Singlespeed & Fixed Gear - 700c track wheel on a motobecane mirage? help?

Hi,

I'm converting an older Motobecane Mirage bike (year unknown) into a fixed gear, and I have just come across a detail I hadn't considered (I'm new to working on bikes). I have a new 700c track wheel on the way from ebay, but I just read that french bikes of this era tend to use 27" wheels. So, my question is - will this 700c track wheel work with my motobecane? I'm not even sure what size the wheels were that came with the frame (bought it for $25). And, if it will work, can I use the 700c wheel on the back, and the old 27" wheel (if it is indeed 27") on the front? All advice is welcomed.

sure itll work. Difference between the two is only 4 mm. If you're running a brake, you MAY need to get a long-reach. but i doubt it...

Yep, ditto.

Yep, ditto.

Nice, this is good to hear. Another issue that has come up in the same thread I started in the Road cycling forum is related to spacing. I don't know what the spacing of my bike or the rear wheel is exactly, but if my frame requires some bending, does anyone have any experience with how easy that is? Say, going from 120mm to 126? I read Sheldon Brown's article on this topic, and it seems pretty doable.

120 - 126 is fine. I believe the Mirage is spaced at 120 - I have a Mirage frame in storage. I've never used it (a tad small for me) but it should work okay. I ran a 130 on a 120 and it's okay. 120 to 126 should be quite okay.

I had a 1975 Mirage which was spaced at 126. I ran a 120 spaced Suzue Jr. on a MA3 and all was peachy. You will have to pick up some long reach breaks though. I got the Tektro 521 AG calipers which worked like a charm; not too bad on the pocketbook either.

I had a 1975 Mirage which was spaced at 126. I ran a 120 spaced Suzue Jr. on a MA3 and all was peachy. You will have to pick up some long reach breaks though. I got the Tektro 521 AG calipers which worked like a charm; not too bad on the pocketbook either.

Thanks to everyone for the help. I really am quite a novice w/r/t working on bikes, but I'm really looking forward to riding my first fixed gear machine.

Since it looks like a few of you have some experience with this particular ride, I was wondering if anyone knows what kind of cranks are stock for the Mirage? I need to take them apart (I think) to remove the chainring and guard and to paint the frame, but if it requires some know-how or special tools it might be difficult. Any other information on the mirage would be awesome. Thanks

My '75 had well-aged cottered cranks. The pins were so well lodged in that I had to saw through the arms to get them off. I ended up putting on a cheapy Shimano UN53 BB and a Shimano 105 crankset. Everything worked fine until I ran into a cab and bent the frame.

And just for a reference point the fork on my Mirage was French threaded.

Hopefully you have a later Mirage and don't have to deal with the stupid cottered crankset. If so you may only need some allen wrenches, a ratchet, and some elbow grease.

-Dave

My '75 had well-aged cottered cranks. The pins were so well lodged in that I had to saw through the arms to get them off. I ended up putting on a cheapy Shimano UN53 BB and a Shimano 105 crankset. Everything worked fine until I ran into a cab and bent the frame.

And just for a reference point the fork on my Mirage was French threaded.

Hopefully you have a later Mirage and don't have to deal with the stupid cottered crankset. If so you may only need some allen wrenches, a ratchet, and some elbow grease.

-Dave

What is the easiest way to tell if the cranks are cottered or not?

http://www.sheldonbrown.com/cotters.html

There are little cylindrical pins that hold the arms to the BB spindle. They are not always a pain in the ass, just most of the time; or so I've found in my limited experience.

If your cranks are cotterless you will still need a puller to remove the cranks from the bike. If you buy one buy a good one, I have a trek one that has been wonderful, paid $10 for it at my LBS. The ones that use an allen screw tend to more difficult to use. there is an old mechanic's saying: if you need a tool once you should buy it and never worry again. Make sure to lube up the threads before use!

Would you like a drink with your order? Fixers servin' up the info! :roflmao:

Would you like a drink with your order? Fixers servin' up the info! :roflmao:

Thanks to everyone. I haven't been able to sit down with it, but I would assume the cranks on this ride are cottered. So, I think I'll just live with the extra chainring and guard attached until I amass the tools and knowhow (or maybe just a new crankset) to do something about it. Also, heavy masking will be required to keep the paint off (a bright kelly green is going on, it should look hot).

I'm really happy I discovered these forums. I feel odd going into the bike shop and asking all these questions etc and not buying anything. But when I go in there and buy some new tires, perhaps they can help me get the rear wheel bolted on with proper alignment / chain tension. And at first glance, it looks like the new cheapo track wheel I got will fit without any bending required. Should be on the road before too long - I'm excited.

My Mirage has a Mavic MA40 (700c) relaced to a Dura Ace trackhub and runs a 52x16t gearing. Most don't run a rear brake anway, but the older brakes have plenty of adjustability.

http://www.fixedgeargallery.com/2004/c/kresge20.htm

My Mirage has a Mavic MA40 (700c) relaced to a Dura Ace trackhub and runs a 52x16t gearing. Most don't run a rear brake anway, but the older brakes have plenty of adjustability.

http://www.fixedgeargallery.com/2004/c/kresge20.htm

Cool, I've looked at your bike numerous times while checking out what other people did to their mirages. It's nice to put a name with the bike, so to speak.

Mine is coming along nicely. I've got two wheels (front is old-timey rim that came with the bike, back is cheapo track bits off of ebay) - now I just have to strip off all the unneccesary parts, do a little cleaning, spray on some sweet kelly green, and hopefully bolt on the wheel without too much trouble and it will be all finished.

Now that you are here I suppose I will ask you the same question - did you have any big problems removing the extra chainring? I'm afraid if I start pulling these cranks apart I'll never get them back together again.