uncle uncle

So... I'm working on a Nishiki Sport, mid 80's I believe, and I'm dealing with a rusty seat post bolt (the one that clamps the seat post tight in relationship to the frame). It was popular in those days to use a "keyed" seat post bolt, where both the bolt and the nut are allen headed. I always seem to pick the wrong side of the joint to apply twisting action, and either end up mangling the key of the bolt, or chipping off some paint. Please share your secrets to knowing which side is the correct side to twist. I've already prostrated myself among my peers by admitting that I'm not smart enough to know, but, if you must, kid away, as long as I go away from this post a bit smarter, I'll lick my mental wounds and be a wiser C&V shade tree mechanic for it.

scarlson 

Normally the side that turns should have a washer. If not, then I dunno, can you peer into the slot with a strong light and try to see which side of the bolt is male and which side of the bolt is female? The male side is the one that turns and doesn't have a key, on any of the bolts I've ever seen.

Doug Fattic 

The key to prevent the bolt from turning is on the non-drive side of the frame. This is because it is easier for a right handed person to turn the wrench when it is on the drive side. When my students are making a frame in my class and brazing on a seat binder bolt, I ask if they are right or left handed because if they are left handed they may prefer the head of an allen bolt to be on the non-drive side.

scarlson 

But a lot of times the frame has a keyway on both sides, so it's not a rule. Chances are higher with a frame like this (not top of the line) that it's not been put together with such attention to detail!

I had to fix the bolt hole on my Trek, which had been mangled on left side, but still has a keyway on the right, so I guess the bike is a switch hitter from here on out. Didn't give that much thought until now, but as long as I have a washer under the side that turns I reckon I won't confuse myself!

juvela

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some allen key seat binders rely upon splines rather than a single tooth/key to secure the nut side from turning

in this case one can often see the ends of the splines even when the bolt is tightened


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merziac

I always use 2 wrenches when I can and look for the washer, splines, etc. and apply a couple drops of penetrant.

Many times the bolt has not been turned for a while and wants to mangle the splines or keyway before it comes loose or has already been mangled so holding one side can minimize paint and further damage.

Maybe even save a crappy Campy specimen from snapping.

SurferRosa

This is the way it should be installed on the drive-side.

Prowler 

+1 always, always. And, OP, don't think about "not smart enough". Many of those sets have been put in backwards by mechanics who did not know nor care. Always use two hex keys and peek inside to find the threads.

repechage

we lefthanders adapted long ago to a right handed world. Fasten from the drive side, it is the side presented most often when working in a bike while in the stand.

I have had to use right handed scissors so much that the scissors I use now have left handed loops but blades oriented as right handed users have. I bought a pair of true left handed scissors and they are useless, I separate the blades.

of course when I was in kindergarten, I placed my Write hand over to my right side... the teacher corrected me, I replied that was the hand I write with! Oh, that other right...

Doug Fattic 

I went to storage to check my stash of stamped and welded lugs to see which ones had a square female key on the seat binder part. This little rectangle keeps a binder bolt with a male key from turning when the nut is turned. Just as a reminder, most frames in the C&V era were made with stamped and welded lugs. In the late 70's more precise (and more expensive) investment cast lugs became available. They most likely had threads to accept a M6 socket head bolt or if it didn't have threads then a Campy binder (or similar) was used. IC lugs were used in the majority of American made frames.

In the picture of my old lugs, I see that the 3 French brands on the bottom had keys on both the left and right side of the binder. The other lugs made in England and Japan had the key only on the left side. The French brands are Prugnat, Nervex and Bocama. I'm not entirely sure what the other brands were. I believe the blank was a Chater-lea and other ones were Japanese made Nikko (maybe).


The 3 French brands are on the left in this picture.

uncle uncle

In this case, there was no washer (though that is a good indication, and I'll keep my eye out for this clue next time). I couldn't see the shoulder of the key bolt... it was positioned at the three oclock position (aka the side nearest the top tube) and not visible to my old dude eyes.

uncle uncle

Original poster here, and a left paw. Next time I'll use the WWRD philosophy... What would a Righty Do? Thanks everyone. I came away with some good knowledge to carry forward, and really don't feel like it was as embarrassing a question as I first thought.

repechage

I think you mean M8 bolt. At least that is what my Nervex equipped bikes use.
As to the notch on both sides of the French lugs... I vote lug manufacturing expediency. the blank is stamped out, no need to tell right from left. Either direction will work in the stamping press next step.
Only wish the set I bought in 1974 had the two ears aligned, they are 2.5mm off, one is higher or lower than the other. Tolerances? The French were quite tolerant of variation.
Yes, can make it work, just fit a tube and fill the region with brass. How the Italians did it. Well, Masi and Fiorelli at least, I have seen those without paint.

merziac

No shame in asking, always the right thing to do, never ok to butcher something unnecessarily IMO.

Doug Fattic 

Most investment cast seat lugs that have a threaded binder bolt use a M6 bolt (6 X 1MM). In my box of binders waiting to be brazed onto a frame I do have one that is M8. It is barrel shaped or it would look too clunky and massive. I always use an M6 bolt size if I am brazing a binder onto a frame. In the old days I would chop off the lug ears and braze the new binder in their place. Here is a picture of a bunch of investment cast seat lugs I have. Most of them will never be used. The 4 on the right are the ones that are cast to take a M6 bolt. The most often used lug sets in the States are Henry James lugs. Unfortunately Hank Folson has retired and they are no longer being made. It is on the right row, 2nd from the top.

A lot of these lugs have a straight hole with a notch on the non-drive side for the key on a bicycle frame binder bolt. I vastly prefer being able to use an M6 socket head cap screw for a binder bolt rather than the 2 part bolts used in the era before investment casting was done.

Glennfordx4

99% of what I've worked on has the nut on the Drive side of the bike, a Motobecane Mixte I just finished has the nut on the Non DS and can't be switched.
Glenn

gugie 

Doug, I've got a buddy with the mechanics feel of a blacksmith. He's snapped off bolts on cantilever bosses, stem binders, and seat post binder bolts. I built a frame for him awhile back and thought of putting an M8 on it, but instead put two M6 binders on it. I call the 2nd one a "spare."

repechage

Yes, I was referring to the previous image of the stamped lugs. Henry James brand I think was sold, then I tried to contact them when in Signal Hill Ca, no response.
There is a website up, now located in Oregon.

Doug Fattic 

Hank's son-in-law Chris now sells frame building materials under the Henry James brand in or near Portland. Unfortunately they aren't going to sell any investment cast frame building parts after whatever supply they have left is gone.

gugie 

That's a shame, Chris is a swell guy, and I could ride my bike down to his place in the St. John's neighborhood of Portland for will call.

Henry James investment cast lugs fit just about perfectly with just a touch of 80 grit cloth.

Doug Fattic 

I liked them for the frames my students made in framebuilding classes. Hank made 4 different angles of down tube lugs that allowed for the their frame design to be done after the student arrived and any angle of lug would be in stock so they didn't have to order before hand. Their absence is our loss. Long Shen no longer makes investment cast bicycle frame parts as well.