Author Topic: New Tubus Carrier Rack for Fat Bikes  (Read 1155 times)

Andre Jute

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New Tubus Carrier Rack for Fat Bikes
« on: April 26, 2016, 01:19:00 AM »
Fat bikes, until now intended for snow and mud and therefore fitted with great big fat knobbly tyres, don't seem like much of a touring choice, except for entirely off-road tours. But Tubus has made a rack especially for fat bikes, which appears at a quick glance to be a touring rack, complete with pannier rails and a solid rear lamp bracket. You can see it at http://www.tubus.com/product.php?xn=83.
More info: http://www.tubus.com/info.php?xn=83
Mounting instructions: http://www.tubus.com/documents/1434353156_FAT_MA_12062015.pdf
Accessories: http://www.tubus.com/zbh.php?xn=83
Photo, fitting instructions and crucial measurements at the links.
Dimension drawing: http://www.tubus.com/documents/1415957461_FAT_449010-001_BM.pdf
[Thanks to Dan for the links.]

Takes tyres up to 122mm wide, inner mounting width adjustable between 205 and 235mm.

I presume one can bend the steel uprights to fit narrower rear axles, and then you would have a good wide rack frame; it wouldn't bother me that the central load area is not filled in -- I'd rather see that as an advantage, as one of the crossbars on my present Tubus rack creates an objectionable protrusion into every single rackbag I own.

The reason I mention adapting this new wide rack is that I have long been dissatisfied with the mean width of standard Tubus racks, like my stainless Cosmo, which might look good on a road bike but on a balloon-tyred bike, like most touring bikes these days, simply looks skimpy and is definitely suboptimal in use (and that's before you even get to Tubus cheap practices of gouging customers for necessary fittings like bolts (!), and then gouging them some more for extension sets that should be included in the price). As for the popular Fly, to me it looks like a schoolboy's tie scissored off an inch under the sloppy knot because the headmaster has made a tie compulsory...

The Fat Tubus looks the business and will very likely do the business.
« Last Edit: April 26, 2016, 03:21:03 AM by Andre Jute »

Danneaux

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Re: New Tubus Carrier Rack for Fat Bikes
« Reply #1 on: April 26, 2016, 01:56:22 AM »
Quote
...I have long been dissatisfied with the mean width of standard Tubus racks...
<nods> I too found the top deck on my Tubus Logo Evo too narrow, so I modified it.

Sunday morning project: The top deck on the blue rando bike's Tubus Logo Evo rear rack is too narrow to properly support my day-ride rack pack, so I made a solid deck out of a thin sheet of DuPont Zytel ( http://www.dupont.com/products-and-services/plastics-polymers-resins/thermoplastics/brands/zytel-nylon.html ) intended for another sort of use on a different kind of rack. It is clamped with 10mm P-clips and stainless buttonhead machine screws with nylock nuts and also fits the Ortliebs on the lower rail without interference. The rack pack sits *solidly* now with nary a wiggle -- yay!

If one wishes for a wider Tubus, the original Cargo Classic and more recent Cargo Evo are much wider (120mm) than my Logo Evo (85mm-99mm, tapered front to rear). The Tubus Fat rack is 162mm wide. In comparison, My Nomad's Thorn EXP rear rack measures 132mm across the top deck, while the Surly Nice Rack (Rear) mounted to my tandem is 160mm wide across the top deck. It nicely fits my tandem's 145mm OLN dropouts.

All the best,

Dan.
« Last Edit: April 26, 2016, 02:01:16 AM by Danneaux »

mickeg

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Re: New Tubus Carrier Rack for Fat Bikes
« Reply #2 on: April 26, 2016, 02:11:40 AM »
...

Dimension drawing: http://www.tubus.com/documents/1415957461_FAT_449010-001_BM.pdf

[..., inner mounting width adjustable between 205 and 235mm.

I presume one can bend the steel uprights to fit narrower rear axles, and then you would have a good wide rack frame; ...

Generally you can bend steel to some degree, but I would be hesitant to bend this rack too much.  There are two tubes that extend upwards from each plate that attaches to the frame at the dropout, the forward of those tubes is attached at its upper end to the horizontal piece that serves as the lower pannier support bar, and bending that tube inward could put undue stress at the weld where those tubes meet.

I bent a Surly rack to fit my Nomad better, the Nomad has those screwy little fittings that convert the rack mounts from M5 to M6 bolts, and those fittings add a lot of width to the lower rack mounts which is why I had to bend the rack to fit better.  But the tubes that extended up from the bottom of the Surly rack were continuous and did not end part way up at a weld like they do on the Tubus.  Also, I only bent the Surly rack by maybe 20 or 25mm.  If you wanted the bend the bottom of the Tubus to fit a normal bike with a 130 or 135 dropout spacing, you would likely be bending it by 50 plus mm.

If you want to risk it, go ahead, but I suspect that the warranty will not cover bending the rack to fit a normal bike.  And even if the rack appears to take the bend just fine, the capacity of the rack might be reduced.

mickeg

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Re: New Tubus Carrier Rack for Fat Bikes
« Reply #3 on: April 26, 2016, 02:17:26 AM »
Quote
...I have long been dissatisfied with the mean width of standard Tubus racks...
<nods> I too found the top deck on my Tubus Logo Evo too narrow, ...
All the best,

Dan.

I like the narrow Logo EVO, but I only use it for touring with panniers.  I think that the narrow top adds to the rigidity.

As soon as I get home from a trip, the Logo comes off and a different wider rack goes on.  The Nomad around home has a Surly rear rack, the Sherpa has a Zefal (I do not recall the model), my new rando bike has a RackTime AddIt rack.

Bill C

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Re: New Tubus Carrier Rack for Fat Bikes
« Reply #4 on: April 26, 2016, 02:29:15 AM »

while the Surly Nice Rack (Rear) mounted to my tandem is 160mm wide across the top deck. It nicely fits my tandem's 145mm OLN dropouts.

All the best,

Dan.

yup got two of the surly Nice rack's 160mm and fully adjustable for height makes it a good choice for a carradice support ;) ,
wish they had lower pannier rails as well though, still think the nice rear rack is a bit of a rip off as the nice front rack is way more rack for the same price tag,have you seen the bag of fittings for the nice front rack?

Danneaux

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Re: New Tubus Carrier Rack for Fat Bikes
« Reply #5 on: April 26, 2016, 03:56:22 AM »
Quote
...the nice front rack is way more rack for the same price tag,have you seen the bag of fittings for the nice front rack?
<nods> Agreed, Bill, but had to sell mine on,due to lateral instability. The brackets are a delight for vertical loading, but proved to be too thin to support a heavy load without swaying unduly for me. I seem to be alone in this, but it happened and made it unsuitable for my needs.

For that matter, the Surly Rear rack proved the least resistant to lateral loads in my instrumented tests. The culprit was the squashed-tube lower and upper mounts. Capturing the ends between large-diameter washers definitely increased resistance to lateral deflection. Similarly, brazing up new mounts with machined spools at the bottom helped even more.

The Thorn EXP rear rack had the greatest lateral stiffness of the four racks in my tests, then a Tubus Logo Evo followed very closely by a Cargo Evo and then the Surly Nice Rack (Rear).

For testing, I mounted the racks in turn to a single bicycle with very beefy seatstays and chainstays, then used a digital luggage scale to apply a traction side load to the upper-rear corner of each rack (in each case the same distance from the dropout mount so the moment-arms were identical) and noted the lateral deflection of each in mm. I then repeated the tests tugging on the corner of the top deck. I wish I had kept the precise figures ready to hand. I still have them, but misplaced. Between the Tubii, the Logo Evo was stiffer than the Cargo at the lowered bag mounts (due to a shorter span of tubing). the Cargo Evo had better less lateral movement than the Logo Evo at the top deck, thanks to the more angular plan-form of the last strut, which had better bracing angles.

I borrowed a friend's Tubus Cargo Classic to compare and found it marginally more flexy than the Evo version. The Classic uses a lower mounting tang made of stamped sheet steel, while the Evo series uses an investment cast 3-D mount with recessed well for the mounting bolt, but at the expense of a second mounting point for rear mudguard stays.

I kept the rear Surly for mounting to the tandem because I already had the rack and the tandem is built with an unusual design that precludes ready mounting of most rear racks. As it was, I had to trim a bit of the rack tubing at the lower forward flare to gain adequate clearance (No longer in production, this bike, has seatstays and chainstays that form a continuous, very large-diameter "hoop" and there is minimal clearance -- ~1mm -- between a vertical rack mount and the seat-chainstays). For that application the Surly Nice Rack (Rear) is about the only ready-made option. I brazed my own racks from cro-moly steel for my folder, but it is a time-consuming operation. Lots of bends and miters to make, but quick to braze once you have built a fixture to hold all the tubes in alignment.

Best,

Dan.

Bill C

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Re: New Tubus Carrier Rack for Fat Bikes
« Reply #6 on: April 26, 2016, 04:38:09 AM »
Dan
i have never been as in depth as you are, i'm glad someone is though as I always know who to listen to ;)
 i just bought the nice front n rear racks from purely a utility point of view, they looked like they'd cope with loaded touring shopping as i'll probably do more of that than anything else
the rear i liked the fact i could trim the height and the front was purely as it had a decent size  platform and a light mount at the front so my cape never get's in the way as it would with a bar mounted light,
I also like the fact i can get rear panniers on the front and being able to mount the front panniers higher if needed
traded some strength for practicality but it's been a  good choice so far

Danneaux

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Re: New Tubus Carrier Rack for Fat Bikes
« Reply #7 on: April 26, 2016, 06:24:28 AM »
Agreed! The Surlys are nice, good racks and I like many of the same things about them you do. I think the shape of the rear one is among the most attractive I've seen, I like the hardware package itself very much, and I am really taken by the closed return at the frame end of both the front and rear Surly racks.

They also have a very durable, thick powder coat that so far has been much more durable (along with the Thorn) for me than the Tubus'.

Having a front platform *and* low rider mount adds a great deal of versatility.

I think this just goes to show that like bikes, no single rack works equally well in all circumstances or for everyone. My expedition needs and loads are sometimes atypical, so my choices are also.

Though I've eventually broken every single triangulated aluminum-rod rack I've used for extended loaded touring on rough roads, they are often my first choice for lesser loads on paved roads, when it just isn't necessary to use a heavier, sturdier steel-tube model. Another case of horses for courses.

All the best,

Dan.

mickeg

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Re: New Tubus Carrier Rack for Fat Bikes
« Reply #8 on: April 26, 2016, 04:05:17 PM »

while the Surly Nice Rack (Rear) mounted to my tandem is 160mm wide across the top deck. It nicely fits my tandem's 145mm OLN dropouts.

All the best,

Dan.

yup got two of the surly Nice rack's 160mm and fully adjustable for height makes it a good choice for a carradice support ;) ,
wish they had lower pannier rails as well though, still think the nice rear rack is a bit of a rip off as the nice front rack is way more rack for the same price tag,have you seen the bag of fittings for the nice front rack?

I used to use the Surly front and rear for touring, but I really did not like the weight.  I eventually gave my front Surly rack to charity and use the Tubus Ergo on the front.  I tour with the Tubus Logo EVO on the back and as noted above use the Surly rear rack around home where I like the wider platform.  Sometimes around home I use a rack top bag, at those times the Surly performs very well.  I think the Logo is more rigid than the rear Surly. 

For touring I like the narrower platform of the Logo because it makes the outside width of the panniers at the rear a bit narrower.  And for touring, anything I put on back (in addition to panniers) sits on top of the panniers and does not sit directly on top of the rack itself, thus there is no disadvantage of the narrower platform.

My Surly front rack (before I got rid of it) was 1,382 grams, the Ergo is only 570 grams.  And on the rear, the Surly rack is 1,100 grams, Logo 860 grams.  So most of my rack weight reduction was getting rid of the front Surly rack, the rear Tubus does not save that much over the Surly.

I was really surprised when I put the Surly on my Nomad the first time, the Thorn fittings that adapt the rear dropouts from M5 to M6 bolts mean that the rack lower mounts has to span about 175 or 180mm.  Those fittings are the stainless fittings in the attached photo, you can see how wide they are.  And the rack is really stiff which made it hard to get on.  I managed to get it on the bike with just muscle, but later when I took the wheel out I had trouble getting the wheel back in because the rack was squeezing the frame stays and dropouts inward.  I eventually got around to cold setting the bottom mounts on the Surly rack to a wider width, but I did not stretch it all the way because I might want to use that rack on a different bike some day.

The Tubus Logo did not need any cold setting to fit it on the Nomad M5 to M6 adapters, the metal was flexible enough to fit quite easily.

Andre Jute

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Re: New Tubus Carrier Rack for Fat Bikes
« Reply #9 on: April 27, 2016, 03:18:19 AM »
...

Dimension drawing: http://www.tubus.com/documents/1415957461_FAT_449010-001_BM.pdf

[..., inner mounting width adjustable between 205 and 235mm.

I presume one can bend the steel uprights to fit narrower rear axles, and then you would have a good wide rack frame; ...

Generally you can bend steel to some degree, but I would be hesitant to bend this rack too much. 
.......etc

Thanks, George. I'll give it a miss, then.