The Gear – ISEN Workshop

If you play a game of word association with anyone who is considering buying a high-end custom-built gravel frame and you say the words ISEN Workshop, my guess is the first thing they that they will say is “ooooooh, beautiful”. While co-owner (and graduate of the Royal College of Art) Caren Hartley was keen to point out that it wasn’t just about the looks, as soon as I pushed through the door into ISEN’s second floor workshop space, a neat row of #sikcandyfadez painted sample tubes and some diminutive klean canteen mini-bottles practically took my eye out.

A killer combination of stunning good looks with meticulous attention to detail is arguably ISEN’s trademark. Set up in 2017, ISEN is made up of Caren and co-owner Matt McDonough, both framebuilders in their own right, who decided to combine forces. “Every tube is finished as though it will be used in a raw unpainted frame, so we make sure there are no blemishes or manufacturing marks” said Matt, as I stood admiring one of their frames on a welding jig. “It takes longer, but it means we’re confident that every frame that goes out is as close to perfect as we can get it” he continued.

I asked Caren what the different coloured “tick marks” were on a tubeset laid out on one of their benches “They’re part of our quality control process” was her reply. “When you work as a solo framebuilder and you manage every stage of the process, communication isn’t important, but when you’re building frames as part of a team, you need to have a system of checks in place. Our production manager checks every tube during the build process and the ticks and instructions written on the tubes are so that everyone who works on a frame knows what has been checked and what is required at each stage” Their attention to detail is incredible “We use a jeweller’s loupe to go over every titanium frame to check for minute imperfections” says Caren.

Planning and Quality Control are key

One of the reasons the Caren and Matt joined forces was that they wanted to build high-end frames, but they wanted to do it efficiently and that meant doing more batch building. With a team of four-and-a-half, Caren, Matt, production manager Robin and Fenella who makes sure the whole place runs smoothly, not to forget the latest addition Connie, a Belgian Malinois, having an efficient production system in place is key. A huge magnetic white board on the wall in the office contained all the vital “flow” information for frames and fully-built bikes as they progressed through the build process.

“We’re currently producing a roughly a 50/50 split of frames to fully built bikes” said Matt. “At the minute there’s probably a slightly higher proportion of frames than normal due to issues with sourcing components for the full builds” he continued.” I asked Matt about the small collection of carbon fibre tubes stored under one of the benches, but I had also noted a fresh delivery of tubing from Columbus and a Reynolds 953 sticker on one of the lathes. “We use a ‘blended offering’ of tubes in our frames, with the most appropriate material used for each application” was his response. This led neatly onto talking about the mix of high-tech and low-tech tools and processes that I had noticed while roaming their workshop.

Low tech and high tech

“We offer our framesets in steel, stainless steel and titanium, with upgrades such as a carbon fibre seat tube” said Caren. Matt chimed in here “Titanium is becoming more important in terms of sales and we’re increasingly using 3D-printed parts such as dropouts and the driveside chainstay yolk.” They showed me how the design for their latest chainstay yolk had progressed from sketches to scale drawings to a handmade model to a full-size 3D print. This neatly showcased the combination of Caren’s artist’s training in sculpture and fine art with Matt’s influence on designs from a practical/functional perspective. ISEN use a mix of outsourced components, such as the Reynolds produced 3D printed dropouts and in-house designed components and accessories like their stunning handmade stainless steel head tube badge.

From scale 3D models

“The 3D printing process is great in that it allows the construction of structures not possible any other way and it’s more efficient timewise. Correctly designed and manufactured components allow us to have less stages in the process of building the frame” said Matt. “The process also allows us to create internal structures, such as cable routing runs, which is great. But it’s a very slow process and is difficult to scale.” 

Both Caren and Matt were keen to talk about how they had introduced modern elements to their frames, such as integrated mudguard mounts and dynamo cable ports, with practical elements such as sleeved internal brake hose routing and having large enough vent holes in the bottom bracket shell to facilitate easier feeding of cables for internal routing.

“But it’s not just about the tech” continued Caren “We’re really passionate about offering our frames to as wide a range of people as possible. We realised that smaller riders in particular couldn’t get the fit they wanted or the parts they needed. Even sourcing things like high quality rigid forks for the 650b wheel size used to be a nightmare.” “Riding our bikes should be all about enjoyment” added Matt “and we want to sell bikes that we actually ride ourselves.” “Customers don’t always have a fixed idea of what they want, so during the pre-sales process we talk to them about what kind of riding they prefer and where they are likely to ride the finished bike. We want to give our customers authentic advice. One customer even ordered an exact replica of my own MTB having test-ridden mine first” said Caren.

Downtube graphics are not stickers – they’re masked onto the downtube during painting. But you can’t have them in red. 

I asked them about their backgrounds as cyclists and how this influenced the kind of frames they design and build. “Initially I got into riding through commuting by bike” said Caren. “I grew up in Torquay in Devon, which is super hilly. Initially I was into road riding, but then this developed into riding audax events and then into XC MTB and off-road touring. I love doing weekends away with no fixed destination, some wild camping and lots of time being sociable.” Matt’s background wasn’t that dissimilar “I was a real fan of audax riding. Type 3 fun, where you delude yourself that you’re enjoying it. But now I’m more into touring and bikepacking. Nothing too gnarly, just a good way to get out of the city and also to spend time with my family”.

“How did you get into frame building?”, was my obvious follow-up question. “I was working as a bike mechanic and started building frames for fun really” said Matt. “Then, when I became a dad, I wanted a better work-life balance and frame building offered me the kind of flexibility I was after”. “I studied at the Royal College of Art and we looked at sculpture, jewellery making, metalwork and fine art during the course” said Caren “But I wanted to use my skills for something practical – turning my knowledge into something commercially viable”

Handmade stainless steel head tube badge

We talked next about the range of frames that ISEN Workshop offer. They split their range into four categories, with differing options within each category and some cross-over between ranges. Most models are available in Steel, Stainless Steel and Titanium and all can be customised.


  • Classic Road. A modern take on a classic road bike.
  • R3 disc. A no-compromise road race machine with integrated carbon seat tube
  • R3 caliper. A no-compromise road race machine with integrated carbon seat tube



  • Goat. Big wheeled off-road MTB tourer. Designed for 650b x 2.4” or 29x2.4” tyres


  • All Season. Big tyre volume, drop bar road bike. Clearance for 650b x 42/700c x 35 tyres
  • All Season Plus. Off-road tourer. Has bigger clearance and dropper post routing. Clearance for 650b x 53/700c x 47 tyres
  • All Season Gravel. Identical to the All Season, but with bigger tyre clearance. Clearance for 650b x48/700c x 43 tyres
  • Derelicte. Modern take on a 1990s MTB. Designed for 650b x 2.4” tyres.

Our final topic of conversation was about the trademark ISEN Workshop “look”. All of ISEN’s paintwork is done in house in order to ensure the highest levels of quality control. “Everything you see on the final frame is in paint - there are no stickers or decals” said Caren “And we offer customers a choice of full custom or signature paint schemes. We can paint match components such as stems and forks too.”

I first discovered ISEN via The Service Course, a high-end bike shop and coffee shop based in Girona, Spain. The Service Course have a long-standing relationship with ISEN – you can hire ISEN bikes from them for example - and it was this image on The Service Course Instagram profile which first caught my attention. Although the All Season Plus in the image has the optional integrated carbon seat post, the paint job is the standard fade. When even a standard paint scheme is as incredible looking as this, it’s no wonder The Service Course were keen to stock ISEN bikes. “There was quite a strict process to go through before they would stock our bikes” says Caren “Their whole ethos is about quality rather than mass-produced. Luckily the owner’s view on bikes is well aligned with ours, so it’s a good fit. It’s a great sales tool for us and a unique selling point for The Service Course”.

Before....and After

Caren’s almost throwaway line about quality being more important than volume summed ISENs attitude up perfectly. I asked them where they saw themselves 3/4/5 years down the line. “I’d like us to grow slightly and have capacity to build more, but without losing our core qualities” said Matt. For Caren “quality is key, but I want to be able to tailor everything to the customer”.

And there we finished our conversation. I tried to sneak out with this beautiful titanium All Season Gravel under my coat, but Caren and Matt noticed, so it will just have to go on my Christmas list instead.

If you would like more details on their frames and full bikes, you can check out their website here

Dear Father Christmas. I’ve been a very good boy this year….

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