Suspension

Veli bikes chose the Vasttech suspension system for its superior performance to create the fastest mountain bike. To understand its advantages, we first have to take a brief look at where modern suspension designs came from and the direction they are going.

Single pivot

The most basic single pivot designs feature a single pivot point set, with a chainstay and a shock mount on the chainstay. If well executed, the design works well enough and has excellent serviceability. Adding extra linkages between the shock absorber and the chainstay can allow a more diverse range of shock leverage curves, at the expense of unsprung mass increase and more complex servicing. There is no limit to the number of linkages that can be added between the chainstay and the shock absorber and some designs are pretty obscene. The original single pivot though is simple and functions well enough.

Linkage driven single pivot, Horst link, Split pivot etc

Feature 4 sets of pivot points, and include a seatstay along with the chainstay and a rocker link to drive the shock. They have been around a long time and there is a plethora of different names they are marketed under. Flex stays can allow the elimination of 1 pivot set to save weight, but the tuning options for the shock leverage curve are reduced which is most disadvantageous in longer travel designs.

Dual link

Include DW link, VPP, Maestro, FS3, CBF, Orion etc. If well executed, the shorter length dual rotating links allow the rear wheel travel path to have a tighter arc than the designs previously mentioned. More rearward for the initial part of the travel allows better square edge bump absorption and anti-squat, while a more forward motion at the end of the stroke resists bottom out. To cut through the marketing hype, here is how Dave Weagle describes the key advantage in Claim 1 of the DW patent. “…where said anti-squat response is higher in the beginning of the suspension travel, and lesser thereafter” (US7048292B2). Dual link systems feature a minimum of four sets of pivot points (many have more) and have greater unsprung mass than linkage driven single pivots due to the extra rigid member connecting the chainstay and seatstay. In short, dual links have better rear axle travel paths, but more unsprung mass. You lose as much as you gain.

Dual link with slider

If well executed, these systems can have a similar rear wheel travel path to a standard dual link, but give a fresh appearance for marketing purposes. Switch-Link and R3ACT are modern embodiments. They don’t weigh any less than a normal dual link, and sliders create more friction than bearings, but you can bury those disadvantageous in marketing material.

DW6 and IFS

Things are getting ridiculous now and these most recent designs bring us up to a whopping 6 sets of pivot points with all its associated maintenance issues and unsprung mass increase. 6 sets of pivot points in an attempt to create a marginally better shock leverage curve. But its modern and marketable until it’s not modern anymore.

When Tim Southall, the designer of the Vasttech suspension system first began studying suspension designs, it was apparent that the basic dual link advantages could be transferred to a much lighter and simpler package by relocating the lower link to connect directly to the rear wheel. The unsprung mass reduction is enormous, while the rear wheel travel path and all its performance advantages are carried over. Just one pivot point set lays the foundation for the most reliable and serviceable full suspension system available today. That’s why we use this system. It’s the future. The frame curves are a straight double diamond design for perfect triangulation of forces leading to the best strength to weight and stiffness to weight ratio available with no need for weird bends in the top tube or down tube to accommodate full size water bottles

Other unique features

Why external cable routing?

Because for mountain biking internal routing offers no performance gain. Drilling or forming holes in the frame does not increase its stiffness (makes it sloppier) or strength (makes it weaker). The extra reinforcement required increases the complete weight, while the servicing and general experience of owning the bike becomes a frustration. Veli bikes feature internal routing for the dropper post only. All other cables are routed externally.

Why use monocoque wheels?

The worlds best airlines, high speed military jets, helicopters, drones, spacecraft, VTOL aircraft, racing cars, moto GP, RC racing etc. have all chosen monocoque wheels exclusively for their superior properties. Big advantages for mountain biking include their superior strength to weight ratio, and unmatched lateral stiffness. The lateral stiffness improvement is worth some explaining:

In a traditional steel spoked radial wheel, the spoke bracing angle from the hub flanges to the rim control the lateral stiffness. In an effort to improve this stiffness there has been a movement to ever wider hub spacing. This stiffens the hub/rim relationship but is detrimental to all other things. The axle gets longer, flexier, and heavier. The derailleur sits wider and is more prone to damage. The drivetrain sits further outboard from the centerline – increasing flex and reducing efficiency. Q-factors widen or chainstays must be lengthened to accommodate heel clearance. – all of which brings a reduction in efficiency and an increase in weight. The superior lateral stiffness of our carbon monocoque wheels soar above these problems, allowing for the highest performing wheelset, with zero compromises to the complete bicycle.