Delta Megarack and Delta Megarack Disc Adapter
Dear Rideon,
Thank you for contacting Delta Cycle. I noticed from your blog that you have adapted the rack and hardware to work on the bicycle. We appreciate your attached blog. We will bring it to the attention of our tech department at our next job meeting.
Best regards,
Tracy
Anyhow, felt that was worth sharing and says something about the company, they care.

Several years ago a customer brought his 26" disc mountain bike to the shop wanting me to install an Axiom Journey Disc brake specific rear rack and the problem was getting the rack stay not to interfere with the brake caliper. Some filing and shaving away of the rack stay was necessary to accommodate the movement of the caliper.
Reading some of the bike forums I heard a lot of folks having problems installing a rear rack on their disc brake mountain bikes. This is due in part to a number of varying factors which are far too many to list. Including frame manufacturer, brake manufacturer, whether or not there are existing braze on's to accept the rack stays, etc.
Based on this knowledge and experience I decided to install an old Delta Mega Rack I found lying around and ordered a Delta Disc Adapter. First of all, the adapter works fine by curving around the caliper of my Avid BB7 Caliper. Simply sliding out the straight steel adjusting rod that came with the rack and replacing with the disc adapter, bolt in to place, done. Nope. First problem presented itself when the pre drilled threaded holes of the adapter wouldn't line up with the pre-drilled hole(s) of the adjustable rack stay. I would be very interested in knowing if anyone else has had this problem. I will be sending a link of this blog post to Delta.
| Images at left show the disc adapter (top) and the original adjustable stay at bottom. With mounting holes facing opposite direction for the disc adapter I drilled a new mounting hole on the front of the rack frame stay. |

Some racks come with spacers for this sort or thing and I had some extras in my parts drawer. Having too long a bolt and spacer would create a weak point and by spreading the rack stays to make it fit would most likely have caused the rear dropouts to be "pinched". I used a 23mm allen bolt with an 8mm long by 12mm (outside diameter) round aluminum spacer that I cut to length. I then added two small lock washers for the the threads to be flush with the inside of the frame's mounting hole. As it was not necessary to create a spacer of equal length to the space created by the disc adapter on the opposite side for the rack to be centered and balanced with the frame.
I like to use the high speed cordless rotary tool from Porter Cable with a Dremel heavy duty cut off wheel to start the cut and then used a hacksaw to finish the cut. Dremel de-burring bit used to remove sharp edges and such.

Hmm, feeling even better about this as a lady bug came in and landed on top of the rack soon after posting this blog article.
Cheers!
NOTE: Despite my earlier criticism of the Axiom Journey Rack, two are now available for disc compatibility with a re designed model. Enjoying this build of the "Rigmaroll" and looking forward to building on it some more.
NOTE: It seems that the Delta Megarack Disc Adapter is meant to be used with the Megarack Ultra Universal Disc Rack had to do some thorough research to discover this. However, reviews claim that because the rack is described as a "Disk Rack" later to learn they have to purchase the adapter(s) separately is causing annoyance with Delta's customers. This article helps clear up the confusion, good design and idea just needs some clarification from Delta.