# Frame #4, You callin' me fat?



## G-reg (Jan 12, 2004)

My trusty Pugsley has seen lots of riding and racing in mostly poor conditions with mostly poor maintenance. So a new Fatty is in order. I'm excited about this one because the the fatbike has really matured quickly since 2008 when I picked up the Pug. So some newer awesomer parts and a good fit with some tweaked geometry should make for a nice North Dakota ride.



















Random thoughts that are starting to solidify:

I'm still finalizing some of the numbers, need to get some physical measurements of the wheels/crank/chainstays/front derail. Geometry is tweaked from my trusty Pugsley, steeper HT, much lower BB, shorter front and rear centers, shorter head tube. Using Hope's 170mm rear 135 front hubs for a symmetrical build.

I've been riding the Pugsley 1x8 using a truncated 10speed cassette. The smaller cogs turn into unusable hunks of ice in bad weather, and by spacing the cassette out you gain tire/chain clearance. This worked pretty well on the Pugsley with 80mm wide Rolling Daryls, but I'd like to gain back some gearing range. So I'm going to use a Direct Mount FD, Middleburn Duo cranks(27t-40t), and again a truncated 10s cassette. I should still have tire/chain clearance even with the wider rims and a nice fat gear range. I had to use a chain guide anyway, it might as well be a Front Derail doing the guiding. I'll "clock" the mount forward from Shimano's spec as Walt suggested in my #2 build thread to keep it away from that big ass tire. Speaking of tires and clearance, I'm planning on using a 45N Husker Du or Escalator 4.0 tires. Maybe a Surly Bud 4.8 out front. The BFL/LOU 4.8's are simply huge to squeeze into the rear end. I'd like to "future proof" this by building for clearance with those on a 100mm rim, but my gearing decisions and bending/dimpling/fabrication skills won't allow it.

I'm going to use 9zero7's Al fork. They make a nice short A/C version, many of the fat forks are made with swapping in a 29er suspension fork and are waaaay long. I have a 44mm ht to use and thought about trying to get a Fatback carbon fork or the Al Salsa Beargrease fork. But decided against it since the 9zero7 is pretty damn light, and uses a standard 1 1/8 steerer. The Paragon 44mm headtubes are pretty beefy, negating much of the weight savings of the Gucci forks. And the steerer isn't the weak link in goofy fat bike handling anyway.

Cable routing is full length run along the bottom of the top tube for the derailleurs and the top of the downtube for the rear brake. My preferred method of derailleur cable routing is exposed on the downtube, but the offset of the guide at the BB so the cables ran clean up to the front derailleur and down the chainstay would have been excessive. The under the top tube routing will keep the high point at the shifters and the low point at the derailleur, any crud wil migrate out the bottom. If I wasn't planning on running Avid BB7's for the brakes I would have the brake cable run under the TT as well. But the BB7's really need a chainstay cable for smooth routing. Maybe in the "road bike disc renaissance" some other cable operated options will surface. And no, I will not use hydro brakes. It gets cold here, and at the moment I only like Shimano hyd brakes and their mineral oil gets pissy at -40f. DOT based brakes do better as far as fluid viscosity, but the seals are still pretty angry at those temps.


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## Feldybikes (Feb 17, 2004)

Sounds like you made your decision (which sounds like a fine one to me), but FWIW, the True Temper 44mm HT is not all that heavy and is easy to get (Henry James).


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## davesauvageau (Jan 8, 2010)

Following another awesome G-reg thread!


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## G-reg (Jan 12, 2004)

Feldy, thanks I'll look into that for later builds. 

DaveSav, Ok Mr. Local Artist...Components are mostly black with some silver. What color should this frame and fork be? Thinking of talking to the Pro-Tech guy about something reflective over something dark. Stealth until lit up by the Snowmobile about to hit me.


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## davesauvageau (Jan 8, 2010)

G-reg said:


> Feldy, thanks I'll look into that for later builds.
> 
> DaveSav, Ok Mr. Local Artist...Components are mostly black with some silver. What color should this frame and fork be? Thinking of talking to the Pro-Tech guy about something reflective over something dark. Stealth until lit up by the Snowmobile about to hit me.


Metal flake turned out really nice in my green and he did the Star-Light clear over top. When light hits that flake it lights up like crazy! A metal flake charcoal would look really nice with those components. Did you have a color in mind? Are you going to do drilled rims with a reflective rim strip?


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## G-reg (Jan 12, 2004)

Dave, I used the black-reflective stuff in my Rolling Darryls and it turned out nice and has held up pretty good. So yea that was the plan for the Clownshoes too.

I got my Anvil 170mm dummy axle today. I snapped up the last one according to Don. It would have been a real bummer to go at this build without it. I feel like a goober looking down the Anvil price list and ordering a single 35$ part. Kind of like going into a Porsche dealership, looking over a GT3, buying a keychain and leaving. 

I was going through a box of random stuff earlier today and had things scattered about the work bench. When I added the axle to the bench I couldn't help but notice that the case of an airspeed indicator from a F-15C is exactly 170mm.


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## TrailMaker (Sep 16, 2007)

Boy Howdy;

I've only done one build, so I feel like I need all the "crutches" I can get my hands on, but I cant see doing ANYTHING without a dummy axle, no matter what. There are enough places to make mistakes without getting the DOs screwed up.

I'm a mega newbie machinist with little more than intuition and a little reading to go on (I'm not so good with reading it. I'm better at seeing it), and my machines have far more _personality _than a hack can get around, so nothing I make is remotely as nice as the Anvil bit surely is, or the 170 I got from Whipsmart Fabrication. However, I made a 135 dummy last week that will be very serviceable, thank you. Nice little project that I am fairly pleased about. Nothing like self reliance!

I look forward to following your build. Fat Rools.


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## Drew Diller (Jan 4, 2010)

G-reg said:


> Kind of like going into a Porsche dealership, looking over a GT3, buying a keychain and leaving.


Spoken from experience?... 

I hate going to my local composites store - we always have maybe a 20 minute conversation, and then I buy maybe a $20 tub of goop, and feel like a jerk. They like customers who leave with thousands of dollars worth of stuff.


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## G-reg (Jan 12, 2004)

Got the Jig set up today. Jig V2.0 will need some design work applied to my HT and ST mounts. The 100mm BB moved my centerline out a bit, the dropout mount was adaptable accurately. The way I made the other mounts I gave up some accuracy to space them out the 12mm needed to bring everything back to centerline.

This has to be a legit method of squarely spacing something 12mm right?


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## TrailMaker (Sep 16, 2007)

That's creative;

Likely more accurate than the extruded framing. Not sure it would be good enough for a GT3 though.


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## G-reg (Jan 12, 2004)

*Front Triangle*

A few pics from the front triangle. The first snow has already come and gone here in ND. I've probably sold off the Pugsley and got my entry into the Arrowhead 135, time to get this thing done!










Nothing mind blowing on the front end, similar to #3 in the tubing sizes and mitre angles. Brazed the mounts for full length derailleur housing front and rear on the top tube, brake cable down the down tube. I added most the brazeons prior to brazing the tubes together short of the DM front Derailleur mount. I'd like to get the FD mount brazed also, but I think I need some physical eyeball engineering to set the final position.


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## G-reg (Jan 12, 2004)

I've had little time off in the last few weeks, a few days of which were dedicated to racing #2 in a 12hr race.

But here's were I was as of this afternoon. I need to finish brazing the dropouts and the FD mount, and then I'm ready for some R&D before cleaning up for powdercoat.


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## TrailMaker (Sep 16, 2007)

Ha!

I'm using the same DOs. Kinda pricey, but very nice. I like'm. Looking Righteous!

I was out on the Humvee this afternoon. 60 degrees! It was an exceptionally articulate performance by us both. Eloquent, even. Nothing like it!

:thumbsup:


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## todwil (Feb 1, 2007)

Nice can't wait to see it finished and slusheed !!


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## Grinderz (Aug 31, 2012)

Looking awesome!

We need more fat bikes where I live.


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## jamescyco (Jan 20, 2009)

Hey Greg --- Nice. Did you bend your own seatstays?


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## Hooder (Jul 21, 2009)

Looking good. Did you decide to go with the Enabler fork shown, or are you going to get a 9zero7? Let us know how it rides. I built one very similar with a 70-deg HTA/enabler fork and it handles a little too slow. I think 71 will be good. If you get a second to measure the width difference in the Husker Du and Larry on the 80mm rims, I would like to know. I've got Larry's front and back and am thinking of going to a Husker Du in back. Thanks.


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## TrailMaker (Sep 16, 2007)

Hey Hooder;

My first build turned out to be around 71.5*, using that fork, and it does not steer as nice as you might think. That big tire has a lot of bite, and it will side pull the wheel right around on you. You have to stay on your toes. HuDu are entertaining, Nate's are worse. Not too quick really, but wandery, and the front will want to tuck if you get lazy. I'm shooting for 70, currently. Let's hope I can actually hit it this time.


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## G-reg (Jan 12, 2004)

I use pre bent stays from Nova. Some bending equipment is on the list iof tool wants. I've been dimpling a bit for clearance that could/should be attained with bent tubes. 

I had planned on the "short" 9zero7 Al fork... But have failed to aquire one. So the Enabler is a stand in until the Carver O'Beast I pre-ordered in September arrives.... Sometime in December. The plan is to use the Carpet Fiber fork in the winter..... And I've plans swirling in my head to cut the Salsa fork down and add some through axle dropouts for a short TA summer fork. 

I was finishing brazing the rear dropouts and ran out of O2... Coked things up a bit before realizing through my cheap goggles the flame was off.... Bush-league.


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## G-reg (Jan 12, 2004)

Little update with cell phone pics. I'll get a more complete writeup now that I have a few days off. I'm 80% done polishing out/cleaning things up. I still need to add the cable guides on the rear triangle, was waiting to build it up so I didn't have to guess where they should go. Rode it to work last night, and it handles great! At least at "high" pressure in the tires, I'll air them down and see if things get goofy at proper fatty pressures before declaring success.


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## Hooder (Jul 21, 2009)

Looks good. I like it.


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## TrailMaker (Sep 16, 2007)

Looks Great, G;

How was the steering? Those are steepish #s for a Fattie.

Through a greenhorn foulup, I managed to get my HT/ST at 71.5 & 74.5 respectively. The steering is a bit darty, and heavy. I attribute this to wide tire drag trying to twist the wheel around when you go off center. It is VERY noticeable on pavement. Less so on dirt, but it still it does not possess the more serene steering motion that I would prefer.

I'm hoping that #2 hits the mark, and then I will have something to compare to.


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## Drew Diller (Jan 4, 2010)

Looking good G-reg.

TrailMaker, what tires are you running?


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## G-reg (Jan 12, 2004)

I was just kinda thinking about modifying the Enabler, but it looks like it would be doable with out any hefty machine tools.

Paragon makes these hangerless hooded rear drops for a 142x12 Maxle

I need to look into if the Fatsno front hub is compatible with the Pro2 Evo axle conversion kits. If that's the case, its some new endcaps away from being a 142x12 front hub.

I'd say on a standard 29er or 26in rigid fork the only reason for a TA would be so your wheel would be compatible with a TA suspension fork. But I think there is room for some improvement for a fork like the enabler.......And it would be cool :thumbsup:


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## TrailMaker (Sep 16, 2007)

Drew Diller said:


> Looking good G-reg.
> 
> TrailMaker, what tires are you running?


120 HuDus or 27 Nates.


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## davesauvageau (Jan 8, 2010)

Went to Paramount today to look at the new fatties. Big Mike told me a bit about it and showed me some pictures. Looks solid once again G-reg! What are you going to do for a finish?


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## G-reg (Jan 12, 2004)

I'm still not sure DaveSav, I was going to talk to the Pro-Tec guy and see if he would be comfortable doing a single layer translucent, some kind of candy without a base color so the brazes show through. 

Not that my brazing is worth showing off, but to my knowledge it is the only brazed fat bike "In the World"(Jeremy Clarkson voice).


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## davesauvageau (Jan 8, 2010)

That would be sweet, what about a metallic clear?


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## G-reg (Jan 12, 2004)

I've been trying to talk myself out of a clear....but I really like the patina that the brass has already picked up. I'd be a shame to never see it again.


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## Drew Diller (Jan 4, 2010)

!!

Do it. I'm with davesauvageau on this one.


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## G-reg (Jan 12, 2004)

I started finishing things for a clear finish... But didn't think it was worth it, the amount of filing and sanding needed to make my metalwork worth permanently showing off was going to be ridiculous. 

If I really want the bare look... I'd leave it bare and clean it up every once and a while. Stainless brazeons would be a must though. Because I used so many cable guides on this one I used Paragon's non-stainless guides and they started corroding really quickly. They were a pain to clean up too. 

I mentioned using black chrome and the guy doing the powdercoating asked if I'd be willing to let him experiment. The black chrome is usually sprayed over polished Al or a silver base. He wanted to use a really bright white base with the black chrome over the top. The result should be a deep shiney grey. Maybe. 

On another note. I toodled around a bit without seat/chainstay braces, and then with them. I didn't really do any measuring but it did seem like there was less bb deflection with the braces.


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## G-reg (Jan 12, 2004)

Back from powdercoat. It turned out way more black (well REALLY black) that he had planned, but it looks great and we both knew it might come out this way. In direct sunlight some other purple/rootbeer/brown colors show through, otherwise it looks like a black with a really thick clearcoat.

Waiting for it to get cold again to start racking up miles. Waiting on the O'beast fork and new BB7's. I have some nice Avid HSX rotors and sintered pads to use with the new brakes. Until then some rando garage rotors and worn out pads from a totally different setup. I just got some new black reflective tape in the mail today. So tonight my project will be replacing the cheap duct tape rimstrip with something more permanent.










I stripped the PC from the windows/outer edges of the stainless Paragon drops, I'll polish them out nicely when time allows. The 11, 12, 14 tooth cogs are replaced by a Miche 14t "outer" cog. The small cogs turn into blocks of ice and moving the cassette out gained clearance for the chain at the tire.










It's tight with the 140 rotor, but not really any harder to set up the caliper...barely. I think Hope is making a 170mm QR skewer that uses a brass bushing for the eccentric, I HATE the rubber thing of the Salsa QR.










Looong mount for the DM FD worked out nicely. It's just a few mm forward and clocked around the bb a few degrees from Shimano's specs. It huggs the chainring nicely and the cage never gets close to the rear tire.




























Now to cover most of it up with a frame bag and get it dirty, probably won't see much of the 8hrs of sun light we have until the spring anyway.


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## Drew Diller (Jan 4, 2010)

G-reg said:


> Now to cover most of it up with a frame bag and get it dirty, probably won't see much of the 8hrs of sun light we have until the spring anyway.


Haha! You're a realist, kudos.

Looks AWESOME.


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## TrailMaker (Sep 16, 2007)

Hey;

Looks great, G. That PC is just DRIPPIN!


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## davesauvageau (Jan 8, 2010)

Pro-Tec worked some magic once again! Looks sweet Greg, did you happen to get a final weight of it?


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## G-reg (Jan 12, 2004)

We tossed it on the scale a Paramount, without paint, and some rando parts. It was 34lb, the frame is 4.5lb ish for a large ish frame. It will drop a pound or so with the final parts build. Not that I was too worried about weight, on a bike with 100mm rims. You know Fat bikes have matured when the weight weenieing begins. It weighs as much as it needs to. 

Though, to counterpoint myself, you are more likely to get yourself into a situation where you are push/pull/dragging a fatty and pushing a heavy bike is harder than riding one.


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## davesauvageau (Jan 8, 2010)

Haha I was just curious, I'm not a weight weenie myself, I put a new crankset on my Karate Monkey and gained .4 pounds! I don't really care if it works the way I want it to. What could you change to drop an entire pound? Mine is about 34 as well.


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## G-reg (Jan 12, 2004)

Sorry for the rant, just miffed the Fat Bike forum is going the way of the 29er forum.....which was the way of the SS forum...At least now I can resurrect the Fixed gear MTB without being asked if I'm a hipster. (which may come to be sooner than later in 650b form......)

The Carver O'Beast fork is nearly 1lb off of the Enabler. And is a few mm shorter and stiffer, so should be a win win. That said the possible TA enabler I talked about earlier might make a nice for too.


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## Drew Diller (Jan 4, 2010)

As usual G-reg, I dig your attitude.


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## toby_g (Jul 29, 2008)

Really beautiful build G-reg. What _is_ the colour? drive side CS shot looks black, HT shot looks Chocolatey. I think it is great whatever it is. Would you call it a happy-accident the way it turned out?


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## G-reg (Jan 12, 2004)

It's translucent black over a bright white. Not really an accident as much as an experiment.


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## G-reg (Jan 12, 2004)

Ready for 135mi of unsupported below zero R&D  Weighing in at 50ish lbs
with a -20below sleeping bag/2.5L of insulated H2O/food/clothing/other required items.

Excluding the Wifey bike (aka#3) I've raced the piss out of everything I've built. #2 made it through a bunch of XC races, a 10hr, a 12hr, and the Maah Daah Hey 100

But oddly enough,when I ride #4 into the parking lot of a casino it will be the proudest moment I've had as a framebuilder.


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## jamescyco (Jan 20, 2009)

Go Greg Go! Nice whip. Wonder if anyone else has done the A-Head on their own handmade bike?


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## G-reg (Jan 12, 2004)

Aaaarg, I bailed 111 miles in. No real complaints about the bike, it was less stable at slower speeds than the mass produced fatties surrounding me. But that was on purpose from a design perspective, though I'd mellow out the handling on a dedicated snow/touring fatty in the future. It was ok if I could carry some momentum, but was pretty tough to get started from a fresh snow standstill.

Other framebuilding perspectives:

Somehow the chainstay mounted disc caliper collects much more snow than a std seatstay mounted caliper. I didn't see what was the cause, but looking over at the other bikes riding in the same conditions mine was the only one really building up snow at the caliper.

Low BB is nice in the slick conditions, sure I dipped a foot every pedal stroke as the snow got above 4in high....but that was far from my limiting factor to forward progress.

Using Surly tubes in the tires makes for a wider/less tall tire than using the QBP 26x3 SL tubes that were installed when I was measuring/designing. So when I installed the bigger/thicker Surly tubes the tire grew a bit in width and killed the few mm of space I had at the chain/tire interface. So the chain did a pretty good job of pealing snow off of the tire and delivering slushy snow to the chain/FD/cassette/RD.


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## TrailMaker (Sep 16, 2007)

Hey;

Good on you for giving it a go. That's some serious mileage in any event, let alone in heavy snow. It's amazing what you learn when you put theory into practice, and how much you've really left un or under-anticipated. I've had some interesting go-rounds with engineers... the ones with "The Knack?" I actually had one tell me that, "if you control all the variables, the outcome is a certainty." As if that were even possible. As if test engineers and R&D were superfluous. I wonder how many engineers and designers throughout time have exclaimed, "I've thought of everything!" ?

Interesting about the low mount crud catcher too. I'll be watching the one on my new ride now. What do you feel are the reasons - those by-design attributes - that caused your bike to be less viable in heavy conditions?


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## todwil (Feb 1, 2007)

Im liken your fatty!!! :thumbsup:Im thinkin your slush build up is from the angle of the caliper being flat 
and the seatstay right there for it cling to. Having the caliper on the seatstay at about a 45*
angle gives it the ablity to shead the snow.


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## Drew Diller (Jan 4, 2010)

G-reg said:


> I bailed 111 miles in.


I am not seeing anything shameful here. A mighty effort.


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## Stevob (Feb 27, 2009)

The snow build up on the calliper might be because its closer to your heel. Also, do you coast right or left foot forward?


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## Meriwether (Jul 26, 2007)

Just read this whole thread. Great build, I dig the color and fillets look great! You wouldn't have been disappointed with a clear. The Arrowhead sounds epic, good go at it! Looks like you got some snow!

So what are your thoughts on the reason you were not feeling slow speed stability? I have always felt the slacker HTA of most the production fatties would be worse at slow speeds than a custom like yours with a hta of 71...


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## TrailMaker (Sep 16, 2007)

TrailMaker said:


> .... What do you feel are the reasons - those by-design attributes - that caused your bike to be less viable in heavy conditions?


To quote myself;

And give a further shout to Whit's question about the handling....


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## G-reg (Jan 12, 2004)

Thanks for the kind words folks,*E-HighFive*

The front end handling wasn't heinous, just slightly twitchy-er than the production bikes at slow speeds. With a bit of momentum I could relax and the bike handled nicely. And I should be a more careful picking nits/making comments about the finer handling characteristics when exhausted riding a 50lb bike with 8psi tires in 6-9in of snow. Tough to be subjective when you're no S*&t hallucinating.

I'm a L foot fwd type guy, though even wearing way oversized boots my heels are sell fwd of the drop outs. I didn't think that just being horizontally mounted would contribute, sometimes the simple answer.... I think any snow shed from the tire by the seat stay probably falls that direction too.


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