Coil suspension has become an increasingly popular option for rear shocks as riders are now appreciating the supple and predictable performance more than ever before. Naturally, many mountain bikers are looking for the same performance benefits from their suspension fork. With major manufactures Fox, Rockshox and DVO not currently offering a coil trail / enduro fork riders are forced to look at after market options. The good news, there are some great options out there from Push and Vorsprung. Both established companies offering a range of suspension upgrades. We've put the Push ACS3 coil kit head to head with the Vorsprung Smashpot coil kit to see who takes home bragging rights for the best coil suspension kit on the MTB market.
Push ACS3
The Push ACS3 coil kit was the first of the two to hit the market, fair to say Push hit the ground running with a neat product. Available to suit a range of different forks from Rockshox and Fox in a range of different travel lengths and springs from 35lbs to 60lbs they have most riders covered. The Push coil kit features an air assisted bottom out platform, their 'ABS' system. By adjusting the pressure of the air chamber in the fork riders can increase or decrease their bottom out resistance, this is done externally with a shock pump.
Pricing: Kit: $449 + Spring $119
Vorsprung Smashpot
Vorsprung are a Canadian based after market suspension tuning and upgrades manufacturer located at the heart of mountain biking, Whistler. The Smashpot may of been released a little later than the Push ACS3 but by no means is this product an after-thought but rather, the result of extensive research and development. The Smashpot features springs from 35 to 75lbs and is compatible with both Fox and Rockshox fork models. A hydraulic system gives riders bottom out control, this is externally adjustable by a dial on the fork lowers.
Pricing: Kit $469
That Coil Feeling
Coming off an air fork the advantages of a coil when you first drop into a trail are by no means small or insignificant. This isn't like adjusting your pressure or turning a few knobs, this is a complete transformation. A coil fork will excel in rough chatter, holding a line with ease to give riders new found confidence. The forks have a pleasant calmness about them as they tackle rough terrain allowing riders to relax and let the bike do the work. Despite this there are some great air spring designs out there. Some riders will prefer an air fork to keep weights down and also utilise the natural ramp of the air spring. Each design has advantages and dis-advantages and the rider needs to determine their riding preferences to see what will suit them best.
Push ACS3 Performance
On the big hits Push's ABS bottom out control performs as advertised with adequate ramp at the end of the stroke. Saving riders from that rude bottom out and letting the push harder and harder. However, when the ABS unit is engaged the compression rod hits the ABS rod within the fork. When this happens we felt a slight, audible knock. When you're on the trail most of the time you'll be too preoccupied to notice it but none the less the constant noise and 'knock' on engagement will annoy some riders.
We also noticed on installing the Push ACS3 kit that pre-load is required on the spring when installing the top cap, pre-load spacers provided by Push. Although not a huge amount this will still have a negative effect on small bump sensitivity. The small bump sensitivity is still superior in comparison to a standard air fork but not fully maximised it would appear.
Vorsprung Smashpot Performance
Something that instantly became apparent after removing the pre-loaded Push setup was how little pre-load was required on the Vorsprung design. As you're not relying on the top tensions the spring you can gently nip up the pre-load collar so that the most minor amount of tension is applied. This in turn maximises small bump sensitivity as much as possible giving riders better small bump compliance than the Push kit.
As a result, the effortless initiation of the suspension stroke meant the fork was moving freely and frequently to absorb trail impacts and keep things tracking. On the big hits the Vorsprung Smashpot Kit once again excelled. The hydraulic bottom out design provides great support as the fork ramps up smoothly in the deep end of its stroke. Where the Push ABS bottom out system stores this energy and puts more force through the fork's rebound circuit Vorsprung's hydraulic design actually dissipates the force. Upon riding the Vorpsrung Smashpot there were no reports of any rude bottom outs. Rather, using all the travel available but without the harsh feeling of your bike trying to throw your hands off the bars.
Push ACS3 - Flexibility
Neither of these upgrades are cheap so its important to many riders that when the time comes you can change travel lengths etc. as needed. Unfortunately the Push ACS3 kit lets itself down here as well. When changing travel riders will need to purchase a new compression rod and ABS system. Without doing so the ABS bottom out control will not work.
Vorsprung Smashpot - Flexibility
With the Vorpsung Smashpot coil kit mountain bikers can easily change travel lengths between 130mm - 180mm (depending on your forks compatibility). The procedure is pain free and requires no additional parts what so ever. The usability of Vorsprung's coil kit gets full marks form us here.
The Verdict
The Push ACS3 kit gives riders the coil feeling many are longing for however, the system seems to be more complicated than necessary and can't deliver the same level of performance that the Vorsprung Smashpot can. Vorsprung haven't re-invented the wheel with the Smashpot, the assembly consists of many tried and tested suspension technologies. What they have done is execute a simple design to the highest possible standard, giving riders a user friendly system with superior performance.
