Arts and crafts
Aaron Barcheck is only 33 years old yet his frame building tally already runs into the thousands. The man behind Mosaic Cycles talks us through his flagship racer, the RT-1
There are many routes into frame building. Some people quit jobs in the City and set up in their shed. Others come at it from engineering courses, fine-art degrees or circuitous routes via aeroplane maintenance. Some just do it in their spare time and it turns out they’re rather good at it. Aaron Barcheck is none of these.
‘I got into frame building straight out of high school,’ says the Colorado-based builder. ‘I went to the United Bicycle Institute [UBI], built my first frame, got a job at Dean Titanium Bicycles in Boulder straight after, worked there for seven years then started Mosaic in 2009. I think that kind of experience is key in frame building. I started at the bottom, doing facing, chasing and reaming, sticking decals on frames, and I worked my way up, bit by bit.’
Barcheck says this with an easy grin, but as he starts to explain this titanium-tubed RT-1 it becomes clear his laid-back demeanour conceals an incredibly dedicated individual. After all, it’s no small feat to make TIG welded joints appear as if they’ve been fillet brazed.
‘At Mosaic we’re certainly known for our TIG welding. It’s my speciality and what sets us apart from everyone else. I know they’re covered up a bit by the paint but I can assure you they’re nice and smooth underneath. There’s no filing those stack-o-dimes.’
The ‘stack-o-dimes’ Barcheck is referring to are the dozens of tiny overlapped puddles of filler metal that encircle the joints on a TIG weld. The smoother and more uniform those puddles, the more skilled a welder is considered to be.
The most obvious place people look for evidence, he says, is at the head tube and seat tube cluster, but the best demonstration of a frame builder’s talent is observed at the bottom bracket cluster, where the angles are acute and the space to work in minimal. On the RT-1 this area is as close to perfect as possible, so it comes as no surprise that Barcheck has a clutch of awards to his name including Best Gravel Bike at this year’s North American Handmade Bicycle Show. It’s somewhat fitting given his first creation.
‘That UBI frame was a cyclocross bike. I’d never welded, never machined,
and in the end I had to chop the stays out and replace them because there wasn’t enough tyre clearance. It’s been refinished a number of times, but you’ve got to start somewhere. I rode it for a few years and it still sits in my office. Every now and then I wheel it out to show people what crappy welds look like!
‘At the end of the day it’s just TIG welding and I just have a knack for it, but if you want to get arty about it, I guess it’s like writing with an ink pen. You never actually touch the paper.’
Tuning in
When it comes to materials, Barcheck’s first love is titanium: ‘It’s one of the most versatile materials there is. I mean, you can make lightweight, awesomely stiff, poppy race bikes with it or you can make compliant gravel bikes, full-on cross racers, commuter bikes. You get that snappy feel when you put the power down combined with that smooth ground feel. It’s the best of all worlds.’
To create that feeling, Barcheck has used a mixture of oversized double-butted and plain gauge 3AL-2.5V tubes on the RT-1. Some of the tubes have been custom made to be exceptionally light and stiff by combining wide tube diameters with thin wall thickness. In this way all Mosaic’s custom frames, of which the RT-1 is one, are rider-tuned.
‘If you’re a 65kg rider you need to be riding an entirely different tube set to a 95kg rider. That will change the weight of the frame a bit, but we don’t focus too much on that – it’s about fit and frame characteristics. I’d take that over a few hundred grams any day.’
Still, the RT-1 comes out at around 1.2kg per frame (size dependent) meaning this full build, dressed in Enve 2.2 wheels, custom-painted Pro Vibe finishing kit and mechanical Dura-ace 9100, weighs a hair over 7kg. That doesn’t include the frame pump, though.
‘That Silca is probably the world’s most expensive frame pump, especially now it’s been painted. Traditionally we just offered raw, etched titanium frames but this year we’ve got a paint programme. I’m sure some people still think painting titanium is sacrilegious, but I love the contrast between the metal and the paint, and the pump just fitted so well with our approach. Living in Boulder, the terrain breeds a certain type of bike – no-nonsense – so on this calliper version you can easily fit 28mm tyres, and on the RT-1 Disc, 30mm. Really all you’d need is a clutch on the mech of this thing and you’ve got yourself a lightweight mountain bike.
‘It’s cool. Bike designs are getting progressive again. Different tyres and gearing have opened up whole new scenes, like gravel, and Mosaics are evolving alongside that. You can really beat this thing up and it will still stay with you for life.’
‘At the end of the day it’s just TIG welding and I just have a knack for it, but if you want to get arty about it, I guess it’s like writing with an ink pen. You never actually touch the paper’