Max tire size on Juggernaut Ultra FS fatty rims?

Slayer33

New Member
Hi All,

I'm curious to know what the max tire size is for the Juggernaut Ultra FS Fat tire version?

I know it comes with 26x4.0, but can a 4.8" tire fit within the frame and rim?

Thank you in advance!
 

lordnox09

Member
I have not tried to change yet but I contacted support and they said the biggest the rims will fit is 4" so if you want bigger treads you will need to buy new rims still thinking of asking my lbs what they think
 

lordnox09

Member
Hi All,

I'm curious to know what the max tire size is for the Juggernaut Ultra FS Fat tire version?

I know it comes with 26x4.0, but can a 4.8" tire fit within the frame and rim?

Thank you in advance!
I just ordered the Terrene Cake Eater 120tpi 4.0 studded tires for this winter commute coming up
 

lordnox09

Member
So after doing some research you should be fine with up to 4.6-4.8 tires was looking at some charts for the rim size of 85mm and all say good up to 5" but says you should go in the middle for a better fit
 

AHicks

Well-Known Member
It's not just rim size (which I agree would be OK). It's also about clearing the frame, the forks, even the chain when in granny gear.

Point being, I think this is an answer you would want to get right from Biktrix. What they have seen work.
 

lordnox09

Member
We'll both are stated for 5 for front fork and rear it was just the rim size issue that we where having
 

lordnox09

Member
Chain could very well be an issue though didn't even think of that issue lol I purchased a set of studded cake eaters that are 26x4 120 TPI. So I will wait for next summer to try anything else hopefully one of you try before me so I know for sure lol but frame and chain are a good distance away from tire I will have to check the clearance at the chain when in "granny gear"
 

Deafcat

Active Member
Ultra FS tire size I think depends which year. Older ones may only clear 4", but they might have updated 2020 model for bigger tire clearance.

If it were me, and I wanted to fit the biggest fattest snow tires, I'd do it on the Ultra 1000 (the hard-tail). more clearance when not dealing with rear suspension. Most serious fatbike snow-riders run hard tail frames for a variety of reasons, and tire clearance is one of those reasons.
 

Beebad

New Member
I have the Ultra 1000 Hard tail and put Maxxis Minion 4.8" on it. I believe the rims that come with the bike are 80mm and with that size rim the tires measure about 4.375" wide. To get 4.8" I think you have to put the on 100mm rims. Anyway, the MM 4.8" tires have much larger knobs on them and look a lot bigger. Very happy with them! This doesn't answer the question about the J 1000 FS though.