Jumbo Jims; "performance" line

Where to ask questions on riding skills, training, nutrition, and bike repair

Re: Jumbo Jims; "performance" line

Postby bbender785 » January 23rd, 2020, 3:45 pm

yeah i ran the JJ 4.8's a couple winter ago and hated them in the snow. built these up for everything but snow.
>>>RAD
User avatar
bbender785
 
Posts: 276
Joined: December 12th, 2012, 11:48 am
Location: Dutton, MI

Re: Jumbo Jims; "performance" line

Postby Steve_Balogh » February 23rd, 2020, 9:16 am

Interesting thread, but what is not being considered is the Rabbit Hole rims. I ran a set of those with Husker DU’s one summer several years ago. I did quite well with that in a gravel grinder in Chelsea. But on the trail, that narrow rim width takes out some of the bite of the side knobs and can make some tires a bit squirrelly. One of my pet peeves about Fatbike tires is the MFG’s never indicate the rim width they are shooting for; only the range that the the tire will work on. I’ve gone through many types of tires on 50, 65, 70, and 90 mm rims and rim width does effect performance.

If the 4.0 JJ’s do not work out, some of the Vee Rubber offerings might work better because a common complaint is the lack of knobs. On skinny rims they might work better, but depending on the tire you will pay a huge weight penalty.
If the JJs don’t work, try some of the Bontrager tires. I’ve used the Rougagrous, but liked the JJ 4.0 better. The tread on that one is pretty uniform, might work on 50MM rims nicely.

I used the 4.0 JJ’s on 65MM Nexties for a couple years for summer use. I prefer running 4.8’s on 90MM Nexties nowadays as I’m mostly on sandy trails. This last week my 65’s now have the new VAN Helgas on them. With so many groomed trails up here in TC floatation is not always necessary in winter, which is something I’m not used to having lived downstate all my life. I do have trails around me not groomed that I did out the Triple B for, on the opposite end of this spectrum.
User avatar
Steve_Balogh
 
Posts: 1445
Joined: June 22nd, 2002, 7:29 pm
Location: Almira TWP /Traverse City

Re: Jumbo Jims; "performance" line

Postby c0nsumer » February 23rd, 2020, 9:27 am

I think these days tires are pretty much designed around ~80mm rims. Outside of custom builds -- which are overall pretty rare -- manufacturers seems to have settled on that.
Steve Vigneau
CRAMBA-IMBA Treasurer

Unless otherwise stated the content of my posts are my opinion and should not be taken as the official stance of, nor representative of, CRAMBA-IMBA.
User avatar
c0nsumer
 
Posts: 7724
Joined: May 18th, 2008, 11:35 am
Location: Shelby Township, MI

Re: Jumbo Jims; "performance" line

Postby Steve_Balogh » February 23rd, 2020, 11:17 am

c0nsumer wrote:I think these days tires are pretty much designed around ~80mm rims. Outside of custom builds -- which are overall pretty rare -- manufacturers seems to have settled on that.



I agree. Try a Specialized Fast Track on a 65MM rim, then an 80. Super skinny and real tall on a 65 but perfection on an 80. Funny, that Ven Helga set I bought is 4.2 wide, but still works great on a 65. I may at some point replace my 65’s. The reason I’ve kept them so long is the deep V shape is awesome keeping mud and snow from piling up.
User avatar
Steve_Balogh
 
Posts: 1445
Joined: June 22nd, 2002, 7:29 pm
Location: Almira TWP /Traverse City

Previous

Return to Tips, Training & Techniques

Who is online

Users browsing this forum: No registered users and 9 guests