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Ron

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So far, at 195 lbs, I'm finding that 7.5F and 6R is working out pretty well in snow, and a bit firmer when it's a mix of snow and bare dirt on the trails.

Does that sound crazy on D4s?

NO, not crazy and as @Slim said, that may be too high. I'm 173 and run ~3 on soft snow.
 

Pierre

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NO, not crazy and as @Slim said, that may be too high. I'm 173 and run ~3 on soft snow.
Ron, what does 3lb give you? I know it gives you float but does it give you lower rolling resistance or more traction to handle climbs?

I am running a custom Titanium e fat bike. 750 watts nominal with 1.100 Wh battery and paniers. It even has heated battery and grips. The problem is not float so much as it will power through up to the crank. The problem is spinning the back tire. That results in an instant dig to China and quick stop. I doesn't uaually happen except if I run off the packed or climb something everyone else would push. My concern would be how many wrinkles before I was in danger of spinning the tire lose on the rim. I suppose that might not be an issue with Fatty Strippers. I will find out when I change from the JJ's to the Wazia's
 

Ron

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Ron, what does 3lb give you? I know it gives you float but does it give you lower rolling resistance or more traction to handle climbs?

exactly, I am still playing around but ~1psi seems to be about the PSI where I can push the tire in a bit more than 1/2 way. thanks @firebanex that was a great tip and it really is pretty accurate. Now that I have the Gnar's, I may be able to run a little more, but that seems about right.

Your issue it too much torque on the rear wheel, you need to back way off. for optimal traction, find a gear or torque where the tire turns easily but with some effort. it should be more of a slow grind as opposed to the granny gear you might use in the summer to power spin up a mtn bike. That's where I like the 27.5, its a longer contact patch and I just seem to be able to modulate the pressure better. A little better efficiency, YMMV.

EDITED: had to edit the PSI.
 
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Pierre

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Ron, about the fastest I get on snow is about 10mph. On climbs it is much slower but some climbs are really steep.

About the furthest I have taken a winter ride was 50 miles in a day.
 

Slim

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@Pierre : Jumbo Jim is a horrible tire. It is light, as low rolling resistance, but has no traction for propulsion or cornering.

with an E bike, rolling resistance is not your concern, traction is.

Wazia was better( every fatbike tire is better for traction than JJ, except Big Fat Larry), but not great. Disappointed a bit, neither better traction nor cornering nor faster rolling than Dillinger 5. I prefer D5, but fairly similar.

Get Surly Lou(pm me, I have a new one in box). And something similar for front.
If you have ice, get Johny 5.
 
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Slim

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With 4.8 tires, on fresh snow, I run less than 1 psi. Can’t measure that very well, as my gauge is up 15 psi.
 

Ron

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just went and set them up for deep snow and @Slim, you're right! Im a little less than 1lb psi! I usually start out at 3 and then let some out as I go but I think I will just set that at 1 and from there.
 

Slim

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I usually do the start a bit higher, then drop for conditions. I don’t measure, because it varies so much anyway, you never what you are going to find for conditions
 

Ron

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thats why I've been starting at 3. the first 1/3mile is on a groomed trail bu then once you go onto the single track, you're never sure of the conditions.
 

Pierre

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@Pierre : Jumbo Jim is a horrible tire. It is light, as low rolling resistance, but has no traction for propulsion or cornering.

with an E bike, rolling resistance is not your concern, traction is.

Wazia was better( every fatbike tire is better for traction than JJ, except Big Fat Larry), but not great. Disappointed a bit, neither better traction nor cornering nor faster rolling than Dillinger 5. I prefer D5, but fairly similar.

Get Surly Lou(pm me, I have a new one in box). And something similar for front.
If you have ice, get Johny 5.
I can think of a whole bunch of tires that are worse than the JJ's. Two things are a premium for me and they are rolling resistance and rotating weight. . Above all to me it's got to feel like a bike and pedal well without any power. Half of the time I have no power on the bike. I can ride it fine at about 12-13mph without power. That effects every level of power for bike range. In the 14-15 mph range I have well in excess of 100 miles of range. Probably closer to twice that. I am currently looking at a build with 2,800 Wh of battery for at least 250 mile range.
I don't do any gnarly single track anymore and most of our trails are hard pack. I don't have what it takes anymore so I have gone more towards the Dirt Touring/Bikepacking aspect of the sport. I am not exactly your typical fat biker. I have on the drawing board a Titanium mid/long tail fat touring bike weighing in at 90'bs. M620 mid drive, 750W @ 190NM of torque with Rohloff gears. It even has climate control, beverage cooling, motor cooling and battery temperature control. all reverse cycle. All packs are aerodynamic. I am an expert at building anything.

I have a pair of Maxxis Minion FBF & FBR sitting in the garage that I have not had on for the last three years. They roll better than most but weigh too much and don't quite roll good enough. The Wazia's roll surpisingly easy.
 

Ron

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I guess it really depends on the terrain you are riding. I dont think I get above 10 unless Im going downhill and only then on a few straight aways . its pretty much long sustained climbs here with a couple of miles traversing along the mountain then downhill on switchbacks. I would guess my avg overall is about 5mph.
 

Pierre

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I guess it really depends on the terrain you are riding. I dont think I get above 10 unless Im going downhill and only then on a few straight aways . its pretty much long sustained climbs here with a couple of miles traversing along the mountain then downhill on switchbacks. I would guess my avg overall is about 5mph.
My max of 10mph is usually with a wide path on a straight away. My average is probably 5-7 mph on packed snow. Around here is wicked short climbs. I ride much faster not on snow. As of late, 50% of my riding is on pavement.
 

firebanex

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Beyond pushing on the tire with my fist method, I have no idea what PSI I'm actually at. I don't have a gauge that reads below about 10psi. As mentioned, it's easiest to start higher and let it out as you get a feel for the ride and what pressure you may need.

Average ride speed is somewhere around 7.5mph according to my last few rides on strava, that said I have not had a solo ride to actually see what I ride at in decent trail conditions yet this year. I did finally bow down to everyone on the internet and my LBS and had them upgrade me to tubeless with a fatty stripper. There is a noticeable improvement in ride quality and perceived speed. After running the same tubes for two years, there was actually a bunch of rubber dust on them from rubbing against the tire casing. I would imagine that they were slowly falling apart from the friction.
 
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Ron

Seeking the next best ski
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One thing I failed to put into the PSI calculation is the loss of pressure when going from my 60* garage to the outside. I think with the new Gnarwhals, I am able to run a bit more air, I think (still working on it) that around 1.5 in the rear and 1 up front it about right..
 

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