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Afternoon project: BIG FAT DUMMY!!!

39K views 51 replies 19 participants last post by  2:01 
#1 ·
I decided to see how simple/involved it would be to run 26"x3.0" Duro Razorback downhill tires with freshly-built 65mm wide Surly Large Marge rims on my Big Dummy. Wow, many hours, and a busted thumb, thanks to one bad swing with a hammer.

Image #1: how lame does the stock 2" wide Schwalbe Big Apple look mounted onto a 65mm wide Large Marge rim?


Image #2: 26"x3.0" Duro Razorback tire mounted on Large Marge rim (looks more appropriate)


Image #3: I cut the front cantilever bosses from the fork, and test fit the Razorback mounted to the Large Marge rim. No clearance problems whatsoever!!! :thumbsup:


Image #4: another angle of the front fitment


Image #5: now the "fun" :rolleyes: part, shoehorning that fatass tire/rim combo in the back, there is only 5/16" of room between the tire and the bottom bolt hole (I had to remove the bolt for the tire to fit)


Image #6: I know, I know, the paint colour doesn't match 100%, but it's such a small area, and I was in a hurry, you know


Image #7: have hammer, will whack-less than 3/32" space here, should be interesting at times when riding


Image #8: holy crap that thing is HUGE!!!


Image #9: crapola, it was getting dark and late, I will have to finish up tomorrow, but the good news is that several test rides have confirmed that this actually works without any major issues… other than not being able to use the two largest cogs on the cassette but I figured that out before going the fat route


I have a bunch of cool iron-on patches I want to put on my FreeRadical bags before I put them back on the Freeloaders, hopefully I will be able to tackle that part first thing tomorrow morning. :skep:
 
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#42 ·
I know the Marge Lites are strong enough to hold huge loads. I have run 400lbs on the bike so far hauling lumber with the wide loaders/long load apt from xtracycle about 15 miles a couple times while doing home improvement projects. I also run the ML on 3 of my Mt Unicycles and it is a very durable rim. Surly does a very good job on there rims and test them with out holding anything back. I know they will be fine.

The red mount on the back is a fork up mount that I use for bikes and my BOB trailer.

Below is also the dual vented break

Tire Wheel Bicycle wheel rim Bicycle Bicycle accessory


Tire Wheel Bicycle tire Automotive tire Bicycle wheel rim


Bicycle tire Bicycle wheel rim Blue Bicycle part Bicycle frame
 
#44 ·
I know the Marge Lites are strong enough to hold huge loads. I have run 400lbs on the bike so far hauling lumber with the wide loaders/long load apt from xtracycle about 15 miles a couple times while doing home improvement projects. I also run the ML on 3 of my Mt Unicycles and it is a very durable rim. Surly does a very good job on there rims and test them with out holding anything back. I know they will be fine.

The red mount on the back is a fork up mount that I use for bikes and my BOB trailer.

Below is also the dual vented break

View attachment 722009

View attachment 722010

View attachment 722011
Wooooooo baby, that is one sweet-ass fat cargo bike! I really really really (really REALLY) hope the folks at Surly are paying attention!!! :nono::madmax: I'd gladly sell my 2010 Big Dummy to help fund a 2013 (or thereabouts) Surly Big Fat Dummy if one existed. And that is a sexy colour yours is painted-I'd be happy with a colour such as that!
 
#3 ·
bacoes said:
Just out of curiousity, why?

Unless you're cargo-ing on really loose soil, wouldn't a slicker tire be more efficient. I mean, I get the larger volume but not the knobby...
Riding on dirty muddy trails with my boys of course! Besides, that extra rolling resistance makes for an excellent workout! :thumbsup:
 
#9 ·
The reason I went fat+knobby on the Big Dummy is because I have become accustomed to riding my Surly 1x1 11th Anniversary Edition with 24"x3" fat knobbies. The added rolling resistance has benefited my riding workouts. I like being able to blast down trails without slowing down for rocks and bumps, thanks to 12 - 20 psi being in the tires. These DH tires have extra girth where the sidewall hugs the outer rim lip such that the possibility of pinch flats or bead unseating is virtually eliminated. The following image illustrates how much larger in diameter the 26"x3" is as compared to the "small" 24"x3" (both rims are of the 65mm wide Surly Large Marge variety):



I had been running some "tiny" 26"x2.5" Maxxis Hookworms, here is how they look in a stack next to some 26"x3" Nokian Gazzaloddis and a 26"x3" Duro Razorback:


 
#10 · (Edited)
Awesome dude, looks like one of those custom moto hill climbers.

You got me thinking, what is the load capacity of the Big D? No wait, Surly site says 400lbs total rider and cargo, naught plus naught carry the naught.

If you put a wood platform on each side in the back I bet it could carry two 5 gal corny kegs of beer, or 4 (two per side). We must test this out!

Heck yeah it would work. A full corney keg will weigh about 45lbs x 4 = 180lbs + a small CO2 system and taps = right at the 200 mark.
 
#11 ·
I went back and forth for about a day on this, decided to go ahead and remove them. I figured I haven't used a cantilever stud for years, probably won't start with this bike either.. Turned out pretty clean after powder, probably could have done a little more work to try and clean up the remnants, but I didn't want to get into the actual tubing. I'm guessing once I resticker the fork, the mod will be invisible.

FWIW, I can't see ever needing the additional clearance, the wheels and tires here look like about 200% overkill, but I can appreciate the concept. That rear clearance looks like trouble though.

Plum

gregclimbs said:
you're just trying to make me kick myself for not removing the canti studs before powdercoating right?

cause it's working.

g
 
#13 · (Edited)
Plum said:
I went back and forth for about a day on this, decided to go ahead and remove them. I figured I haven't used a cantilever stud for years, probably won't start with this bike either.. Turned out pretty clean after powder, probably could have done a little more work to try and clean up the remnants, but I didn't want to get into the actual tubing. I'm guessing once I resticker the fork, the mod will be invisible.

FWIW, I can't see ever needing the additional clearance, the wheels and tires here look like about 200% overkill, but I can appreciate the concept. That rear clearance looks like trouble though.

Plum
as to the canti bosses, I've kept them on my BD. The main reason(s) are to use the bosses for stabilizing a rack. i.e. Old Man Mountain.

While I also ride a Pug, when Surly was initially doing their prototyping, I had asked, and was highly hopeful that the BD would be spec'd to accommodate LM's

which interestingly enough, somewhere in the Surly Spew, the 24" LM's would fit the BD, shod in 24" Endos...

the main issue with 24" wheels, on the BD, and/or a combo of 26/24", is the BB height/change in the fork rake...

as to "why"... in my personal experience... I'm on my 3rd wheelset with my BD.
what happens is that you get this killer cargo bike... and if you start to use it in a Car Free/Car Lite Lifestyle, you start to become obsessed with hauling big stupid loads, like tool boxes, a 1/4 cord of fire wood, furniture, etc... incidentally wheels get bent.

the obvious Surly Answer are LM's

but why Surly avoided spec-ing the BD to accommodate 26" LM's is beyond me.
what Surly did for the en mass Fat Bike movement with The Pug
they can easily do the same with the BD and Cargo Bike scene

when I got my BD, and still to this day, the passing comments usually are, "Nice XtraCycle"

I'm not a marketing genius, and maybe Surly purposely intends to align their product so closely to X
it would seem to me that by making the BD compatible with Endo's, arguably Surly's most spotlighted product, that a Fat Dummy would be obvious. There'd be no mistaking a long tail cargo bike with Endo's and know its a BD.

however... as I've been on my BD for a couple of years now, settling on a set of WTB LaserDisc DH, and now shod in WTB MutanoRaptor 2.4's, I have come to re-experience the wide range of standard 26" MTB tyres, from Sefras Drifters to WTB Vulpines, and all the gears are accessible, yes... at times I do like 22x34t
 
#14 ·
SelfPropelledDevo said:
as to the canti bosses, I've kept them on my BD. The main reason(s) are to use the bosses for stabilizing a rack. i.e. Old Man Mountain.
This was my main consideration with losing them, but I threw caution (and steel cuttings) to the wind and hacked them off in the name of a clean looking setup. I figure, most heavy stuff will be in the back, if I ever end up with a front rack, I'll try to keep the weight down up there. Also, if push really comes to shove, replacement BD forks are pretty cheap..

Plum
 
#15 ·
Plum said:
This was my main consideration with losing them, but I threw caution (and steel cuttings) to the wind and hacked them off in the name of a clean looking setup. I figure, most heavy stuff will be in the back, if I ever end up with a front rack, I'll try to keep the weight down up there. Also, if push really comes to shove, replacement BD forks are pretty cheap..

Plum
no doubt, and there is always the use of P-Clamps.

btw: I'm really digging the Fat Dummies!

I'm just jealous.
 
#16 ·
FINALLY had the chance to take the Big Fat Dummy out for a proper loaded ride today… well, by loaded, in this case it was with my 4.5 year old in the Xtracycle PeaPod seat mounted atop the deck. I made sure to ride on the muddiest terrain I could find along the local trails. As expected, the rolling resistance was more than with either the tiny-ass 2" Schwalbe "Big" Apple tires as well as the properly-sized 2.5" Maxxis Hookworms, but going through mud, gravel, and loose soil was almost effortless. Did a 20 mile loop with approximately 700 feet of altitude gain, with a couple slightly steep gravelly/rocky sections. My son loved the ride, he likes the oscillations going through his spine from the knobby tires when we're on the pavement. On the dirt, man, this thing tracks amazingly sure-footedly. Goes through squishy mud pockets without any noticeable washout/understeer. Awesomeness!!! The really convenient thing about having such minimal clearance on the back part of the Big Dummy frame to the tread of the rear tire is that it sort of "automatically" cleans the mud off the tire! :thumbsup:
 
#18 ·
Yep, I’m a big pussy. I rode all the way to Los Altos Hills from the Almaden Valley area a couple days ago, loaded up with a couple large produce boxes filled up for a trade. Approximately 30lbs. of stuff (including an ice-filled cooler with a couple 750ml bottles of Belgian ales, and some organic butternut squashes). Seeing as it was ever so slightly uphill to Los Altos Hills from where I started from (a mere 17.2 miles away), with these MONSTER BEAST-ASSED HEAVY 26"x3" Duro Razorback DH tires, the ride was fully aerobic the entire distance. On the ride back, the resistance was about the same (traded the above listed goods for a crapload of backyard persimmons), however, the ride was mostly downhill. The ride seriously schooled my ass, but then again I was trying to maintain a 14MPH average speed, which, when loaded as mentioned, takes a bit of doing. I honestly have no idea how much the whole setup weighed, but I felt as though I’d been riding up the hills all day, even though I only gained a couple hundred feet of altitude through the entire ride! :eek:

So, yesterday, I pussied out, and replaced the heavy-assed DH tires with some plenty-capable 26"x2.5" Maxxis Hookworm tires… of course I am still using the 65mm wide Surly Large Marge rims!!!
 
#19 ·
dude: I totally understand. I've had my Pug for 5 years now and have a lot of time on those Endos, and to top it off the LM's that I have are the older 36h DH versions. I think it was sometime in March when I rode The Pug about 95 miles in around 6 or 7 hours. its a lot of work.

on the BD, at the moment, I'm using a set of WTB Mutano's in 2.4" on WTB LaserDisc DH.
last wednesday I hauled about 100lbs of tools, parts, etc... to wrench on a couple of bikes. Mutano's handle it no problem.

climbing up Carmel Hill, is at least 500ft.
returning at over 35mph on knobs... no problem.
the upshot about Mutano's is the center line in the tyre.
http://connect.garmin.com:80/activity/embed/59393992
 
#21 ·
Plum said:
I think I'm going to use those same rims on my dummy Devo, pretty cheap, wide and stout. Was thinking about some Nano's maybe, good street/hardpack tires, no idea how they wear though..

Plum
nano's are great tires.
give em a shot
out of all the tires, I haven't tried them on the BD.

they are a bit on the grippy side

I've used them on my Hunter 29er and put a bunch of paved miles on them between jaunts in the dirt. They are like riding on Velcro.

the Mutano's while being 2.4" are pretty damn big, about as big as you can get if you run a rear fender.

the knobs are large.
the center line knobs are large and sturdy enough to let the bike get UP onto the center section.

nano's are similar, but not as much. its the shape of the tire.

nano's are more rounded
while Mutano's seem to have more of a "V" shape

I keep meaning to convert the LaserDisc DH rims to tubeless.

Nano's handle stans well.
Vulpines are a bit on the thin side, they tend to leak for a few days until the latex totally seals things up.

I'm thinking Mutano's will be a kin to Nano's in that their sidewall has more rubber than Vulpines.

blah blah blah... the LaserDisc DH rims are a solid choice. + you can use any of the gazillion 26" tires on the market.
 
#22 ·
Rumor has it that WTB will be releasing the Nano's in a TLR tire, ready for conversion. I've read mixed reviews on the current crop of Nano's tubeless, busted beads and such.

JP

SelfPropelledDevo said:
nano's are great tires.
give em a shot
out of all the tires, I haven't tried them on the BD.

they are a bit on the grippy side

I've used them on my Hunter 29er and put a bunch of paved miles on them between jaunts in the dirt. They are like riding on Velcro.

the Mutano's while being 2.4" are pretty damn big, about as big as you can get if you run a rear fender.

the knobs are large.
the center line knobs are large and sturdy enough to let the bike get UP onto the center section.

nano's are similar, but not as much. its the shape of the tire.

nano's are more rounded
while Mutano's seem to have more of a "V" shape

I keep meaning to convert the LaserDisc DH rims to tubeless.

Nano's handle stans well.
Vulpines are a bit on the thin side, they tend to leak for a few days until the latex totally seals things up.

I'm thinking Mutano's will be a kin to Nano's in that their sidewall has more rubber than Vulpines.

blah blah blah... the LaserDisc DH rims are a solid choice. + you can use any of the gazillion 26" tires on the market.
 
#23 ·
Plum said:
Rumor has it that WTB will be releasing the Nano's in a TLR tire, ready for conversion. I've read mixed reviews on the current crop of Nano's tubeless, busted beads and such.

JP
I've read similar things.

however, I haven't had any problems with the 29er set that I've had for 2 years, and recently I ran them tubeless on CrossMax with Stans for about 3 months... so that would be at least 2k miles.

I will be looking forward to the tubeless bead, but I've also become very adept to handling the current setup.
 
#24 ·
Well in the meantime, all the trails around here are sloppy mucky stuff or just plain closed, so I think the 26"x2.5" Hookworms will be serving a purpose this winter. Bummer, I really liked taking the 26"x3" Duro Razorbacks on the muddy stuff.
 
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