Bicycle Mechanics - French crank confusion

I tried to tighten the bolts on a 6 arm chainwheel and managed to break 2 (the second while laughing in dismay at the first:mad: ). There are replacements for double chainwheel sets (just longer) at sheldon's online store, but its for all the little bits and thats $17+shipping, and I'm rather poor right now. I went to a hardware store that had alot of metric bolts, but the .4mm bolts with the standard pitch and .7 pitch would not screw in far enough (an uncommon pitch). Ive searched around some online, but I have no idea what the pitch is thats now pretty futile, at least without knowing the real pitch.

http://www.sheldonbrown.com/harris/french-cranks.html

Can anyone tell me what the pitch of these bolts might be, where I might be able to buy more, or where I might be able to buy a complete new set(bolts, nuts, washers) of them for a single chainwheel?

on sb.com, item 25 might provide the bolts that are the right length, and item 64 is for the double chainring.

This bike is actually an old ss raleigh that i bought before I knew much about bikes, I didnt think much of the 6 arm crank at the time.

I'm just tired of intuitively doing the wrong thing with this bike, I've learned alot so far and its cost me money every step of the way...:rolleyes:

If you can't find out the size of the bolt, take one to a machine shop and they can measure it and might even have the size that you need.

thanks!

Anyone else know where to find french chainring bolts

*bump*

I haven't quite been able to get this problem worked out. I'm considering just using alot of red loctite and some bolts that go in 2/3s of the way but are actually the wrong thread pitch. Would that be a terrible idea? I'm about to give up on this damn crankset. It just keeps costing me more money... and even worse I havent been able to ride my bicycle for quite awhile :(

I'm guessing your French 6-arm chainring is a TA Cyclotouriste/Pro 5 Vis. TA bolt/spacer sets go on eBay for around $10 including shipping. They are not always there, but if you watch, something will come up before long. Make sure you buy the right thing: there are the 6-bolt sets for double rings, the 6-bolt sets for triple rings, and the 5-bolt sets for attaching the large chainring to the crank.

I broke one too from over-tightening. They seem to be made of something pretty soft! Definitely learned my lesson, tighten firmly but not as hard as you can.

I switched from triple to double, so I have an extra set of used TA triple bolts/spacers in my parts drawer. Sorry but I don't think I'm ready to part with them yet - gotta take on the hills first and make sure I don't need to go back to a triple! I've been warned that southwestern Wisconsin is granny-gear country.

EDIT: Sorry, now I see you are looking for single chainring bolts. You see those on eBay too, though often in a complete 54-piece set that includes bolts for single, double, and triple ring builds. Like this one: http://cgi.ebay.com/crank-bolt-nut-spacer-lot-54-pc-Stronglight-TA-new-NOS_W0QQitemZ250091893681QQcategoryZ56197QQssPageNameZWDVWQQrdZ1QQcmdZViewItem

I see your thread on this topic is a bit old, but I'm hoping you might be still able to help. I was wondering if you ever found out what thread pitch and such these cranks need. I have the same problem with trashed bolts. Thanks,

Dave