Factory Tour – Guru Cycles, Part 1: Office Visit, Carbon Bike Design & Stress Testing

For quite some time we’ve been talking to Guru Cycles about visiting their headquarters and factory near Montreal. Following Interbike, we finally made it happen, giving us the opportunity to see close up how they make the amazingly light ~670g Photon HL carbon frame. I even got to ride one, as well as see how they come together from the time you talk to your shop until the time it’s boxed and shipped. And every last bit of the frame is made there in their own facility. Rolls (not tubes, mind you) of prepreg carbon comes in, frames go out, and that goes for all of their carbon bikes, not just the top of the line HL.

They also make titanium bikes, which will be the subject of Part 3. Here, and in Part 2, we’ll show you how the carbon frames are designed, made and tested, along with an overview of their entire operation. Come along, join the ride…

The first stop is the showroom, upstairs from the production floor and adjacent to the offices. One or two iterations of each model sit dressed to impress.

Inside the glass room is their fit studio. If you’re in the area or willing to travel because your own shop can’t do the fit, they’ll be happy to dial you in on their Guru fit device.

Behind the fit station is their workshop, and across the floor is their cafe. Not sure if there’s free coffee for all, but the espressos were flowing when I was there. C’est bon! On the right is the conference room, where we spotted the requisite-for-any-factory-tour prototype sketches:

“No comment.”

Behind the cafe are all the offices, with sales and customer service taking up the middle space. Above is the graphics department, where they make your wildest (paint scheme) dreams come true. They offer quite a range of colors, but can basically do anything you’re willing to pay for:

The Guinness bike was reportedly quite a fun project.

Once the graphics for a customers’ bike are finalized, they’re cut and prepped in a bundle and head over to the paint and finishing to await the frame. That’s Jodi, their marketing/PR director and my lovely host for the visit.

CREATING A BICYCLE

The process begins with a good, professional fit from a certified fitter. That’s why they developed their own Guru sizing system, which has since been sold to the Cannondale Sports Group. It’s one small example of the innovation that comes out of this small Canadian company. Another is one of the first production sub-750 gram frames with the original Photon. And the new Photon HL that can come in just under 670g for a stock H1 in size 54 thanks to some trick carbon cutting (you’ll see).

Start to finish, it’ll take about 3-4 weeks to make a Photon. Actual hands on time is at least 20 hours -more for the HL- with a good bit of that time used for drying and curing. Then add a week for delivery.

Once the rider’s measurements, body metrics (weight, height, etc.) and preferences (stiffness, comfort, riding style, etc.) arrive, they’re plugged into Guru’s software. After dropping in the numbers, the system warns of any potential issues like toe overlap. If it’s all clear, they generate three drawings: A rendering to show the customer, a build sheet showing dimensions with the seatpost, stem, fork and other parts, and a geometry chart for the actual frame builders to use. That gets approved, then it generates cut patterns for the carbon and we’re off to the cutting room.

Each tube and section of the frame has it’s own specific group of plies.

It’s plugged into a router that cuts the shapes from rolls of prepreg. They cut parts to make every bit of the frame, including the tubes. That makes them one of the few brands that actually makes their own carbon tubes in house. They use two different grades of prepreg carbon -standard and ultra high modulus- and control the layup from start to finish.

This is one tube. Shapes are cut in exact designs that minimize overwrap where it’s not needed, which saves weight and waste. It makes for much prettier layups, too. They’re cut and stacked so the fabricator can work on a single tube or part at a time.

One of the secrets of the HL’s amazingly low weight is the patent pending striped design. The finished tubes look like strips of carbon were laid up over the rest, but in reality strips are removed from the outer layer. Believe it or not, that saves up to 60g per frame, all without sacrificing strength or rigidity. They use this pattern across most tubes on the frame.

They weigh and QC-check each tube and part before molding, after molding and various other times during the process to make sure things are in spec. Each frame supposedly comes out within 5g of target weight before it goes to paint.

Once cut, the pieces move next door to the clean room where everything’s laid up around latex bladders.

These are bladders for the headtube and seatstays.

The bladders are filled with glass beads to give them enough shape to wrap around, then emptied before going into the molds, which are machined in-house out of aluminum. They use aluminum because it’s easier to machine and lighter (easier to carry the molds around by hand – you’d need a lift to move steel molds). Since they’re a comparatively small volume operation, they don’t need the durability of steel molds.

The exception to that method is the seat tube and bottom bracket, which is what’s being fabricated above. The seat tube and bottom bracket shell are wrapped around a metal mandrel covered by a bag, then wrapped together before going in the mold. This creates a co-molded part with the tight tolerances requires for pressfit bottom brackets.

They admit the silicone bladders result in a smoother (near perfect) interior wall, but in order to co-mold the piece the way they do, it required a bag. So, they chose the smallest bag they could that most closely matched the size of the mandrel to reduce wrinkles as much as possible. It’s removed after curing, so all that’s left is the carbon. Taking it out saves about 15g. Yep, I’m just teasing the actual wrap method here – the complete carbon bike construction follows in Part 2. But, we’ve gotta get things ready first.

While we’re looking at molds, here’s their collection. The ones pulled out are for their TT bike (which was updated at Interbike) and uses a lugged construction method rather than the Photon’s lighter-but-more-labor-intensive tube-to-tube build. The lugged construction lets the parts sleeve together quickly for easier, more price-competive builds.

This adjustable mold lets them tweak the size of the tube based on the customers’ dimensions. Also made in house, just like all their tooling:

All of the dies and other bits used to craft their frames are machined in house. Having it all under one roof allows for quick testing and development. From the time they develop a concept, it’s on the factory floor being prototyped within a couple weeks. And if they need to change something or want to test an idea, they can machine the tooling or lay it up quickly and integrate it into production within days.

They have a lot of bladders for different size and type frames.

The carbon tubes on the left are house-made tubes for a Photon SL, which gets custom geometry but uses “stock” tubes.

Once the mold or bagged mandrel is wrapped, it’s inflated to compress the carbon against the alloy mold. Those are clamped together and placed in the heat press. That machine compresses the molds with 20 to 25 tons of pressure, then heats them. Once the temperatures are correct, which is monitored by a computer, air pressure is put in. Both temperature and pressure are ramped up gradually, reaching up to 135 degrees C and 120-130 psi. The whole process takes 30 to 40 minutes for the larger molds, much less for the smaller molds since they heat up quickly. The curing process is customized for each tubeset based on the makeup of the fibers and resin type. Just another example of how they control the process for every bike. Once this process is over, any resin flash is removed, tubes are sandblasted to remove any residue, and they move on to the mitering station. As parts are finished, they’re assembled into a bin for initial tack up, then come back to the clean room for the outer wrap that actually turns the parts into a whole. Again, Part 2. Tomorrow.

TORTURE TESTING

Fast forward to the complete frame. Once it’s through production, Guru engineer Nicolas McCrae will occasionally pluck a frame from the line and bring it here to die. They have four different test rigs, which can all be set up with different load cases to test deflection on specific parts of the bike. They can mimic tests used by Asian manufacturers and Tour Magazine, plus their own protocols.

This bike was being tested for front triangle flex. McCrae built it up normally and tested it to pass. Then he added a couple layers of strategically placed (he wouldn’t tell me where – top secret R&D and all) high mod strips of carbon and increased front triangle stiffness by 30% for a weight gain of just 2%.

He also tests prototypes and new layups. This woven pattern did well, but isn’t practical from a production standpoint. Or at least that’s the story McCrae’s sticking to. There were some other ones we couldn’t photograph.

Ultimately, the physical tests are done to verify the computer simulations and virtual designs.

The other side of the equation is the torture testing, shown on the right. Their machine simulates 100,000 left/right pedal revolutions with a 1,100 Newtons of force (242 pounds) on each side. So, that’s like a 240lb person putting 100% of their weight and 100% of their effort riding routinely for years. McCrae said it’s far more load than any bike will see in the real world. He adds in a short burst of 1,700 Newtons for 4,000 cycles (375 pounds) just for fun, too. He says if a frame passes the first 4,000 cycles, it’ll likely last a couple million cycles. All of their bikes, even the insanely light Photon HL, pass the test easily.

If those numbers seem meaningless, watch this:

Oh, and don’t worry. These frames aren’t dropped back into the sales cycle. If they pull one, a duplicate work order is submitted so you’re getting a fresh frame.

Continue on to Part 2 and Part 3 for the rest of the tour!