| Unit | Max. Dimensions | Type | Weight range | Weight increments | Warranty |
|---|---|---|---|---|---|
StairMaster TwistLock 100 lb Check Discounted Price | L:14.5" W:7.9" H:7.5" | Adjustable, twist handle | 5-50 lbs | 5 lbs | 2 years |
StairMaster offers all kinds of fitness equipment, including ellipticals, climbers, treadmills, exercise bikes and others. They also offer some of the finest free weights that you can find at the moment: the TwistLock adjustable dumbbells.
The StairMaster TwistLocks are some of the dumbbells with the fastest adjustment system (if not the fastest). They don’t feature any knobs or dials. As their name suggests, you simply twist the handle, and depending on the setting selected, the dumbbell will pick up the apposite weights.
Before we proceed presenting all the aspects regarding these dumbbells, one important aspect needs to be clarified. The TwistLocks come as a set of two dumbbells, each one with a maximum weight of 50 lbs.
Technical Details and Specifications
- Maximum dimensions: 14.5L x 7.9W x 7.5H inches (36.6L x 19.8W x 19.1H cm) (each)
- Weight range: 5 to 50 lbs (2.26 to 22.6 kg) (each)
- Weight increments: 5 lbs
- Accessories: Cradles and exercise guide
- Warranty: 2 years
Overall construction
The construction of the StairMaster Twistlock dumbbells combines metal with plastic parts. The weight plates are steel-made, but coated with a sheet of heavy-duty plastic material. This comes with a series of pros and cons. For example, plates won’t rattle or make a lot of noise, 
they won’t catch rust, and they look pretty neat. But on the other hand, if you’re not careful when working out and drop them, their plastic shells may crack. This also stands for the internal parts that sustain the weight plates. So, these being said, exercises that put a lot of pressure on the dumbbells, such as push-ups for example, are not recommended.
The handles are steel made, and their grips are nicely rubberized and contoured. This makes it quite easy to turn the handle and adjust the weight, and also supplies a lot of comfort during your workouts. This type of handle-grip is far less abrasive to the hands than the regular knurled finish of classic steel handles. You don’t really need gloves for working out with these dumbbells.
When it comes to their dimensions, these adjustable dumbbells are actually quite slim, compared to others. In fact, if you’ll compare one of TwistLock dumbbells set to 35 lbs for example, with a hex 35 lbs dumbbell, you’ll see that it’s only by approx. 1″ (2.5 cm) longer.
With all the weight plates attached, each dumbbell is 14.5″ (36.6 cm) long, and approx. 8″ (20 cm) wide. This being said, even at the full 50 lbs (22.6 kg) weight, these dumbbells are pretty slim, compared with other adjustable models such as the SelectTech 552 from Bowflex, for example. Conversely, without any weight plates attached, the handle is considerably smaller, only 9.4″ (23.8 cm) long, and 3.5″ (8.8 cm) wide. So, these being said, the TwistLocks won’t feel awkward for any exercises.
Adjustment system and increments
As we’ve mentioned above, the StairMaster TwistLock are dumbbells with an extremely fast adjustment system. You place them on their cradles, twist the handles to select the desired weight, and simply lift them up. They feature a locking mechanism that prevents the handle from twisting when their not in their cradles. The cradles actually feature small “keys” that 
unlock the handles and allow them to be twisted.
All weight plates, except the 2.5 lbs (1.13 kg) ones, are circular, similar to the classic, cast iron weight plates. So, as you twist the handle, the main axle extends, picking them up. The plates also cannot spin on the axle, as they lock up together.
When it comes to weight, the handle without any plates weighs 5 lbs (2.26 kg). The first plates weigh 2.5 lbs (1.13 kg) each, while the rest of the plates weigh 5 lbs (2.26 kg) each. This being said, these dumbbells have a weight range of 5-50 lbs (2.26-22.6 kg) each, with the following possible weight settings: 5, 10, 15, 20, 25, 30, 35, 40, 45, 50 lbs (2.26, 4.5, 6.8, 9, 11.3, 13.6, 15.8, 18.1, 20.4, 22.6 kg). In other words, you can basically increase the weight by 5 lbs on each dumbbell.
One aspect that requires mentioning here is that you cannot have an offset weight for these dumbbells. Just as for the PowerPak 445, the weights on the sides can only be equal. Therefore, in case you might want to do curls with an off-set, for a superior workout on the forearm muscles, you cannot achieve that with these dumbbells.
Accessories
In terms of accessories, the first ones to put on the list are the adjustment / storage cradles. These are actually necessary accessories for these dumbbells, as they cannot be adjusted unless they’re placed on them. These cradles are made of aluminium and hard plastic, having the following dimensions: 16L x 9.1W x 3.6H (40.8L x 23.2W x9.2 H cm). There’s the option to attach them to a stand. However, the stand is not included with the set.
Another accessory supplied with this adjustable dumbbell set, is a workout guide, which basically covers all the exercises that can be carried out with these free weights.
The Pros
- Space-savvy. One set of two dumbbells, can basically replace 20 fixed ones;
- Versatile. They offer the possibility to quickly adjust weight in order to alternate exercises, great for P90X for example;
- Sturdy. Compact construction, safety lock system;
- Weight range between 5-50 lbs (2.26-22.6 kg), great for beginners, intermediate and even advanced users;
- They cover more than 20 exercises that can be accomplished with dumbbells;
- Steel weight plates, encased in durable plastic composite shells, which keep rust away;
- Weight plates lock together and don’t rattle on the handle;
- Sleek design, which can be quite a motivation factor;
- Rubberized grip for maximum comfort and easy twist;
- Storage / adjustment cradles included;
- Training guide included;
- Excellent warranty for a dumbbell set.
The Cons
- Plastic internal parts. Even though it’s heavy-dusty plastic which can take a beating, by dropping the dumbbells the internal elements may sustain damage;
- Weight is always equal on each side of the dumbbell, you can’t have an off-set weight setting, such as for the Bowflex for example;
- May not be a challenge for advanced users.
Final Word
The StairMaster TwistLock adjustable dumbbells are great to use especially if you follow exercise programs involving different weights, such as P90X, due to their top-notch, extra-quick adjustment system. They’re actually some of the dumbbells with the quickest adjustment mechanism on the market at the moment. Evidently, they are space-savvy, great for anyone who doesn’t have a lot of space to spare. But on the other hand, like most adjustable dumbbells, they are rather fragile, and cannot take a lot of abuse such as fixed hex dumbbells, or cast iron, classic dumbbells. Even though they’re not exactly the most affordable dumbbells, due to the fact that they actually replace a full set of 20 dumbbells, and their quick adjustment system, their value matches their price.