And this time I stayed out for a couple of hours.

My picture originally had the thermometer in it, but since it was not readable I cropped it out to reduce the filesize. The temperature was a bit under 20 degrees F, a beautiful day for riding, the trails packed into "white asphalt" by the snow machines and dog sleds.



If you'd like a better picture of the bike, see this post. Oh, and the car buried in the snow is not the ShoWagon, although it too is equipped with an award-winning stereo system.

(edited to update link to URL)

tanstaafl.

If you'd like a better picture of the bike



The bike is made by Amp Research, is a full suspension bike, weighing about 25 pounds, although equipped as shown it is probably closer to 30 pounds.

The equipment includes the locally made handlebar covers (called "Pogies" for no reason that anybody can remember now), the tool bag with spare inner tube, tools, chain lube, etc., and the special winter wheels with 44mm wide rims to give flotation on soft trails. These rims are available only from All Weather Sports here in Fairbanks, and are frequently the difference between riding the bike and pushing it when trail conditions are soft. With these rims, and the "give" of the trail surface, we can run tire pressures as low as five to eight psi pressure to maximize the size of the tire footprint.

Other winter preparation involves repacking all the bearings (headset, wheels, bottom bracket) with very lightweight winter grease, and removing all lubricant from the freewheel mechanism (even the lightest oil will keep the ratchet pawls from engaging at 20 degrees below zero or colder).

These rims are much wider, stiffer, and stronger than conventional rims, and because of that require fewer spokes, particularly in the front wheel where there is no stress from being driven by the pedals.

The bike is equipped with hydraulic disk brakes front and rear. These work much better than conventional rim brakes in the snow, particularly with temperatures in the 20s, where rim brakes will warm the rims up above the freezing point, melting snow on the rims which then re-freezes. The coefficient of friction of ice-coated brake pads on ice-coated rims is not particularly conducive to rapid deceleration. The disk brakes also ice up, but because the tolerances between the pads and the disk are so small, the amount of ice is literally only a few molecules thick and dissipates the instant the brakes are applied. Plus, being so far away from the trail surface, they are less likely to be hit by snow.

There are some electronics on the bike -- a bike computer that shows current speed, average speed, maximum speed, total distance traveled, trip distance traveled, current altitude, total altitude gain, trip altitude gain, elapsed time, time of day, and a few other functions I don't remember because I never look at them. Also, a wireless heart rate monitor that in addition to displaying current heart rate also records heart rate as a function of time and replays it at the end of the ride, or downloads it into a PC for detailed analysis. The tail light is a nice little LED unit that requires new batteries about every two or three years, and is visible on a clear night from more than half a mile away. I only put the headlight on when I know I will be riding in the dark -- the motorcycle battery that powers it is heavy enough that I don't carry it around unless I have to.

The chain stays, seat stays, and fork blades are carbon fiber. The frame is aluminum. There probably is not three pounds of metal on the bike that you could pick up with a magnet. (Freewheel cogs, brake disks, ball bearings, pedal spindles... most other things are light metals like aluminum, titanium, etc.)

For winter riding I prefer pedals with toe clips and straps to the more secure clipless variety. The mechanism and cleats of clipless pedals tends to get packed with snow, and if the temperature is right the pressure of foot on pedal compresses the snow turning it into ice, making it impossible to clip in. (Some clipless pedal designs are less prone to this than others.)

It is a pretty high-end bike (when I bought it four years ago it was the high end mountain bike) and I paid more for it than I have paid for any car I have purchased in the last 25 years. More than any TWO cars, in fact...

tanstaafl.

In order to read that post, I had to copy/paste it to a text editor, since it was substantially wider than my 1024x768 laptop...sort of annoying....

-brendan

Nice bike!

The frame is aluminum. There probably is not three pounds of metal on the bike that you could pick up with a magnet.

Hmm. What kind of aluminum would tht be then?!

i believe hes saying that there is very little on the bike that will be picked up by a magnet. not that the aluminum is special and only 3 pounds of it is able to be picked up with a magnet.
id be willing to bet that all of the aluminum on the bike is the normal, non-magnetic type, that is so prevalent these days

the normal, non-magnetic type, that is so prevalent these days

LOL

Ah...I understand now;

There probably is not three pounds of metal, on the bike, that you could pick up with a magnet.

Very nice bike.

Pretty cool bike, and a good 3-5 pounds lighter than my own Specialized full-susp trail bike. I would really like to see more of a close-up of the front suspension, if you could. Most unusual that !

Cheers

Those are crazy looking rims! Very cool!

Pretty cool bike, and a good 3-5 pounds lighter than my own Specialized full-susp trail bike.

That's because the rims are made from drillium.

I would really like to see more of a close-up of the front suspension, if you could. Most unusual that!

It's an Amp Research F4, one of only a few linkage-based front suspension designs (the only other that I can think of is the Girvin/Noleen fork, which was found mostly on K2 bikes).



A small addendum commemorating my 1000th post.

Other winter preparation involves repacking all the bearings ... with very lightweight winter grease, and removing all lubricant from the freewheel mechanism (even the lightest oil will keep the ratchet pawls from engaging at 20 degrees below zero or colder).

What do you do with the suspension at 20 below? I can't picture an elastomer squishing or oil flowing. Or is it all in the tires?

I can't imagine biking at 20 below; my knees don't like to bike when it's colder than 40 above! Brr!

-jk

What do you do with the suspension at 20 below? I can't picture an elastomer squishing or oil flowing. Or is it all in the tires?


The Amp is one of the few bikes around here where the suspension still works at 20 below (and colder).

Conventional oil telescopic forks do not work much below zero -- at least, not until you hit a pretty good bump and blow the seals out of them, then they actually work pretty well, due to the cold-induced viscosity of the little bit of remaining oil in them creating a damping action through friction on the moving parts. Some riders keep a set of winter forks just for that purpose -- blown seals, just enough oil in them to keep them from grinding themselves to bits.

Elastomer forks just stay completely rigid until the weather warms up.

The Amp front suspension is different -- it is all linkages and springs, with two very small damping shocks mounted externally. These dampers are of the air/oil type (don't know exactly how they work, but it is not through restricting oil flow through a small orifice, they make a hissing sound as the air does the damping) and they work in the cold.

The rear suspension is more of the same -- lots of linkages, pivot pins, and bushings, controlled by an air-damped shock. The shock that came with the bike is worthless -- knowledgeable AMP buyers generally remove it and drop it in the trash as they're wheeling their new bike out the door of the bike shop and replace it with the Risse shock that is on my bike. It is a $200 shock, and the difference in performance and reliability is amazing. It is adjustable in damping, rebound, and spring rate. In three years I have not even had to adust the air pressure in it (abut 160 PSI if memory serves).

The downside to al this high-tech is that it is all high-maintenance. It probably costs me $200-$250 a year to keep the bike running. All those pivot pins and bushings wear quickly and expensively, and have to be replaced. The brakes cost me about $35 a year for brake pads and occasional caliper overhauls at $40. (Hydraulic, remember?) The front dampers have to be sent off to AMP for rebuild every other year when the seals fail (possibly cold weather contributes to that) at $40 each. Then there's normal wear and tear -- tires, tubes, chains, cables, chainrings, the occasional bottom bracket assembly, wheel bearings, etc.

I'm not the kind of maintenance freak who thinks that all the bearings have to be removed, cleaned and re-greased every time the bike is ridden in the rain. In fact, just the opposite: Ride it 'til it breaks, and then fix only what's broken. It doesn't make sense to me to spend an hour of my time doing preventative maintenance on 80 cents worth of wheel bearings. Bike parts are cheap -- it's just that on this bike, there are so damn many of them that it does add up in the end.

tanstaafl.

The downside to al this high-tech is that it is all high-maintenance.

I went with the Luddite approach for my current bike. It's an Otis Guy Softride build, the one with the beam and handlebar suspension. Quite odd to look at, but fits my (lazy) maintenance needs and my (no longer overly aggressive) riding style nicely. It has a steel frame with mostly XT, and the whole thing is under 24 lbs (and that includes my toolkit). I spend most of my time riding in the DC area and the mountains of NC. But never in the snow - I'm sure I'd break my neck!

I've been wondering about light, full suspension bikes for my next one, but all those complex linkages seem so, well, complicated that I just haven't gotten the urge to start spending the money. My bike's about 9 years old, and needs almost nothing but new tubes, tires, brake pads and a bit of lube here and there. I did upgrade my drivetrain and brakes a couple years ago - they were getting a bit sloppy.

-jk

Most unusual that !

If I remember, that was one of the early fork designs that came out. The next fork I get is going to be the Fox TerraLogic. Distinguishes between bumps and pedal induced bobbing.

Somehow if I lived in Alaska I would want a Nice heavy bike that way I have something to throw at the bears if they get too close and have that "were are going to eat you" look in there eyes.

SO is a bear faster in then show then the person on a bike he is chasing ?

Luckily the UK is a little more forgiving! I currently have a Sintesi (Italian) hardtail frame and Pace Evo2 carbon forks. If I have some spare money this summer I might replace the frame with a Pace RC200 - made in Yorkshire where they build 'em tough. The used to build some superb downhill equipment but seem to have got out of that market.

Gareth

I've been wondering about light, full suspension bikes for my next one, but all those complex linkages seem so, well, complicated that I just haven't gotten the urge to start spending the money.

If complexity is what's stopping you, then let me recommend the Santa Cruz Superlight. Extremely simple design. I used to own a Heckler, which is the same frame design, but made of thicker/different tubing, and I was incredibly happy with it. I got rid of it when I bought a full on downhill bike (Titus Quasimoto DH), and went back to a hardtail for XC riding. I've been thinking about getting rid of the hardtail in favour of a Superlight...

SO is a bear faster in then show then the person on a bike he is chasing ?

I've never had to find out -- I don't have to outrun the bear, only the slowest rider in the group I'm riding with.

In truth, by far the most dangerous encounter we have out on the trails is moose.

More people in Alaska are killed by moose than are killed by bears. When we're out on the trails and come across a moose (not at all uncommon) we just quietly turn around and go the other way. I'd far rather come across a pack of wolves than a mama moose and her calf. (Not that I'd ever actually see the wolves -- they are so shy that by the time I got within a quarter mile of one he'd already be a half a mile away)

tanstaafl.

by the time I got within a quarter mile of one he'd already be a half a mile away

now that makes for an interesting image
im seeing an elastic wolf.

If complexity is what's stopping you, then let me recommend the Santa Cruz Superlight

Thanks! I'll go take a look. What sort of regular maintenance did your Heckler need?

-jk

What sort of regular maintenance did your Heckler need?

Uh... I lubed the chain a few times. Seriously, beyond the basic maintenance required of any bike, not much. I checked the pivot (there's only one) a couple times, but the bolts had never loosened, and the bearings/bushings (can't remember which it had) never had an ounce of slop in them. Ditto with the bolts holding the shock to the frame. I bought it after having cracked two Specialized Stumpjumper M2 frames. At the time, I weighed about 190lbs, was doing 2+ foot drops (to flat landings), and riding rooty, rocky, muddy trails. It even survived some downhilling at Bromont (site of a few World Cup races, for those not in the know -- about an hour south of Montreal).

I'm with him! I have a Heckler right now (I was too "large" for the Superlight at the time I bought my bike), and it's great! Very low maintenance. As far as the frame itself, the pivots are sealed bearings and work extremely well. I have only done the normal maintenance that you would do with any bike. I would definitely say to check out the Blur if you are into XC riding. Very sweet bike!

Thanks for the info! I'll definately put it on my test-ride list.

-jk

I'm with him! I have a Heckler right now (I was too "large" for the Superlight at the time I bought my bike), and it's great!

Cool. Umm... Without revealing embarrassing details - wha'ts too "large"? I'm not exactly "small".

When I got my bike I was weighing in at about 220... and the rider weight limit was 190. Looking at their website it appears as though all weight limits have been removed. I did watch it raise from 180-190-210-250... But you may want to email them if you are unsure. If I was to get a new bike today, like I said above, the Santa Cruz Blur.

If I was to get a new bike today, like I said above, the Santa Cruz Blur.

Yeah, I thought about that, but he said he was concerned about the complexity. Can't get much simpler than the Superlight/Heckler design.

Can't get much simpler than the Superlight/Heckler design.

Very true!

Hello;

Very nice AMP! Are those still being built? For example, yours is the first i see with carbon chainstays; very nice! i saw some AMP's here, but rebranded as mercedes-Benz bikes, and they were sold at M-B dealers only...kinda like the Porsche bikes.

for my part, I'm currently riding a '01 GT iDrive 2.0, that I upgraded with Magura Gustav M discs and Marzocchi front and rear shocks. I have to admit that I was concerned about spare parts and such, because when i got it GT had it's financial problems...but their idrive (wich I thougt would be the weak link) is strong and quite simple to check; I can do it myself. In all, I have to say it's a good bike, although right now it's quite heavy, at 17,5 kg (with 24" wheels), but it's excellent for enduro/light freeride.

btw, glad to see there are some bikers in here

I went for mountain bike ride today too. Of course here (northern California) its at least 60 degrees F out and sunny. Your nuts man

-Mike

I would really like to see more of a close-up of the front suspension, if you could. Most unusual that !




The advantage of this fork design is that it is very light -- probably half a pound lighter than any "normal" front fork with comparable travel (over 3") and durability.

The disadvantage is mechanical complexity and high service requirements. I probably average $75 a year keeping it tight.

tanstaafl.

Very nice AMP! Are those still being built?

No, they stopped production about two years ago, although as you pointed out they did make some Mercedes branded bikes, but I believe those are also no longer in production.

Parts and service are still available from Amp Research in California. Last year they replaced my complete rear triangle under the lifetime frame warranty when one of the dropouts separated from the carbon fiber seat stay. I had to stop every quarter mile (the tire would rub on the chain stay) and bang the dropout back into place with a rock. Fortunately I was only about five miles from my car. The new triangle has an improved attachment method, adding a rivet to the glue joint.

They also rebuilt my brake calipers and front shocks, and replaced the link pins and bushings in the rear suspension and front fork, all for about $200.

tanstaafl.

I went for mountain bike ride today too. Of course here (northern California) its at least 60 degrees F out and sunny. Your nuts man

Here is why I'm not nuts!



1) Get a bunch of us together on a pretty nice day -- temperature above zero. I'm the really handsome guy on the far right of the picture.

2) There are hundreds of miles of trails like this all around Fairbanks, within a 5 minute drive from down town. That's not me riding there, I'm much better looking than that.

3) Not relevant for today's ride, the trails were excellent (see #2 above) but when the trails are soft, we will actually ride with our tire pressures this low. That really is me. See how handsome I am?

Interior Alaska in the winter time has some of the best mountain biking you will find anywhere.

tanstaafl.