Vince's Mutt

In the winter of 2023, Jean-Daniel and I went to Tucson, Arizona to take a framebuilding class with framebuilder Dave Bohm of Bohemian Cycles, and this is the frame I made during that class. It’s basically a Hog’s Back with a few tweaks. At the time, I didn’t have a need for a specific type of bike I didn’t already have (I know I know, n+1 blah blah blah), so I thought it would be a good exercise to start from a bike I know very well and make subtle changes to see how big of a difference it would make. I think I’m a bit of an empiricist: even though I read just about everything that exists on framebuilding, I still have to test it myself to really believe it, or really understand it at least. Since building the frame I’ve only had the chance to use it in its intended environment on a handful of weekenders. This winter, though, I was lucky enough to go test it on 800km of Colombian trocha (the common word the Colombians use for their dirt roads). So, two years later, I’m glad I can finally give it a proper review and assess how different it is from the Hog’s Back.

To begin with, there wasn’t much I wanted to change from my beloved Hog’s Back. A couple of millimeters here and there to better fit my body proportions and a switch to thru-axle and adjustable dropouts were the main modifications I had in mind when designing the frame. Then I wanted to experiment a bit with one aspect of frame design that still feels a little esoteric to me, and that is front-end geometry. The Hog’s Back, with its relatively low trail measurement (63mm or so?) always felt a tad twitchy when unloaded, but very stable with the slightest weight at the front. But then most bikepacking bikes nowadays tend to have longer trails, closer to mountain bikes. I was curious to see what that was all about, so for the Mutt I decided to go with a slacker 70deg head tube angle, which bumps up the trail to 80mm, with the fork having a similar rake to the Hog's Back's. Then the slacker head tube paired with the slightly steeper seat tube allowed me to lengthen the reach (and, by extension, the front-center) to accommodate my long arms. This also resulted in a bigger front triangle for a framebag, despite the lowered top tube. The rear got a little longer too, mostly because of limitations in chainstay options, now going from about 445mm to 460mm. Those few alterations made the bike considerably longer, with the wheelbase clocking at 1128mm with the dropouts at the rearmost position.

What do all these numbers mean when riding the bike? Let’s just say some changes I feel were for the best, while others not so much. First off, I don’t think I’m a fan of longer trails after all. Although the bike does feel more stable, I did notice it’s a little slower to steer, and the front wheel tends to be floppier when climbing. Is it drastic? Not really, I easily got used to it, but it’s enough of a difference for me to know that I prefer low(ish) trails. That being said, the bike felt incredibly stable bombing down those dirt roads, probably thanks to both the high trail and the pretty long wheelbase, and still felt nimble when needed. The longer rear-end didn’t seem to bother me at all. The rear wheel did slip a couple of times when climbing standing up, but I think it had more to do with the steepness of the hills rather than lack of weight on the rear wheel. And I don’t know about you, but if I'm climbing for two or three hours straight, I much prefer staying seated anyway. I guess those few lil’ “experiments” turned out pretty conclusive, in the sense that I learned a bit more about what I like and don’t like. In the next iteration of this frame the goal would be to maintain a similar wheelbase with a lower trail, probably by simply increasing the fork rake.

In terms of features, I already mentioned the switch to thru-axle, which I’m very glad I did. While I don’t consider it to be a big deal, disc brakes with QR’s are a bit of a hassle, and I noticed less disc rubbing in the front when pedaling standing up. I opted for Paragon Machine Works adjustable dropouts because I always like to have the option of going singlespeed. I put pretty much all the eyelets you would expect for a bikepacker, and even tried fitting cargo cages on the seatstays but the result isn’t very convincing. They don’t have quite enough heel clearance for anything bigger than a normal water bottle, so I never really use them.

Now on to the tubing. The steel tube selection was limited by what Dave had on hand and what could be ordered last minute. The tubing for my frame ended up being a mix of Dedacciai and Velospec, nothing too fancy, with tube profiles pretty similar to the Hog’s Back's Cromor. Except! The fork blades are from the prestigious Reynolds 853 heat-treated series, paired with a Pacenti crown. The heat treatment on the blades makes a noticeable difference, making them extremely stiff yet somewhat lightweight. The complete frame turned out to be noticeably lighter than a Hog’s Back even though it is a bit bigger and has more steel, the fork probably being the main reason for that weight loss. While riding loaded, the frame felt quite comfy and compliant, without feeling squiggly, which is usually the perfect in-between you’re looking for.

In the end the frame came out mostly the way I expected it. The whole process of designing the frame and building it really gave me a better sense of how different parameters impact each other and what problems you can run into and what solutions are available.

Dave Bohm offers classes for all three main methods of joining steel tubes: Tig-welding, fillet-brazing and lug construction. Since I already learned the basics of Tig-welding in trade school I decided to take the fillet braze class. While most of the frame is fillet-brazed with bronze, the seat tube sleeve and fork crown allowed me to learn a bit of lug-work and brazing with silver. The rear dropouts even called for nickel-silver to be used. At first I wanted to leave the fillets raw, as I am a big fan of that look, but Dave said they need to be extremely well done for him to let students get away without filing, which is… fair. It takes time to achieve beautiful raw fillets and filing is as much a skill to learn as brazing is.

I find brazing to be very pleasing to do. To me it feels less stressful and more forgiving than Tig-welding. It also has that kind of romantic feel to it, more old-school and “artisanal”. There is just something about working with an open flame, and the look of those fillets, raw or filed, that speaks to me. I think both joining methods have their benefits and their applications and I’m glad I got to touch both.

Now, it took a while but I finally painted the frame last spring, using Spray.Bike. Although it didn’t pan out exactly how I imagined it, my original inspiration for the colour palette was the album cover of Feeding the Abscess by Martyr, one of my all-time favorite death metal albums. Then my friend Kellyann graciously made the amazing “Mutt” logo for the downtube. It all pairs really well with my custom Gurp olive framebag, which I absolutely love. Someone I met on a group ride said the bike is giving Mad Max vibes, which made me sooo happy because that is literally the aesthetic I’m going for. I tend to see bikes as these long-lasting, highly functional and practical machines that are made to survive through the (post-)apocalypse.

Now a little about the build, since some of it has changed or been thoroughly ridden out since my first write-up about my original Hog’s Back build. Thanks to hub adapters, I really just slapped all the parts onto my Mutt. My Hog’s Back had flat bars for the longest time, but I eventually realized I’m more of a dropbar kinda guy for all things touring and bikepacking. I wanted to see what all the hype was around the Crust Towel Rack, and after riding ‘em for some time I totally get it! The handlebar is very comfortable and has so many different hand positions, perfect for all-day riding.

Since I’m a little picky about handlebar position, I had a custom stem made by WZRD in BC to have the bar exactly where I want it. Although there were moments in Colombia where I thought a flat bar would’ve been better suited, the wide dirt-drops never really felt like an hindrance to me and I actually liked having them on those few paved sections where I could really tuck in.

Next, I switched out a couple of things on the wacky drivetrain I had going on. I found this cool Sunrace derailleur, which is the cheapest wide-range derailleur you’ll find (can do a 51t cog), and has a normal Shimano 9spd pull ratio. These are all great features but the derailleur really showed its limitations during the trip. It ended up needing almost daily adjustments to be able to reach the granny gear, the main problem being the pivots getting very grindy and needing constant lubrification. What didn’t help with that situation was the Rivendell shifter also got extra grindy. I assume the swings between extra wet and extra dry conditions were tough on the ratchet and ended up washing out most of the lubrication. It's probably not anything a good overhaul can’t fix! I’m still running the same gear ratio, 36t chainring with a 10spd 11-46 cassette, which proved to be very adequate for me, even in Colombia with 1500-2000m of climbing per day. A lower 32t chainring probably wouldn’t hurt, but I liked having a usable high gear for slight downhills or flat paved sections.

The rest of the build is pretty much the same. My Klampers are still going strong, except for a little mishap right before leaving where the moving pad adjuster somehow completely stripped. So for the trip I rocked a BB7 at the back while waiting for a replacement part from Paul. “Honestly, can you see a difference?” Eh, a little. My experience with BB7 is that they have very little modulation, meaning you don’t need much to lock the wheel, which can be good at times but which I generally don't like. The Klampers have more modulation, although maybe less initial braking force. Whatever, they’re brakes, they stop.

Then the wheels have… survived. I think I reached the limit of the “lightweight” Velocity Blunt SS (a racing rim, not a touring rim, as evidenced by yet another of Vince's famous mechanical mishaps —ed.) at some point through the trip by punching a dent so bad the rim cracked a little. Somehow the tire still holds air and sealant and it didn’t keep me from completing the trip (although I did inflate my tires a bit more and was a little more careful on downhills after that). Oh right, I also replaced the tire before going to Colombia, trying out Vittoria’s Barzo and Mezcal combo, in 2.3”. They felt perfect for that type of road, quite grippy without being overkill for softer surfaces.

Another mishap during the trip happened to my bottom bracket, where a few ball bearings got all squished. I was expecting the IRD Tenacity open ball bearing BB to be a little tougher than that, although as some people pointed out, caged bearings aren’t as tough as loose ball bearings since you have less support. But the beauty of serviceable bottom brackets is that I just had to hitchhike to a bike shop a couple of towns over. Fresh grease and new ball-bearings were all I needed to keep going. I’ll keep the bottom bracket like this and see how the loose ball bearing theory holds up, otherwise I might switch to a good quality sealed BB.

Lastly, my dynamo setup has been less than satisfying, partially by my own fault. I already had to replace the dynacoil on my Kasai FS dynamo hub after only a few years of use, but while looking into that replacement I stumbled upon the manual that very specifically says the hub should never be submerged in water, which happened repeatedly during my time living in the Maritimes. Oopsie! Then the Kasai Trailbeam light was rather disappointing since the beginning. The beam isn’t very bright, and the micro-usb port makes it almost impossible for the cable to stay in. Then the light just completely stopped working during the trip, which I know also happened to other people with much less km’s on it.

All in all, the Mutt was an absolute joy to ride throughout the trip. From mountain bikey rock slabs to loose sand roads and fast paved sections, the bike felt capable of taking on any type of terrain. Not only was it very stable and capable, it was also extremely comfortable. I think this comes down to the combination of many factors: the frame geometry, the tubing, low-pressure tubeless tires, wide flexy handlebar, all this contributed to the perfect plush ride for those long 1-hour rocky downhills. The various mishaps somewhat confirmed some of my choices in components, as all of these issues were easily fixed or endured as minor annoyances.

My brain is already full of ideas for the next version of this bike. That's one of my favorite thing about framebuilding and frame design: learning, tinkering and improving. Hopefully I’ll be able to get to work on that soon enough, although I also have plans for a few other frames that may come before. Bikes are cool, and building them is even cooler!

Pics by Troy