Schwinn Homegrown Model Identifier Forums Sticky-CTB’s excellent write-up on rear disc adapters for the 4 Banger

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    CTB put together a thorough write-up detailing what he went through trying to adapt modern rear disc brakes for use with his 4 Banger. Special thanks to him for taking the time to detail his attempts and final solution, complete with pictures.


    The A2Z adapter is absolute garbage, in my opinion.

    If you can still find one, the Woodman “VRX Adapter” is a much better part for this than the A2Z adapter. It is much more precisely made (machined aluminum instead of stamped steel), and does not require a larger rotor. I paid about $30 for mine in 2006.

    Here is a photo of the woodman adapter. I will try to remember to take a photo of my rear brake setup and post it here. 


    I do not think the A2Z adaptor is garbage, but for me it was, for what it offers, overprized – so I produced my own adapter (12 USD):

    It is true that in most cases, you need bigger rotors. But most of the times you have to buy the brakes anyways and it does not hurt to ride on 180 rotors, does it?

    I still try to figure out which brake calipers are useable – in case of small hardtail frames. But at least you have more options than the one hard to get Hayes modell!

    For the Woodman VRX adaptor I found several offers in the UK – as usual – for around 40 – 50 USD incl the S&H.

    Ride on!


    The whole issue of using a 180mm rotor confused me.  First off, all you need to do is use a “front” adapter on the rear caliper with the A2Z.  The adapters all say either 140R/160F or 160R/180F.  Use the adapter that says 140R with an A2Z and all is fixed.  I learned the hard way when trying to use some XTR 965 ISO brakes.  That setup would have worked fine if I used “front” calipers fore and aft.  Who made the standard 20mm different for the front and back anyway?  

    With a Schwinn banger frame, I found that the 180mm rotor rubbed the lower pivot bolt and should not be used, so I consider a 160mm rotor the max on those frames (never tried a 170mm). 

    BTW, that Woodman looks great.  One complaint with an A2Z is that the bolts are so close you may have issues.  I went to the hardware store and bought “button head” bolts to fix the clearance issues.  I failed to use blue lock tight, and had to frequently stop and re-tighten the bolts and align the caliper.  The Woodman looks as if it would work with standard bike bolts.

    Just my 2 cents. 



    Your adapter looks very nicely made. Much nicer than the A2Z part. But like bikeric said, it would probably not work on our frames if a 180mm rotor is needed. 

    Yes, the woodman worked very well. Easy to bolt up, align, etc.


    I was just going to post a topic regarding rear disks on Bangers. I’ve got Avid BB7’s front and rear on mine, both 185. My rear rotor makes all sorts of noise, and I thinks it’s rubbing the bolts like you said bikeric. Just sitting there, there is clearance, but it’s close. I think that carbon swingarm flexes while riding, and causes rubbing.

    Oldschool, I’d be interested in fiding out of your adapter could run my BB7’s with a 160mm rotor. I’ll get some measurements, and if not, maybe I could pay you to make something up for me.


    This must be a different CTB than me, cuz that isn’t my work.  Nice work, tho!  🙂


    Not sure how I managed that one but I guess it’s time to go through the mail archives and set that one right.

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