# Afternoon project: BIG FAT DUMMY!!!



## Leopold Porkstacker (Apr 21, 2010)

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"  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&#8230; 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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## bacoes (Feb 27, 2004)

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...


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## Leopold Porkstacker (Apr 21, 2010)

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:


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## backcountryeti (May 21, 2004)

This is one of the most amazing things that I have ever seen! I have no use for something like this whatsoever, but boy do I want one! Nicely done!


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## buddhak (Jan 26, 2006)

Nothing exceeds like excess, LP. I salute you and those who boldly go where nobody has gone before. Good luck finding your way back...


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## Pigtire (Jan 13, 2004)

Looks like one of those earth mover tractors.:thumbsup:


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## vikb (Sep 7, 2008)

I wouldn't want to pedal those knobbies on pavement, but they do look lovely and monstrous!...:thumbsup:


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## gregclimbs (Sep 21, 2006)

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

cause it's working.

g


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## Leopold Porkstacker (Apr 21, 2010)

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:


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## scottybinwv (Jun 29, 2010)

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.


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## Plum (Sep 14, 2004)

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


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## carbontubulars (Dec 20, 2009)

That would be an awesome snow bike setup. I'm running 2.55 Weirwolf LT's, and they are pretty good. My rims are the new velocity P35s.


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## SelfPropelledDevo (Oct 2, 2005)

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


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## Plum (Sep 14, 2004)

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


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## SelfPropelledDevo (Oct 2, 2005)

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.


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## Leopold Porkstacker (Apr 21, 2010)

FINALLY had the chance to take the Big Fat Dummy out for a proper loaded ride today&#8230; 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:


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## SelfPropelledDevo (Oct 2, 2005)

hell-a-cool!
need pics!

dude, I think you just nailed a whole new gig for parents; being able to take their kids on a MTB ride!


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## Leopold Porkstacker (Apr 21, 2010)

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!  

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!!!


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## SelfPropelledDevo (Oct 2, 2005)

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


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## Plum (Sep 14, 2004)

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


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## SelfPropelledDevo (Oct 2, 2005)

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.


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## Plum (Sep 14, 2004)

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.
> 
> ...


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## SelfPropelledDevo (Oct 2, 2005)

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.


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## Leopold Porkstacker (Apr 21, 2010)

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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## gregclimbs (Sep 21, 2006)

he he he..

My 1fg (26er) just got swapped with a 1fg (29er) and I have this stans kit and mutano 2.4s sitting around.

And the thought that crossed my mind was "ya'know, in the spring I think I'll put the mutanos on the dummy and ride it off road..."

And like Devo, the dummy is rolling on the speedisc xls too...



Like minds and all that...

g


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## SelfPropelledDevo (Oct 2, 2005)

when you see something like this: http://forums.mtbr.com/showthread.php?t=674189

how can you not want a fat tired cargo bike

obviously thats a tandem, but you get the gist


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## Leopold Porkstacker (Apr 21, 2010)

SelfPropelledDevo said:


> when you see something like this: http://forums.mtbr.com/showthread.php?t=674189
> 
> how can you not want a fat tired cargo bike
> 
> obviously thats a tandem, but you get the gist


Leave it to the Belgian!!! (I am currently enjoying a 750ml bottle of Affligem Triplel!!!) :cheers: (hopes there's an emoticon for that one!)


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## Anthony King (Aug 29, 2010)

Leopold Porkstacker said:


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


Glad I found this. I ordered parts earlier this week to do the same project. Your pictures aren't working, so I can't see if this bike had a derailleur. If so, I assume the Razorback prevented you from getting to some of your rear cogs. How many did you lose access to b/c of the tire width?

To get into the nearest "big" town me and the kids have to ride a very steep, loose path for about a mile before we hit a rails to trails. I have BA's on my Dummy right now and we don't have enough traction plus I'm getting some complaints from the passengers about bumpiness. I'm hoping the Razorbacks will solve both problems.


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## Leopold Porkstacker (Apr 21, 2010)

Sorry, I used to host my images on my then-reliable .mac service account, but they end of lifed an otherwise useful service. I still need to find an image hosting service. Yes, running a rear derailleur. Zero clearance issues on a 2x9 drivetrain setup. I’ve since changed the tires to 2.5" Maxxis Hookworms since the bike sees fewer trail rides and more paved surface rides.


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## Anthony King (Aug 29, 2010)

Leopold Porkstacker said:


> Sorry, I used to host my images on my then-reliable .mac service account, but they end of lifed an otherwise useful service. I still need to find an image hosting service. Yes, running a rear derailleur. Zero clearance issues on a 2x9 drivetrain setup. I've since changed the tires to 2.5" Maxxis Hookworms since the bike sees fewer trail rides and more paved surface rides.


Are you running a true double? I have a 22-32-guard on a triple and I was rubbing in my lowest gear w/ 2.35 BA's (haven't taken calipers out to do a true width measurement). I had to space out my bb 2mm to the drive side to fix this.


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## Anthony King (Aug 29, 2010)

Well, that was underwhelming.

I received the Razorbacks yesterday. The good is that I like the tread pattern a lot and I think it will work well for my intended use.

But the main reason to drop to 24" was to get more volume. My Big Apples (26x2.35) measure 58mm in real life. I don't expect tires to correspond exactly to the stated width, but I expect them to be close. The Razorbacks (stated width 3.00") measure 65mm in real life. I'm using a 39mm rim (Alex DX32). 

I dont' think I could have used a larger 26" tire on the rear of my bike, so building the 24" wheelset wasn't a total waste. But I was certainly expecting to gain more than 7mm tire width.

I chose the Razorback over the Felt Berm Master 24x3.00 because of the tread pattern. The Razorback will certainly do better in mud and slop, but I'm going to try to find out what the real measurement is on the Berm Master and try those out if they get me more volume. The 24" tires are more about giving my kids a smooth ride on bumpy paths than anything. I'll try try to post some pics as time allows.


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## MooseCaboose (Aug 30, 2012)

*Nice, here is my BFD*

It took 2 1/2 years to build but its been rolling for awhile now. Just have to do a mod to my bikes at work trailer and I can haul anything. :thumbsup:

[/ATTACH]


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## MooseCaboose (Aug 30, 2012)

Here are the pics


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## SelfPropelledDevo (Oct 2, 2005)

wow that is so freaking awesome!


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## MooseCaboose (Aug 30, 2012)

Thank you! I LOVE IT!! so fun to ride...


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## SelfPropelledDevo (Oct 2, 2005)

MooseCaboose said:


> It took 2 1/2 years to build but its been rolling for awhile now. Just have to do a mod to my bikes at work trailer and I can haul anything. :thumbsup:
> 
> [/ATTACH]


do I see lights on the front rack?


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## MooseCaboose (Aug 30, 2012)

Look under the front rack right next to the fender, they are black and look like a big camera canister. I do have 2 Lupine betties with red rings to mount there, just have to figure out were to mount the battery and how to run the spitter wire with out looking crazy.


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## Leopold Porkstacker (Apr 21, 2010)

WOW!!! :thumbsup: Hello Surlybikes.com??? Are you guys paying attention???


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## Anthony King (Aug 29, 2010)

MooseCaboose said:


> Thank you! I LOVE IT!! so fun to ride...


That's my dream car.

What a magnificent beast. Even the kickstand is beautiful.


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## Anthony King (Aug 29, 2010)

Moose,

Do you know the trail measurement on your bike? Would you mind asking the builder if you don't know?

Putting the 24" wheelset improved the handling my lowering the trail. Especially when climbing something steep it is much easier to keep the front end tracking straight with reduced trail. This is even more pronounced on bikes with a front rack. Ideally, if the builder knows the bike is going to have a front rack either the head tube angle should be steeper or fork rake should be increased (either change reduces geometric trail).


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## Volsung (Nov 24, 2011)

Are marge lights strong enough to support a full cargo load?


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## MooseCaboose (Aug 30, 2012)

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


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## Yoreskillz (Feb 10, 2011)

I got to say again, that bike is all full of Winning Awesome!!! Someday I have to have a Big Fat Dummy or any flavor....


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## Leopold Porkstacker (Apr 21, 2010)

MooseCaboose said:


> 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.
> 
> ...


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!


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## tractopelle (Jul 20, 2012)

This is a gorgeous ride!
Congratulations!


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## Fat Bob (Mar 5, 2004)

Amazing!


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## tractopelle (Jul 20, 2012)

Do you have a dynamo hub? I'm wondering if large marge can be installed with a dynamo hug...


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## MooseCaboose (Aug 30, 2012)

I don't have a dynamo on this bike but I do on 2 others and the one is a Supernova laced to a L.M. And it works great.


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## tractopelle (Jul 20, 2012)

Thanks a lot, that's perfect!


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## tractopelle (Jul 20, 2012)

What is that fork up mount? Is it available somewhere?
Thanks.


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## NOBBY605 (Apr 12, 2008)

Absolutely beautiful...full props on this!!!!:band:


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## 2:01 (May 10, 2010)

Just bumping this up. I'm having thoughts of going fat(ter) on my Big Dummy. Leopold - Your pictures don't show up. Mind putting them back up? I'd like to see what the clearance is like. Some 26x3 Knards or DW's would be pretty cool back there. Would offer my kid some cush as well.


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