My "new" 1977 Mondia Super "gravel" bike.

 A few years back, my pal Shawn surprised me by shipping me this lovely Swiss Mondia road bike frame for my birthday.  It hung on a hook in the shop for a couple of years, while I pondered how best to build it up.  Finally, after riding my fully equipped Goshawk touring bike on the C&O Canal and Great Allegheny Passage for years, I realized the Mondia might make for a fun, lighter option for those unpaved trails.

Originally intended to be a sporty/racy road bike, the frame is built from the well known Reynolds 531 double-butted manganese-molybdenum tubing, with the very pretty Nervex Professional lugs at the joints. Intended for 700C road wheels and tires, it would probably fit around a 25 or 28mm wide tire, which wouldn't be ideal for the kind of riding I wanted to do on this bike.

On the other hand, over the last 15 years or so (how time flies!), the bike world has seen the resurgence of a tire/wheel size that many had considered obsolete - 650B.  Wait, what the heck is all this "700C" and "650B" stuff anyway?  Well, both of those are tire/rim size labels that come from the French cycling industry.  In the original scheme of things, the number (700 or 650) indicated the nominal outside diameter of the tire in millimeters.  The letter was used to indicate whether the tire was narrow or wide, with A being the narrowest, D being the widest.  As with so many things in the bike industry, how things started out is not where we are today, and a typical 650B tire is much, much wider than a typical 650C tire is today, and 700C tires range from 23mm to 50mm or wider, while 700A, B, and D have vanished as labels. Confused?  Welcome to bicycle tire size "standards" which are anything but standard.  Some good info can be found here:  https://www.sheldonbrown.com/tire-sizing.html#french

Okay, what does this mean for my Mondia?  Well, 650B tires and wheels are smaller in diameter than 700C by 38mm.  Mounting a set of those on a frame designed for 700C wheels gives you room for wider/taller tires, which give more cushion on rough surfaces.  In the case of this Mondia, I was able to easily fit 40mm wide tires on a bike that normally would have only allowed for 28mm or so.  I even had room for a set of fenders to boot!  I had a set of 650B wheels I'd built some some time ago, with older parts, Sansin hubs and Alesa rims with Panasonic Col de la Vie tires.  I'd thought about using them on a couple of other projects, but it wasn't until the Mondia that it came together.

The rest of the parts are things I've used on a number of other builds, because they just work for me.  Sugino Mighty Tour crank with 40 and 52 tooth chainrings, MKS Touring pedals, SunTour 14-30 freewheel, SunTour VX derailleurs and Power Ratchet bar end shifters, Nitto bar and stem, and of course a Brooks B17 saddle.  The brakes are long reach Weinmann centerpulls, which work great.  Accessories at this point include SKS Longboard fenders, a Velo Orange Randonneur front rack and handlebar bag, and Carradice Lowsaddle Longflap saddlebag.

 More photos can be seen here:  1977? Mondia Super

Progress on V-O Mixte

Well, it's been slow going on building up the Velo Orange Mixte for my girlfriend.  I've been a bit busy with adjusting to being a business owner, for one thing.  And while the bike shop season hasn't really "hit" yet, we've been teased with just enough spring-like weather to ramp up the demands on the service area, so I've been busy with that too.

But I did manage to get some work done the other evening.  Specifically, I prepared the frame and fork for headset installation, then installed the headset and fork.

For those that may not know, the headset is the bearing assembly that allows the fork to turn smoothly. It's important that the head tube (the part of the frame the headset fits into) have nice, smooth, clean, round bores into which the headset is pressed.  In addition, the top and bottom "faces" of the head tube need to be parallel to each other and have a nice flat surface to them.  A bit of time and care with the proper tools, and all is good.  Similar work generally has to be done to the fork to prepare it as well.

Once the frame and fork have been prepared, the headset simply gets pressed into place, using a special tool that applies a good amount of force while helping assure alignment as it presses the pieces in. It's entirely possible to do it using homemade solutions, but I have the benefit of a well equipped bike shop at my disposal!

The final step to the process is sliding the fork into the headtube, through the headset cups, then installing the adjustable cup and lock nut on top.  Final adjustment will happen later when the bike is just about complete.

I chose a Velo Orange Grand Cru headset, which looks spiffy and has sealed, cartridge bearings, which hold up well and make for easy servicing down the road.

Meanwhile, the front wheel with Shimano Dynohub is ready to go, and the rear wheel with Shimano Nexus 8 speed internally geared hub is awaiting final tensioning and truing.  Most of the rest of the parts have been gathered, and will be addressed as we proceed.

More photos are here:

Velo Orange Mixte 3-6-2011