These types of dumbbells are the most common for home and commercial gyms. This guide will help you navigate among the advantages and disadvantages of each.
Hex dumbbells are made with chromed solid steel handles and welded-on cast iron heads with a painted finish. They're typically found in home gyms and in some smaller fitness establishments.
Rubber hex dumbbells are the same as the above, with steel handles and iron heads, but with a rubber coating instead of paint. So while they are really just rubber coated, we call them rubber dumbbells for simplicity.
Pro style dumbbells are found in most commercial gyms. They're made using solid steel handles and standard "pancake" style weight plates. They differ from standard adjustable dumbbells in that the handle ends are a precise length to fit an exact number of plates, it's bolted together so as to be semi-permanent, and they usually have end caps to further smoothen out the edges.
Rubber pro style dumbbells are the above with rubber coating on the attached weight plates instead of paint. Again, for short we call them rubber rather than rubber coated. Keep in mind that regular pro style dumbbells can also be made with only rubber end caps.
All types above can have contoured handles rather than straight. Contoured handles are thicker in the center than the edges, making for a wider and more ergonomic grip.
COST
The relative difference in cost varies widely depending on weight, because pro style dumbbells start at a higher price but the price doesn't increase as much as the weight increases. Hex and rubber hex dumbbells are generally just priced per pound, although the smallest and largest sizes might be price-adjusted for minimum retail margins or to factor in skewed shipping costs.
#1: Hex
#2: Rubber Hex - 1.5 to 2 times the price of hex dumbbells.
#3: Pro Style - Anywhere from 1.5 to 8 times the price of hex dumbbells.
#4: Rubber Pro Style - Anywhere from 1.5 to 11 times the price of hex dumbbells.
PROTECTING THE FLOOR
Rubber dumbbells are softer and won't scratch your floor. The winner here is rubber pro-style because of the smooth edges of the heads. Even rubber can be kind of hard, and the comparably sharper edges of rubber hex dumbbells can conceivably stab into a sensitive floor if you aren't careful. But that may be reaching because the edges are really not very sharp. Painted iron is the biggest threat to a sensitive floor, so hex dumbbells with their sharper edges and rougher surface score last.
#1: Rubber Pro Style
#2: Rubber Hex
#3: Pro Style
#4: Hex
DURABILITY
Even the high-quality baked-on finish on modern iron hex dumbbells will eventually chip when the dumbbells are banged around a lot. Rubber dumbbells are made to be banged around. However, rubber exposed to the hot sun will expand as it heats, and repeated exposure can cause the rubber to start cracking from all the expansion and contraction, so if you're in a hot climate, it would be best to keep them out of the sun. Assuming you can manage that, rubber comes out ahead.
The plates on pro style dumbbells have a flatter finish that's more resistant to chipping than the finish on hex dumbbells. If you've ever dinged old hex dumbbells together at the top of a bench press rep and gotten paint flecks in your face, you know how significant this is. A rubber coating will of course prevent this, and non-rubber pro dumbbells can be assembled with rubber end caps.
Hex dumbbells are welded together, and while the welds are usually very good, the small risk of a bad weld here has to be acknowledged, particularly for dumbbells that don't go through the quality checking of one of the top US manufacturers. The way to break a dumbbell is to drop it from high up at an angle, so one head hits first and puts a lot of torque stress on the handle. When a weld fails the head won't usually come clear off, but it may become a little loose and wobble. The risk of this isn't really a safety issue, because it's pretty obvious when a head is just loose or if it has smashed around enough to actually fall off.
On pro-style dumbbells the plates are secured in place by an allen bolt that is quite tight from the factory. It's pretty obvious when it starts to come loose after a lot of usage, and it's a simple matter of tightening it.
#1: Rubber Pro Style
#3: Rubber Hex
#4: Pro Style
#5: Hex
BEST USE OF SPACE
The smallest hex dumbbells take up minimal space, while the largest ones have a larger diameter than pro-style dumbbells and will consume more rack space. The size of pro style dumbbells reaches a maximum diameter (the size of a 10lb plate) and it just keeps adding more plates onto the end. So for larger sizes the pro are actually the most space-conscious.
The rubber coating of rubber hex dumbbells is thick enough that rubber hex dumbbells take up the most space on a rack at larger sizes.
The deciding factor here is going to be that pro style dumbbells tend to roll around and are often used on racks with individual saddles for each dumbbell rather than a flat rack. This looks extremely nice and keeps them organized, but it takes up so much space. In that case, rubber prostyle would take up the same space as regular professional style.
#1: Hex
#2: Rubber Hex
#3: Pro Style
#4: Rubber Pro Style
ODOR
Recycled rubber stinks. It varies, and it usually isn't too bad, and you might not even notice it unless you put your nose up to it, and it fades over time. However, virgin rubber, like the Troy TSD rubber hex dumbbells are made from, as well as all Troy rubber pro-style dumbbells, has no odor.
#1/#2: Hex, Pro Style
#3: Rubber Pro Style
#4: Rubber Hex
DON'T ROLL AWAY!
The worst thing that can happen is your dumbbells roll away, causing a passer by to trip and smash their head open on a machine. But it's also annoying when you're trying to set up for an exercise with heavy dumbbells and they keep rolling away on your uneven garage gym floor. Garage gyms are always sloped towards the entrance. And you want dumbbells to stay in place on the rack so they don't get mixed up.
As far as pro style, rubber is slightly ahead here, just because the softer rubber surface creates more stability and might not roll away when regular iron ones will. Rubber hex is actually more likely than hex to keep rolling downhill once it gets going, due to friction preventing it from sliding and stopping, and the fact it's going to bounce better.
This also may affect the type of rack you get. Racks with curved saddles are made to have one professional style dumbbell sit in each saddle, and they take up a considerable amount of floor space.
#1: Hex
#2: Rubber Hex
#3: Rubber Pro Style
#4: Pro Style
MAINTENANCE COST
For higher weights, the maintenance on damaged hex dumbbells is considerably higher. If you aren't the only one using the equipment, you can bet that people are going to drop weights. Clumsiness, injury, no respect for equipment, whatever, it's going to happen with enough use. When a dumbbell hits the floor at an angle, too much stress can be put on the end of the handle, and it can bend. A hex dumbbell instantly becomes trash, and you have to buy a new one, and heavy ones aren't cheap to ship, either.
When a pro-style dumbbell is dropped and breaks, it can be disassembled and the handle or any weight plates can be replaced at minimal cost.
Durability is covered in an above category, but in considering maintenance we have to consider how likely a dumbbell is to break or become damaged. Rubber is far less likely to break than bare iron when dropped on concrete, but it's also more expensive to replace. However, the most common damage on a dumbbell is not chipping of the head due to being dropped on bare concrete, as most people have more sense than that, but bending of the handle due to being dropped badly. So I'm giving higher rankings to the non-rubber dumbbells here considering the higher cost of replacing rubber dumbbells or rubber pro-style plates.
#1: Pro Style
#2: Rubber Pro Style
#3: Hex
#4: Rubber Hex
WEIGHT RANGE
Hex dumbbells start at just 1lb, whereas pro style dumbbells start at 5lbs. But really when you're reading an article like this to decide among these dumbbells, you probably won't be too concerned about having so many weights under 10lbs. Neoprene dumbbells are popular for those sizes. So I'm going to kind of ignore the lower end and look at the higher end. Prostyle dumbbells go up to 150lbs or even higher, while hex dumbbells might not go over 100lbs.
The popular PlateMate magnets, which are used to add weights in small 1.25 or 2.5 increments to dumbbells, won't stick to a rubber coating. Another method of microloading is using wrist weights, so you aren't totally out of luck, and you might even find that you prefer wrist weights over magnets, but the non-rubber dumbbells take the cake here for being more versatile.
Some people also like the cheap method of buying dumbbells in 10lb increments and using PlateMates to fill in the 5lb weight gaps, and in that case any iron dumbbell set is an even better deal.
#1: Pro Style
#2: Hex
#3: Rubber Pro Style
#4: Rubber Hex
