Seven Cycles Blog

Trail, Rake and Bikes That Handle Well

March 26th, 2015 by Seven

Our friend Phil tests the 622 SLX (and its handling) on the cobbles of Northern France.

For a simple machine, it can be hard to understand how to make a bike handle the way you want it to. While a lot goes into how a bike feels on the road, the basic mechanisms of good handling are trail and rake. Trail is the distance between the axis of the headtube, where it intersects the ground, and where the tire actually contacts the ground in front of it. Rake, or offset, is the distance between the axis of the headtube and the axis of the front axle, usually between 4 and 6cm.

Our approach, here at Seven, is whenever possible to keep trail constant. The trail sweet spot is just under 6.0 cm.  “Sweet spot,” in this case, simply means consistent and predictable handling at any and all speeds.

For example, if a rider is looking for a criterium bike (think: quicker, more agile steering), we keep the trail fixed, and adjust the head tube angle.  Steeper is quicker. Of course we’ll change a lot of other geometry elements, too:  drop, chainstay length, front center, ride position, tubeset, etc. Conversely, if the rider is looking for a century bike (think: stability), we keep the trail fixed and make the head tube angle slacker. And all the other geometry elements change, too.

Altering trail to affect handling seems like a logical move, but the result is handling that changes throughout the speed range. A high-trail bike will be super stable at high speeds and pretty squirrely at low speeds. High speed stability might sound good but it also means that when getting in and out of corners the bike will fight you. Messing with trail basically means the bike behaves poorly.

Unlike a Seven, plenty of stock bikes don’t have trail in the sweet spot. Riders get used to bad trail. This is particularly noticeable on really small production bikes. Small stock bikes are trying to avoid toe overlap by using a slack head tube angle without an appropriate fork rake; most companies use one or two fork rakes across the size range, so the trail is terrible on bikes with top tubes shorter than about 53 cm. Otherwise, they’re doing something goofy with the geometry somewhere else – seat tube angle, drop, etc., always making compromises because they don’t have the fork rake options to get them back to a reasonable trail.

It’s really interesting when that same, smaller rider gets on a Seven with the right trail; the feedback is that the bike handles amazingly.  “It’s on rails,” “telepathic,” and “I descended faster than ever,” are common phrases we’ll here.

Of course there are exceptions to every rule.  A few examples of rare instances when we’ll change trail from the sweet spot are:

  • We have no option:  For example, the rider wants to use a non-Seven fork that only comes in one rake.
  • Some specialty bikes:  Sometimes on heavy duty randonneuring bikes we’ll do low-trail because this makes the bike more stable at low speeds – and it can help with handlebar bag weight on the front end.  On some triathlon bikes we’ll break the trail rule and increase it to make the bike more stable at high speeds. And on most mountain bikes the trail standard gets ditched – in part because of fork rake limitations.

At its most simple:  Handling is dictated by head tube angle. Predictability of the handling is determined by fork offset.

The Cycling Media Reacts to Mo Bruno Roy’s Retirement

March 25th, 2015 by Seven

It’s been a happy/sad week for Mo Bruno Roy, since she announced her retirement from Elite Cyclocross racing. New beginnings are like that. It’s a testament to all the things we said about her just a few days ago, that the cycling press has covered her retirement in a way they don’t usually mention other riders moving on.

There were kind words on VeloNews, a nice interview on Bicycling, and a photo series on The Radavist, showcasing Mo’s Mudhoney PRO race bike, all-in-all the nicest way to sign off from elite racing that we can imagine.

Stay-tuned for our own interview with Mo, and don’t think you’ll stop seeing her on her Seven or in these digital pages. She’s not racing elites next season, but, in literal terms, she can’t stop/won’t stop.

The Big Ideas – Single-Piece Flow

March 24th, 2015 by Seven

Last week we wrote about our customer interview, and that process came from our need to be able to build exactly the bikes our riders wanted. It got us thinking about this whole bike building project we embarked on in 1997 and the foundational ideas that make what we do possible. These are our “big ideas,” and over the next few weeks we’ll walk through all of them, from our unique build process to the way we collaborate with our customers, to the way we deliver our bikes.

This first installment is about Single-Piece Flow (SPF).

We always wanted to be a different kind of bike company, one that offered both a product and a service, in our case a bike and the experience of customizing it. We wanted to give our customers an experience that was about them and their cycling, not just about the bike. In a very real way, we didn’t want to be a bike company. We wanted to be a rider company. That’s where we started.

But that idea has to be more than marketing. It has to be manufacturing, too. It has to be real. How do we do that?

The simple answer is Single-Piece Flow, a way of building things that unleashes the potential for deep customization. Single-Piece Flow literally means building things one-at-a-time. By building each bike one-at-a-time we can focus on the individual rider it’s being built. Their name is attached to every order. All their personal information travels with the bike through every stage of design and build.

Building by hand, to order, never in batches, allows for the greatest level of customizability. Every order is unique, so we break it down into its constituent parts. We spec tubes specifically for the rider in front of us. One builder works on one bike, refining all the raw tubing, the dropouts, to match that one rider’s needs.

SPF is also where quality comes from. By focusing on one bike at a time, the builder is only ever responsible for one thing, the work in front of him or her, one set of details. The fewer hands touch each frame, the more responsibility each set takes. Typically only 2 or 3 builders work on a Seven, a machinist passing a perfect frameset to a welder, the welder passing that frame to a finisher and/or painter. This approach maximizes accountability while still allowing for a high-level of specialization by each builder, whether machinist, welder, finisher or painter.

The kind of focus and experience SPF demands isn’t cheap. Our team of builders has more than 300 years collective experience. We invest a lot in them, and that investment requires another big idea to sustain in a competitive world. Next time, we’ll talk about Just-in-Time (JIT) manufacturing and how it helps us put our capital in experienced craftspeople, rather than inventory.

Things That Last – Before and After Axiom repaint

March 23rd, 2015 by Seven

We built this Axiom SL in 2002, for a customer who has since worked with us on two more bikes. This winter, he decided he wanted to update the look of this bike after 13 years on the road. He sent it to us to strip and repaint. This is what it looked like when we got it, not bad for its vintage, not bad at all.

We tell our riders we’re building them a lifetime bike, that they’ll still be riding it in decades. We think it’s one of the big selling features of a Seven, but in the excitement of getting a new bike, few really appreciate the value of the long term. You can’t blame them, they’re getting a new bike.

But now, 18 years into our bike building adventure, we are seeing bikes coming back for refinishes and repaints, and we send every one back out the door looking as good as it did when it was new. Many of these frames are a decade or more old.

There’s a story in this that resonates with these times:  about quality, about not making disposable stuff, about caring for and fixing things instead of throwing them away and buying something new.

Here is the after shot of the bike above:

We hope we’ll see it back again in 10 or 15 years for another update.

On the Road – Daniel Sharp Goes Stampede Solo

March 20th, 2015 by Seven

One of the nice things about Daniel Sharp’s photographs and prose is that they don’t over-glorify his exploits. He acknowledges his miscalculations, his struggles and his suffering. Because that’s what adventure is, right? The intersection of suffering and fun?

This time Dan is riding solo near his Oregon home. His photos and excerpts from his trip journal below: