So, despite the fact that the SLS spring material is lighter than standard steel alloy, the coil spring does set the Z1 back roughly a half pound compared to its air sprung counterpart, which is already slightly portly.
The clean simplicity and light weight of the Kabolt axle was very much a welcome upgrade over the slightly clunky nature of the stock QR. My one quip with the hardware, would be the quick release axle that comes standard – although that is a small matter, given this fork’s incredible performance:dollar ratio. That shouldn’t surprise anyone as it shares a similar structure to a FOX 36, save for the M shaped arch, which is a nod to Marzocchi’s history. As far as steering is concerned from the standpoint of the chassis, this fork was excellent. In my case, the SB-165 called for 37mm so I was golden. Lastly, wrapping up some basic points – with forks nicely positioned 7mm apart at 37, 44 and 51mm, the spread in offsets is logical between wheel sizes. All in all, the innate feel of the spring side in particular was straight up heavenly. Another interesting facet was that it provided loads of pop and a lively feel. However, what did surprise me was the supportive mid stroke and the fact that no matter how hard I tried, I just could not get a violent bottom out…Even when I was riding a little under sprung on the “medium” spring. Unsurprisingly, the small bump sensitivity was superior to that of an air fork. So, the bath oil in the spring side is serving two purposes it lubricates all the internals and it controls progressivity. On trail, I found this provided an incredible ride. We use this lower leg pressure to generate spring force and control how much pressure is generated using bath oil volume. According to engineer Bill Brown: We have a trapped volume of air/oil in the lower leg that builds pressure as the fork compresses. Typically, coil sprung forks don’t build up all that much resistance at the bottom of their travel and can bottom out rather easily. One thing I did not expect, but certainly did appreciate, was how progressive the Z1 Coil was. Overall, it’s safe to dub the Bomber Z1 Coil a very utilitarian fork. The widely hailed 4 way adjustable Grip2 damper is a truly excellent design, but having a version of it with far less to keep track of has its benefits too. I’ve got to say, the simplicity of the fork was rather refreshing. Most times I went to about 80% locked, which helped efficiency greatly, but still left me with some traction and give on bumps. On trail, since I rode the longest travel (180mm) offering, I did use the lockout a fair bit. With a single, but very effective compression adjuster and an equally simple rebound adjuster, I didn’t find myself doing much dabbling. Getting down to brass tacks, there isn’t much to talk about in the way of setup. Long story short long – improved adjustability and range, one of the typical advantages of an air spring over a coil is not really as much of an issue with this fork. You should be able to find the perfect spring for your weight and riding style, and the preload adjuster offers quite a bit of range as well. The point being, Marzocchi didn’t cheap out and only make 3 springs, thus leaving consumers in the lurch. While the firm spring was dead on perfect for me, I found that neither the medium nor the extra firm were completely out of the question, depending on usage and taking the preload adjustability into account. The cool thing about this miscommunication was that I got to feel out how each spring rating is spread apart. Interestingly, I started out on an extra firm spring, when I should have been on a firm – after it was clearly too stiff, we accidentally skipped over the firm and I wound up on a medium, which was just a bit soft, even with the preload bottomed.
Most times, I rode it roughly around the 1:00 o’clock mark on the descents to provide a bit more damping than full open. The FIT Grip Sweep damper is rather simple and all encompassing – it combines both low and high speed compression adjustment and ranges from open to full lockout. In any case, the fork’s action was ultra silent, so the isolator works quite well. This extra firm is yellow, the firm is green and the medium is blue. Each isolator are color coded based on the spring it mates to. The coil spring is wrapped in a two piece plastic isolator, which helps keep it quiet.