Sunday, November 22, 2009

Niflheim S600 Review

I finally got a chance to properly put my new rollerskis through the ringer. They are the Niflheim S600's. They come stock with speed reducers. I own a set of V2 Aero's with speed reducers, but I got sick of buying tires and tubes for them. Plus you never know when a tire will disintegrate. You could be 8 miles from your car. The V2 speed reducers work great.  I like to do hills and I'm not skilled or brave enough to go 30mph down roads with no means of slowing down or stopping. You roadies out there, would you go 30mph down a hill with no brakes on a free wheeling bike? I bet not.  Too much shit can happen, like cars, dogs, debris or potholes.  I've been using my Pursuit rollerskis most of the last two years. These use 4" solid rubber wheels, but do not come with speed reducers. The Pursuit's limit how hilly of terrain I can tackle. The loop I do at work has a modest blip in it, staying under 20mph on the descent. So I was looking for a low cost, low maintenance rollerski that could be equipped with speed reducers. The Niflheim's perfectly fill this niche.


Niflheim 600's with Pursuit's in background

I ordered a set immediately after learning about them on Alex's blog. I transferred bindings over from an old set of skate skis that are beyond "rock ski" condition. Out of the box, the Niflheim's felt quite heavy, at least compared to my Pursuit's. Some of the weight is in the speed reducer mechanism, but I suspect most of it is in the alloy shaft. The extrusion has at least 50% thicker wall thickness than my Pursuit's. Perfert for 200 lb guys. The shafts are also about 2" longer than my Pursuit's, presumably to accommodate speed reducers with big footed skiers. Longer rollerskis should emulate skate skis better.  I also noticed that in higher resistance settings, a sharp jolt could dislodge the speed reducer back to zero resistance. This worried me some. Could a crack in the road do this, right when you needed the most resistance? The escapement latch has a very wimpy spring in it. A spring with twice the torsion would solve this concern. The shape of the latch teeth contribute too. They angle down. I found that the powder coat paint was very slippery. I scraped it out of the latch teeth. The latch was much less likely to slip then.


Nothing but walls with no brakes

Sunday morning I met up with Brett R at his house for a two hour roll. He warned me to make sure I bring good working speed reducers (like my big-wheeled Aero's). I brought my new Niflheim's instead. Brett's route is more or less an out and back in Westborough, MA. It was friggin hilly. None of the Littleton gentle rollers, these were full-on walls. I think Brett wanted to hurt me. The steepest climb had a sustained grade of 16% per my Garmin. The pavement was not good, chip seal over busted asphalt. At the top, Brett said we had to go back down that! This is from a guy who's more cautious on the descents than I.

We hit a chip seal descent that was really rough. With no speed reduction set, the latches rattle something fierce on the S600's. It was so loud it was hard to talk to Brett over it or hear approaching cars. The rattle wasn't the only annoyance. The stiff aluminum shafts sent all that vibration into the ankles. It was so intense that it tickled funny bones in my feet, making me recoil from the vibration. I think my Pursuit's would behave similarly on this particularly harsh section of chip seal, but without the rattles. The extra heavy duty shafts on the S600's don't exactly help dampen vibration.


Min and max speed reducer resistance settings

Now here's the deal with the S600 speed reducers. If you set them to just rubbing the tire in the off position, you get only about 50% of the braking power of Aero's when going to max resistance. If I accept more resistance in the off state by adjusting the resistance bearing tighter, I get a little better max state resistance. But then I'm killing myself on the flats. Basically, the range of speed reduction is quite small. You can get 0 to 1/2, 1/4 to 3/4, or 1/2 to full by wrenching the initial preload in the resistance bearings. Starting with little resistance means you'll never get a lot in the max state.  I can get 0 to full with my V2's with no wrenching. Now you may counter with say, "competent skiers don't need all the speed reduction," or "if you really need that much speed reduction, route choice needs improvement." These are valid criticisms. I found I pretty much was using all or nothing of the S600 speed reduction range. Even in minimum state, slower rubber wheels and the residual speed reduction resistance made the S600's much slower than my Pursuit's, which frankly were too fast anyway.


Two ways to improve speed reducer resistance range

There are two ways to address this resistance range deficiency. One is to move the resistance arm pivot point back slightly so resistance ramps up more aggressively. The other is to space the teeth further apart, using a slightly longer latch mechanism that lets the resistance arm swing further. I just may make my own latch. It is very simple, laser cut aluminum. I could probably make a pair with a band saw and belt sander.

On our return, Brett and I went around the 16% descent but hit an almost as steep descent one road over. Brett yelled something at me as I bolted away. It sounded like "it get's steep," but he really said "it stops at a tee." I had my resistance on maximum, was snowplowing like crazy to scrub more speed off, and was still going over 20mph. It got steeper. Then I saw the stop sign at the bottom with ZERO run-out. It was hard to tell if cars were coming or not, so I was looking for holes through trees and rocks to bail if it came down to that. No cars were coming. I merged onto the cross road at about 20mph. I waited for Brett, who had and used twice the resistance I had available. I could see panic on his face coming through that stop sign too, at half my speed. Then he's laughing when I told him how insane that was. Proof he was trying to kill me. I think he's trying to eliminate a potential threat at the races this winter.


Plummet of Death with stair step climb in distance

We had a long stair step climb coming up next. We had been out about 90 minutes, and I still felt pretty good. Kind of knowing the way back, I passed Brett and ratcheted the pace up a notch. I V2'd pretty much the whole way up the sucker and put a little distance on Brett. That was payback for the hairball descent. We got back to Brett's house in exactly 2hrs rolling time, covering 17.0 miles with 1600ft of climbing. Seems really slow, but you'd have to see the climbs and some of the pavement to have the whole picture.

In summary, here's what I like and don't like about the Niflheim S600's:
Likes
Seem ultra durable
All stainless steel hardware (salty roads no problem)
Anodized shafts
Speed reducer releases easily (V2's are awkward)

Low price includes speed reducers

Dislikes
Speed reducer range is very limited
Speed reducer rattles in lowest setting
Tad on the heavy side (still 200g/ski lighter than V2's)
Sturdy construction transmits more road vibration

I'll definitely be using these more. I'm sure the speed reduction range is just fine for the Littleton loop. The Littleton course feels safer to me anyway. There was only one gradual descent to stop sign, and the asphalt on average is much better in Littleton. I felt quite stable on the S600's. They really don't handle much differently than my Pursuit's.  I think the S600 speed reducer design is quite clever, certainly worthy of patenting (if patents didn't cost so much).

6 comments:

Anonymous said...

Doug - thanks for your observations about the Niflheim's...I was also thinking about getting a pair &, after your review I think I'll still pick some up...I like my v2s alot, but am equally concerned about burning through tires & tubes (or having to bring a pump and tire changing gear)....thanks. Patrick

Luke S said...

Never seen a reason to reduce speed in Littleton, as I've said before. Nice review of the niflheim's, its such a new product that its bound to need refinement.

About a month ago, while on an unknown (but supposedly scouted) loop with only a map, we hit a long, frighteningly steep descent with bad pavement and a one lane bridge at the bottom. I was on my extremely skittish classic rollerskis, but had too much speed to stop by the time I saw the extent of the hill. Two of our group laid themselves down on purpose, and two of us skied it. I thought I was going to die.

Cary said...

Nice honest review. Knowing owner Ed, if I take the plunge back into rollerskis, I would definitely start with a pair of these.

Matt Simpson said...

we should talk, intersted

edwarddes said...

Thanks for putting in the time to analyze the skis that much. I think all your points are fair.
I do have a few suggestions that may make your use of the skis easier.
Speed reducer range: for maximum reduction, put the speed reducer bracket all the way on top of the ratchet paw. This is equivalent to moving it up a couple more notches. Since the increase in resistance from notch 4 to notch 5 is greater than from notch 1 to notch 2, it probably doubles the overall resistance to put the speed reducer on top.

Rattle: The speed reducer is set up so that on the lowest stop the bearings and shaft are as close to the wheel as you can get without them hitting the shaft of the ski. Therefor as they get grit under them or just bounce up and down, they rattle against the shaft. You can move it up into the second position, which still does not have very much resistance and the rattle should stop.

The skis are really not designed to be fast skis, as I prefer to have slow rollerskis, so I generally don't have a problem with leaving the speed reducer on most of the time.

If you really want no resistance from the speed reducer at the lowest setting, you can move back the bearings and shaft, but that will sacrifice range on the top end.

In regard to the powder coat making the parts slippery, the next batch of parts I have coming in are actually going to be black passivated instead of powder coated, so this should solve much of that problem. Ill send you a set of the new parts when I have them and you can give them I try.

Weight: The skis are definitely heavier than some of the pursuit skis, but lighter than most of the V2's. The weight should be very similar to a set of Elpex F1's. I think the worst thing that could happen while rollerskis is to have the shaft break. If you look at the end profile of the shaft, you can see the the side walls are significantly thicker than most skis, but the top and bottom of the shaft has been thinned out where the strength is not needed.

One of the other upcoming changes in the skis is that I am going to be moving to laser etched graphics on the shafts instead of stickers. Its just one more little thing that should make them last longer while looking good.

If you have any other questions or comments, let me know, Ill try to address them.

Ed Despard
Niflheim Nordic

Hill Junkie said...

Ed - thanks for the response. I checked out placing the speed reducer bracket on top of the latch pawl. It will indeed give me a couple more notches worth of resistance, probably equal to maximum on my V2 Aero's. If I do anymore crazy double-digit grade descents, I'll keep that in mind. For normal routes, I believe the designed resistance range is adequate.

I'm not really worried about the S600's being slow. In fact, I just put four new wheels on my Pursuit's with "slow" rubber. I wasn't getting the workout value I wanted on the mostly flat terrain at work. I definitely don't want to back off the initial resistance on the S600's. They are set pretty much at factory default right now. If I hit chip seal again, I'll bump up the reducer a notch to avoid rattles.

Hope my review didn't come across negative. As an engineer, sometimes I can be too objective. Overall, I feel the S600's are the best value on the market. They certainly appear to be more durable than my Pursuit's or V2 Aero's. No doubt you could charge more. Looks like I don't have a reason to keep my V2's any longer.

Thanks,
Doug