by Emma Smith September 06, 2018

The Redshift Shockstop Stem is one of the most exciting products we have brought into the UK. Having sold 100's of stems, we felt that we needed to answer your questions, talk about the installation and ask one of our customer's to review (still to be completed).

If you haven't heard of the Redshift Shockstop Suspension Stem then watch Redshift Sports' official video below when they were launching their kickstarter campaign:


Redshift Shockstop Stem Overview

Redshift Sports are genuine innovators. Their first foray into cycling component design was the clip-on aerobars and dual seatpost for triathletes. Essentially these products were designed for the beginner triathlete aiming to simply and easily convert their road bike into a triathlon bike position in only a few seconds (there are some images below of these products). 

 Redshift Sports Quick Release Aerobars

Redshift Sports Dual Position Seatpost

After solving this unique problem for triathletes, they turned their attention to suspension and anti-vibration stems and seatposts. At the time of writing the seatpost is being crowdfunded, but the stem has been available for quite a few months, and we wanted to give you our low-down on the product.

Redshift Sports Shockstop Seatpost

Redshift Shockstop Seatpost (above) to be released early 2019 (contact us for the latest update:

What is the Redshift Sports Shockstop Suspension Stem?

Redshift Sports Shockstop Stem

Made of 6061 T6 aluminium (a carbon version is in development), the patent-pending Shockstop Suspension Stem smooths out road imperfections, reducing fatigue and strain on the hands, fingers and wrists. It does this by using 5 swappable elastomers of varying densities. The reason there is 5 is so that you can swap according to your weight, riding style, terrain and bike type. Generally a heavy, road cyclists who use drop bars often (more detail to follow).

The elastomers naturally dampen the feeling of the road or gravel, creating a smoother ride. The effective suspension travel is up to 20mm on a drop bar road bike and up to 10mm on a flat bar road bike.

Shockstop Stem Data reduces road buzz

Who should consider buying a Redshift Shockstop Stem?

Numb Hands on a Bike

There are many situations where a Redshift Shockstop stem is useful, but the primary reason for the design was to help those cyclists that suffer from:

  • Numb fingers
  • Numb hands
  • Wrist pain
  • Fatigue in their arms
  • Neck pain
  • Shoulder pain
  • Those that grip the handlebars too hard

Whilst there are a plethora of reasons for getting the above, the shockstop provides a mechanical aid to make symptoms better. We have to be truthful and say that a bike fit is a much better option to get to the route of your pains on the bike, but if you have had a bike fit, or can't afford a bike fit, then we believe this is the best option out there today.

In terms of road versus mountain bikes, we have used the shockstop on both without any issue, and it worked equally well on both terrains.

Does the Redshift Shockstop fit my bike?

Redshift Shockstop Fit my Bike?

The shockstop has been designed to fit most road and mountain bikes, including road, gravel, CX, commuter, hybrid, and even non-suspension mountain and fat bikes used for road/trail riding. 

But let's go through how to check if it fits your bike:

  1. First check your steerer tube diameter, the end of the stem fits a standard 1-1/8 inch steerer tubes.
  2. Next check your handlebar diameter, the stem naturally fits a standard oversized 31.8mm handlebars (25.4mm and 26.0mm shims available).

If either of these aren't standard then you may consider using steerer or handlebar shims. Handlebar shims are easy to source and Redshift supply their own 25.4 mm and 26.0 mm shims (which can be purchased from Kit Radar). 

If there are lugs (like Specialized Sirrus) or a quill stem, then unfortunately the shockstop stem won't fit (without bike modification).

One thing to note is that you will need 40 mm of steerer to attach the stem (steerer tube clamp stack height is 40mm).

How do I choose the right length and angle for my bike?

The stems come in a variety of sizes (all with the same steerer and handlebar clamp diameter):

  •  +/-6 deg, 90mm (Weight: 264 g)
  • +/-6 deg, 100mm (Weight: 274 g)
  • +/-6 deg, 110mm (Weight: 286 g)
  • +/-6 deg, 120mm (Weight: 298 g)
  • +30 deg, 100mm (Weight: 274 g)

Generally the more upright and shorter the stem the more neck and hand comfort the user requires. In this case you will want to flip the stem (if you buy the 6 degree version, see option B below) to give you as much height as possible (and likely choose the 90 mm length)

  1. If you are replacing an existing stem and want to match it, then start by seeing if the length is printed on the stem. Choose the length of ShockStop that most closely matches your existing stem's length. If the length is not printed on the stem then go to #2.
  2. You can measure the length of your existing stem by measuring the length from the center of the handlebar to the center of the steerer tube.
  3. Once you determine the length of your existing stem round to the nearest 10 mm and choose the closest match.
  4. If you are unable to measure the length of your existing stem then choose 100 mm. This is one of the most common lengths and tends to be a good fit for most people.

There is a rider weight limit of 135 kg (300 lb or 21 stone).

Redshift Shockstop Stem vs. Girvin Flexstem 

Redshift have never claimed to be the inventor of a suspension stem, but they are certainly the most revolutionary. Many times have we heard people say: 

"I had this in the 90's, it was terrible"

Well fortunately Redshift have updated the suspension stem for something more reliable, lightweight and adjustable. 

To understand more, Redshift Sports have answered critics in this post.

Will the stem bounce or flex when I am climbing out of the saddle or sprinting?

With the ShockStop there is no need to change your approach to riding. The suspension is “pre-loaded”, meaning that it will not start to move until a certain amount of weight has been applied, so there isn’t a “squishy” feel as you start to apply weight to the stem. Because of this and the inherent torsional rigidity of the pivot design, the feel when climbing or sprinting is going to be nearly the same as with a rigid stem.

Which shockstop elastomers should I choose?

Redshift Shockstop Stem Elastomers

The ShockStop comes with 5 different elastomers to choose from so everyone can dial in the perfect feel. Redshift provide lots of great guidance on elastomer selection in the instructions you get in the pack.

How do I install the Redshift Shockstop Stem?

We have created a handy video to help you install the shockstop stem.

Is the stem safe and how long will it last?

All Redshift Sports components are tested to the latest ISO 4210 standard for Racing Bicycles. These standards typically specify "Static Strength" tests (i.e. one-time application of force) as well as "Fatigue" tests (i.e. repeated application of force) for different bicycle components. Redshift Sports also run our own independent tests to better understand lifespan which typically involve cycling well beyond the specifications in the ISO 4210 standard.

Even though all Redshift products pass the ISO 4210 tests with margin, all aluminum components are subject to fatigue failure over a sufficiently long period of use. Hours ridden, riding conditions, and rider weight are all significant factors that make it impossible to declare an exact lifespan for any given product. 

Redshift recommends periodic inspection of aluminum components for hairline cracks or other signs of damage. Any indication of part degradation is grounds for stopping use of the product immediately. This includes visible cracks, creaks or other sounds while riding, or a change in the amount of movement during use.

Redshift Sports spent a significant amount of time on the pivot design focused on torsional stiffness and durability. The pivot is constructed using very high tolerance full compliment ball bearings (like the ones used in mountain bike rear suspension pivots) and a high tolerance custom pivot bolt. And we are not just clamping at the pivot we are also press fitting everything together to eliminate the possibility for wear. Without wear the pivot will stay stiff and will not develop play over time.

Typically, temperature does affect elastomer stiffness (as temperature drops stiffness increases). In ShockStop, we use a special material for our elastomers such that slight stiffening would only begin to occur well below freezing and the material remains flexible well past -40 deg F. So, while you would see some stiffening at very cold temperatures we expect it to be minor and only slightly reduce the magnitude of shock absorption. In general, we would not recommend riding when the temperature is below -40 deg F.

The elastomer life depends on a number of factors including rider weight, riding conditions, and how much you ride. In general we expect the elastomers to last more than 3-5 years under "normal" recreational riding conditions. The material that we use for our elastomers enables them to holds up really well in harsh environments (moisture, oils, temperature change, compression cycling, etc.). We see very little degradation and no discernible change in how much they compress under different loads after a very large amount of test cycles where they are compressed and released which gives us confidence that they will stand up to years of use.

If premature elastomer wear occurs we will happily provide replacements free of charge. In addition, we sell replacement elastomer kits.

How do I mount my GPS computer?

Redshift Shockstop Stem Computer MountsThere are two different mounts available: the bike computer mount, and the utility mount:

The Bike Computer Mount is an integrated mount that is compatible with your Garmin, Powertap/CycleOps Joule, CatEye, Mio, or Magellan computer.

  • The Utility Mount puts a small section of tube in front of the stem that provides a location to mount anything you would normally put on your handlebar (bike computer, phone, light, etc.).
  • If you are mounting a bike computer that is either a Garmin, Powertap/CycleOps Joule, CatEye, Mio, or Magellan select the type of computer you have in the pulldown menu associated with the mount. You can quickly determine what computer you have just by finding the brand name printed on it or searching the model number to see what the make is.

That's it!

At Kit Radar we ask our customers through our ambassador program to trial everything in store. We have two customers trialling the Shockstop Stem at the minute, and will report back on this blog.

If you are interested in buying the Redshift Shockstop Stem, then please click below:


Emma Smith

Emma is the queen of our social media and editor of the Kit Radar Magazine. Always in pain from running on the track, Emma's has a passion for positive mental health from sport.

Leave a comment

Comments will be approved before showing up.