• Required reading for all forum users!!!

    Welcome!
    Register to access the full functionality of the GSResources forum. Until you register and activate your account you will not have full forum access, nor will you be able to post or reply to messages.

    A note to new registrants...
    All new forum registrations must be activated via email before you have full access to the forum.

    A Special Note about Email accounts!
    DO NOT SIGN UP USING hotmail, outlook, gmx, sbcglobal, att, bellsouth or email.com. They delete our forum signup emails.

    A note to old forum members...
    I receive numerous requests from people who can no longer log in because their accounts were deleted. As mentioned in the forum FAQ, user accounts are deleted if you haven't logged in for the past 6 months. If you can't log in, then create a new forum account. If you don't get an error message, then check your email account for an activation message. If you get a message stating that the email address is already in use, then your account still exists so follow the instructions in the forum FAQ for resetting your password.

    Have you forgotten your password or have a new email address? Then read the forum FAQ for details on how to reset it.

    Any email requests for "can't log in anymore" problems or "lost my password" problems will be deleted. Read the forum FAQ and follow the instructions there - that's what we have one for...

  • Returning Visitors

    If you are a returning visitor who never received your confirmation email, then odds are your email provider is blockinig emails from our server. The only thing that can be done to get around this is you will have to try creating another forum account using an email address from another domain.

    If you are a returning visitor to the forum and can't log in using your old forum name and password but used to be able to then chances are your account is deleted. Purges of the databases are done regularly. You will have to create a new forum account and you should be all set.

front end swap -wheel bearing advice needed

  • Thread starter Thread starter Tukn20s
  • Start date Start date
T

Tukn20s

Guest
I'm currently working on a zx6r front end swap on a 78 GS750 frame with a GS wheel. The zx6r axle is 25mm (25x47x12 bearing) and the gs750 runs a 15mm axle (15x42x13mm bearing). So in theory I would need a 25x42x13 bearing. However, that is an oddball size. 25x42x9 seems to be the common size for that ID/OD. I'm trying to keep cost down and do things as easy as possible, so I would like to avoid machine work since I don't have the equiment to do it myself. However, safety is number one priority so I want to make sure this is all done safely. I did locate a place in the UK that has 25x42x12 bearings. I have spoke with them via email to confirm the size and they tell me that is correct. I have not found that size anywhere else. I also found a 25x42x18 double roller. However, I don't know if I could make that width work and they are $40+ each which is getting pricey for bearings.

So I guess my concern is if the 25x42x12 bearing will be suitable for use as a wheel bearing due to the minimal difference between the ID/OD. Or would the 9mm be sufficient? It was also suggested to use two of the 9mm on each side. I'm not sure if that would be ok to do. So any suggestions/opinions would be appreciated.

Thanks.
 
get a spacer/sleeve made, 15mm i/d x 25mm o/d. same width as the GS axle and use that in the wheel with the GS axle. a machine shop will charge peanuts to knock that up
 
get a spacer/sleeve made, 15mm i/d x 25mm o/d. same width as the GS axle and use that in the wheel with the GS axle. a machine shop will charge peanuts to knock that up


Pretty sure he's not using the GS axle.
 
Last edited:
Pretty sure he's not using the GS axle.

Correct. The GS axle is about an inch shorter than the zx6. Also the zx6 axle is hollow so I can't have that turned down.

I did also discover that the xs650's use 47od bearing and are 36 spokes as well (btw im using spoked wheels if I didn't mention that already). So that would be another option if it came down to it.
 
well he didn't mention that in his first post. again, it wont cost a lot to have a new longer axle machined.......

No it wont cost a fortune to have an axle made, but certainly more than the $5-10 that a pair of bearings cost.
 
If he can source the correct bearings for the job! otherwise some machining may be the only option.

25x42x9 bearings are easy to get. I also found a source that supposedly has 25x42x12 which would be ideal. My concern is.....even though these bearings fit, are they safe for my application
 
25x42x9 bearings are easy to get. I also found a source that supposedly has 25x42x12 which would be ideal. My concern is.....even though these bearings fit, are they safe for my application

they will be perfectly safe as long as they are deep groove roller bearings. 1mm less on the width will not hurt at all.
 
http://www.wibearing.com/NTN-6905Z/

these are deep groove bearings, ideal for wheel bearings. but, the 6905's are only 9mm wide instead of 13mm. i guess they would be ok but i would get a 4mm spacer made to sit in the wheel hub to make up the extra space. consider replacing them more often as a precaution
 
Back
Top