[htrdoug]

I have 2 fatbikes,a Corvus and a Wo, the wheel sets are 70mm Blizzerk in 27.5 and the stock Mulefuts in 26 from the Wo. Dropouts changed on the Wo so that both are 197 rear throughaxles. Wheels interchange between bikes no problem as both have the same size discs.
I also have another set of hubs to buildup but can’t decide on rim size. I will stick with alloy rims so I can put the money into tires and even though we don’t get good snow here I think I would like to splash out for studded tires so If I do a winter road trip up north I will equipped(studded tires much cheaper than emergency rooms)
But I can’t seem to decide on which to build up,27.5 or 26. I realize it really doesn’t matter much as any studs will do the job but I just need a nudge, Is there a better choice in studded tires in one size vs. the other?
The tires I run right now are the 27.5 Van Helgas and the stock Jumbo Jims from the Wo (2016 so I should really think about replacing them too,self steer seems to come in below 8 psi even in snow, likely from age? )

BTW,both bikes will accept 4.8 with room to spare front and rear.

 

[Mk3Rider]

Whats studded tire do you want to run? You will be limited on selection on the 27.5" rim.

With that noted, i run 27.5 x 3.8 Gnarwhals studded on 65mm rims. I also run 27.5 x 3.8 hodags on the second wheelset on 65mm rims. This covers 95% of the riding in Minnesota. The second fatbike I run 26 x 5.05 on 105mm rims. This covers the other 5% of the riding.

When you need studs, you usually don't need huge tires. As most surfaces are rock hard and fast.

I personally like the larger overall wheel diameter of the 27.5 fat over the 26" fatbikes I've had previous. I come in at 6'1" tall if that helps.

Since you have two bikes, maybe have one ready in the winter months for ice and hard pack. Then have the second bike ready with as wide of a tire as you can get for the soft snowy days. Just a couple of thoughts, as this is the conclusion i've come to after playing fatbike for the past 10 years or so.

 

[htrdoug]

Thinking either Gnarwhals in 4.5 27.5 or Johnny5. There is no such thing as grooming in our infrequent accumulations of snow so some float is needed.

 

[bitflogger]

I did have similar Farleys with 26 and 27.5, have or have had Hodags in the different sizes and the big Gnarwhals studded. I don't race and love how the biggest possible diameter and big knobby studded make so much possible. There's been more times with less than ideal fast riding.

With that experience and use I'd only do smaller diameter and faster fat bike tires if they didn't fit or I wanted to optimize for fast groomed or non-snow riding. If going to the big studded Gnarwhal is slower, not so slow that I can't do a group ride with most people.

 

[mikesee]

Thinking either Gnarwhals in 4.5 27.5 or Johnny5. There is no such thing as grooming in our infrequent accumulations of snow so some float is needed.

These are both readily available at stocking dealers. I have them on the shelf.

Not sure anything grips as well across a range of conditions as J5 studded.

But man -- if you don't need all that grip it's a lotta tire to push around.

I really, really like the 4.5" Gnar's. They feel more versatile, more sporty, than J5's by a longshot.

 

[htrdoug]

So gnarwhal might actually be enjoyable to ride more than just the rare snow dump? Sounds like the wise choice then. There is a small detail I like about the tread pattern over the aggressive 45 Nrth tires that should help if crossing muddy roots at a angle. Closest Trek dealer to me is a Amish bike shop, which would be a fitting place to buy “Bontrager” tires I think! Next closest Trek dealer is in a city which does not get my business due to their policies. I will give the Amish shop a call and see if I can order through them. I’ll just put them on the Blizzerk 70s I have right now at first. Thanks for the opinions. Next thread will be what to replace the Jumbo Jims with.

 

[mikesee]

So gnarwhal might actually be enjoyable to ride more than just the rare snow dump? Sounds like the wise choice then. There is a small detail I like about the tread pattern over the aggressive 45 Nrth tires that should help if crossing muddy roots at a angle.

Yes, they're actually pretty fun to ride. The rowdier the trail surface, the more you'll like them.

I like the siping, too.

They're not available to be ordered through Trek right now. Either your LBS has them already, or they don't.

If the latter, drop a line.

 

[CanmoreBruce]

I’ve only ridden the 4.5 Gnarwhal on borrowed bikes but I was impressed. I’d get a pair, but then I’d need another wheel set to put them on!

J5 is great at float and grip. But as they say, it’s a big tire to push around…Gnarwhal rolls speedier on firmer surfaces (or so I seem to remember).

 

[Jayem]

But I can’t seem to decide on which to build up,27.5 or 26.

I tested both a LOT before the ITI last year, doing hill-climb rides every other day and switching wheels for the training, having several timed sections, both more gradual and steeper.

I couldn't find one was faster than the other, objectively, as far as the times. The 27.5 is more weight to spin up, you spin up weight a lot on a bike, especially a fat-bike. It supposedly carries momentum better though over little bumps and so on. 26" is easier to spin up and doesn't feel like you have to work as hard to get moving, accelerate, etc. But as far as speed, neither were coming out on top. Where I found differences was 27.5 was definitely superior climbing, which seems to be due to the longer contact patch. This did not translate into more traction elsewhere though, the float was simply a function of tire and rim width, so a fatter rim/tire combo on 26 would outperform 27.5 for float/ability to ride in soft conditions...again except for steep climbing, where that went to the 27.5.