The deflection diaries, part 4: Redshift Sports ShockStop stem review

After whittling down the various methods of adding suspension to a road bike to just Redshift Sports’ ShockStop suspension stem, then installing it onto Hyro’s fork steerer tube…how does it feel out in the real world?

STATIC IMPRESSIONS

I was half-expecting it to be a floppy mess, with lots of unintended movement every which way, but the ShockStop moves in an arc in only one axis (up and down) with zero lateral slop. The only uncontrolled movement you’ll feel is when it has no elastomers in it – which then highlights the smoothness of the pivot bearings. It might have gained 80 g over a rigid stem of the same length, but that weight went into areas that mattered.

The whole deal with the pre-load wedge, and the need to press your weight on the stem before screwing it in – that was a little strange but simple enough to follow. I found you could release the weight once 2/3 of the bolt’s length is in, after about 20 turns clockwise.

The utility mount is also nicely made. It gives you an extra floating section of 25.4 mm handlebar to mount stuff to – perfect for moving bulky items like my Cat Eye Volt 1200 front light to free up space on a narrow drop handlebar. Its shape does mean it’s impossible to use a torque wrench on it unless you have some sort of extension…and even then, it would have to go in at an angle, which isn’t ideal for hex-key-driven fasteners. I think the original design of the utility mount was more torque-wrench-friendly. 

ON THE TURBO TRAINER

Thus equipped, hooking up Hyro to the turbo trainer and mashing my pedals off, it’s surprising how very little happens up front. The only real indication that there’s something different is when cranking up the watts while out of the saddle, and only while on the hoods…and only if you’re consciously looking for it. I noticed a non-dramatic bit of deflection or sag at the stem, unless I was shoving all my weight into the brake hoods, where it deflected all of 1 cm downwards – and rebounded immediately.

Clearly, this thing needed a proper road test.

ON SHORT RIDES

Spins around the block, and around Makati CBD, over a route of concrete roads with humps and other irregularities, revealed still no lateral slop or torsion in the stem. Sprinting, riding out of the saddle, changing hand positions – it all felt pretty natural to me. Attacking humps and road acne at moderate speed, the feeling up front was that of running a slightly softer front tire, despite having an actual pressure of 85 psi.

How would it feel on long rides over the varied streets of Parañaque, Taguig, Muntinlupa, and Bacoor?

ON LONG SUNDAY MORNING RIDES

Riding from my house to Daang Reyna took up the first 25 kilometers, and I didn’t really notice anything different – at least not with the 80A + 70A combo installed, which is recommended for my weight. Continuing the ride with time trial efforts around the Daang Reyna loop, though, had my palms and hands go numb every time I approached the Palazzo Verde U-turn and slowed from 40 km/h. I thought this elastomer combination was a little too stiff, but repeated visits with other combos yielded the same hand numbness, so that might be down to Daang Reyna itself. Impressively though, there wasn’t any undesired front-end “dive” under braking. Numbed fingers aside, I was able to retain as much control as I could, without having to fight with a sagging stem.

Tuning Hyro’s ride feel with other elastomer combos yielded interesting results.

• The pre-installed 70A + 60A combo was way too soft and had insufficient damping. I could tell without riding that it wasn’t for me and I swapped it out straight away.
• The 80A + 50A combo is listed as the next step in increased stiffness, but felt similar to the 70A + 60A combo. The static sag is noticeable, although not disconcerting. I could feel the stem moving through its travel when I yanked on the bars via the brake hoods, though.
• Finally I tried the 80A + 60A combo. This is what I’m currently on, and was my Goldilocks setup for a good long while. Going over a “washboard” of closely-set speed bumps, there was enough compliance left in the ShockStop, but the elastomers tightened up the damping and reduced the static sag to a more natural amount. That said, it seems like this combo has broken in and there is now a bit more movement, so I’m considering a return to the 80A + 70A combo.

The 80A + 60A elastomer combo. The deformation on the 80A elastomer is from the pre-load wedge.

Even with the mushier elastomer combos, it’s impressive how little the ShockStop affects handling. The stem will provide 1-2 cm of actual squish in the handlebars, but I didn’t really notice it unless I unweighted the handlebars quickly, or deliberately pulled up on them as in a bunnyhop. It simply let me get on with my riding, in the saddle or out of it, with no unpleasant pogo-stick sensations.

VERDICT

So the ShockStop stem is a little heavier and quite a bit pricier than a normal rigid stem of aluminum alloy. It’s nowhere near the price of a carbon stem though.

Then again, it can introduce front-end riding comfort to any bike with a 1-1/8″ (1.125″) threadless steerer tube; its stiffness can be tuned to your liking; and it can do its job without resorting to any other engineering compromises. There’s not much that can touch it, in my opinion. The only thing I’ve seen most similar to it is the TranzX AntiShock suspension stem, which also uses a single-pivot design. However, it involves a two-piece steerer tube clamp, and comes in a slightly greater range of lengths (as short as 80 mm), but no +30-degree option.

People have taken their ShockStop stems riding in the cold, and have reported no adverse effects on the elastomers. Redshift says the elastomers will last 3-5 years in normal operation; if you need extras, they can sell you a full set of five for a small fee.

Given how well the ShockStop works on the ridiculousness of Philippine road surfaces, I am seriously impressed. Highly recommended.