Vorsprung Telum
Adjustments: Rebound, high- and low-speed compression, hydraulic bottom-out, climb switch
Sizes offered:
- Metric:
- 210 x 47.5 / 50 / 52.5 / 55 mm
- 230 x 57.5 / 60 / 62.5 / 65 mm
- 250 x 67.5 / 70 / 72.5 / 75 mm
- Metric Trunnion:
- 185 x 47.5 / 50 / 52.5 / 55 mm
- 205 x 57.5 / 60 / 62.5 / 65 mm
- 225 x 67.5 / 70 / 72.5 / 75 mm
MSRP: $1,200 USD / $1,600 CAD (includes a Sprindex adjustable-rate coil spring)
Intro
Vorsprung hasn’t been shy about the fact that they’ve been working on a coil shock — their first full, standalone suspension product, after making a lot of very good upgrade parts for other manufacturers’ forks and shocks over the years. But they’ve kept a lot of the technical details more quiet, until now. And there’s a lot of interesting stuff going on here, so let’s get right to it.
Design
Vorsprung founder Steve Mathews laid out a lot of the high-level design of the Telum when we spoke on Bikes & Big Ideas early this year, and the stuff he divulged back then hasn’t changed. The Telum is coil sprung with a twin tube damper featuring adjustable hydraulic bottom out, high- and low-speed compression, a single rebound adjuster, and a climb switch. It’s available in metric eyelet and trunnion-mount sizes from 47.5 to 75 mm stroke (i.e., 210, 230, and 250 mm eyelet and 185, 205, and 225 mm trunnion lengths). The eyelet version uses spherical bearing hardware where applicable, but standard cylindrical ones are also available if needed (e.g., for bikes with a shock yoke) where spherical bearings aren’t viable.
[If you really want to nerd out on all that stuff, Vorsprung has published an excellent guide to shock mounting design for frame manufacturers that lays out the important criteria in general, and some Telum-specific compatibility details. The TLDR on the latter is that the total length of the shock plus any yoke used can’t exceed 315 mm for eyelet shocks or 290 mm for trunnion ones; yokes should clamp directly onto the shock eyelet, not any reducer hardware; and the yoke must use some sort of rolling element bearing (i.e., not a plain bearing / bushing) at its pivot.]
There are some interesting things going on with the Telum’s damper architecture, mainly that it uses a solid main piston with no oil flow through it whatsoever. All the damping (in both compression and rebound) is generated in the bridge between the main body and the reservoir which in turn helps facilitate what projection calls “Rapid Revalve.”
The idea is that it’s possible to completely change the valving of the Telum in under five minutes, without any oil loss or need to re-bleed the shock. Vorsprung kept the details of how the system works quiet at the initial launch but has now shared a lot more about the system, and opened up its use to the general public.
Vorsprung has a four-part video series that covers the design of the Telum in general and the function of the Rapid Rebound system in particular in great detail, which you should check out if you want to learn more. Part 1 covers the concept and overall layout of the Telum; Part 2 goes through some of the design specifics in more granular detail; Part 3 explains how shim stacks and conventional damper adjusters work; and Part 4 describes the inner workings of the Rapid Revalve system and how you use it.
The short version of the Rapid Rebound system description is as follows:
The Telum’s regular adjusters work fairly conventionally. The low-speed adjusters (both compression and rebound) are needle-type designs that vary the size of an orifice through which the majority of oil flow happens at lower shaft speeds before the shim stack opens much. The high-speed compression adjuster preloads the compression shim stack, requiring more force to open the shim stack as you close the adjuster.
That’s similar to how most high-end dampers do things, but there are limitations to what you can achieve with that style of adjustment, which is where the Rapid Revalve system comes in. Rather than requiring you to open up the shock and change the shim configuration to make more fundamental changes to the shock’s valving, the Rapid Revalve system varies the amount of leverage the oil pressure in the damper has on the shim stack, thereby effectively changing the stiffness of the shim stack. This is accomplished by varying the effective clamping diameter of the shim stack, by rotating an oblong clamping face to change where the shim stack bends. That allows the Rapid Revalve system to change the gradient of the damping curve in a way that conventional external adjusters can’t.
It’s also impressively easy to use. Essentially all you need to do is (1) open all the adjusters fully; (2) loosen the end camp for the side of the damper (rebound on compression) you want to adjust using Vorsprung’s pin spanner tool (available on their site for $40 CAD); (3) turn the Rapid Revalve adjuster to the desired setting; and (4) clamp the damper end cap back down to the correct torque spec. There’s no need to open the shock up, no fluid loss, and no need to swap shims around or rebleed the shock afterward.
As per usual for Vorsprung, their case for why Rapid Revalve is valuable is both convincing and amusingly stated. As they put it: “Should you ever want a re-tune for any reason (different bike, different preferences, overdosed on ice cream, overdosed on Ozempic, moved to BC, moved away from BC etc), that’s also extremely cost-effective to do.”
Also unsurprisingly, given Vorsprung’s history of custom suspension tuning (check out Ep.60 of Bikes & Big Ideas for a lot more on that), the Telum comes custom valved for a given rider / bike combination — there’s no “stock” tune to be found. The ordering process involves filling out a questionnaire that covers the bike that the Telum is destined for and some questions about the rider, their typical terrain, and a few other details. The “Vorsprung Tuning Hub” then generates a damper tune and recommended spring rate based on all of that information. If the initial valving isn’t to the rider’s liking, Vorsprung will work with them to get it sorted out. And in a very neat additional touch, the Tuning Hub tracks all prior valving configurations based on the shock’s serial number, so you can easily keep track of what’s been tried already if you’re working through various options. The Telum also comes with a Sprindex adjustable-rate coil spring to make dialing in the spring rate a bit easier. Vorsprung doesn’t offer spring exchanges, but will sell an alternate one at a discount if the initial option winds up being off base.
The Telum is built by Vorsprung in their new home of Kamloops, BC.
Some Questions / Things We’re Curious About
(1) First and foremost, how does the Telum perform, and how does it compare to many of the other high-end coil shocks on the market?
(2) How does the Rapid Revalve system work? Vorsprung isn’t going into too much detail publicly, but we’re quite curious.
Bottom Line (For Now)
The Telum has been in development for over three years now, and Vorsprung hasn’t kept it much of a secret, but it’s finally getting a full release now (and some of the earliest pre-orders have already started shipping). We’ve got a Telum on the way for review (actually, scheduled to be delivered today, as of publication) so stay tuned for much more on it very soon.
I’m looking forward to hearing about this one.
I have five days of bike park on the Telum mounted to a DH bike, riding both tech and jump trails. My impression is that this is a premium shock. Damping profile is higher than my previous 2024 DHX2. I would describe a “quieter” feel with a better platform to pump the bike, I don’t notice any downsides. Running recommended compression settings and two clicks faster than recommended rebound, also slightly increased compression in my fork to match the shock.