DMC707

Ive been doing this since i got my first road bike way back when also . I came to the sport when life happened and motocross got too expensive for me --- the front brake on the left alwys felt odd to me

cudak888 

That's one hell of a bow. I can't imagine it being something resulting from the top tube being inserted last, or even something from the heat. The bow suggests there's sprung tension on it, as if the downtube shrunk. Perhaps the lower headlug or BB were brazed in last, and they kept coming up a bit short in mitering?

Really? Did we need to go all OT with the A&S stuff? All because this Masi had a reflector

-Kurt

majmt 

From an earlier post, this makes sense:

majmt 

The bike was supposed to come with the original pump but the box the bike was shipped in was damaged and there was a hole where I figured that the unobtainium pump had been sucked into UPS purgatory. Turned out that the eBay seller took it off for safe keeping while the bike was being packed and then forgot to include it the package. He later sent it along. It doesn’t really work that well - probably needs new leather. But, it is the correct pump although I’ll probably just save it as an ornament.

I did get a pair of the ALE Masi bottles, I couldn’t find any with the white tops but I’ll keep looking for any bottle with a correct top to salvage.

I rode mine this morning too. Easily up a steep grade and down the other side fast and stable. I have a couple other top-shelf bikes and I’ll say again that this is the finest bike I’ve ever had. I love the feel of it, even over my Ottrott. And, although it’s 47 years old, I’m pretty sure it’s my fastest bike now. But then, I don’t own a road bike that’s less than 10 years old either.

majmt 

Thanks. I cleaned the tire savers up and put them back as they were but I flexed them up out of contact with the tire. I was thinking of leaving them on as a relic but I may just take them off altogether since they seem to kick more crud on the frame than naked wheels.

cudak888 

Now that you highlight these two comments in context, I see where I interpreted it incorrectly - for a moment, I thought the top tubes were bowed 6mm (!). Sloping 6mm makes a lot more sense. Curious if the drop was proportional to frame size - thus intentional - or completely random. (Side note: If random, this would be an interesting test to expand to other manufacturers of the period).

Either way, it's the one tube in the frame that a builder doesn't have to be as particular about. The head and seat tube angles yes. Bottom bracket/chainstay drop, yes. Top tube? There for the strength, primarily, and no different if sloping or otherwise.

-Kurt

repechage

yep- Falerio goofed, if you must have a level top tube.
Mario did make some corrections at least for the later Carlsbad GC’s but not completely.
I have a slew of these bikes. A slew defined as 15.
The most curious is a 1974 Italian GC with a rising top tube of 8 mm. One would have expected that things might have been ironed out by then.

from my referencing, Alberto “fixed” the Prestige and Volumetrica.

later USA GC’s, Moulton and Starck era had level top tubes. Comparing those two and they are really different bikes from the Italian and Carlsbad designs. Short reach brakes made this easier in my view.

good the pump is about, that gold foil Masi on the barrel is unobtanium. I am working on it though.
for the waterbottles, the fastest way I think to get to the original look is reference the German eBay seller selling various ALE bottles - some with white caps- then mix and match.

repechage

some rise AND are bowed.

cudak888 

How much bow? Seems odd unless something wasn't mitered right. It's not as if Columbus SL reacted any different to the torches at Masi's factory than any other builder BITD.

-Kurt

repechage

2mm out of line on one.

I have a number of tube sets kicking around
Tange is the straightest from my observation

himespau 

Are they a little out, or are we talking 2x4's at home depot out of whack?

Doug Fattic 

Just to be clear, most bicycle double butted tubing comes from the factory not perfectly straight. The crookedness can average a couple of millimeters but sometimes it is twice that and occasionally they are almost straight. I teach my framebuilding class students to roll their tubes on the alignment table before they are mitered to find where the bow is located and mark them so the placement of the miters will put the bow in the plane of the frame and not sticking out to one side or the other complicating alignment. They also mark where the end of the butts are located on the tube. They can't go by company specs because where they say the butt transition ends is not usually where it actually ends. This is just another example of manufacturing variation from true. Different models of tubes have longer or shorter butts on either end. The position of the miters along the length of the tube can effect how the frame feels. I prefer to have the thicker butt located at the moment of eneria behind the head tube. I can guarantee that many builders (especially production companies) are not bothered where the bow or butts are located and how perfect their miters are/were because none of that is visible and would increase labor and reduce profits on an issue a customer doesn't see or understand. Their concern is price and delivery time.

You might wonder why tubing manufacturers don't make more perfect tubing and the answer is because it would increase the cost with the result that they lose market share. The Japanese tubing in my experience has tighter tolerances than tubing from Italy or England.

repechage

Falerio was a closet low trail builder.

At one point Mr. Fattic had a later Carlsbad Masi frame at his shop... I think a 56 Masi Measure in Spanish Blue, be interesting to hear how it measures out.
Hint, hint.

repechage

@Doug Fattic - I have one of the jig frames. it is "off" for the top tube to sit level, the fork would have to be like a pista fork, with very little tire room. There are notations on the frame for corrections. I have two other Carlsbad 55 cm bikes and neither match. Granted one is a "special" with a shorter top tube. I am not sure about all of the sizes, but a number of the frames had a key design error. I know Mario did not use the jig frames, I saw them up high with dust collecting. Brian Baylis noted as much but his beef was that the very small frames, like he would ride had slack head angles and too much fork rake. He also noted the Falerio liked to give a bit more "umph" at the crown that even added more. One reason that some of the bikes show a fork that looks over raked at the crown. I have an early Milano GC and they solved the problem at bit differently, the fork is short, the brake mount hole is cheated up near the headset, so much that the concave washer was filed back to clear the crown race. I saw other early bikes also with this and a late Special as well way back. On my bike I swapped out the front caliper for a short reach, fortunately finding one with Brev. Inter. stamped into the arm vs Brev Int as many later piccolo calipers received. By doing so the brake blocks now fully contact the rim. I have Milano GC's from '73 and '74 that have minimal reach for a regular caliper, but both run slightly uphill to the headset.
After Mario departed, much intellectual property went with. Long go Brian reported that when Albert Eisentraut was reviewing the jig frames to take dimensions for the contract bikes he was to make, he was perplexed, "this is wrong" as Brian reported back on the old CR bikelist.
It does show that there can be quite a variation and a bike is still rideable.
Masi geometry evolved at least twice after Carlsbad. I have a 55 from 1981, and a 55 from the mid 80's and they are both different again.

to be overly clear, the Carlsbad bikes (and Confentes later) had the forks brazed up with blades straight, and the rake was induced over a heavy steel fixture mounted securely to a sturdy worktable. It retained the dropouts and with a long cheater bar slid over the steerer, the blades were curved over. There were check guides I will call them to review the fairness of the parabolic curve but not the actual offset. A different set for the track bikes.
An interesting mix of control and variability.

Road Fan

Yes, of course, but the bright yellow tape could have just gotten dirty quickly, in the first few rides. Rewrap with black would have been the natural solution.

repechage

A few received Blue tape, in general those were bikes with a blue background in the Downtube graphic panel and blue fill on the chainstay type.
For the yellow or the silver bikes ( sometimes )
no idea how judgements were decided.

that the bike was modified before it left the bike shop, saw it frequently.

rare was the bike that left with Hunt- Wilde plugs. ( the result of an oversight in the parts package sent over from Italy )

there were lots of potential changes. As time went on, there were custom order components, SL pedals, freewheel gearing, saddle, bars and stem, there was an interval of 3ttt bar and stem, the stem engraved, the bars decorated with a custom Masi stamp. And later, braze-ons- shifter bosses being the most common.
Most of all this was “off menu” they really wanted to keep things uniform.

majmt 

Just when I think that I may know a thing or two about bikes, I read through these CV threads and realize that I’m really pretty clueless. I really appreciate the expert knowledge shared here.

Glad to see this thread exhumed. We’re planning to do the CA Eroica this year and I was thinking that this bike might be an interesting entry into the Concours d’Elegance. I haven’t modified anything and the swaps that I’ve made to conserve original components can be easily reversed. I’d like to see how it might score in the “Original” class and I’d like to stay true to original spec but I’m not sure if re-taping, adding cable crimps, and the daubs of yellow paint etc would be considered restoration. I know nothing about showing a bike.

I’m really thinking that this bike first hit the road as shown below after probably being customized a bit at the time of original purchase from the Bicycle Shop in Concord, CA when it first opened.

Road Fan

I’ll have to put together a posting on my 1980 littler GC, and a photo of how I measure fork offset. I finally gave up on looking at pictures and waiting for “the number” to swim into my head. I can check offset pretty easily, but I have to have the frame off of the bike. I can also measure it pretty roughly by a method involving kneeling next to the fork with a yardstick and a small scale trying to hold all three of these (four If you include the bike) stationary in mid air as I read the scale. I think I’m too old for that now!

repechage

get over to Doug Fattic’s in Niles. He has a solid way to measure the actual bike. Accurately.

Road Fan

I'm sure he does, and we've talked a few times. But it's not like he has an LBS where he welcomes people to just come in and gab or just to take advantage of his special capabiities in measurement. I know with his reference tables he can make a measurably flat, level surface, within the limits of his measuring tools. I'm nowhere so well equipped, and I don't think I need such accuracy. But, if I measure 60 mm offset and compute whatever, 30mm trail, I would like to know my trail is within a few mm of the truth. The math does not have noise or variability since I am a skilled calculator, but the input data can be variable. That's why I found a way better than my old multiple straightedge method, which I no longer use. I have a digital angle measuring device for the head tube slant.

Basically I take off the fork and set it on a flat level surface with the blades resting on the dropouts. I clamp a bare front wheel hub into the dropouts, then put a level on the steer tube and put blocks or stuff under the steer tube until the level on the steer tube indicates 0 degrees slant. Now the axis of the dropouts is the centerline of the axle or QR, and the axis of the steer tube is the steering axis of the bike (I assume these two identities are true; call them axioms.). With digital calipers I can make a differential measurement of the axle and compute the height of the wheel axis above the flat surface. I can similarly measure/compute the height of the steering axis above the flat surface. The difference between the height of the steering axis and the height of the wheel axis is the fork offset. At that point I can use the commonly known trail equation and the measured head tube angle, the measured radius of my wheel, and the offset to compute trail in millimeters. From there I can compute flop if I want, as well. Pretty basic mathematics, just have to collect reasonably accurate input data. By far the most difficult is the fork offset.

It's also possible to check for a twisted fork by placing a digital angle gauge on the fork crown running perpendicular to the steering axis, to check if the fork crown is showing any tilt. If the fork crown is symmetrically shaped and the digital angle reading is 0 degrees, I assume the fork blades are bent symmetrically.

That is my method. It works well enough, without any truly special tooling. And I don't have to drive 200 miles round trip, when it's convenient for somebody else.

Feel free to ask me questions if it is not clear.

repechage

Doug has a scaled sliding apparatus- mimics the tubes, and the fork key numbers, the most recent was cut and marked in the Ukraine.
quick, accurate. Easy.

Road Fan

Don’t get me wrong or paint me wrong! I have seen Doug’s stuff a number of years ago. You’re correct about the quality of Doug’s ability and equipment. I will never argue that what I’m doing is better than what he is doing. But I don’t need that level of precision, since I do not build frames at the top level nor at any level. I also want to be able to measure my bikes or those of friends without a long drive to an expert’s shop. If for example I got Doug to build me a frame, I would tell him to use my technique. You don’t tell a master professional craftsman how to do his job.

Bottom line, I have an approach which works for me.

If anyone wants to try it, have at it! I’ll try to answer questions if what I wrote is hard to understand (pics or a sketch would be reasonable, huh?). I do not believe it has master machinist accuracy. I think it can give a good idea what your trail is and maybe help you understand if your frame is within some range of the manufacturer’s spec. I would not consider it evidence of for example errors published in BQ or to fuel complaints about inaccurate geometry charts in the old Trek catalogs.

repechage

Manufacturer's spec.- On a Masi that is a moving target. There are outliers on both sides of the Atlantic.

repechage

clear but convoluted- requires some digital measurement tools. I think everyone will have to buy in to that method including all the similar tools you have or figure it out independently.

Masi has another possible item to note that if one makes the wrong assumption will lead you astray- assuming the top tube is level.
for the handling geometry, one needs to work axle centers as the horizontal plane.
there are other brands that stray in this way as well, some 60’s-70’s paramounts.

Doug Fattic 

Here are the pictures showing my Masi that I got from Milan in September of 1972. I had my letters in English translated into Italian so the size could be determined. The slightly sloping top tube threw off my seat and head angle measurements when I made a frame for myself when I was learning how to build frames in England, I unintentionally choose seat and head angles based on their relationship to the Masi's top tube instead of the ground.

One of the benefits I've gotten from our charity bicycle project in Ukraine is that the laser company that made our dropouts and fork crowns (and other attachments) could also help refine the design of my frame fixture before they cut and etched the pieces from a plate of stainless steel. Over many years I've been able to make a number of refinements with the help of various people. It is multifunctional. I can custom design a frame on it by placing the chosen seat and stem in the position required after a fitting session. I also can spot tubes together into a frame before fully brazing them together.

I don't mind visitors to my frame shop and have no trouble explaining any time restrictions I may have because of work obligations. If I am in the middle of a frame building class of course I have to focus on the paying customer.


A picture of my 72 Masi in my frame fixture


Its seat tube angle is 72.5º


It head tube angle is 73º


It has a BB drop of 75mm

the c-c seat tube length is a hair under 56cm


The actual top tube length is a bit over 56cm


the fork rake is 50mm


This T is to level a top tube and you can see that the top tube slops up towards the head tube.