Wednesday, August 12, 2009

Mongoose Cyclocross Bike Dropouts



Mongoose has a somewhat elegant, neat looking aluminum dropout on the rear of their cyclocross frame which allows for both a disc brake (it's coming, oh yes, mark my words) and a rack + fender mount. If only I could read Hungarian.

Many companies have tried this with varying levels of slick-ness. For example, here's Voodoo's attempt at making the rear dropout that is all things to all people:

My take on putting a disc brake braze-on on a non mountain bike is that you want to localize the stresses of braking in the forged, stamped or CNC'd dropout part instead of transfering them onto the slender, flexible seat stays. Niner places theirs there, but then has to beef up the joint with a welded-in gusset.

I particularly like the Mongoose approach because it keeps the disc brake out of the way of the fender or rack, which prevents this giant kluge:



6 comments:

Slonie said...

I noticed a similar disc mount on a Schwinn on the train the other day:

http://www.flickr.com/photos/slonie/3816243972/sizes/l/

-p said...

Yep, same idea. And, that appears to be a steel frame. As a result, that might be one heavy dropout.

-p said...

BTW, are Mongoose and Schwinn just making these dropouts, waiting for disc brakes to catch on? Or are they sourcing a single dropout for mountain and cross/road applications? Why put the details on there and not use them?

Slonie said...

They might be speccing out the bike with discs on the high end and V-brakes on the lower models... It's probably just easier to build the same frame for all trim levels.

I was previously fairly close to building a Soma DoubleCross DC, which included both Disc and Canti mounts... Good for the noncommittal! :D

Jason said...

Paragon Machine works in Petaluma, CA is making a new dropout for framebuilders as shown here:
http://www.flickr.com/photos/jmuirfromsc/3580852850/
Allows rack, fender AND disc brakes to all coincide nicely.

-p said...

The Paragon dropout looks like a nice piece of laser cut steel that gets the job done for a steel TIG or brazed frame, much like the Mongoose part in Al. Paragon is a cool shop, manufacturing right here in Norcal USA.
BTW - Best of luck to you and the Sheila Moon CX team this season. Pink kits hide blood stains :-)