The Best Adjustable Dumbbells – Ironmaster vs PowerBlock vs SelectTech


Jump to:

  1. Introduction
  2. Quick Overview of Each
    1. Standard Dumbbell Handles
    2. PowerBlock
    3. Ironmaster Quick-Lock
    4. Bowflex SelectTech
    5. Universal Power-Pak
  3. Detailed Comparisons
    1. Adjustment Mechanism
    2. Comfort & Usage
    3. Size & Shape
    4. Weight Range and Upgrade Options
    5. Durability
    6. Price
    7. Warranty
  4. My Humble Opinion
  5. Where to Buy



For many years now, the adjustable dumbbells market has been mostly dominated by 3 big players. They are the PowerBlock, Ironmaster Quick-Lock, and Bowflex SelectTech.

Several imitations have come on the scene. We can get the idea that imitations are of lesser quality and are only competing on price, taking advantage of the big players’ marketing and then undercutting them. But I want to be fair about it, in case there’s a new model out there that’s worth buying over the rest. So I’m including in this article the Universal Power-Pak, which it seems to me is the next most popular one out there.

The thing with a lot of fitness equipment is it does start to break quickly. Home-grade cardio equipment, for example, literally is not engineered to be used seriously. It’s light weight, shakes as you move, and starts falling apart if used daily. They’re counting on you using it for a few weeks, then tapering off, and eventually folding it up into the corner and vowing that someday you’ll get back it.

Freeweight equipment tends to be really good in comparison. Generally with freeweights we’re talking about pretty simple cast-iron weights.

The closest type of product we can compare adjustable dumbbells to is an olympic barbell. Barbells were designed a hundred years ago and have been tine-funed over the decades to perform better, feel better, and last longer. You really can only appreciate the features once you’ve been lifting for a while and had a chance to compare different models of barbells. There are strict IWF and IPF requirements for barbells certified for competitions. Even the ones not certified look pretty much the same at first glance.

The adjustable dumbbells of the type I’m talking about in this article are a whole different story. They aren’t just barbells made smaller. Well, some are.

These shown in the pic are standard dumbbell handles. These is what we used to have to use, before the SelectTech came out as the first widely marketed alternative. I’m going to go over those too.

With all the dumbbells here, there are no specs they’re trying to follow. They all include proprietary plates and designs that each manufacturer thinks is the best or most cost-effective way to do it. Each one is different. That’s why this guide is necessary: to weed out the bad ones and figure out what the best design really is, or at least be clear on the tradeoffs.

The main reason adjustable dumbbells are so experimental is they’re marketed towards home users, personal trainers, and small gyms, not health club gyms or competitive lifters. There isn’t any elite level heavy duty models that they’re trying to imitate the look of. As long as they look pretty much like dumbbells, home users and trainers might give them a shot.


Quick Overview of Each

Standard Dumbbell Handles

These are the originals. Well, kind of. They’re the only ones you could find before about 2005, if I remember right. i’m sure I’m off somewhat on that date. There were apparently some kind of dial-select dumbbells in the 1990s, but I don’t remember them. The Bowflex SelectTech were the first ones I remember.

Anyway, here  ‘standard’ is the word we use to refer to plates with 1″ holes, and the bars to fit them.

The important thing is to get solid steel handles, not hollow. You can tell because the solid ones weigh 5 lbs each. The hollow ones are…I don’t know… a pound? If you drop them at an angle, loaded with weight, they’ll bend. That’s why you want solid handles. Most solid ones will be 100% steel, no fancy rubber covered handles, just knurling. Well, there is one rubber part, that being the O-ring on the collars that helps keep everything in place with friction as you tighten then against the plates. Anyway, we sell the good ones that will last.

There are some drawbacks to standard dumbbells. There’s always the ends that stick out, making them kind of pokey, especially as you’re sitting the dumbbells on your thighs setting up for presses. I’ll get into everything else below.




PowerBlock is one of the most popular brands, maybe the #1 right now. They’ve been making adjustable dumbbells since 1993. They’re one of those old companies that are slow to change. They did come out with some new models like the Urethane series several years ago, and I think they’ve been the same since. Their homepage at has literally not changed by one pixel in the last 4 years, and some of their links don’t work.

PowerBlocks are the most unique of the bunch. Unlike a traditional dumbbell where you just grip the handle, with these you reach your hand inside the enclosure. 

There are like 20 different models to choose from, but relax, it’s not as overwhelming as it sounds. You can ignore half of them, and most of the rest are just variations of weight. 

Here’s what you do. Ignore everything but the Elite or Urethane series. Period. Those are the ones that are upgradeable, and they’re the newest models.

Technically the Elite are part of the Classic series and have mostly the same design, so anything said about the Classic, it applies to the Elite too, except for the upgradeability aspect. 

The PowerBlock Elite has a 4.7 star rating on Amazon.

Bowflex SelectTech


Bowflex makes these dumbbells with a dial selection for the weight for easy weight changes. They make two models, the 552, which is 5-52.5 lbs per hand, and the 1090, which is 10-90 lbs per hand. 

Right away the name Bowflex pops out. They are of course known for their unique home gym machine that uses flexible rods as resistance and most of the time ends up as a coat hanger until its given away for pennies on the dollar at a garage sale and then resold on Craigslist. To non-lifters, Bowflex is a leading brand. To people who lift regularly and know a little about equipment, Bowflex machines are a joke. They don’t provide enough resistance for some exercises like leg presses, the resistance curve is annoying for exercises, and it can be too cramped for larger users.

So hopefully these dumbbells are better.

The SelectTech has a 4.7 star rating on Amazon.


Ironmaster Quick-Lock


Ironmaster LLC was founded in 1978, but I really don’t know what they did before making these dumbbells. These have been around since at least 2006, or at least some model of them.

These look way more like a traditional dumbbell than the Bowflex. They’re still squarish, but they don’t have the weird enclosure. They come in a 45lb per hand and 75lb per hand model. Other than the weight, there’s no difference between the models, and it’s upgradeable to 165 lbs. If you buy the 75lb one you get a stand, which can store the removable weight plates on the lower shelf.

The stand is not free. If you don’t want it, you will get a better deal buying the 45lb version with the upgrades.

These have consistently gotten positive reviews by the regulars on the equipment forum. The main reason for that is they’re durable. We’ll see if they’re really the most durable.

The Ironmaster 5-75lb currently is rated 4.6 stars on Amazon:


Universal Power-Pak


Universal is one of Nautilus’ brands. Nautilus also owns Bowflex. I hesitated on including both this dumbbell and the Bowflex SelectTech, but as I examined the dumbbells I found they are different enough to warrant being treated as if they’re two different brands. And they’re marketed separately. 

This one is not as well known. It just doesn’t come up in discussions. The reason I’m including it is because it sells like crazy on Amazon and gets very good reviews. It’s also sold at big box stores like Walmart, Dick’s Sporting Goods, and Sears.

The Power-Pak is currently 4.5 stars on Amazon, a tad lower than the others here.


Detailed Comparisons


Quick adjustment is important if you’re doing drop sets. You might also just be impatient. One reason this might not be a big issue is you normally rest a while between sets anyway. The reliability and ease of adjustment is still important, though. After enough times it can get annoying, and you wonder what your life would be like with a quick dial adjustment.

Standard Dumbbell Handles – They come in a couple types. One has smooth ends where you slide the weights on, and you then slip on and tighten any kind of spring or compression collars. The most popular type, though, is threaded ends with spin-lock collars. The collars spin into place and hold very well by friction with the built-in O-ring. You know if they’re going to come loose, because they start rattling, and then they would need to start rotating and getting crazy loose for the collar to spin all the way off. So it’s extremely safe unless you’re trying to load it up to the max and barely fitting the collars on the ends. It does take a moment to do. You’ll have a pile of extra plates either sitting on your floor or that you can do the responsible thing with and rack on a plate tree. So you’ll need to get a plate tree. If the rest of your plates are olympic (2″ holes), sorry, that olympic plate tree won’t work, and you’ll need to get another. It makes your handles the black sheep in the family and a pain in the ass. 

PowerBlock – It’s kind of like one of those pin-selectors for weight stacks for commercial gym machines. You stick the pin into the desired weight, which are color coded, and then grab the handle and lift the dumbbell. The weight you select comes out and the remainder of the weight is left behind. It’s very possible to get the pin misaligned and try sticking it each part of the pin into two different weights until you realize your mistake and do it right. It’s not a safety issue, because you can’t push it in very far if it’s off. You can tell something is wrong, pull it out, and put it in right. The wrist guards or pillars are hollow so you can add and remove the steel rods for 2.5lb increments. That’s pretty easy to do, but it takes a moment. You pull the weight pin out so you’re only lifting the handle, unlock the holes with a switch, slide the rods into the holes, and lock the switch back. It works good. Even if you were to inadvertently hit the switch during lifting, which isn’t really that likely, the weight plates are on the outside of the holes and further prevent the steel rods from slipping out.

Bowflex SelectTech – Its dial mechanism is easy. Even though you have to dial each side of each dumbbell rather than inserting a single two-pronged pin into the side, it’s arguably quicker to adjust than the PowerBlock. This makes it arguably the quickest weight change out of all the dumbbells. So if you’re lazy, or you’re doing supersets, or you just want to save time, the quick weight change is one major thing the Bowflex SelectTechs have going for them. The two dials on each dumbbell actually can be an advantage, say if you’re doing triceps extensions and want to select more weight on one side of the dumbbell to keep it balanced better when you stick one end up. The weight selection, lifting the weight out, and replacing it when you’re done with your set all work smoothly. Nothing tends to catch wrong or get in the way. It’s not hard to do. Basically it’s well engineered, for what it is. Sometimes the weight selection doesn’t catch right.

Ironmaster Quick-Lock – They improved their mechanism recently to be a little quicker than what you see in the video above. What you do with these is unscrew the end cap, stack plates on the end, and then screw the end cap back in. It’s ok. It’s still not as quick as turning a dial. If you want something extremely quick, these might not be for you. And you have to store the extra plates somewhere. You can’t store them on a weight tree at all, because the holes are too small for even a standard weight tree, so you’ll need a shelf. The threads on the long screws can kind of stick against the edges because it’s made to fit tightly… which it has to be for a snug fit with no rattle while you use it.

Universal Power-Pak – They have a dial like the SelectTech. It’s a little harder to turn the dial, but not to the point where it’s a negative. Just worth mentioning I guess. It seems to work more reliably actually than the SelectTech as far as the dial causing the weight to catch. The other thing is only one end has the dial, making it easily the quickest to adjust. So there’s some interesting tradeoffs.

Comfort & Feel

Standard dumbbell handles – They have a knurled, straight handle. It’s a little thin at 1″/25mm, not the best for most people. That goes for all standard bars, from these handles all the way up to a standard 7ft bar. The problem is the ends get pokey on you, because there’s always some length left after you tighten the collars. Even if you have it loaded to the max with the collars all the way on the ends, they still poke you while sitting on your thighs as you sit on your bench to set up for exercises.

PowerBlock – The handle is straight or contoured, depending on the model, but nice and thick either way. Your hand and wrist is surrounded by pillars that they call wrist guards. If you have unusually large hands or wrists, it could be cramped. For the average Joe it’s not an issue, but it is definitely different. With some exercises it will restrict your movement, such as hang cleans. Or skull crushers, where you grip the head of the dumbbell, will be done a little differently. For typical dumbbell exercises like presses, curls, reverse flies, rows, etc, you shouldn’t have a problem. The Elite has padded wrist guards, with a small opening. The Urethane have larger openings without padding, and the handle is contoured rather than straight. So they say the Elite is best for people with weak wrists or who are new to dumbbell work, because the pads help support you if your wrists start to bend back from fatigue. Kind of like training wheels. Unlike with training wheels, if you don’t need the wrist supports, it won’t affect anything and you can still use these just fine. The Urethane reduces noise by a lot. The others have some rattle to them. That’s kind of unavoidable with a weight select mechanism like this. The urethane rattles too, but it just doesn’t make any noise because every one of the plates is coated in urethane. One more thing – The pins kind of stick out and could stretch against your hips when you raiser or lower them against your hips with a neutral grip (palms facing your body). 

Bowflex SelectTech – It feels ok and is more smooth all around the sides of the weight plates. It has a weight distribution problem with higher weights. The weight distribution is on the bottom, or the side facing down as you grip it from the top, so as you’re doing heavy exercises the handle wants to rotate to keep the heavy part down. That’s not good. Also, there’s a bit of a rattle. That’s inherent in this kind of design. There has to be enough slop for the weights to come out easily as you adjust it.

Ironmaster Quick-Lock – Hands down, these have the most traditional feel of all the new-fangled adjustable dumbbells. The handle is nice and thick at 32mm / 1.25″, compared to the 1″ thick steel handles of the standard dumbbell handles. Ironmaster is all about a traditional and rugged feel with the solid steel knurled handle. The thickness is just right. Many solid dumbbells have 32mm handles, or varying anywhere from 28mm to 34mm from my experience, depending on size or model. Also, these don’t rattle like the others, assuming you tighten them good enough, making them feel more like solid dumbbells.

Universal Power-Pak – Similar to the SelectTech, and wouldn’t you know it, it has the same issue with the funky weight distribution at higher weights. You can see it visibly, from the gap in the top. They can also not lock in all the time when you replace them into the rest of the weights after a set, forcing you to jiggle them so they lock. Annoying. And of course they do rattle like most of the others, because of their adjustment mechanism that has to allow for enough looseness in the plates.

Size and Shape

A few inches difference in width can be a big deal. This helps your range of motion significantly. You can bring them down farther when doing presses without hitting your chest, and you can move your arms straight up towards the top of the press without the length of the dumbbells getting in the way of each other.

Standard handles – 14″ long. The ends stick out. The sides are ideal, with the round smooth 10lb and smaller plates you load on it, and a good size of 8″.

PowerBlock – Very compact. The weight stacks don’t extend out far. At 25 lbs, all their models are only 10″ long. That goes up to only 12″ at 50lb, and then it starts to get significantly longer as you go up from there. One reason they can do this is they put some of the weight around the front and back of your wrist and not just on the heads of the dumbbell. They have a bread loaf shape, or more rounded tops than the bottom. That helps because at the bottom of presses you won’t be poking your chest or shoulders so much. 

Bowflex SelectTech – It picks up the weight differently, and it has the same length of 16″ no matter what weight you choose. So yeah, that’s pretty long. You get no break when you choose a lighter weight. Big loser here.

Ironmaster Quick-Lock – 9″ long at 20lb, and 14.5″ at 75lb. Pretty good, similar to the PowerBlock in compactness. So again, it helps a lot for getting a good range of motion without the dumbbells getting unwieldy and awkward.

Universal Power-Pak – 15″ long, just an inch shorter than the SelectTech.

Weight Range and Upgrade Options

Here are the max weights of each one, and any upgrade options should you start hitting the limit.

Each weight noted is per hand.

Standard dumbbell handles – Up to 75 lb. Some people try to get tricky and use 12.5lb plates instead of 10lb, but you know, the 12.5lb are a little thicker, so it doesn’t help. You could use 20lb plates, but then it gets ridiculously wide and restricts your range of motion. We currently sell sets at 45lb and 75lb, but it’s arbitrary and is just a matter of how many plates you want to buy with it. And you can adjust them in as small as 1.25lb increments.

PowerBlock – Urethane: Available in 32, 50, 90, 125, 175lb, and all upgradeable to 175lb. Elite: Available in 50, 70 and 90lb max, and all upgradeable to 90lb. All adjustable in 2.5lb increments. Don’t get any models besides the Elite or Urethane, because anything else isn’t upgradeable.

Bowflex SelectTech – 52.5lb or 90lb. Not upgradeable. They adjust in 2.5 lb increments, but only on the lower half of the weight range. 

Ironmaster Quick-Lock – 45lb or 75lb. Both upgradeable to 120lb or 165lb. All adjustable in 2.5lb increments. Worth noting also that their large steel end caps accommodate PlateMates or other magnetic weights in case you want to do smaller increments.

Universal Power-Pak – 4-45lb, in 5lb increments.


Solid dumbbells are the most durable, while any adjustable dumbbells have parts that are much more prone to damage when you drop them after a set.

Standard Handles – Great. It’s all steel and iron. Even if you drop them from high enough and manage to bend a handle, you can just replace the one handle.

PowerBlock – You can bang them around quite a bit, but don’t be dropping them from any distance. 

Bowflex SelectTech – I’m not going to do drop tests to find out what happens, but these feel the least durable in the bunch and most prone to breaking. Again, you can be rough with them, but no dropping!

Ironmaster Quick-Lock – Awesome! The big reason people go with these is because they are so tough. The manufacturer actually tells you that you can drop them. This makes them stand out among the others. Some of the other dumbbells have coating over the handle, but these have the thickest steel inside the handle (and in this case, the handle is all steel, just chrome plated, with no rubber or other coating) and therefore is the most durable when it comes to dropping it. It will be extremely hard to bend these handles. See this video of the madman tossing these down the stairs and off the second story.

Universal Power-Pak – Same as the SelectTech. They’re cheap and not made to last forever if you aren’t careful with them.


It totally depends on how heavy you go, so I’m just going to compare the 50lb models, or as close to it as I can get. These prices may or may not include shipping. It all depends on where you buy it from, and I list some places further below.

Standard Handles – Everyone sells them at a different price, but expect around $140 for the 5-50lb.

PowerBlock – $445 on up, depending on the model.

Bowflex SelectTech – $289 for the 52.5lb.

Ironmaster Quick-Lock – $379 for the 45lb.

Universal Power-Pak – Varies, but the lowest I can find right now is $292 for the 45lb.


I can’t remember the last time I called in a warranty claim for something I bought. Even for strength equipment I’ve sold, it’s just so rare. Either there’s something wrong right away and you need it replaced, or you take it as it is forever. At least that’s the pattern.

However, the warranty does give you a good indication of how rugged the equipment is. Manufacturers set their warranty (or in reverse, set the quality of the components) to ensure that under expected use it will almost always last through the warranty period. Expected use usually doesn’t mean daily for home grade equipment. The point is, they don’t want to be servicing too many warranty requests. So something with a 10 year or lifetime warranty really stands out IF (and that’s a big IF) they don’t deny every warranty claim, such as by saying “Our product doesn’t break, and if you broke it, you dropped it on the floor, and we don’t cover that.” 

Standard Handles – None,  Anything you buy online new will have at least a 30 day warranty against major manufacturing defects. Or at least I know that’s California law.

PowerBlock – Lifetime warranty on the Urethane series. 10 Years on the rest! Not warrantied against dropping.

Bowflex SelectTech – 2 Years. Not warrantied against dropping.

Ironmaster Quick-Lock – Lifetime warranty. It sounds like they’ll cover everything, and they tell you in writing you can drop them.

Universal Power-Pak – 1 Year. Not warrantied against dropping.


My Humble Opinion

With all of the above in mind, I absolutely have to go with the Ironmaster. I like stuff that lasts and is made to be durable. There’s no plastic on it. I’m used to spending a minute changing weights on barbells, and doing that on a dumbbell is not a big deal to me. They warranty is forever, and they’ve been around a long time. I’d get the 75lb version, along with the add-on kit to 120lb. That would do me great.

My next choice would be the Bowflex SelectTech 90lb. It seems to be well made enough, it gets good reviews, it’s been around for a long time, and I do like the round heads that are more like traditional dumbbells. I could see if you like their easy weight adjustment dial, or you’re doing drop sets where you need quick adjustments, you’d go with them instead of the Ironmaster. 

The 45lb max of the Universal Power-Pak just isn’t enough weight for me. They don’t make a heavier one. If you start lifting regularly, you’ll outgrow it quickly. Some younger people and females will do great with it. It’s one of the best sellers on Amazon, so hey, that means something. It is definitely the quickest to adjust weight on out of all the models here.

Personally I don’t plan on doing business with PowerBlock Inc again, nor will I recommend any of their products. Full disclosure: I did a large amount of business with them several years ago, until the relationship suddenly went south. I’ve had great relationships with all my suppliers over the years, and occasionally I had to part ways with some because it wasn’t working out, but in this case it was bad enough that I don’t want to give them another chance. Other than that, the quality of their dumbbells is good, and I wouldn’t have sold them if I didn’t think so. So that’s just me. Maybe my experience isn’t that important, and PowerBlocks are just what you’re looking for. Do me a favor and order on Amazon (link below) instead of directly from them. The price is lower on Amazon, and not only that, but they have to pay Amazon a cut and they aren’t making as much. That’ll make me happy.


Where to Buy


Ironmaster Quick-Lock 45lb

Buy from Ironmaster  Buy On Amazon
Ironmaster Quick-Lock 75lb Buy from Ironmaster  Buy On Amazon
Ironmaster Add-On Kit to 75lb Buy from Ironmaster  
Ironmaster Add-On Kit to 120lb Buy from Ironmaster  Buy On Amazon
Ironmaster Add-On Kit to 165lb Buy from Ironmaster  
  If you don’t want Ironmaster’s stand, you get a better deal by buying the 45lb along with the add-on kits.


Bowflex SelectTech 52.5lb Buy from Buy On Amazon 
Bowflex SelectTech 90lb Buy from Buy On Amazon


Universal Power-Pak 45lb Buy On Amazon buy-walmart


PowerBlock Elite 50/70/90lb Buy from Rogue FitnessBuy On Amazon
PowerBlock Urethane 32/50/90/125/175lb Buy from Rogue Fitness


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  1. David Kiesling
    David Kiesling 10 December, 2016 at 15:30 Reply

    That’s interesting, I didn’t notice that you would save money by starting with the 45lb set and foregoing the stand. I’ll have to update the article with that tip. What are you using for a stand?

    • Randolph Knackstedt 18 December, 2016 at 13:53

      Sorry for the late reply.

      I just have the IM’s on the floor, sitting on top of flattened cardboard. I was thinking of buying a heavy duty utility cart to have the dumbbells on top, and extra plates on the bottom. Depending of which cart you get, they’re rated at around 500lbs capacity.

      Love the blog, btw. Also, i’m planning on ordering some York Legacy plates from you guys. Nice prices and shipping cost’s. Being that I live in the Bay Area, it’s nice to be able to support local business.

      Take care

  2. Randolph Knackstedt 10 December, 2016 at 13:09 Reply

    Great comparison.

    I’d been wanting to invest in dumbbells and decided on the Iron Masters during their free shipping black friday deal.

    I’m VERY happy with them. They feel like dumbbells I’d use in a commercial gym. And very solid too.

    I got the 45lb set + 75lb and 120lb upgrades. I would have gotten the 75lb set w/ the stand, but the stand isn’t included free with the 75lb set like they suggest. You’ll pay more for the 75lb set than you would if buying the 45lb set + 75lb upgrade separately.

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