Gitane mixte chainring choices

[cchaven]

I'm currently rebuilding a Gitane mixte. It came to me with a no-name cottered crank with 52/36 chainrings. I also have an early Nervar Star alloy square taper crank with 54/42 chainrings. I'm just not sure which would be better to use.

I'm removing the Simplex Prestige deraileurs, which have seen better days, and replacing them with a Suntour Compe-V and V-GT front and rear. Wheels will be Mavic Module-3 on Maillard hubs. Freewheel on the rear is an Atom 77 (14x30) 6 speed. It will need to be rebuilt though as it no longer spins freely.

Test fitting of the Nervar Star crank with it's correct spindle suggests that it would work fine with the existing bottom bracket cups. Test fitting of the 700c wheels suggest the Mafac Racer brakes have just enough reach for the wheels, including the remounting of the fenders.

Suggestions on how well either crank would work with this setup?

Thanks

 

[Nob]

Go with the alloy crankset as it’ll match the allot sun tour kit.

 

[non-fixie]

The Nervar Star probably has a 122mm BCD, which is obsolete, that will be difficult to find rings for. Earlier versions had a 128mm BCD, which is so close to the current 130mm standard that a bit of macgyvering might enable you to use many modern chainrings. 38T will be the smallest size, though.
Having said that, if the current rings are in good shape, and the tooth count works for you, you're good to go.

The steel cottered cranks are heavier and a bit of an acquired taste. I like them. They just look right on many older bikes and the weight adds a certain smoothness to the pedaling experience that I like. Your set has the added advantage of a 36T small ring, which is nice if you want lower gears for the occasional hill.

The SunTour V-GT is an excellent derailleur and rated for a 34T max cog size and 36T max chain wrap, so will work with pretty much every combination you can think of.

Rebuilding the freewheel may not be necessary, as usually they are just gunked up with old grease/oil/dirt. I've gotten very good results from flushing them with WD40 and re-oiling them. Easy, fun and rewarding (if a little messy).

 

[cchaven]

Re:

Thanks for the suggestions.

I'd been leaning towards the original cottered crank, as I felt it'd be a better fit with the big gear in the back. It isn't flat here, so it would come in handy. The chrome on it isn't cleaning up too badly but I still have a ways to go yet.

The alloy crank would look nice and be lighter but I think the smaller chainring on the cottered makes up for that in this case.

 

[cchaven]

Re:

BTW the BCD on the Nervar crank is 128. It is the earlier style Nervar Star with BSA threads for the pedals.

 

[non-fixie]

In that case you might try the 130 to 128 conversion. TA sells 38T chainrings for around $30. You'll need a Dremel and some patience.

 

[cchaven]

Re:

Thanks for the suggestion...I'll look into what chainrings are out there.

Today I worked on the original bottom bracket and the headset. The cotters came out before without any issues but the drive side cup won't budge so I left it and cleaning everything up from the adjustable side. Here's a picture of it with some of the parts fitted just to check things out. The rear derailleur and fenders aren't fitted in this picture though. I think the original cottered crank looks pretty nice with the setup.

 

[hamster]

I assume you know that the drive side has a left hand thread?

 

[cchaven]

Re:

This s my first French bike with the French bits, but I knew there were differences. I'll have to double check and make sure I was trying to turn it the proper direction.

 

[slartibartfast]

I assume you know that the drive side has a left hand thread?

I was under the impression that some french bikes, especially earlier ones, were a right hand thread on both sides? May be wrong but I'm sure I read it somewhere. I take it there's no easy way to tell other than trying to undo it, and hopefully not keep tightening it instead?