrow. You aren't going to find a true BMX crank with a 50mm chainline. Depending on the size of the chainring, there also is a chance the chainring will not clear the chainstay.

You are better off looking for a mountain bike singlespeed crankset which will have a chainline much closer to 50 mm.

Last edited by mihlbach; 01-15-20 at 01:29 PM.
mihlbach is offline  
Likes For mihlbach:
Old 01-15-20, 01:50 PM
  #6  
Russ Roth
Senior Member
 
Join Date: Dec 2019
Location: South Shore of Long Island
Posts: 2,762

Bikes: 2010 Carrera Volans, 2015 C-Dale Trail 2sl, 2017 Raleigh Rush Hour, 2017 Blue Proseccio, 1992 Giant Perigee, 80s Gitane Rallye Tandem

Mentioned: 12 Post(s)
Tagged: 0 Thread(s)
Quoted: 1073 Post(s)
Liked 999 Times in 710 Posts
Really depends on if it is thru axle or square taper. My daughter's road and track bikes both have 130mm bmx cranks on them. With the road bike it is a little less then ideal, the thru axle crank limits the amount of adjustability though a couple of thin spacers allowed the cranks to be moved slightly enough to solve the chainline while still making sure both fixing bolts were over the axle for security. The track bike has the same rear spacing as a BMX track bike and isn't remotely an issue. If it uses a euro BB then you can find a spindle that will work with no trouble in a 1x setup
Russ Roth is offline  
Old 01-17-20, 04:09 PM
  #7  
Viich
Hack
 
Join Date: Sep 2015
Location: Ottawa, Ontario, Canada
Posts: 1,251

Bikes: TrueNorth CX bike, 88 Bianchi Strada (currently Sturmey'd), 90's Giant Innova (now with drop bars), Yess World Cup race BMX, Redline Proline Pro24 race BMX Cruiser

Mentioned: 4 Post(s)
Tagged: 0 Thread(s)
Quoted: 343 Post(s)
Liked 181 Times in 127 Posts
Some BMX cranks I've seen have spiders to fit a chainring on either side, and many good ones you can add spacers to move the drive side out a bit. Most of the spline BB spindles are available in several lengths.

You can probably get it to fit with a decent chainline if you start with the right crank and work at it.
Viich is offline  
Old 01-18-20, 08:39 AM
  #8  
Viich
Hack
 
Join Date: Sep 2015
Location: Ottawa, Ontario, Canada
Posts: 1,251

Bikes: TrueNorth CX bike, 88 Bianchi Strada (currently Sturmey'd), 90's Giant Innova (now with drop bars), Yess World Cup race BMX, Redline Proline Pro24 race BMX Cruiser

Mentioned: 4 Post(s)
Tagged: 0 Thread(s)
Quoted: 343 Post(s)
Liked 181 Times in 127 Posts
Originally Posted by Viich
Some BMX cranks I've seen have spiders to fit a chainring on either side, and many good ones you can add spacers to move the drive side out a bit. Most of the spline BB spindles are available in several lengths.

You can probably get it to fit with a decent chainline if you start with the right crank and work at it.
I didn't read properly. You should test fit, then measure the chainline. Different lengths of ISIS bottom brackets are available. Sounds like a nice solution.
Viich is offline  

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