Saturday, March 17, 2018

No Illusion, its Finished! (1973 Motobecane Mirage)

I learned recently that the Hindu god Ganesha is the remover of obstacles.  He could have been my mascot for this build.  The first obstacle was me, after doing a lot of work on the Mirage during the July 2017 bike blitz I couldn't find the motivation to tackle the wheel hubs.  I had done the; tear down, frame clean up & wax, bottom bracket, headset, brake pads and brake mounting but I let the wheels derail me.

With the right tools, cone wrenches, taking apart a hub is pretty straightforward, and then its all elbow grease and sonic cleaners to get the parts cleaned up.  For the rear hub I decided to leave one cone in place thinking it would be faster to put everything back together and get it adjusted.  Wrong.  During the disassembly the cone had actually moved so I had to remove it anyway to get the cones correctly centered on the axle but the keyed washer for that cone was stuck and required an overnight with some liquid wrench to come loose.  Then when trying to reassemble things, one cone had a hard time screwing onto the axle, after spending time cleaning the axle threads I realized there was a bur on the cone threads! I finally got everything where it needed to be but my short cut turned out to be a long cut.  I also had the all to common issue in adjusting both hubs in that everything was great until I tightened the lock nut and my no slop/no grind adjustment went to heck and the end product had too much play.  After doing this three times I changed my strategy and made the initial adjustment too tight (grind) and after I tighten the lock nut it was just right.  He can be taught.

Since I was working on the hubs that gave me a chance to clean up the filthy FW and spoke guard.  I could have probably just replaced the freewheeel but the teeth were in good shape and I was trying to do this rehab on the cheap.  It got a WD-40 bath, a wipe down between the cogs and 3 in 1 oil in the creases on the back.

When I was getting old wheels ready for scrap I made sure to save as much as I could, one old rear hub was a great template when I had to re-space the cones on the Mirage rear hub and when I discovered the front skewer was missing a spring I had a spare to use.  And finally, I had finished the set of wheels that had been holding things up for so long.

I also found a place for the rack off the Gitane Tour de France, I had tried it in other places but couldn't find a fit until the Mirage, which was good because I had misplaced some key pieces for the pletsher rack it came with.

I have had this bike for nearly three years and worked on it intensely last July, but it wasn't until last week I realized it had cool MB branded bar end plugs.  I kept the original bar tape because it still looks great and it saved me some time and $$.

Back in July I had the foresight to label the drive side cotter pin so I would remember where they should go back.  I could have replaced the cotter pins but again I was trying to this rebuild on the cheap and since I use a cotter press the pins mostly come out in good shape.

My next obstacle was the non drive cotter pin, something didn't feel right as it went in and then it was in tight enough that I couldn't just pull it out.  I though I would need to spring for a punch to remove it but thought to give an old drill bit a try and it popped right out.  As I write this I wonder why I didn't just use the cotter press to back it out....bleary thinking I guess.

You can see the cotter acquired a crease on the lower part of the ramp about dead center of the pin from going in slightly off kilter which is why it felt "wrong", some work with a file and then carefully aligning it got it back in and finished off the cranks.

aligning the rear brake cable guide

When dialing in the brakes I found my 3rd hand tool to be very valuable.  When I was tightening the seat post clamp the rear cable guide, which has the seat post bolt pass through it, got out of alignment with the rear brake.  I used a piece of wood and the mallet to "persuade" it back into the right line.

I'm screwed

After getting the new chain installed, I didn't totally cheap out!  I noticed a potential issue.  The rack screw was protruding, could be a problem...test....yes its a problem, interferes with the chain.  Some spacers on the outside of the rack solved the issue and I didn't even have to take off the rear wheel.....yet.

While testing the shifting I noticed the chain was getting bound up in the largest FW cog, not sure if somewhere the RD or FW was changed from the original but it was not going to work..sigh.

Fortunately I A) used a chain with a master link B) have Park Tool Master link pliers -MLP 1,2 and C) had a new in package SunRace RDM10  rear derailleur.  In theory you can take a master link chain apart without tools but I find that the pliers save a ton of aggravation.  You can see that the Simplex RD has a very short cage which I think was the main issue.

New RD installed and working like a champ with no binding.  I really like the SunRace RDM10 because it's cheap, 10 bucks, and it looks the vintage part, and it works.  In my post on Sunday I said I was close but not quite there.  After getting the shifting sorted I found the following; the brakes weren't dialed in to my liking because the wheels need more truing, both front and rear, the headset was loose and the rear rack wasn't quite level.  Since it was late Sunday I hung it up at that point.  I then had my first week in a new job and didn't get time to address those issues until Friday.  

I was using the cable and housing spares I had and since I had some Jagwire shift housing I used it to make the gold pin striping and lug lining pop a bit.  I didn't get the rear rack totally level and would have needed to remove it to accomplish that, its good enough.  Finally she is done and on CL.

Until next time.  Ride.Smile.Persevere.Repeat.


  1. Persevere, yeah, I understand...How satisfying to finish! Bike looks good.

    1. Thanks Annie it feels good to have it done and ready to be sold.