Rear Rack Design
 

Hello everyone, goofy question, but hey why not... :rolleyes:
Rear racks (not panniers) seem to come in two different designs, triangles or rectangles that come with or without top shelves.
Which style do you like better and why? Why not the other?
Thanks.

{edited for racks not panniers}
Triangles are structurally stronger. The blackburn style uses 3 struts with the rear ones at a different angle, canting inwards for full triangulation in all planes. It is immensly stiff for the weight.
Using Al or steel tubes, you rather than rod, you can add stiffness but use a squarer design which prevents the panniers catching in the spokes.
Top plates are for fenderless riding. I find that they restrict your options for strapping stuff to the top.

Or are you talking about the ones that are connected at the top - so you have 1 bag that is on both sides of the wheel?

If so, the main reason is so you can use one at a time. And you don't have to take both of them off to pack it etc. Also when off the bag, two separate bags back to back is easier to carry.

Do you perhaps mean rear racks, not panniers?

Oh my goodness! :eek: I'm such a goof-- You are all right, I am talking about racks and didn't even catch my error. Not panniers. I'll fix my post right now and appologize for the error of my ways :)

Now that I'm not confused anymore..... :)

Or maybe I am. By "triangular" and "rectangular", you mean the view from the side? The difference in design IMO is simply to give greater stability to a set of panniers. The rectangular ones have an extra tubing piece that might keep the panniers from twisting toward the wheels.

This is in theory, I've never had problems with my Blackburn Expedition (a triangular design; without top shelf by the way). If you're gonna carry a lot (say more than 25 lbs), you should get a rack with three vertical struts (e.g., the Expedition). Two struts are OK for lighter loads. A "rectangular" design probably adds a bit to carrying capacity, but as I said, it seems to be for pannier stability. My panniers have a rigid internal plastic plate (don't they all???), so I haven't had any problems with stability.

The only reason I see for a shelf is for bopping around town with a bag of groceries -- it would help keep things in place. It would also be useful for road spray, but fenders are 1000% better; besides with a touring load, road spray isn't going to get past the rack, shelf or not.

-- Mark

Edited title.

Rectangular design = more surface area for lateral pannier support.

Oooh! I love it when you talk physics!

The rectangular shape is supposedly better - that's what my Tubus has. But folks who use the other design like the blackburn don't seem to complain about it.

I have the Blackburn Exped on the rear of my Trek 520 and it is strong and light, but I get some flex in it with loads over 35lbs when climbing out of the saddle. On my 970 mtn-touring bike I went with Jandd racks front and rear - the Exped rear is a rect shape and extra long for better heel clearance. It is very beefy and also has a shelf which I really like for strapping stuff to it when I'm riding around town. Serves as a fender, too.

Thanks for all your comments! It's always interesting to find out what people like and why.