Blog

Originally Published February 8, 2007

In this edition of the 650Blog, I'm going to review my recently built Kogswell P/R, and provide some background information on a relevant topic that many of you have probably never considered; front end geometry.

The Kogswell P/R is a new, limited production 650B-specific frameset produced in Taiwan. The tig welded steel frameset is sold as a package consisting of frame, threadless fork, 1-1/8 inch headset, seat post, seat collar, cable hanger, and a complete set of full length metal fenders. It is offered with one of a selection of three possible forks. The forks differ in the amount of offset to tailor the handling for use with or without a front rack, and I'll go into detail on why that is significant further into this article.

My particular Kogswell was powder coated in a rather understated gray color, which is reminiscent of older French bicycles. And I chose to assemble this bike with components which enhance that visual and practical French style. What do I mean by this? Well, the French developed and refined two types of bicycles that are still relatively unknown here in the US; the porteur, and the randonneuse. The Kogswell P/R can be assembled in either of these styles, hence the designation "P/R".

So, what are these porteur and randonneuse styles, and why are they uniquely French?

The porteur style bicycle is a machine designed and built to carry heavy loads on platform racks mounted to the front fork. These machines saw widespread use as vehicles for newspaper distribution on the rugged streets of French cities in the latter half of the twentieth century. The bikes typically had a swept handlebar and geometry that made for stable handling while carrying a heavy payload on the front rack. They were workhorses, and they can still be found on the streets of Paris. 

The randonneuse is a bicycle designed for touring the countryside on rough, paved and dirt roads, and it is also intended to carry a load on a rack mounted to the front fork. In this case, the load would be the rider's essentials for the outing; clothing, food, tools, spares, etc. And if the journey was to be of any length, there may be some additional gear for camping or sleeping. Although there is a class of machine yet further refined for camping, many people just used their randonneuse and packed it with additional gear. Most authentic French randonneuse bicycles have fenders, racks, and integrated lighting systems. They are meant to be all-conditions, all-roads bicycles, and many will argue that there are none better. Bikes such as this are still being crafted by Ernest Csuka of Cycles Alex Singer in France today, and there are several artisan craftsmen building this kind of machine in North America and Japan. The randonneuse is a sporting machine, or a touring bike in the French fashion.

These bikes are uniquely French in that they were designed to carry their payload in the front; they are front-loaded. And they typically rolled on 650B wheels with large volume tires to be comfortable on the rough pavement, cobblestones and dirt roads of France and surrounding countries. The front end geometry of these bicycles was optimized for stability and predictable handling with the load carried up front. British bicycles, on the other hand, were typically rear loaded, and the large capacity saddlebags seen hanging from the loops of Brooks leather saddles is characteristically British. Most of the road bicycles sold in the US today are evolved from British and Italian designs, but this French school of design has been making a resurgence in recent years, especially since the revival of the 650B wheel.

When the 650B products became available once again in the US market a couple of years ago, those of us who had been longing to experience this type of bicycle began to configure some of our new 650B machines with front racks and bags, and we came to understand that the French bikes had unique front end geometry that made this carrying arrangement practical and pleasant to ride. They were different.

In today's bicycle market, few people pay attention to front end geometry. For the most part, the designers of today's bikes pick a standard trail figure which is typically in the high 50mm to low 60mm range, and they then determine the head angle and fork offset which will yield that desired number. When you put a loaded handlebar bag on a bike like this the handling will suffer; the bike will require quite a bit of effort to control, it's nearly impossible to ride hands-off at any speed, and it can become tiring after some time on the road. High speed stability on unloaded bikes favors the higher trail front end, and so most of today's racing inspired road bikes are typically designed with those parameters.This is why so many people have come to dislike handlebar bags and front racks; most bikes simply weren't designed for them.

To design a bicycle to carry a payload on a front rack, it is necessary to reduce the adverse effects of putting the weight out in front of the steering axis. A French front end typically has a moderately steep head angle to reduce wheel flop, and a relatively large fork offset, which results in a low trail figure. Although a fork with a lot of offset looks old fashioned today, it is a proven method to reduce front end trail, which improves handling for front loaded bicycles. With a trail figure of 25mm or 30mm, a front loaded bicycle is easy to ride, even no-hands, and it can be easily maneuvered. These French constructeurs really knew something about front end geometry.

The Kogswell P/R geometry is essentially copied from the French bikes. Early in the development cycle, several P/R prototypes were built and a team of test riders evaluated the various fork offsets for loaded and unloaded riding to determine which were best. My own Kogswell P/R is configured with the fork that yields 40mm of trail. This is the middle of the three options of 50mm, 40mm and 30mm. The 30mm is intended as the best option for rider's who will regularly carry heavy loads. The 50mm option is for those who will not often carry a load, and the 40mm is the choice for people who expect to have a light to moderate load on occasion.

I've configured this P/R in the randonneuse fashion, and it is sporting components to that effect. The fenders originally supplied with my P/R were fabricated from steel, and were painted to match the frame. But I decided to fit Japanese Honjo Koken aluminum fenders, which are patterned after the French Lefol fenders often seen on old Rene Herse and Alex Singer bicycles. The crankset is a Sugino PX, and it is similar to the TA Cyclotourist. Unfortunately both of those cranksets have been discontinued, but they turn up as new old stock from time to time. The rest of the parts were picked because they fit my ideas for aesthetic and practical purposes. Some of the components are recent offerings such as the SPD pedals, the 105 rear derailleur, saddle, stem, etc. And some are vintage items, like the brakes and levers.

The handlebar bag and rear bag are French products. Gilles Berthoud manufactures these bags from high quality canvas and leather. The front bag rides on a Nitto M-12 rack, and is secured at the top with a device called a decaleur. The decaleur has a quick release feature which allows the rider to easily remove the bag. These are top quality bags, and they're built to last.

The front handlebar bag is very handy while on the road, and the numerous pockets provide ample storage. The top compartment is easily accessible, even while riding. The top cover can be hooked over the stem, and in this position it will provide an extra measure of wind and weather protection for the rider's hands when gripping the top of the handlebar. The rear bag is an ideal place for essentials such as tools and a spare tube. It can be used alone for shorter rides that don't require the additional capacity of the front bag.

This new Kogswell P/R is different than the Trek 650B conversions that I highlighted in the last article, the P/R styling and execution are more traditional and typical of a classic randonneuse bike. Comparing them, I think that you can get a better appreciation of the types of bicycles that are possible to create with 650B wheels; they are not all the same simply because they have the same wheel diameter.

The Kogswell P/R frameset package can be the basis for a modern rendition of the classic French porteur/randonneuse, and it can be configured for use as the owner intends. The frame has horizontal dropouts, and so it is suitable for building as a single speed, fixed gear, or with an internally geared hub. It's a cost effective 650B-specific offering that builds on the experience of the legendary French constructeurs, and makes this kind of bicycle available to the 650B enthusiast who is looking for that French front end geometry, and is willing to take the time and effort to make the parts selections and do the assembly. If you have these skills, or know of a shop that can provide them for you, the Kogswell P/R is an excellent choice.

Perhaps you don't require front loaded carrying capability, and you're just interested in having that allroads, "650B experience". Then maybe a 650B conversion is suitable for you. In the next iteration of the 650Blog, I'll cover the basics for determining which bikes are 650B-convertible. There are thousands of bikes out there which are suitable for 650B conversion, and we've found that they can be amazingly good!

Thanks for reading along,

Ed 650Braley