# Tapered Head Tubes / how and why



## tektonics (Feb 1, 2006)

Is anyone else interested in discussing tapered head tubes?

I think it is clear at this point that they are not just a quick fad, and with the availability of them steadily growing, they are starting to pop up on handmade bikes more and more often.

As the component industry rapidly moves toward tapered steerers as the standard, it changes how we approach the design of the front ends of our frames. Sometimes just as a reaction to the massive nature of the modern fork crowns.

Where there may not be a performance advantage in using a tapered head tube, there can be an aesthetic gain.

I love them and rarely find a reason not to use them on one of my frames, but am also cognoscente that in the wrong context, they can look really bad. 

That's my take on it anyway-

Hinmaton


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## briderdt (Dec 14, 2012)

I'm just now building my first frame with a straight 44 head tube, and the unfortunate part of all that is (1) my jog doesn't have cones to fit that diameter, and (2) none of the shops around me have the reamer/facer to fit it. Means that I'm building it on the table with V-blocks (not a huge deal -- I've done it before), and I'll have to buy the head tube reamer/facer with 2 sets of cutters... Hey, it's only money. And this will (hopefully) be the only MTB I build. It's a gift for my nephew, and he only rides MTBs, so... My thing is road/'cross/track/TT.

For most steel builds, especially on the road, the 44's just look out of proportion with the rest of the bike, and tapered only looks half-way as goofy. Internal headsets and properly tapered carbon forks are the only way they look good, in my book.


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## tektonics (Feb 1, 2006)

I did the same, beg, borrowed, or stole whatever worked to get the job done.
the when it came to the 44mm or the 1.5" reamer, no one had one, which wasn't that odd as it just wasn't as common then. These days you would figure that your LBS would have it, but I don't know that shops are doing as much facing and reaming as they might have years ago. Bike shops used to do frame alignment too, but if you can find a store bought mega brand bike that is straight, you might have the golden ticket.

If you haven't already, get an account with BTI, Hawley, QBP, J&P, Mel Pinto, ect... just so you aren't buying those tools at retail.

Heck, another builder such as myself may be willing to loan out the cutters in a pinch. It's worth an ask anyway, particularly if you are certain you will not be making another frame like this ever again.

But then again, I see a faster trend toward over sized head tubes with Road then with MTN. Personally, I think this is where the trend originated.

Anyway- good luck and happy building!


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## adarn (Aug 11, 2009)

I don't really see any advantage over a straight tube. Headset options are plenty, weight different is negligible, and the cost of a straight tube is wayyyyyyyyyy less. 

I also think straight headtubes look better.


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## tektonics (Feb 1, 2006)

As far as I'm concerned, it's all about personal expression and overall aesthetics. 
Fortunately we are in an era where we have these choices.

I assume you are referring to a straight 44mm head tube from True Temper or similar?
Yes these are way cheaper, and are nearly universal in size, right!?
From a fabrication stand point, I have a problem with the ID on these tubes (at least those that I have used), they is not enough meet for reaming and yet they are pretty heavy walled...
From a design stand point, I feel- the lower half looks great, the inset headset transitions nicely from the head tube into the crown of the fork. 
The upper half wants a larger top tube (which is fine), but it gives the area a heavier, beefier feel. Then when you pop out your 1.125" steerer, add a few spacers and your stem, the area in contrast can look a bit pinched or stunted. If you go with a smaller lither top tube, then it looks even stranger (to me).

The 44mm straight gauge head tube also is also smaller in diameter than the upper inset headset which lips over and doesn't look right. This is where a machined head tubes or adding a machined collar helps, both aesthetically and structurally, but it is no longer a cheaper solution.

These are the reasons I prefer to use a tapered head tube.
You still may have the same 44mm top portion, but in contrast with the lower portion it begins to make sense as you now have a graduation of sizes. You can run a size larger down tube to offset the increase in the top tube diameter, and it won't look oversized on the head tube.
Or if you prefer to run smaller diameter tubing in general, you can use a 34mm / 44mm tapered head tube and the upper portion looks just like it should on an 1.125" steerer.

Again, that is my taste and reasoning.

Adam, I believe I have seen some pretty cool head tube shaping from you with those reinforcement rings, no?
Anyway, keep up what you're doing its awesome.

Hinmaton


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## Walt (Jan 23, 2004)

44mm straight:
-cheap
-light
-easy to work with/miter to
-1cm or so less stack height in cases where it's needed from putting bearings in the frame. 

It looks fine to me, but I'm not one for "personal expression" since I have no taste and mostly build for folks who are going to ride the living crap out of their bikes and not even wash them. YMMV. I've personally never run into a problem reaming the TT ones, I guess maybe if you were distorting them a lot it could be an issue.

-Walt


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## tektonics (Feb 1, 2006)

Cheap- yes-
light? Maybe in contrast to a Paragon... Otherwise, I would have to disagree.

The miters are are simpler on straight for sure, but once you get the hang of it, it's just about the same. 

Walt, I can't attest to your taste but you have plenty of style! I see all those nice curves you got.

Riding the crap out of a bike and lacking personal expression are not synonymous. 
I like to think people come to me because of my personal expression amongst many other things. People can buy blah bikes anywhere, right?

I've never run into a problem either with the TT tubes, but the idea of only leaving .05mm to ream out seams awfully risky. You can press the headset in without reaming...

If I provided head tubes to clients like that, I would think I would loose business.
So why are builders just ok with that?

Hinmaton


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## adarn (Aug 11, 2009)

Cool. Yeah I understand how a tapered tube might be preferable for some people. Different strokes fer different folks...

I don't think you could press a headset without reaming out the TT tube, are you sure about it only being .05mm undersize? either way, unless you have a lot of distortion that shouldn't really be an issue.

I didn't like how thin the tube was on the ends, so I had Paragon machine these reinforcement rings: 
DSC_1736 by SklarBikes, on Flickr


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## tektonics (Feb 1, 2006)

TT head tube 46.4mm OD 1.25mm wall thickness.
Equals 39.9mm ID
.05mm per side to remove. 
That's .002" of material.
If you can weld your headtube and keep it within .004" TIR, you are a god!

I believe what happens with these tubes, is they just push back into shape when the headset is pressed in.


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## Walt (Jan 23, 2004)

I've done at least 100 bikes with the TT 44mm head tube and never had a reaming or headset install problem. Looking in the head tubes the reamer is definitely removing material all the way around. You can do rings if you're worried about it, I guess.

-Walt


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## tektonics (Feb 1, 2006)

Based on the math, either the tube is conforming to the reamer or you are as good as they all say!
All kidding aside, with a wall thickness that thick it doesn't matter. The TT head tube stock is tried and true, and for the money it's a near perfect solution for those that prefer the look of an oversized straight headtube.

How about integrated head tubes? 
They seemed to have gone out of fashion, except the new gigantic tapered ones.
I always like the look myself.

Hinmaton


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## Eric Malcolm (Dec 18, 2011)

I'm kinda on the fence with this one.

To date, and using a 28.6mm Steerer only, I observe the headsets for both 34 and 44mm HT's utilize the same bearing size, so to me there is no advantage in the bearing load born by either method. 50mm however, does.

In terms of load created on the HT itself, assuming you use larger OD downtubes, there is greater surface areas for welding to, but really best suited to bikes that are hammered in riding style - Downhill bikes, Jump bikes etc. I recently used a 44mm only because I had multiple tubes fighting for the same space and they added up to 44-45mm, plus I wanted clearance to internally fit cables to squeeze past the steerer tube.









I took this picture next to a current World speed record holder motorcycle (Vintage Indian 1000cc) with my 44mm HT. To me, if a motorcycle can use this size of HT at 200mph on the Salt Flats, and the loads at that speed might be a wee bit greater than just riding down a single track, maybe a little over-engineering is being employed by this fad.

I note that a 120 x 34mm HT, with 1mm wall and shouldered that I get machined up compared to a 120 x 44mm version, also 1mm wall, weigh 112g to 168g. If you're into watching your grams and cannot justify the higher load capacity, I'm scratching to find a good reason to use a 44 or larger.

It seems odd to me to add bigger and larger tubes beyond reason and therefore weight to a bike when carbon can replicate the look, and be a ton lighter.

I also question this whole trend in the context of frame breakage. If bikes are coming apart due to either fork stems breaking or head tube joint areas snapping there is a case to look at, but by and large, most postings that I have followed here on the forum come up with seat/TT/clamping cracks, nothing on the HT that I can immediately recall.

My 2 cents worth.

Eric


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## Walt (Jan 23, 2004)

I personally find that there's a qualitative difference in the ride of even shorter-travel suspension forks with a tapered steerer. Not enough that I'd throw away all my 1 1/8 stuff, but it's a little nicer. And the ship has sailed on that - if you are building mountain bikes, you need to be able to deal with tapered stuff. If you're just doing road bikes, you may be able to avoid doing it (and discs) for a few more years but the writing is on the wall.

So we can wail and gnash our teeth and compare with motos all we want, but at the end of the day you gotta build what people want (and can actually buy suspension forks for).

-Walt


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## tektonics (Feb 1, 2006)

I believe the evolution of the oversized head tube has more to do with the development of a stiffer stronger steerer than the surface area of the bearings. And I think it was due to carbon road forks in particular, as the 1.125" carbon steerers were failing at the connection to the crown? I think this is why there are so few straight steerers anymore? 
Someone please correct me if I am wrong.

That vintage Indian had a 7/8" or 1" heavy wall steerer, large loose ball bearings, and a heavy wall head tube, married to a heavy wall frame. 
I built motorcycle frames, and tinkered on a lot of old bikes, including my '48 Panhead. Those frames are burly, and the stresses put into them are not that similar to bicycles.
I wouldn't want to put a 44mm headtube and an inset CK headset on 200mph motorcycle, that sounds terrifying.

Most of the 44m straigh gauge head tube stock I have seen is 1.25mm thick, where are you finding this 120mm 1mm thick piece?
Most of the 34mm stuff I have used is .9mm which I think is the perfect wall thickness.
Best I can tell figuring out the weight per MM of different True Temper head tubes.
The 44mm x 1.25mm WT is 30% heavier than a 34mm x 1.25mm WT tube.
Which is quite a bit. But when you consider that a 34mm x 1.25mm WT tube is 25% heavier than a 34mm x 1mm WT tube, you may wonder why you would go with a 1.25mm WT head tube if you are concerned about weight.

There are slimmer oversized head tubes to be had. 

But in the end, I think it's less about performance and weight, and more about staying current with the direction of the market and embracing modern frame design.

Not that there is anything wrong with the classics, I love it. But it's not what my customers come to me for.

Hinmaton


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## tektonics (Feb 1, 2006)

What's funny is that below this reply is the "Similar Threads" box which has a bunch of folks from other forum areas discussing where to get bikes with tapered head tubes or who is making bikes with tapered head tubes?
I think it's clear people want them, hell the huge industry goliaths are all but telling them that this is what they want. 
I don't know about you all, but I like to make bikes and sell product-

I think what Walt said above is spot on!


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## Eric Malcolm (Dec 18, 2011)

That vintage Indian had a 7/8" or 1" heavy wall steerer, large loose ball bearings, and a heavy wall head tube, married to a heavy wall frame. 
I built motorcycle frames, and tinkered on a lot of old bikes, including my '48 Panhead. Those frames are burly, and the stresses put into them are not that similar to bicycles.
I wouldn't want to put a 44mm headtube and an inset CK headset on 200mph motorcycle, that sounds terrifying.

But in the end, I think it's less about performance and weight, and more about staying current with the direction of the market and embracing modern frame design.

Terrifying - YES. I do however get an amazing amount of inspiration off that old 'cycle.
I only offered a counter argument with perhaps some reflection on the madness of fads. I do agree that the larger carbon crowns are the root of this trend and it is good to look at and trendy, but is it really necessary for steel to conform to a carbon trend from a sound engineering standpoint - probably not. I do agree that it is here to stay.

I have a friend who machines HT's to my spec. I do this as I have found that I have no distortion in the Brazing process, so it is more to my taste. I like Adams style of shoulder, I might try a little artistic licence on my next build. I also am a hobby builder these days so I am not inclined to customer wants, but I am also a progressive builder and thinker and do play around with ideas more radical. I'm more interested in the integrated head/TT/H-bar stem look that looks streamlined that Time-trial bikes and some custom Tri-bikes are using. In an off road type bike off course.

Eric


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## tektonics (Feb 1, 2006)

I think that sounds awesome and look forward to seeing it if I get the chance.

I really like the way TT bikes have smooth clean lines, with little bulging or protruding out.
In steel I'm guessing? 
Yeah that is a cool-
wait, off road? Hell yeah!


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## shirk (Mar 24, 2004)

tektonics said:


> What's funny is that below this reply is the "Similar Threads" box which has a bunch of folks from other forum areas discussing where to get bikes with tapered head tubes or who is making bikes with tapered head tubes?
> I think it's clear people want them, hell the huge industry goliaths are all but telling them that this is what they want.
> I don't know about you all, but I like to make bikes and sell product-
> 
> I think what Walt said above is spot on!


You happen to look at the posts dates on those threads? 2011 old news.

For a garage builder that wants to be able to run current suspension fork offerings the 44mm just works. A single cutter/reamer, single size of cones for a jig. Easy to get now.

In my opinion it won out over the tapered option.


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## Walt (Jan 23, 2004)

Yeah, I'm not sure why we're discussing this. It was a hot topic 3 years ago. Now you can do straight, you can do tapered, you can add rings and do whatever you want. Lots of vendors, lots of choices, all of them are good. But hey, it's the internet. We gotta rehash everything every 6 months, right?

-Walt


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## D.F.L. (Jan 3, 2004)

If motorcycles had stayed with single crown forks, they would have adopted an oversized/tapered design around 1918. Structurally, it's bending vs sheer, and since dual crown forks aren't good for bicycles that get pedaled, we're now using tapered steerers.

I used a Nova tapered HT recently. The DT miter required paper templates and some creativity. I don't know if the customer sees an external upper HS cup as a "modern" feature. If they don't tapered HTs might not catch on. Thoughts?

(Tilt your head)


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## tektonics (Feb 1, 2006)

I dig it- I think I would have used the trim ring on the top as well. 
But hey-
Classic angular lines with modern sleek flowing components and it doesn't look all herky-jerky.
Look great-

For anyone interested, I am giving a seminar at Philly this year and again at NAHBS next year on how to cope to tapered or shaped head tubes. With a couple of little tricks, it is really easy. 

Hinmaton


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## tektonics (Feb 1, 2006)

The reason I brought it up is that as recent as a few weeks ago someone asked about sourcing them, and no one conclusively answered. 
3 years ago, only a couple of us had figured how to do it, and the word really never got out. If people can't source the parts they desire, they will go with what they can get-
the straight 44mm head tube from Paragon. Just like any part that is not mainstream- like the BB30 and PF30 it took a long time for that part to mature, now it's mainstream.
If you go to any bike shop you will find a sea of tapered head tubes, because they are popular and large manufacturers are not burdened with a very limited supply chain. Your certainly don't see that many straight 44 headtubes in bike shops.

Tapered head tubes are just now starting to mature and become available in a wide array of choices and styles, but it's not mainstream yet. 

I'm not fishing for business either, I swear, I'm doing just fine.

I just think it's good for the building to communicate about whats happening in the industry. Discuss design, technique, components, materials.
Some folks prefer a limited palette, I'm just not one of them.

Based on my sales alone, I forecast a noticeable shift in the market. 
And there are some heavy hitters changing things up.
If you think I'm an ass (well, of course you do), take a look at how many different styles of head tubes are starting to emerge in the market.

So for those who are interested in breaking away from what you know and trying something a little different, I am here saying: hey, I know a little bit more about the subject than the average bear, and I am happy to pass on what I can.

Hinmaton


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## Walt (Jan 23, 2004)

Wut? Nobody said anyone was an ass that I remember. You should post up your tapered miter technique as a how-to, that would be great!

-Walt


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## BungedUP (Aug 18, 2003)

Regarding reamers - I not uncommonly make my own reamers for special jobs. Do not believe that you are confined to only acquiring a cutter through purchase. If you have a lathe, and a way to heat treat some metal, you can make your own reamer if you need to.

Regarding tapered head tubes, I have an ethical objection to them that most will probably not share, and there is a way around the objection as well. Some manufacturers produce them via turning on the lathe, producing an enormous amount of scrap, and wasted energy. I very much find that this is a waste of resources for no acceptable reason. I realize that this might sound crazy, but when you see the enormous chunks of material coming in get whittled down to a thin little tube, it's depressing. I'm sure some produce them via swagging, and that I have less objection to.


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## tektonics (Feb 1, 2006)

no- that was me-

If I can figure out a way to efficiently convey the information I try-
I have broke it down into 4 different methods with a couple of tangents here and there.
The first two are really hard and I don't recommend it.
The other two are better and I have video, photos, bikecad files, solid works files, physical examples, hand gestures, ect... 

I'll think it over.


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## tektonics (Feb 1, 2006)

cutters too if you're really clever.

I hear where you are coming from, as I have made many a head tube from solid material... it can be a little depressing at times.
But where do you draw the line.
Do you only use non-relieved BB shells? Or cast dropouts? Do you use a jig, was that 100% cast, extruded, or forged?

I have made so many chips making all kinds of parts that I just see it as a part of the process. I recycle as much as I can, heck I even use my drop to cast other parts. 

The art that fascinates me with a machined product, is that you can keep material where you need it and remove the material that's not.

Plus the part has a really good chance at having a long life time, so it's not energy wasted on a short cycle part that is going to end up in a land fill.

I guess we can rationalize all sorts of things, right.

Anyway- swagging is really cool, and I wish I could get my hands on one. Machining those dies would be a trip.


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## Walt (Jan 23, 2004)

That is some serious machinist-geek ethics, but I share your objection. When I see a big pile of swarf and a before/after pic of some block of aluminum (or steel cylinder) with 90% of it gone, it depresses me a lot of the time. How much machine time/cutter wear and tear/energy/etc went into that? The XX1 cassette is a prime example. Probably 100-150 bucks of the outrageous cost/machine time is to save the last 50g of weight. Would anyone have noticed if the cassette was 300g instead of 250?

-Walt



BungedUP said:


> Regarding tapered head tubes, I have an ethical objection to them that most will probably not share, and there is a way around the objection as well. Some manufacturers produce them via turning on the lathe, producing an enormous amount of scrap, and wasted energy. I very much find that this is a waste of resources for no acceptable reason. I realize that this might sound crazy, but when you see the enormous chunks of material coming in get whittled down to a thin little tube, it's depressing. I'm sure some produce them via swagging, and that I have less objection to.


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## cable_actuated (Jun 7, 2012)

The tapered headtubes I've seen all seem to create more problems for me and solve no needs.

Why would I want to do a complex miter on a down tube when I could do an easy one to mate with a 44 mm straight tube?

Why would I want a tall external 34 mm top cup when I could get shorter ZS variety to go with a 44 mm head tube?

Aesthetically, I find 44 mm head tubes easier to blend a fillet to versus a tube with a similar diameter like the top portion of a tapered tube. As adarn showed you can certainly dress them up to look nice too.

I'm a very amateur brazer and I managed to keep the Nova 44 mm head tube round on my last frame, despite pushing my top tube fillet right to the upper edge of my head tube without a reinforcement ring. I'm sure the pros have no trouble keeping things round.


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## BungedUP (Aug 18, 2003)

tektonics - 

I can understand other people being reluctant to share my thoughts on the matter. I try to apply some sensibility to the use of raw materials - I don't act dogmatically. I think that wonton wastefulness though is not something to be ignored - it already permeates our culture in so many ways. I try, when possible, to consider that when designing something. I certainly don't expect others to share those feelings!

As far as your questions, I do use relieved BB shells, and I often make my own dropouts, some of which involved an unnecessary amount of material as well. I don't like that they do, and I try to rethink them when I can. I have used/made many fixtures and jigs - including bicycle frame fixtures, tubing fixtures and jigs, as well as tooling for non-bike related parts. Some were overbuilt, some were underbuilt, some were just right. 

I have lots of philosophical thoughts on the matter, but I won't belabor them any more than I already have. I really mostly just wanted to throw out the encouragement for people to try and make one's own cutters, and then threw in a little personal opinion while I was at it.


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## tektonics (Feb 1, 2006)

cable_actuated said:


> The tapered headtubes I've seen all seem to create more problems for me and solve no needs.
> 
> Why would I want to do a complex miter on a down tube when I could do an easy one to mate with a 44 mm straight tube?
> 
> ...


I'm not here to try to convince anyone of anything! 
I think I have already answered why I choose the method I employ.

I'm a pretty open minded person, so I use and find both to be equal in value and simplicity. I know for a fact that you do not have a 46.3mm hole saw, which means you have to employ a file some.
Once you get good with a file, there is little you can't do, and rapidly.

But I'm pleased to hear that you are doing so well with your chosen method, keep it up.

Hinmaton


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## Walt (Jan 23, 2004)

Ok, cool - so how about those mitering tricks?

-Walt


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## D.F.L. (Jan 3, 2004)

I made 2 paper templates, one for the diameter of the HT @6 o'clock on the DT and one for the dia @ 12. Some thought was put into determining the transition point from straight-dia to taper, and then the transition from the larger dia to the smaller needs to be drawn onto the template or the tube.

Someone could turn a mandrel in the shape of their favorite tapered HT and wind and glue emery to it for abrasive mitering.

In China, they just use lasers.


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## tektonics (Feb 1, 2006)

BungedUp-

I appreciate your comment and in many ways agree with you.
I started this journey as a Blacksmith, all about moving material you have to gain the shapes, and somewhere down the line turned into a machinist, which is the exact opposite.
But what makes me smile, is that your comment was the one that I hadn't expected to hear.


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## tektonics (Feb 1, 2006)

I don't want to spoil it for those who want to see the lecture, which is going to be far more informative than I can provide here.

But if people are interested I think I can distill it down the what I think is the best way, but it requires some investment in tooling. Which many of you may already have, and if you don't you may find them useful for all kinds of things in the future-

IE: Bikecad Pro, a decent belt sander, and a vinyl plotter.

Walt am I allowed to link out of here, or do I need to keep it within?
If I'm going to do this, I might as well put it on my website right?

Hinmaton


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## unterhausen (Sep 28, 2008)

I posted a link to a paper here a while back that goes through the math you need to draw a template for the intersection of a round tube to any solid of revolution. I was too lazy to follow through with writing a program to do it


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## Walt (Jan 23, 2004)

Link all you want! 

-Walt


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## tektonics (Feb 1, 2006)

Alright- got it all together... I think:

How To Cope To A Tapered Or Shaped Head Tube ? Loco Machine


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## jgerhardt (Aug 31, 2009)

With carefull measureing you can get a fairly accurate template out of bikecad. The lightest (and my prefered method) is the 44mm TT. However the Nova and Columbus tapered headtubes look real nice when finished.

As for difficulty the Columbus was a major PITA!


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## tektonics (Feb 1, 2006)

jgerhardt said:


> With carefull measureing you can get a fairly accurate template out of bikecad. The lightest (and my prefered method) is the 44mm TT. However the Nova and Columbus tapered headtubes look real nice when finished.
> 
> As for difficulty the Columbus was a major PITA!
> View attachment 932194
> ...


I thought I already replied to this,sorry.

I agree that the Columbus is a biznatch to miter to, this is precisely why I used it as my example.

These look great by the way!

Hinmaton


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## HELLBELLY (Jan 16, 2004)

Walt said:


> Link all you want!
> 
> -Walt


*Yes...er, uh speaking of links. I am not a frame builder. I fix choppers, but that's another story. Anyway, I have a frame that I love that I want to run 27.5 wheels on. It is a '02 Surly Instigator and the rear clearance should be fine. However, I want to run a longer travel fork up front (140mm+) and there is a dearth on straight 1 1/8" steer tube forks like this available.

So, my bird brain starts think about tinkering possibilities like having the head tube on the frame modified. The Surly is just good old 4130 so nothing exotic and I am not concerned about weight (the thing is a tank). Is something like this possible? Worth doing? Sure, a better option would be to track down a Revelation from a couple years ago or just the upper assembly, but I am not having any luck. Any suggestions or links (see, I brought is back around) would be appreciated.

Thanx, Dr Ray* :devil:


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## Eric Malcolm (Dec 18, 2011)

You are going to increase wheel diameter and increase fork travel so you will change the whole steering geometry.

In this case, not worth doing, Sorry.

Eric


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