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Liked a comment on the item Custom-Tuned Versus Stock Mountain Bike Suspension - Vital MTB Advanced Class 3/23/2020 12:23 AM

Thanks Steve. Tons of good info in there for us armchair engineers

Added a comment about video Custom-Tuned Versus Stock Mountain Bike Suspension - Vital MTB Advanced Class 3/22/2020 12:20 AM

Very cool video guys. The Runt is a solid product for sure. However, I would respectfully disagree with a lot of the assertions made in this particular post:

What we would say is that for a rear shock, the coil is a really great option. Rear air shocks require tight seals to be able to handle the air pressure, especially at full compression. This in turn creates at lot of extra friction on the entire system. With the coil spring, it alleviates a ton of friction, and gives you un-matched suppleness and mid-stroke support.
Obviously, air springs have more friction than coils. However, the frictional values of rear shocks are generally lower overall than forks - they only have one wiper/shaft seal instead of two, and the squeeze on the air seals is actually comparable to what it is in forks, though at lower pressures and surface areas. However having measured this, once the additional leverage of the linkage is taken into account, the frictional value at the wheel is far lower on the rear than that front. On top of that, the additional weight on the rear wheel and the lower sensitivity to impact of people's feet as compared to their hands makes fork friction a way bigger concern than shock friction. This isn't just speculative, this is measured on the dyno (well not the hand/foot pain thing, people don't seem to like being crammed into the dyno for some reason!).

The limitation of the coil spring has always been being able to find the exact right spring rate for every rider. Most riders find themselves between rates, and depending on riding style and preference they end up choosing between a spring that is either too stiff or too soft. In most cases, riders can get away with the stiffer rate because it's better for the overall suppleness than dialing in the preload. Sprindex adjustable coil springs may be changing the game on this front as far as dialing in your rate. We're looking forward to testing some of their springs here in the near future.

I would not agree that the spring rate needs to be as precise as you're making out here, nor that the limitation of coils has been finding the right spring - if that were the case, there'd be the same problems with rear shocks as there are with forks, because the typical 50lbs/in increments are approximately equivalent to the 5lbs/in increments that fork coils are usually offered in (eg with the Smashpot). In my opinion the limitations of coil springs in forks come from the fact that you have a dead linear motion ratio between the wheel and the spring/damper the whole time, whereas with frames there's the variable leverage ratio that can be used to control progression. That means many people end up overspringing the fork JUST to prevent bottoming out, when the ideal spring rate would be lower 99% of the time and they're compromising that for the other 1%.

So, when it comes to forks, we're dealing with a totally different animal. Because of the design, especially self-equalizing air springs (Fox NA2 EVOl and RockShock Solo or DobonAir), modern forks do not require the tight seals that we see in rear suspension designs. So we ultimately have much less friction in the fork, freeing up the potential with tuning the air spring.
Agian, not actually the case - rear shocks are also self-equalising, that has no effect on the necessary seal squeeze or friction. Forks do have smaller surface areas and lower pressures, both of which do contribute nonlinearly to frictional values, but again they lack the leverage and weight that the rear end has, so they still come out behind. I mean, easy way to tell even if you can't measure it - how often do you hear people complaining about sore hands compared to sore feet?

With coil conversions and coil fork offerings, the same issue we see with people being between rates on the rear shock, is even tougher with fork offerings. Most companies only offer 5, maybe 6 spring rates, which makes it even more difficult for riders to find the correct rate. In turn, the companies that are making these conversions and forks are improvising bottom-out mechanisms to essentially help keep people from hitting full bottom out when their spring is too soft.
The idea of anti-bottoming systems is not to compensate for a spring that's too soft, but to open up the range of useful spring rates so that preventing bottom out is not a tuning consideration. If the spring rate that's optimised for 99% of your riding time happens to be soft enough that you can bottom the thing out hard from time to time, it makes more sense to simply prevent the hard bottom outs than to compromise the spring rate the rest of the time. We also offer 11 spring rates with the Smashpot, though I realise a lot of OE spring options are much more limited.

The other issue with coil forks is that, instead of being on the outside of the rear shock body, the spring is confined to the inside of the fork stanchion. These fork springs are very long in comparison to a rear shock spring, so as the fork goes through it's travel, the spring needs room to move around, which adds more friction to the system.
It doesn't actually add friction or stiction - it creates (very) small nonlinearities in the spring rate, that are measurably tiny. There is no additional stiction because the spring itself can still flex in spite of whatever guides it's contacting, until the spring surface slips (which usually happens within such a tiny displacement, like microns, that it's effectively non-existent anyway)

Visualize pushing rope. To be perfectly clear, coil forks can be a great option for some people, but the likely-hood of nailing the spring rate for the rider weight is slim.

So, with the RUNT, you can actually take the linear rate of a coil spring, and dial it in to the exact rate you need for your weight, riding style, preference, and the terrain you're riding. Depending on the accuracy of your shock pump, this means you can adjust the L chamber in 2.5 psi increments, which we have found makes a noticeable difference.

Dual chamber systems like this are not actually truly linear though - they're digressive by nature in the middle of the stroke (which can be a good thing compared to a standard air spring, I would agree) and also falling rate by nature at the start of the travel as all air springs are. The stiff initial rate still doesn't compete with a coil in terms of that initial compliance, for any given mid-stroke spring rate.

It's worth noting as well that we don't really have a dog in the coil vs air fight, since we make products to suit both. Both have their strengths and weaknesses.

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Liked a comment on the item Get Better Performance from Your Air Fork: Vorsprung Suspension Luftkappe 7/25/2019 10:14 PM

The Luftkappe is great and works as advertised.
But...my opinion is to save your pennies. The Vorsprung Smashpot increases performance through the roof by comparison! I cannot recommend it enough. The extra grip on the front end is immediately noticeable, as is the reduction in hand...more

Added a comment about product review Get Better Performance from Your Air Fork: Vorsprung Suspension Luftkappe 7/19/2019 10:57 AM
Vorsprung

Quick note on the pricing - those figures should actually be in CAD not USD. So for under $105USD ($133CAD) you actually do get the roll pin tool included smile

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Added a comment about press release Vorsprung Launch Smashpot Coil Conversion System 1/31/2019 11:00 AM
Vorsprung

Push ACS3 MSRP is $389USD including spring - Jenson sell it for $309 WITHOUT spring. Our MSRP is ~$315USD including spring. We use hydraulic anti-bottoming so that you don't have a spring plunger physically impacting an air spring plunger mid travel. There are no moving seals to worry about wearing out, no air seals to leak, and it dissipates kinetic energy instead of storing it and then releasing it again - there's a reason it's easier to tune rebound damping with linear springs than progressive ones. It can provide equivalent bottoming resistance with lower peak forces too, because peak hydraulic forces occur earlier in the travel (where velocities are higher) than peak spring forces with the Smashpot, whereas with the ACS3 the peak force of both the air and the coil springs occur simultaneously at max travel.

Should you ever wish to move it to another fork, everything except the top cap (and possibly foot stud) will transfer over. It's internally guided to reduce spring buckling and noise as well, which the ACS3 is not. Replacement springs are cheaper too ($60USD vs $80USD).

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Liked a comment on the item Vorsprung Launch Smashpot Coil Conversion System 1/31/2019 10:50 AM

They did mention why their bottom out system offers advantages and you mentioned it in your comment. They dont have air seals that need more maintenance than the system they offer and you can adjust it without a shock pump on the fly. What else do you want them to say? MSRP on...more

Added a comment about press release Vorsprung Launch Smashpot Coil Conversion System 1/31/2019 10:49 AM
Vorsprung

Yes it will. Obviously the travel won't be adjustable on the fly anymore though.

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Liked a comment on the item Vorsprung Launch Smashpot Coil Conversion System 1/30/2019 6:54 PM

Thanks for the reply! It's definitely a product I'll look I to for other builds as the Asc3 is very expensive but for my main build to match the 11.6 it seemed like it was the only way forward.

The luftkappe is a quality product, I had on my pikes! Keep up the work man! Cheers

Added a comment about press release Vorsprung Launch Smashpot Coil Conversion System 1/30/2019 6:53 PM
Vorsprung

The Rhythm/Smashpot will feel very similar to the standard 36 yes. The Rhythms still run the Grip damper (rather than the Grip2) which is not quite as adjustable but fundamentally a pretty decent damper. Fox do some weird stuff with their forks though - if raising the travel beyond 160mm ALWAYS call Fox USA first with your serial number to check what the maximum travel is. You may need a new damper tube or you may not - no way to tell other than calling Fox.

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Liked a comment on the item Vorsprung Launch Smashpot Coil Conversion System 1/30/2019 4:12 PM

Love Steve and the guys, they always have time to answer stupid questions. I have the luftkappe and corset fitted and they make a genuine difference (even from the evol aircan). Now please god they'll make this for my 34 and I won't have to buy a 36 hint, hint guys (push don't...more

Added a comment about press release Vorsprung Launch Smashpot Coil Conversion System 1/30/2019 10:49 AM
Vorsprung

As posted elsewhere: the Push kit is a really good concept - coil performance for the first 2/3 of the travel with an adjustable anti-bottoming system. Fundamentally both the ACS and Smashpot are pretty similar there, and with any given spring rate you'll notice absolutely zero difference in performance during the first 2/3rds of so of the travel since a coil spring is a coil spring. Both have anti-bottoming systems which as a whole achieve a pretty similar thing.

However, the Smashpot is cheaper, has internally adjustable travel, goes to both longer AND shorter travel settings, has a wider range of spring rates available, is transferable between forks at a minimum of cost, has no components impacting one another mid travel, has no air seals to worry about, doesn't need a shock pump to adjust and is guaranteed* to get you laid.

*eventually, probably.

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Added a comment about press release Vorsprung Launch Smashpot Coil Conversion System 1/30/2019 10:45 AM
Vorsprung

Yes and yes. What country are you in?

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Liked a comment on the item Vorsprung Launch Smashpot Coil Conversion System 1/30/2019 10:43 AM

You know, I was skeptical of Vorsprung's business model when they first came out with the Corset and then RS and Fox came out with their own versions of large negative air chambers literally a season later, but they consistently slot themselves ahead of the OEM improvement (almost...more

Added a comment about press release Vorsprung Launch Smashpot Coil Conversion System 1/30/2019 10:43 AM
Vorsprung

I guess now's not a good time to mention that a DVO kit may or may not be under development... smile

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Vorsprung Launch Smashpot Coil Conversion System
Vorsprung Launch Smashpot Coil Conversion System
(Press Release)

1/29/2019 5:15 PM

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Vorsprung - Fractive Fit4 YouTuned Valve System
Vorsprung - Fractive Fit4 YouTuned Valve System
(Press Release)

3/19/2018 10:05 PM

0
Updated photo album Luftractive 12/6/2017 9:04 PM
Luftractive

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Added a new video The Tuesday Tune Ep 21 - High and Low Speed Rebound Adjustments 11/21/2017 9:04 AM

This week in the Vorsprung workshop, we take a look at how HSR and LSR adjustments work, how they interact and suggest some tuning methods to help you get the best out of your damper. Quite notable with these adjusters is the huge overlap between the effects of the two as well as the interference they each have with one another. When tuning these, simplification is important, and we show you why that is and how to make setting up your rebound damping as simple as possible. There are, as always, a few notes: 1. Simplification to remove variables can be beneficial because it allows you to get to 95% of the potential performance ceiling very easily, as opposed to a theoretical 100% of the performance ceiling that is very difficult to find. 2. Advanced tuning of these two adjusters can go beyond what we suggest in this video - the difficulty though is understanding exactly what interference effects you're causing.

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