A short time back, I posted the first pics of the frame Fred Cuthbert from Wolfhound Cycles built for me. It isn’t just your garden variety 29er hardtail mountain bike either. Hidden within the cool retro theme, is a ton of ridiculously cool stuff going on with this frame. I bugged Fred via email to find out the full story on the creation of the Wolfhound “RetroSled.”
A quick word of warning: what follows is essentially two huge bike geeks having a conversation about some seriously nerdy bike stuff. If you aren’t obsessed with this sort of thing, you might just head on to the next post- in addition, it is a conversation that was held over email, and is therefore, pretty raw. You have been warned!
Fred Cuthbert, Frame builder, about to cut into a perfectly good top tube.
All photos by Fred Cuthbert, Wolfhound Cycles. Used with permission.
Me: Wow, Fred. You really out did yourself. The frame looks incredible, and the side profile of it is sweet. retro cruiser inspired, but definitely Wolfhound-style. I see your split seat tube, and bent seat stays – your Wolfhound trademark. But what is going on with the seat tube? It looks like the seat tube is designed to flex?
The Wolfhound 29er "RetroSled" designed and constructed for Jason Van Horn
Fred: Man o man, that ST is actually a combination of 2 different things I’ve done before. The pictures of the black bike show the top half, on this bike combined with the Split ST. I was thinking this is perhaps a “floating” split ST. Talking about flex and ride quality: I think this bike is a rare instance where the pursuit of shameless over the top style actually produced an enhanced performance characteristic by default. I think this frame has a chance of riding like nothing else, given the amount the ST, and SS could flex, but the truth is, this one is the first, and probably only of it’s kind, so you will soon know more than I do about the ride quality. I think when I look at the profile of the frame, I can almost “feel” what it will ride like, better than explain what I think it might ride like. I can tell by your comments you see the same thing.
Toptube/ seat stay assembly
Me: Love how the top tube ends prior to connecting to the seat tube. It looks really cool. What is going on there? That must have been a bitch to construct that!
Fred: The 1.25″ TT started as a 4foot tube, curved in my large bender, then one end clamped in a vise block and bent back…..just the right amount in the right way to produce the progressive radius you wanted in your TT curve. At that point I had to determine where to cut it so that I was getting the portion of the tube that best represented that curve. Because the actual length of the tube could be a little flexible, I was able to take a couple tries to get the HT miter perfect, and it really had to be dead on balls perfect, or the whole design is a bust.
The Retrosled in progress
The next step was ovalizing the TT so it could blend in with, and be mitered to the 3/4″ seatsatys. This was also critical, because the ovalization had to blend perfectly with the curve continuing into the SS. I was actually surprised I was able to achieve the shape I wanted, and keep it through the brazing process. Ovalized tubes, move back toward their original shape when heat is applied. I thought for sure it would distort somehow and I would be redesigning, but I was extremely careful about the order that I tacked everything in place. Keeping the miters tight was also key, and most importantly, controlling the heat when brazing. The overall design of this bike is unique and definitely a first for me, but that TT/SS junction felt especially like playing jazz, I was out of the box, and building over my head. To tell you the truth, I think I got a little bit lucky with this one.
Me: I’d love to hear a run down of exactly what building this frame entailed. I remember from first time I saw it in the jig it had a straight top tube. What happened next?
Um, there is a chunk missing from the top tube.
Fred: The dummy TT was needed to locate/align the ST. Normally the TT locates the ST on a split ST bike, and the legs of the split ST are then mitered and brazed. Without contact with the TT, there was no way to orient the ST. I took the TT length and miter angles from the bikecad draft and made a temporary (dummy) TT. I tacked the dummy TT into place w/the ST, then added the legs of the split ST, and brazed them to the BB shell. At that point the ST was perfectly oriented and permanently welded in place, and the dummy TT could be cut out.
On most frames, the front triangle is fully constructed before the stays go on (least that’s how I do it). On this frame the HT, DT and BB shell were welded into a sub-assembly, then the chainstays were welded onto that, sort of like the lower foundation. Then…….bend and ovalize the TT as discussed above, tack it in place, so there’s this curved tube w/an ovalized end sticking out from the HT. Then bend, and re-bend the SS, to obtain the progressive downward curve, aalllllllllllllllmost straight in the middle, but not quite – Right?
The front triangle in progress
Then miter them into the side of the TT sticking out, ovalize and miter the drop-out end.
At this point, I needed to think ahead about the internal cable routing. It’s got to be fully in place before the whole TT/SS assembly is put together, so now is the time to drill the oval holes where I want the cables to enter/exit the frame – showing the least amount of cable housing possible. The internal conduit is 1/4″ stainless steel X .016 wall thickness (very thin), but it can be curved and shaped, and if done carefully, will produce nice gradual curves, no crimps, and retain the ability to hold a cable/brake housing. bending the conduit can be challenging when there’s two internal lines that have to clear each other.
Sooo, now the SS are mitered, and the internal cable conduit is routed through the tubes. It’s time to tack the SS to the tacked on TT and the drop-outs. The main concern here is keeping the ovalization of the TT from distorting when the heat is applied. Ovalizing from 11/4″ down to 3/4″ is a pretty extreme manipulation. The short 3/4″ cross tube at the end of the TT, mitered between the SS is the key to pulling this off, along with keeping the miters relatively tight. Tacking the TT to this little cross piece prevents the end from distorting back to round when the big heat is applied to run the actual fillets. Tacking in many places along the SS/TT interface was also helpful. At that point everything is well fastened in place, and it’s time to run those fillets, with the above average heat control stated above.
Those cool, now it’s time to cut the tiny tacks at the HT and dropouts, and remove the whole TT/SS assembly for finish work. A similar process was repeated for the struts connecting the ST to the SS. The last tube added was the one between the TT and DD a the front, the “sex tube” as some call it.
The Wolfhound Retrosled in progress
Me: The final aesthetic of “retro-beach cruiser” meets Wolfhound style is so spot on the money for what I was imagining. Is this the first “cruiser-style” frame you’ve built? I can’t imagine it will be the last. What is your take on the aesthetic?
Fred: The overall aesthetic came out almost exactly as I was visualizing, just a little bit better. As the build progressed, I became more and more excited about how the final lines were coming out. Once I conquered the The TT/SS curves, and the ovalizing of the TT down to 3/4″ I knew it was going to come out the way I’d hoped.
As we’ve discussed, I never would have come up with that retro overall top line for a frame on my own. I have always liked the look of Retrotech, Blacksheep, Coconino, etc., bikes with a retro (meaning counter productive for stand-over clearance) TT line, but it just wasn’t my usual style. I had a lot of time to ponder the design, after we first discussed the curve you were after. The unusual (for me) curve really gave me a chance to explore a different style. It was fun to figure out the basic fit/geo numbers…..then pursue everything in the name of shameless bling, something that flat out reeks of style, for no other reason than showing what I can do. You pretty much ordered a home run, or rather a grand slam. So I just started in pondering how to take this new style, and make something that was undeniably NOT a copy of something, more like a copy of several things blended together.
Constructing the fork legs
You mention building more retro style bikes…I guess we’ll just see what people come to me for, but I doubt anyone will get one quite like yours. The price I would have to charge would be truly ridiculous, it just takes too much time. It would have to cost more than any hardtail you or I have ever heard of, in any material. I don’t mean to imply this frame is better than any other hardtail, it’s just the degree of difficulty. Many more tiny steps that have to be planned ahead by 4 or 5 steps to make it all work out. That combined with the amount of fillets to finish….All that said, now that it’s done, I’m very glad I did it!
Occasionally, they say, someone comes a long w/more money than sense, who will pay whatever it takes to have something so trick that nobody else could ever have simply because nobody else can, or would afford it. That’s the only guy who is eligible for a frame like yours. But retro curves in general are definitely an option for future customers.
The fork in progress
Me: No question this time, I just want to hear more!
Fred: OK, you might like this:
- 10 different tubing sizes not counting CS or Fork blades
- 4 different bend radius’ (not counting my hand manipulated ones) from 3 different benders- all done in my shop! -5 if you count shaping the CS
- Wolfhound designed HT, BB shell, ST lug, and drop-outs
Me: Internal cable routing! Can’t wait to see how that will come together. How will that work?
Fred: You will love it, the conduit allows a housing to slide through reasonably easy, but holds it tight enough, that there’s no room for water, or movement of your housing/hose. One thing you may notice is that it will be a tiny bit more quiet. No matter how good regular cable routing is, there is always a tiny bit of noise from slapping or other movement — this will be eliminated. There is about a 100 gram combined weight penalty for both lines(maybe a little more). I’ve really come to love internal routing from a builders point of view as well, it just makes a finished frame so much nicer, and the more I do it, the less risky it seems. I’m considering making an internal brake line standard and raising the price to compensate. You’ll also be surprised how much nicer it feels to pick up the bike w/out cables fastened to the frame.
Me: with the strut connecting the top tube and the down tube, in addition to the 20mm axle fork, The front end of this bike will be stiff! How much compliance does the bend of the chain stays actually do?
Fred: I think you are right on in expecting the front to be stiff, and the rear a bit more compliant, like I said above, you will soon have a way better idea of how the design has affected the ride characteristics than I do. I don’t like to count chickens a head, or whatever, but……the back 2/3 of the frame are one continuous, uninterrupted curve – ideal for making a frame flex where you want, and the seat tube is suspended by 4 curved tubes…. I humbly believe there are a few subtle aspects of weight/force distribution here that we really haven’t seen before, at least not in this application. I think you did the best possible thing by going rigid specific, because this thing is going to come alive and talk to you, and you’ll want to feel it.
I really can’t wait to hear about it, cause I’m pretty much pullin all this out of my ass — meaning the bike designs, and the words.
It’s gonna be pretty fun to show this in San Diego…..
