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Discussion Starter #1
There is an excellent but kind of in-the-weeds thread here on MTBR about steering dampers. It was started by and is aimed at people whom are trying to more effectively ride their fatbikes on snow.

It is here.

I think many, many, many more people could benefit from running a steering damper than currently are.

But they are rare and little understood, such that few are even aware of their existence, much less function. Almost no one has seen or used one.

Thus, I've shared a little more zoomed-out primer not so much on how they work, but on *why* they work, and where.

It is here.

At the very end of that post, it links you back to the in-the-weeds thread mentioned above, where you can ask/answer questions about dampers if you've suddenly become interested.

Check it out.

https://vimeo.com/389885322
 

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I have an honest question. And if I am mistaken on the concept, please be sure to enlighten and inform me.

Thinking back to older bikes, 1", threaded, with caged ball bearings where achieving proper adjustment was harder, you could overload the bearings and have too much preload. Would "overloading" a headset with preload achieve a similar result as the steering damper? I know that many of the new bikes won't have, or would need to be "downgraded" to do similar, but I was thinking hypothetically.

Thanks, MC
 

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Discussion Starter #3
Thinking back to older bikes, 1", threaded, with caged ball bearings where achieving proper adjustment was harder, you could overload the bearings and have too much preload.

I haven't done it on purpose, but I've certainly ridden '80's and '90's bikes with too-tight headsets that felt similar to what these dampers are doing. More indexed though -- with a tight spot near the center and then they smoothed out toward the "edges".

Not sure if you could get them to last long when misadjusted like that?

I once deliberately installed my top (threadless) headset cup with a bit of a tilt to it. It was off by ~1mm at most, such that when I preloaded the top cap it tightened the steering up a lot like a damper.

It was an interesting experiment that I undid after one ride. No idea how long it would have lasted if left as such.
 

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Thanks. It was a hypothetical in my mind so that I could understand what the steering damping would be doing. They don't last too long overloaded, as you mentioned, and the indexing is annoying. Might be able to loose-ball it, but that is it's own other can of worms to deal with.
 

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Mike, I still have a damper that was available in the late 80's or perhaps early 90's. It had an adjustment knob on the end of the shaft that provided more or less damping and was actually rather cool in the day.

Glad to see you doing the experimentation and such.
 

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Thanks for that Mike. (from the OP of the other thread)

I must admit I've not seen either of the two main dampers here in the UK, talk to other riders about them and you just get blank looks. Then again we've had all of 150mm of snow so far this winter and that lasted all of 36hrs. :rolleyes:

Went to Norway to get proper winter conditions and basically got ice:madman:
 

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Discussion Starter #7
Mike, I still have a damper that was available in the late 80's or perhaps early 90's. It had an adjustment knob on the end of the shaft that provided more or less damping and was actually rather cool in the day.

Glad to see you doing the experimentation and such.


Pics? Details? Manufacturer?
 

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Discussion Starter #9
There was a product called the Dampenator and there was another used specifically by Rotec

Thanks for the info and the links.

Never seen a Dampenator. Couldn't find one on eBay, nor any other info about how it worked.

The Hopey is one of the two I'm still using today.
 

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I can't help thinking the real culprit is slack Modern Trail Geometry with far too much flop for ruts and soft surfaces.

My preference (based on my experimentation) for those sorts of conditions is very little flop - usually achieved through very steep HAs with lots of trail.

It might be worth exploring. I prefer the handling of the earlier rigid fatbikes before they started slackening the HAs to cater for telescopic forks.

Tony Foale did a lot of interesting work on this in the 1970s.
 

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Pics? Details? Manufacturer?
I'll try yo locate the silly thing. It was a 6" cylinder with a rod though it that clapmed to the crown of the fork and had a heim joint on an adapter plate that mounted on the down tube bottle bosses that we had to install if they weren't present.

IMG_1356.jpg

IMG_1358.jpg

Odyssey Pro Steer System. It can be very stiff, light or anywhere between. Keeping in mind, this was an early design that was on the market before squish came from places other than running your front tire at 15 psi! :p

There was a product called the Dampenator and there was another used specifically by Rotec that was bolted to the frame with using a threaded bung in the TT.

1996 Trek Y33 mountain bike on display at Classic Cycle Bainbridge Island | Classic Cycle Bainbridge Island Kitsap County

The comapany is Stable Tec and there's a Dampenator on ebay.


This is the one Rotec used, I believe.

Gravity Hopey Steering Damper Product Information
I do remeber seeing a few of those in the wild...
 

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I sort of stumbled on this thread accidentally. After reading through everything Mikesee has written, I’m considering the Viscoset for my 29+ mountain bike. I experience lots of wheel flop when climbing, and it sounds like the Viscoset might help with that.

Thank you for the detailed posts and answering questions Mikesee. Once again I’ve learned something new and valuable from you!


Sent from my iPhone using Tapatalk
 

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Discussion Starter #14
I can't help thinking the real culprit is slack Modern Trail Geometry with far too much flop for ruts and soft surfaces.

My preference (based on my experimentation) for those sorts of conditions is very little flop - usually achieved through very steep HAs with lots of trail.

You've been suggesting this for years. Possibly decades. I think you've shared some anecdotal data, but I can't remember ever seeing any science or hard proof. Do you have any?

Steep head angles *might* work better for the conditions you ride. But those conditions have very little (almost nothing) in common with deep, soft snow.

On each of the custom snowbikes I've had built, going back 22 years now, I've gone a titch slacker on head angle and kept the trail roughly constant at ~100mm.

And with each successive iteration the control in deep, soft snow has improved.

That said, the HTA of our 2 custom Meriwether bikes is 68*. A far cry from "slack" or "modern", and by some metrics decidedly old school.

Still slacker might even be better. When I next get the itch to spend the $$$$ to experiment with fatbike geometry, I'll probably find out.
 

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I tried being my own steering damper by stiffening up my arms a bit, resisting turning the bars with my own willpower. I really see how steerer damping helps resist turning the bars too much, and forces proper steering through the hips. Try it, it's not sustainable in the long run, but a fun experiment.
 

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Discussion Starter #16
I sort of stumbled on this thread accidentally. After reading through everything Mikesee has written, I’m considering the Viscoset for my 29+ mountain bike. I experience lots of wheel flop when climbing, and it sounds like the Viscoset might help with that.

Thank you for the detailed posts and answering questions Mikesee. Once again I’ve learned something new and valuable from you!

You're welcome.

Definitely try one out. How well it works for you depends a lot on how much pavement/rock you have on your average loop. Damped steering feels really funky on hard surfaces -- not unlike self steer with fat tires.

I have a Viscoset on my 29+ daily driver, ridden on chunky, ledgy, high desert and alpine Colorado Plateau trails. When new, and run at max damping, this Viscoset had a *tiny* bit too much damping for my preferences. Now that it's been in service for ~9 months, and the damping paste has thinned out some, it feels like not quite enough damping.

I'll likely re-up the paste on it sometime this week.

Happy experimenting.
 

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You've been suggesting this for years. Possibly decades. I think you've shared some anecdotal data, but I can't remember ever seeing any science or hard proof. Do you have any?...
No. That's because it wasn't done scientifically, but crudely and empirically, and for my own benefit. I never thought to document it because it was for my own purposes.

I raised it now because if steering dampers are needed, then it's a band-aid solution for a geometry problem in the design IMO. (But if you have a bike that needs one, then you need one)

That's why I suggested looking at Tony Foale's research. He did document it and did do it with measurement, although for motorcycles. Take a look and see if you think it's worth pursuing.

While I got the results I wanted by steepening HAs and increasing trail (much the same as for you, 100mm seemed to work well), lately I have wondered if the critical factor is the amount of flop in the steering.

It is possible to have minimal flop with a slack HA by playing around with offset, and that would be worth exploring too.

For those unfamiliar with what 'flop" means, the bigger the flop figure, the higher the wheel lifts off the ground at any given angle when the wheel is turned to the side. My recent thinking about flop may be wrong, but I visualise it working like this sequence:

If the leading edge of your tyre strikes an obstacle, the impact tries to turn the wheel sideways. Especially if it impacts high as its leverage is increased (eg ruts, deep snow).
The wheel is angled sideways and momentarily loses contact with the ground.
There's a very short period before the angled wheel descends and the tyre touches down again and the trail corrects the deviation.
The higher the wheel is off the ground the longer the impact has to overcome the rider's steering input and continue to angle the wheel sideways.

We're talking microseconds here, and my current thinking is that there must be a correlation between rider reaction time and the the time it takes for the steering to self-correct. The higher the wheel goes when it is angled sideways the faster the rider reaction time will have to be to keep it straight, or in other words less flop reduces the need for rider reaction. (EDIT: I think this may be a blind alley. I've done some free fall calculations and the wheel is going to touch the ground far sooner than even the fastest human reaction. Ironically maybe the human is simply acting as a meat steering damper :) )

Obviously this is ignoring a host of other factors such as the effect of suspension, tyre profile, and tyre pressures which will counter this to some extent. Loading the front helps on hard surfaces, but that's no good on soft surfaces like snow because then the front digs in.

My thinking on flop could well be off track, so you're welcome to blow it out of the water. :)

As always, in any discussion on bike geometry, it's always worth remembering that people ride unicycles, and that makes a nonsense of many cherished bike geometry theories. :)
 

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Discussion Starter #19
We've had this conversation (in writing, here) before, several times. You've often referenced Tony Foale. I have looked at what he did way back then. It was (IIRC) interesting and informative, but has little to do with low pressure tires on soft, changeable, sometimes non-existent surfaces.

There isn't any one answer to what works best on soft snow. There is simply "what works best for you". Perhaps this is your larger point, and I'll grant it to you.

Part of the reason that I have continually gone slacker on HTAs is for the sake of efficiency. Steepening the HTA changes the point at which the bubble of air you're pushing along within your front tire contacts the ground. Effectively pushes that bubble further forward. As that bubble gets further forward, the amount of perceived rolling resistance increases -- to the extent that you no longer feel like you're riding on top of that bubble so much as inefficiently pushing it out in front of you. Do it for 5 minutes and it is noticeable. Do it for an hour and it is maddening. Do it for a few hundred miles -- at 2mph, at 1.5psi -- and you'll lose your mind at the inefficiency.

I have done all of these. And while doing all of these I realized that if you could bring that bubble of air further back -- effectively behind the steering axis -- then you'd be getting a comparative free ride. Slacking out the HTA brings that bubble further back, and (bonus!) at the same time lightens the steering and keeps you from having to counter the front wheel's desire to track into every sled rut or be deflected by every chunk of ice.

I haven't quoted any absolute numbers here because there aren't any absolute numbers. There is just what works for you.

Going slacker on HTA achieves a set of compromises that works better than any other I've found for riding soft, dry snow. And the negative aspects of those compromises can be largely cured with a bolt-on steering damper.

Going steeper on HTA achieves a set of compromises that a steering damper can't really touch. That can really only be cured by (wait for it) going slacker on HTA.
 

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...I realized that if you could bring that bubble of air further back -- effectively behind the steering axis -- then you'd be getting a comparative free ride. Slacking out the HTA brings that bubble further back, and (bonus!) at the same time lightens the steering and keeps you from having to counter the front wheel's desire to track into every sled rut or be deflected by every chunk of ice.

I haven't quoted any absolute numbers here because there aren't any absolute numbers. There is just what works for you...
That's a good point and adds a parameter I hadn't considered beyond wondering about the effect of low tyre pressures on actual geometry.

Edit: what's your flop figure?
 
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