Rear Disc Mounting alignment? Special adapter or spacing?

[cannondalefanatic]

At first I thought it was a brand adapter issue, but now I'm starting to wonder if something else is going on here. I'm running Avid BB7-S MTB Brakes, and made sure to get the matching Sram Disc Adapters. However the bolt alignment on the rear is WAY off. See picture. Anyone else running into this? I tried other brand adapters, but ran into the same issue, so wondering if Cannondale had special spacing requirement for their rear brakes.

 

[cannondalefanatic]

Follow up. Had to run some washers to get the alignment where it needed to be. Very strange, but for now it works

 

[MikeA]

Interesting. The inside of the IS mounting pad on my Caffeine frame is flush with the inside of the dropout, which is right where your washers place it. Your mount may be specific for Coda disc brakes with the Coda 4 bolt hubs since that was all they sold them with back then. Although, my V brake 2000 Jekyll swingarm has the same offset caliper mount as yours, and I remember they advertised it as compatible with "coda and other IS standard disc brakes".

 

[black lightning 1987]

Mike, your input is appreciated. We need a few more knowledgeable members like you to check in and comment regularly.

I'm interested in the question and answer, even though I've not owned a Cannondale with disc brakes. My first thought was that it might be something related to the Coda calipers.

If you can get the optimal thickness of the required spacer figured out, I'd be happy to turn some AL spacers to the needed dimensions.

 

[MikeA]

I wish I could help more. Here's an old thread on MTBR i found confirming the need for spacing by Craig at Mendon Cyclesmith:

https://forums.mtbr.com/cannondale/upgrading-coda-disc-brakes-417731.html

The exact wording from my manual is "The mounts on the Jekyll's swingarm and fork are designed to fit a CODA Compact Disc Brake caliper. Other brands of disc brakes which conform to the international mounting standard may fit as well."

The International Standard is flush with the dropout though:

 

[black lightning 1987]

It would be nice to see pics of the original Coda setup. I'm wondering if they used a spacer too.

 

[Len]

Hey guys, sorry for the late input here...
Here's what I did with my 2000 F700SX when I upgraded from the (garbage) stock Magura brakes:
First, here's was my bike when I first bought it and all stock.

Had Magura disc brakes and CODA wheels with 4 bolt hubs and rotors. After fighting those and trying to keep them working I decided to bite the bullet and upgrade everything. Bought a new/used 6 bolt Lefty wheelset and brakes. Here's what I bought from Jenson USA to complete the brake upgrade:
Purchase Information Unit Price Quantity Extended Price
Shimano BR-M396 Disc Brake
Item #: BR222C00BLK 1000 FR $31.99 1 $31.99
Shimano BR-M396 Disc Brake
Item #: BR222C00BLK 1700 REAR $31.99 1 $31.99
Shimano 160mm Is Disc Brake Adaptor
Item #: BR270C06SKU $5.99 1 $5.99
Shimano F160P/S Disc Brake Adaptor
Item #: BR256K02BLK $5.99 1 $5.99

This is the only pic I have on hand right now. I'll take a closer one of the adapter fitment when I get home:

 

[MikeA]

Well, looks like I don't need to worry about this upgrade anymore...

 

[cannondalefanatic]

Well, looks like I don't need to worry about this upgrade anymore...

View attachment 5766

Doh! How'd that happen?

 

[MikeA]

Doh! How'd that happen?

I rode over a small tree across the trail I ride every week, this time I went sideways and couldn't clip out. Sprained my shoulder, still not healed completely after 6 weeks, and the bike came down on a rock. I went back and found the broken piece, I figure I can JB weld it back in place and touch up the paint for aesthetic reasons at least.

 

[cannondalefanatic]

I rode over a small tree across the trail I ride every week, this time I went sideways and couldn't clip out. Sprained my shoulder, still not healed completely after 6 weeks, and the bike came down on a rock. I went back and found the broken piece, I figure I can JB weld it back in place and touch up the paint for aesthetic reasons at least.

Ouch! Speedy recovery! Heal up quickly.

 

[MikeA]

Ouch! Speedy recovery! Heal up quickly.

Thanks! I'm almost there. I took my hardtail out last week and just rode on the forest roads to avoid stressing my shoulder, but it was kind of boring. I can't wait to hit the trails again.

 

[JohnnyD]

I'm going to revive an old thread here. During recent e-mails with Uniefex about his disc brake conversion on one of his Super Vs, yes he has more than one, we talking about him having to use spacers on the disc brake tabs to get the alignment of the adapter right. Another friend of his also had to use them on his Raven as well. I thought it was curious because my 2004 Jekyll doesn't need them. I would be curious to see if other 2004+ bike need them, or what year Cannondale changed the IS mount tabs so you didn't need to use them.
Thankfully, this bit of information came to light right as I was buying the 2001 Jekyll and it had the spacers on the rear, as well as some on the Lefty. The ones on the Lefty kind of make sense because of how the brake has to pivot out of the way to allow the wheel to be removed, so the spacer acts like a washer and allows for some movement once loosened.
2001:

2004:

Lefty:


Super V rear:


Raven: