Tag: crown

PB Crown with Rack Bosses

I have been working with Kirk Pacenti of bikelugs.com fame to get the Paris Brest fork crown made with M5 rack bosses built into the shoulder of the crown during casting.  I Samples are here and I am very excited for these.

Until now if you were working on a Porteur / Randonneur style of bike you options were limited to bosses that were hand brazed into the top of the fork.  Having the bosses as an integral part of the casting will shave man hours and result in a stronger more consistent product.  These crowns will make this style of front rack mount more approachable for builders and designers.

There are a couple of strong benefits to having crown mounted rack bosses.  Foremost is the added stiffness you will get from a rack with two well spaced upper mounting points as opposed to the more common single point in the center.  Running a close second is having redundancy of upper mounting points, two is better than one.  If a bolt were to come loose or a rack strut fail, the loaded rack is less likely to immediately drop into the rider’s front wheel.  I believe this mode of failure is more common than thought if the number CPSC recall notices on production front racks is any indicator.

I hope that by pushing this fork to market we will see an increase in the number of well designed front loading bikes and front racks on the market in the coming years.  The crown specs are the same to the existing Paris Brest in every way other than the added rack bosses.  Spacing between holes is 80mm.  If we as designers and builders were to adopt this as a standard it will help with the proliferation of the niche. bringing a level of consistency across brands.

After talking with Kirk today, these crowns will be available through Bikelugs.com  in 6-8 weeks.

Mark’s Rack Fit on the Rambler

The Rambler while a well handling bike with no load aside from the rider, is designed to ride well with a modest front load.  As part of the design there are integral rack mounting points: two eyelets at each dropout, two mid fork hourglass mounts, a hole drilled through the crown at the traditional brake mounting point and two M5  bosses set into the shoulders of the fork crown.  One of the questions that keeps comment up with the Rambler is what front rack do I recommend.  In particular a rack that will work well with the rack mounting bosses located in the shoulders of the fork crown.  While popular among custom bikes of this genre, this mount is less common on production bikes.  By providing for two upper mounting points, the rack can be more stable and have redundancy.  In the case that one upper mount should fail, loose a bolt etc., you have a second mount in place helping to prevent the load from crashing into the front tire.  Trust me, loads into the tire are not a good thing.  Solid rack mounting helps to keep things where they belong and you rolling safely.

The most versatile and well made small front rack on the market at the moment is the ‘Mark’s” rack produced by Nitto of Japan, and designed by Rivendell employee Mark Abel.  This rack is made of brazed CrMo steel with a nickel plate finish for long corrosion free service.  The mounting has provisions for four struts and a center bracket to the crown.  These options allow it to easily mount to just about any bike as a strong and attractive solution.  I have been using it on the Rambler with the central mount to the crown and the two front struts connected to the mid-fork.  I recently replaces the central mount to the crown with two aluminum struts between the rack and the upper crown mounting points.

Rambler with Marks rack

Rambler with Marks rack

Rambler with Marks rack

With the mount to the center of the crown the rack was stable, now it is rock solid.  I had to reshape the supplied mounting struts a bit, hammer and bench vise.  After trimming things to length it all bolted right up.  While I knew it would fit fine, it is exciting when a plan comes together.  Next, since I have a habit of fiddling with things, I will work out a way to attach the fender r added support and fine tune the fit.

The way I have it set up I can quickly install/remove the Bruce Gordon low-rider pannier rack.  I will have a pictorial of this process in the next week.  The keen of eye will notice that I have all of this mounted to a band clamp on the mid fork.  Production Ramblers will have the hourglass mounted such that the racks will bolt right up.  So far little details like this are all that needs to be adjusted between the samples and production.  Testing continues, but I am ecstatic with how these are turning out.