Hi All,

I recently bought a road bike and i want to use it to commute to school. I was going to give it a test run today (Sunday), but when i finally loaded up my gear to the rack it actually seemed a little heavy. Given that i mounted the gear to the sides of the rack, i was nervous that the bike would give way and slip outward when i am turning.

My question is, how much weight can i put on each side of the rack? Should i keep it balanced? Should i just wear a backpack and have one central back on the middle of the rack? What i the best method to load up a big rack?

thanks!

Balance is generally good, but exactly how unbalanced you can get depends.

Different racks have different weight limits, though I doubt you're getting anywhere close to the rack's rated limit, much less the actual physical limit. A rough guideline is to take the rated limit of the rack and divide it in two. That would be a reasonable weight for each side. In reality, you can load more on one side than that without compromising the rack.

Balance in terms of the handling of the bike varies even more. Different rack/bike/bag combinations will mount the weight higher or lower, resulting in a higher or lower center of gravity. Higher center of gravity = less stable = more problems with unbalanced loads. Lower center of gravity = more stable = fewer problems with unbalanced loads. There's no easy rule; it just comes down to what feels comfortable with your set of gear.

A backpack, while inherently balanced, raises your center of gravity quite a bit, making it less than ideal for heavy loads. A more-or-less balanced arrangement in panniers will be more stable. Plus, panniers mean no sweaty back, and no bag possibly obstructing your view when you look over your shoulder.

What are you carrying (and how heavy is it) that makes this a problem?

Well i am carrying my backpack on one side, full of 5 notebooks and miscilleneous papers. On the other side would be my laptop bag with my laptop, of course, and a change of clothing. The reason i brought up this concern is because i loaded up the bike, and while i was pushing it outside, i tilted it and it gave way. Does the weight of the rider balance out the bike once im riding, making it less susceptible to loosing traction?

The bike will generally be more stable once you start riding. Use how it feels when you're riding as your determining factor, not how easily it tips over when stationary with you not on it. I carry loads on my bike that will tip it over the kickstand if I'm not holding it up, but are quite stable once I'm moving.

You should invest in some proper bike panniers though. It sounds like you're just strapping ordinary an ordinary backpack and laptop bag to your rack somehow, which is liable to cause problems with them not being attached securely and bits getting caught in your spokes. Depending on exactly how they're attached, they might swing out as well, which will screw up your stability. I wouldn't consider that scheme safe.

I mostly agree w/ Arcanum, but I will state that re:
I, for one, DO doubt. There are a number of racks out there with some pretty low weight limits and you might be close to them, e.g. some are only 20 lbs stated limit. OTOH, you might not. Check your rack and your mounting mechanism / fasteners, etc. As stated, there's a safety margin in there, but I like my safety margins.

As for it feeling heavy and the balance issue:

• Concur re COG and the value of low weight to stability.
• I've been amazed at how little the left/right imbalance between panniers matters in practice, though in theory the closer to centerline and more balanced the better.
• I've been amazed at how heavy (to lift) the bike can feel when you have all your kit loaded on it, and how light you might think your load is if it is all on your back, but you're hauling it either way. It's almost a Jedi mind trick in favor of backpacks, but the force is with me and I opt out of the sweaty back.

I usually ride with just one pannier, on the left side, carrying a 15" mbp, lunch, clothes, first aid kit, u and cable locks, ski goggles, gloves and hat (at least now that I'm not wearing them and until it's nice enough to forgo them), rain jacket... it's probably 20-25lbs loaded and although it's pretty unstable when I'm walking the bike down the hall, it doesn't even feel like it's pulling when I'm riding. But my rack has a 55lb weight limit and my bike has big cushy tires so YMMV

Ok, thanks a lot for the advice. I really am looking forward to commuting with my bike and giving my car a rest .

I was actually not aware of the weight limit concept, but it does make sense. Although I cannot seem to find the specified weight limit. i have a topeak explorer rack. I went on the website and all i found was basic dimensions. Does anybody have experience with this rack?

Also note Race bikes have short chainstays.
so kicking the bag with your heel, is a distinct possibility.

Some racks mount using the QR skewer for frames without eyelets.

I don't understand what you mean by "give way" - did the bike tip over due to inertia and/or a high center of gravity, against your efforts to stabilize it? This can happen when you are standing on the ground and not on the pedals, depending on where you are holding the bike, and what fulcrum exists (e.g your leg against the frame) below the center of gravity that could work to flip the rear wheel sideways and off the ground.

When your body weight is on the bike the, all that force against the ground and your tire traction will prevent the rear wheel from flipping sideways or up. The bike handling will feel weird if you stand up out of the seat - the frame will have a lot more lateral inertia when you try to lean or turn quickly, but you probably won't notice anything when you are sitting unless it's a particularly heavy load or it is positioned high on the bike.

If you are attaching things to the sides of the rack, real pannier mounts are recommended rather than DIY straps.