The 2021 Handmade Bicycle Show Australia was held over the past weekend and it proved to be the usual showcase of Australia’s thriving builder scene. The Melbourne-based show certainly attracts more road and gravel bikes, a symptom of where the custom bike scene is strongest, however many of the builders come with deep roots in the mountain bike world too.
The
Trinity MTB was one of the attention-grabbing steeds on display, and then trail bikes from Devlin Cycles and TOR Bikes were well worth a closer look, too. That TOR will be covered next, but for now, let’s look at Devlin’s prototype.
Devlin Cycles Prototype DetailsFrame material: Steel
Travel: 140mm
Wheel Size: 29"
Intended Use: Trail
Head Tube Angle: 66°
Reach: 490mm (for 5'10" rider)
Price: AU$8,500 (approx US$6,500), painted frame with shock.
More info: devlincc.com An intro Devlin Cycles Devlin Cycles is the creation of Brisbane-based steel frame builder Sean Doyle. Doyle is an engineering draftsman by profession, and the merger of his profession and passion for bikes dates back to the 90s when he first drew up a first full-suspension mountain bike frame.
Fast forward to today and Doyle has a number of custom-built frames to his name, all sharing steel tubing, brazed construction and a few stylistic flourishes inspired by classic lugged construction that serve as his build signature. Those flourishes are effectively carved out sleeves that sit over the steel tubes, something that is known as bi-lam construction, and in addition to looking great, they help distribute forces through the tube and greatly increase the surface area of the brazed joints.
Devlin Cycles started as a classic custom steel road racing bike maker, however, Doyle has quickly expanded his builds into other realms. His most recent creation is this yet-to-be-named trail bike that he built for himself as a prototype to help refine the concept.
Long reach geoThe goal with this bike will to offer entirely custom geometry, however, the concept of that geometry centres around a long reach that ideally overcomes the need for a super slack head angle or long trail figure. Standing at 5’ 10” (178 cm), Doyle is rather average in height, and yet this 140 mm travel 29er trail bike is built with a lengthy 490 mm reach and a 1230 mm wheelbase. That’s combined with 440 mm chainstays, a 77-degree effective seat angle and a not-so-slack 66-degree head angle. Doyle had originally designed a custom 20mm bar and stem combo but is happy with the existing 35mm stem.
“I’ve gone for a moderate head angle,” said Doyle. “I’ve done a lot of reading and absorbed some of what
Peter Verdone has written about and what Sam Whittingham from
Naked Cycles discussed on the
Cobra frame building podcast regarding long reach frames and moderate head angles. I did some thinking, and thought, well let’s just do a platform that makes sense in my head. Fortunately, it’s kinda got really close first go.”
The bike also looks tall and that was by design. “The bottom bracket is relatively high, firstly, my local area has a lot more rock and steps than a lot of South-East Queensland trails. [And then] one of the ideas in my head is that with the longer wheelbase, I wanted it to be a little bit more tippy, which may be a weird way to describe it, but as opposed to being really sat down and into the wheelbase and making it hard to turn, I wanted the weight higher up to get it to flop over a bit.”
“At the moment, for me, I wouldn’t change anything in the geometry.”
Suspension design and the buildCreating a new full suspension bike from scratch doesn’t come together quickly, Doyle suggests he had over 400 hours in CAD work (Doyle’s profession) before spending a further 200+ hours creating the bike.
This prototype makes use of a traditional Horst Link suspension layout, however other designs were certainly considered. “I had spoken with Canfield at one point. I had also considered the DW linkage. But I went this route as I’ve got a lot of experience with it and I think it’s a good mix of pedalling platform, bump compliance and ease of design.”
“I had initially designed the main pivot to have some adjustment for anti-squat so I could tune that but it seems the centre position was right first go, so when I rebuilt the swingarm I took that out of it.” The result is a ride that Doyle claims to be quite balanced in the amount of anti-squat it provides and is well suited to his riding area where the terrain is rolling.
As shown, the front triangle is built with a Columbus 38 mm 29 downtube that’s been flipped upside down and extended in its length. The top tube is a Columbus 35 mm Zona tube, while the seat tube is a 35 mm Reynolds that
Prova Cycles helped to bend. “I then chopped up the seat tube, the top half is a thick 1.8mm walled tube to cope with not having the brace to the top tube.”
“[The] front triangle is using my bi-lam sleeves which carry over from my road frames,” said Doyle of the design element that’s both aesthetic and function. “It creates a really thick end tube section so that when you mitre the tube to the head tube you’ve got a really big surface area that creates a lot of strength in the joint... It comes back to aesthetics in that I don’t have to have such a big fillet in there and it creates a tidier finish.”
The frame is all silver fillet brazed, however, Doyle suggests that doing so makes for an extremely expensive frame. “I may go back to doing bronze because it’s cheaper, and there is a lot of filler. Bronze is harder to pull through the sleeves, silver is a lot easier, so it might be that the head tube stays silver because of the bi-lam sleeves and the rest moves back to bronze.”
Looking to the back of the bike, this prototype uses a swingarm that’s made with 4130 Chromoly round tubing and seat stays that are actually Columbus Zona chainstays, dropouts are the Syntace model from Paragon Machine Works. “There’s a lot of manipulation with the 4130 tubes and I have a lot of scrap from getting that right. This is the second swingarm I’ve created, this one is a lot stiffer and it’s to the point that I’m thinking maybe I need to back it off a little. I didn’t expect it end up here, it’s quite direct.”
Currently, a 29 x 2.5in tyre fits in the back, but Doyle has plans to replace a portion of the manipulated 4130 tubing with a 3D printed stainless steel yoke that should more breathing room around the tyre and ease the build process, too. Doyle is considering using 3D printed stainless steel for the dropouts, too.
“I’d like to do another prototype to nail out some things. For example, the bearing configuration details, I’d like them easier to make and using less parts. That main pivot would likely annoy people to pull apart and put back together again, I’m already upset with it. So that will be redesigned so it’s simpler.”
And Doyle is still thinking through a few other elements, for example, the suspension linkage is currently CNC’d aluminium from a Brisbane-based supplier. The original plan was to use a printed metal part here, but Doyle quite likes the organic look of the machined alloy.
Want one?The fetching two-tone candy paint on this prototype is the work of
Wallis Paints in Brisbane and would add further cost to the bike. Speaking of the paint, Doyle joked that it’s not the most practical thing. “Don’t make it look like a show bike, any touch up requires a full respray.”
Doyle is clearly still sorting out the finer details but didn’t dismiss the idea of taking on orders already. Of course, a custom geometry bike with this number of fabrication hours isn’t cheap, and you can expect to pay about AU$8,500 (approx US$6,500) for a painted frame with shock.
Nice bike, clean lines. The reach is massive yet the head tube is relatively steep for a bike that seems to be designed to get rowdy?
www.swarfcycles.co.uk/contour-29er-fs.html
Also drool-worthy and a frame I’ve ogled before as well! It has a totally different industrial, sturdy, no-nonsense kind of cool. The performance is probably similar, and the performance-to-dollar ratio waaaaay better. But this frame is just off the hook in terms of detail
I just know him as the guy that put together the sus fluid viscosity chart which i ref when I want to tune my fork/shocks by changing the fluid properties or buy a cheaper non mtb branded equivalent fluid because you can't trust the listed weights as they aren't standardized across mfgs. For that public service, i give him a pass on what ever personality quirks he has.
Like other people have said, there's no doubt he puts work into what he does and can back up his claims with numbers. It's those claims that make me eye roll every time he spouts them out. He seems to think his geometry and ideas are the end all be all for cycling as a whole, yet his frames are designed with just himself and his very specific riding area in mind. His frames are never ridden by capable and talanted riders against "traditional" bikes in areas outside of Marin County. Leaving most of his claims down to just that, math and numbers. Not speed, stability, or comfort. Long story short, he lays big words and claims on bikes that are very, very far from proven. Call me a shill, a sheep, or whatever but I'll stick to the more "common" geometry of bikes that are out there getting podiums and winning medals.
That sounds amazing. At the risk of exposing my utter slackness here, do you have a link?
My Murmur is very similar to this frame more than materially, at 490mm reach, but 64 ha and way longer wb. At 181cm, its too much, I don't need that kind of reach to be comfortable and I don't need that kind of wb to feel stable (and we have some fast trails here)
Is WallstreetBets leaking?
It really bugs me when reviews, etc. list reach without stack.
Edit: this is a gorgeous bike. Well done, Mr. Doyle.
no but really. ape index=difference in wingspan(hold arms parallel to the ground and straight to your sides. think crucifiction. now measure the distance between tip of your longest fingers.) from your height. normal is about -1" to +1". I am a +5. lol
Poles sizing for a person 5'9" is like a 510mm reach.
Looking at Kona, their suggested for a 5'9" is M or L, and their process has a 480mm reach in L.
Specialized, for their St Evo, for 5'8" - 5'11", recommends their s4 size, which is 475mm reach.
If I took my ~800mm seat height, +/-1deg from this 77deg effective STA changes the saddle-to-bars length by ~+/-13.5mm. How can anyone compare reach numbers alone without considering seat tube angle?
Maybe it's just time to switch everything to RAD/RAAD: www.pinkbike.com/u/leelikesbikes/blog/dialing-in-your-bike-for-your-riding-style.html
Beautiful bike, did have the pleasure of seeing this in the flesh and talking to Sean. Such an amazing amount of work has gone into this and it shows!
Edit: also, it's custom made, so really the reach number basically can be whatever the customer wants/needs!
There's a reason people are downsizing now when only a couple years ago everyone was upsizing.
The better question is how can anyone compare reach alone without considering ett, the answer to which is you can't!
RAD/RAAD is just marketing what's already implicit in stack & reach (which annoys me) but I'll concede that RAD at least is easy for folks to measure on their own bike after throwing in variables like stem length, bar rise/roll, stem spacers, etc.
Pole are in their own stratosphere and hats off to them, geometry wise.
(At my height of 6’3.5” you would think any XL would work for me, until you found out I’ve got short legs, a long torso and even longer arms)
But it's all personal. I'm 5'10" also, but I know it would take me a minute to get my arms and shoulders used to a 490 reach (from 455) and really be able to drive the front really hard into tight or slippery corners. But since the front center of this bike is pretty much the same as my current bike it'd feel pretty nice legs- and hips-wise (no extended wall-sit position hanging off the back to stay in the front door) for fast sweepy corners that don't need as much front-end traction management.
“Your mom’s bite point wanders!”
The red paint job reminds me of my Saracen Ariel 30 Pro - www.saracen.co.uk/products/ariel-30-pro
The Saracen isn't steel, obviously, but the HA is slacker and it has even more reach (despite only being a 130mm trail bike).
Oh, and it only retails for £3000... ;-) Honestly, if the Ariel 30 was included in the latest Affordable Trail Bike Field Trip, it would have wiped the floor with the other bikes!
So far only liteville were smart enough to offer reach/stack adjustment for sizes
I had the pleasure of working with Sean on a big coal washplant design and construct job(where he was working as a drafter).
Should I use side flags, Oversized Load Sign and lights, just in case I carry in the rear?
Will you be doing more on PB?
youtu.be/5KsjPjE-sTw
Thanks Adam Sandler.
I can become One & purchase this frame.
I’d ride that bike.
www.pinkbike.com/news/whyte-bikes-vs-rich-energy-what-happened-next.html
,,....... is this a go fund me or go scam me for 7500 canadian for a frame? a steel frame not a titanium or carbon....WTAF
And there are a ton of steel mountain bikes being used. I mean how many Surly mtbs are running around nevermind Chromags, Niners and a ton of smaller brands.