Below is a review by "86 & Still Kicking", a well known reviewer and blogger of Electric Bike Review
I first heard about a product called StaFast from my local bike mechanic who, having worked with full suspension bikes for years, was curious as to whether a stem mounted air shock could serve a useful purpose and work well enough to offer a light weight alternative that, in the right situation, could provide greater stability and comfort. The short answer is yes. Definitely Yes!
I contacted, Charlie Brickey, one of the owners of AerForge, makers of the StaFast suspension stem and asked if he would be kind enough to send an evaluation unit for the specific purpose of seeing how the product performed on an ebike. I am not a professional reviewer and not affiliated or paid by any publication or manufacturer. The following review is done simply for the benefit of electricbikereview.com forum readers. Please feel free to offer any and all comments and ask any questions you like. If I cannot answer the questions, I will contact Charlie Brickey and get an answer for you.
Most readers know well that a fast and heavy ebike without suspension does not take kindly to road imperfections. The test bike we used for this review is my own Stromer ST2. It is a fantastic bike but, even with a carbon front fork, and Schwalbe Big Ben tires, hitting a bump/crack/pothole at speed is a real wake up call especially for your arms and shoulders.
In The Box
While there is no retail distribution, the product arrived in a nicely packaged box that had nice graphics but none of the necessary product detail or descriptive text normally found on packaged goods. The box contained:
- (1) Air Shock Stem
- (1) Spanner Wrench for adjusting the angle of the stem
- (1) Handheld air pump
- (1) “D” washer and 6MM bolt
- (1) Installation Card (a very good one)
A Quality Pump is Provided
The StaFast stem is available in two stem lengths. The 95mm length is typically found on Mountain and Urban bikes, while the 105mm length is typically used on road bikes with drop handlebars. I measured the stem length prior to receipt and found the Stromer ST2 to have a 95mm stem length (as measured from the center of the steering tube to the middle of the handlebar).
Fit and Finish
The StaFast stem body is made from the 3D forging of aluminum alloy 6066T6.
The cylinder is manufactured via a Swiss CNC machining process with controlled and tight tolerances. The fit and finish is excellent and you can tell that attention was paid to delivering quality materials and tight tolerances. While not intentional, the matte black finish provided a very close match with the Stromer ST2 stem I removed and I am surprisingly pleased that most folks would not know that the StaFast stem was an aftermarket add-on.
I weighed both the Stromer ST2 stem (269 grams) and the StaFast stem (362 grams. The difference is negligible as the 93-gram difference turns out to be about 3.3 ounces. Typical front suspension forks weigh about 1500-2000 grams.
This is the front side of a step-by-step installation card with clear photos and well-written instructions.
The installation was performed by Zack Black, a seasoned bike mechanic at Bike Station Aptos, California and a Stromer Authorized dealer.
To make installation easier, we removed the front wheel of the bike prior to installation. We also removed the handlebars and the custom mounted Super Nova light.
Removal of the Stromer ST2 stem, while not difficult, required a little time to fish the compression shims (4) typically used on a carbon fork out of the stem. We simply rotated the bike upside down on the work stand and used a small rod with a hook at the end to nudge them out of the stem.
The StaFast stem can be adjusted 25 degrees to accommodate different rider preferences and is shipped with this adjustment set to the max (25 degrees).
The StaFast stem works with standard 1-1/8th steering tube diameters and the Stromer ST2 has, thankfully, a standard steering tube diameter. The StaFast Stem requires the use of spacers to create 1-1/2 to 1-5/8 inches from the top of the spacer to the top of the steering tube. Luckily the existing Stromer ST2 space was just perfect so we did not have to find or fiddle with additional spacers.
Give the quality of construction and the tight tolerances on the StaFast stem; it requires a delicate yet firm push to properly seat the stem. We did notice that the StaFast stem scraped the carbon fiber steering tube but there was no damage and the scrapes are covered up completely by the StaFast stem.
One installation challenge was that the Stromer ST2 compression plug was too big and had to be replaced with a Profile Design Adjustable Plug that is designed for carbon steering tubes. This is about a $15.00 part (online) and most bike shops should have this plug in stock or can get it easily. We then had to use the supplied “D” shaped washer and 6mm bolt. Please be sure to tighten everything to spec and then grab your brakes and stomp on the front end to make sure that the stem and front fork are tight and nothing moves.
The Stromer handlebar clamps have an indentation on the underside to accommodate the SuperNova light. Unfortunately we could not tighten the StaFast handlebar clamp to the specified torque with the SuperNova light in place so we created a temporary handlebar mount for the light. SuperNova makes a very nice handlebar mount so we ordered one. I will post more photos of the StaFast stem with the properly mounted SuperNova light shortly.
The stock cabling on the Stromer ST2 presented no problems and did not require rerouting or replacement. However, you should move your handlebar to the extremes to check that no cables are unduly tensioned.
Lastly, be sure to adjust your handlebars so that your grips and shift/brake levers are at your preferred angle.
Adjusting the StaFast stem requires some time and patience to dial in the settings to your preference. There is no right or wrong adjustment. The StaFast stem has two adjustments: a. stem angle and b. air pressure. We found that it is best to adjust the stem angle first as the angle affects the amount of air pressure you prefer. As stated previously, the StaFast stem is shipped with the maximum angle of 25 degrees. I found that, after some test rides, that a 10-degree angle was just about right. Adjusting the stem angle should be done with no air in the stem cylinder and is a very simple procedure. StaFast provides a spanner wrench that is easy to use.
When I talked to StaFast they gave me some recommendations on a starting point for air pressure. The basis for the recommendation stems (no pun intended) from the type of bicycle, the kind of roads you ride on, and your height and weight. I told Charles Brickey that I was 5’11” and weighed 250 lbs and ride solely on the road. He suggested I start with 150psi. We did just that and, besides me, I had a fellow Stromer ST2 owner and the shop mechanic take it for a test ride. All of us were a little disconcerted by how the handlebar moved up and down. It takes a few minutes (or hours) of riding to understand that nothing is going to fall off and that you are not going to lose control. We also agreed that the movement was much too soft as the handlebar would move over almost every road imperfection.
After the initial test ride, we went back to the shop and reset the air pressure to the maximum 275 psi. My fellow Stromer rider felt it was too stiff and didn’t seem to move at all, while another shop mechanic who is a mountain bike rider felt it was just perfect.
When you attach the air pump, the air in the StaFast cylinder will escape into the pump. Since the volume of air that the StaFast cylinder holds is very small, it appears as if the stem is losing air. This is NOT the case and the StaFast stem holds air securely. I will say it makes checking the air pressure a tiny bit difficult to do, but when you attach the pump just pump it back up to the desired psi level. I recommend you use your air pump every 30 days or so to make sure your air level pressure is optimum. Also, we noted that due to the thickness of the Head Tube on the Stromer ST2, I had to turn the front wheel to one side or the other in order to have enough room to thread the air pump on. This, of course, may not be necessary with every bike.
What I discovered is that the StaFast stem, while only providing about 25-30mm of travel, gives the appearance of a much broader range of suspension. The good news is that, except for those that do very rough terrain mountain biking, the StaFast stem will work well on trails, country roads, and urban commutes.
Currently, I have settled on 205 psi. My goal is not to have a soft cushy ride but to take the sharp edges off the sudden jolts I experience on certain road surfaces. If I have to give ebike riders an analogy, it seems to do for the hands and shoulders what the Cirrus Body Float does for your butt and back.
I still have some testing to do but on my usual routes, the StaFast stem provides consistent relief from road imperfections and also provides better control over rough surfaces. I tend to ride at speeds above 22mph all the time. I have noticed that my body position and hands stay planted when encountering rough patches. Strong yet supple suspension provides better control of the bicycle over rough terrain.
I talked to Charles Brickey about the target market for the product and while he believes in the benefits of the StaFast stem for the everyday rider, he did indicate that early feedback from road racers has been very positive as the stem provides much better body and hand control.
I’d like to spend a few more weeks testing the StaFast stem and will report back to the readers of electricbikereview.com. For now, the product delivers an immediate and noticeable benefit and makes my rides more comfortable and stable. According to StaFast:
“Stafast’s force dampening capabilities enable road cyclists to focus on performance instead of resistance. Bikes equipped with Stafast have the ability to deliver results unmodified cycles aren’t built to achieve. Composed of extremely durable lightweight alloys and engineered with road cycling in mind, Stafast is manufactured to handle the impact of both urban pavement and country blacktop.”
The other benefit to a more compliant and comfortable front end is the reduction in arm, shoulder, and neck fatigue over longer rides. It does take some getting used to the slight downward movement of the handlebar and an assumption that everything is installed firmly and tightly. The fit and finish of the product is very very good, and the support level is consistent with a quality manufacturer. Durability is an issue I cannot address at this time, but given the attention to detail, I’m confident that the product will delivers years of use.
- Very little weight penalty over existing stem
- Excellent build quality
- Clear-cut installation instructions
- Great for city, country, and light trail roads
- Works as advertised
- Attaching air pump gives false impression that the StaFast stem is losing air
- 25-30mm of travel is all you get (which is sufficient for most)
- May require obtaining another compression bolt
- Could not get pump firmly seated without turning the front wheel (took me a few seconds to figure out)
- Handlebar movement takes some time in the saddle to build confidence
To view the original review posted by 86 & Still Kicking, please click here.