Commuting - Sirrus Sport Disc back-rack problem.

I've recently purchase a Specialized Sirrus Sport Disc bike to commute back and forth to work about 50 km. I love biking back and forth to work - but the shoulder straped back pack (holding everything from clothes, books, lock, etc.. ) is starting to wear me a little thin. Especially in the heat. I decided I need to get the pack off my back and onto the bike.

Putting a back rack on the bike and invest in some panniers seemed like a very solution but ....

After spending an entire day visiting reputable 7 bike shops in my area (Ottawa, Canada) looking for a back rack that will properly fit the bike (28-700C) and some 35 - 40 litre panniers, I have returned home with no back rack on the bike. :(

The difficulty stems from the disc brake assembly interfering with the mounting of a rack. The assembly is very close to the the mounting screws for a rack. It also appears that normal back racks (MEC, Axiom, and a myriad of others ) are not quite wide enough for the frame. The only solution so far was a rack by Norco (marketed as Axiom) that was made specifically for bikes with disc brake components. After 2 bike mechanics spent 30 minutes trying to "gizmo it on" it was deemed unusuable as it still didn't to fit my bike.

Here is a link to a picture of the bike for visual reference: http://www.specialized.com/SBCBkModel.jsp?spid=5996&JServSessionIdroot=4dlavaj2bl.j27007 .

A rack that attaches to the seat post was suggested as well. However, the suggestion was quickly retracted when I explained that I was going to put 40 l panniers on it and biking 50 km a day. These racks are apparently not very stable.

Needless to say I'm quite disappointed with Specialized at the moment - I've looked through the Specialized product offerings and found no racks. :( I have raised the question on their website FAQ - so far no answer. :( One would think that a $800+ bike sold to me for the purpose of commuting would have the ability to have a back rack mounted without much difficulty. :mad:

Anyway, enough of the rant -

Is there someone who has had a similar problem found a solution? Has someone found a good rack that can be properly mounted with enough clearance to stay way from the rear disc bikes?

I would greatly appreciate any help you can offer! :)

I'm no help, but I will say at this point that I'm glad I went with Trek's 7500FX instead! It was a very near thing, and I'd be as consternated as you apparently are right now.

Too bad. The Sirrus is a very nice bike.

Good luck finding a solution!

I don't have any details, but an acquaintance of mine has a Independent Fabrication bike with a rear disc brake and he does have a rack on his bike. He has some sort of extension-thingy for his rack that went out and around the disc brake.

I can't imagine this is a new or unique problem. Somebody has to have a solution.

Delta makes a seat-post pannier support rack. Nashbar sells it:

http://www.nashbar.com/profile.cfm?category=112&subcategory=1079&brand=&sku=1665&storetype=&estoreid=&pagename=

The site says the capacity is only 25 pounds, though.

Does the rack itself actually hit the disc brake assembly? Does the assembly stick out further than the seat stays? Too bad I didn't see this before I went over to the LBS today, as I could have looked at a Sirrus and maybe come up with an idea. If the rack doesn't clear the assembly you might be able to put some kind of spacer in to hold the bracket supports out a bit, and use longer screws to secure it. If you do this make sure it doesn't cause problems with any alignment on screws near the top of the seat stays, if you have them. If your rack doesn't use screws, but has nylon coated thingies that wrap around the seat stay above the brake cross piece on the frame, you might be able to do this.

hi radshark, the rack you need is made by [URL=oldmanmountain.com].i have two of these racks and they our of hi quality but a little expensive. they have models for disc brake set ups and they sell online.

I put a rack on my Novara Big Buzz ( has Avid mechanical disc brakes ) with a bit of effort. The rack I used was a cheap Trek branded model with adjustable height. The height adjustment is implemented by having bolts in the bottom end of the rack frame where it attaches to the eyelets at the dropouts. By screwing the bolts out to raise the rack, it cleared the disc brake body. I have seen several other racks with this feature. Also, I had to bend out the rack leg on the left side and put a small spacer between the dropout and the rack. You could also use a stack of washers instead of a spacer.
I hope this explanation makes sense!

Delta makes a seat-post pannier support rack. Nashbar sells it:

http://www.nashbar.com/profile.cfm?category=112&subcategory=1079&brand=&sku=1665&storetype=&estoreid=&pagename=

The site says the capacity is only 25 pounds, though.


The Delta seatpost rack can handel 30+ lbs with ease. I have been using one for the past year with great success. The only issue it that if they are ounted to high, you will get a bit of sway in the rear of the bike. But if you can mount then lower like on a sloped frame or a MTB frame then the center of gravity is lower and then it is hardly noticable. I have tired it on a road bike and a sloped frame Hybrid like the Sirrus and they work alot better on the Hybid (and I do a 35 mile round trip commute over some cinderpack trails here in Philly that are often washed out when it rains).

Thanks for the help guys!!! :)

I checked out the racks and advice - you guys are great! Those old man mountain racks look like pretty serious racks - probably worth the $200 CDN for them! The work around using the spacers on that adjustable trek looked like a possiblity, but ...

... I decided after a bit of deliberation to take the bike back to the point of sale and push for a return/credit. ( I was also having some difficulty with the calibration of the front disc brakes.) Fortunately I recieved credit and I'm now looking at purchasing an entry level road bike (that can have a back rack properly fitted :)) ... and NO disc brakes! ;)

Thanks to all that posted - great advice - nice to know there are people out there willing to help :)