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Questions tagged [framebuilding]

Building the frame of a bicycle, starting with just a pile of tubes.

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4 votes
1 answer
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How do I attach an axle/wheel to an aluminum frame using n55 DIY document?

I'm trying to simplify this design below. Instead of making a trike, I just want to make a simple trailer. https://www.n55.dk/MANUALS/SPACEFRAMEVEHICLES/DIY.pdf I want to use their methodology for ...
chris's user avatar
  • 51
3 votes
1 answer
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Bent Marin team issue steel derailleur hanger. Can I salvage this incredible frame? What's next step?

I found a marin team issue on a local marketplace. The frame is in good shape it seems and I have many m900 parts from the time so I'd love to re-build completely. The main issue so far is the ...
tweedi's user avatar
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1 vote
0 answers
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What is the main concept for the turning mechanism on a n55 tricycle?

I was looking at this spec sheet and all looks simple except how does the turning work. https://www.n55.dk/MANUALS/SPACEFRAMEVEHICLES/spaceframevehicles.html XYZ ONESEATER construction plans Is there ...
chris's user avatar
  • 51
1 vote
1 answer
118 views

Another carbon damage assessment?

Mostly cosmetic? Chip is located on the bottom of the top tube. Did it go through a layer of carbon, or is that just paint/resin? Dime sized. This is an enduro mtb frame, so assuming it's built ...
levbec's user avatar
  • 11
4 votes
1 answer
243 views

Aluminium frame alterations

I know it is possible to make almost any type of frame alteration to a steel frame. But what about aluminium? I would like to know if anyone has a first-hand experience in adding braze-ons, and doing ...
Art Gertner's user avatar
  • 2,722
4 votes
1 answer
128 views

Butted tubing - lighter but is it more fragile (child seat)

Looking to build a daily on a steel frame, tempted to go for a higher end (Marin, Kona, some Raleigh) but I am wondering if the double or triple butted tubes are more fragile ? For example if you put ...
tweedi's user avatar
  • 587
6 votes
1 answer
384 views

What is the advantage on road bikes where the seat stay merges into the upper part of the seat tube, but well below the top tube

For a few years now, you see more and more road bike manufacturers building this new frame shape. What is the advantage of this geometry?
Maik Lowrey's user avatar
9 votes
4 answers
2k views

Is there a reason why it was said that the distance between the seat tube and the rear wheel should be as small as possible on a road bike?

I recently saw a steel road bike in a road bike shop where the distance was well over 1cm. 99.9% of old road bikes had a very small distance (~5mm). At the time, they thought it was more aerodynamic. ...
Maik Lowrey's user avatar
1 vote
1 answer
151 views

How thick is a traditional steel road bike lug?

I want to create some bike lugs for my specific geometry using 316L and 3D printing. What is the thickness of traditional steel lugs? Are there any other suggestions on this build?
Zyleyus's user avatar
  • 191
5 votes
1 answer
287 views

Any good / free software to design lugs?

I'm thinking of making a lugged bike frame. Tubes will be either steel (brazed) or carbon fiber, like the old Giant Cadex bikes, where carbon fiber tubes are inserted & glued into logs. I can weld ...
Barış Atasoy's user avatar
2 votes
2 answers
358 views

Is T300 carbon fiber sufficient for a bike?

I'm planning to make a diy carbon-alloy bike, Bastion Cycles style. In which I bond carbon tubes to 3d printed aluminum lugs. I live in China and can't find T700 or above tubes online for sale, there'...
Zyleyus's user avatar
  • 191
2 votes
5 answers
2k views

How do vintage steel frames compare to modern ones?

I got myself a nice vintage Koga Miyata road-speed from 1978 and am planning to converting most parts of it while keeping the frameset intact. The bike rides really nice and have no issues but it got ...
Luca Matteis's user avatar
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4 votes
1 answer
259 views

DIY cargo bikes and recumbent bikes seem to use rod end bearings with an axial load. Is that ok?

I have been looking into possibly building my own cargo bike (inspired by the xyz cargo bike). That said, I am interested in possibly modifying the design - including how the steerable wheels are ...
bvz's user avatar
  • 143
3 votes
2 answers
549 views

Question about different frame construction details. Dropped seat stays, Mono seat stays and ISP Carbon seat tube

I'm thinking about having a custom Titanium/Carbon gravel frame made. I would like the design to be a bit special, and therefore I would like it to come with a ISP in carbon, dropped seat stays, and ...
Frederik Sølver's user avatar
6 votes
1 answer
118 views

Is it strong enough to braze stainless steel tubings with silver?

I was told that you could not braze stainless steel tubing with brass as you would with non-stainless ones. And you should use 56% silver instead? Isn't silver too weak to braze tubes together? I know ...
Zyleyus's user avatar
  • 191
23 votes
6 answers
8k views

Why did curved forks disappear?

Forks on historical bikes are often curved forward in a smooth curve, sometimes called a "French bend". This is sometimes claimed to add a small amount of compliance and comfort. It ...
Erlkoenig's user avatar
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2 votes
2 answers
1k views

What are these parts of the frame called?

Intro I am drafting a question about a frame problem, but I'm struggling with terminology. It seems "appropriate for stack-exchange" to start by asking about the terminology first. Main ...
pateksan's user avatar
  • 2,364
1 vote
2 answers
694 views

Do recumbent bicycles cause knee pain?

I've been thinking about the way the body is positioned on a recumbent bicycle and it seems like knee pain might result. Even if you use a low gearing I think the force direction will always be in a ...
rigganbigga's user avatar
2 votes
2 answers
192 views

Are worse QC'ed carbon frames chosen for pairing with lower tier components? Does it matter?

I am wondering if in carbon (or any other material, for that matter) manufacturers explicitly choose the better crafted frames to pair with higher tier components. By better crafted I mean of all ...
calofr's user avatar
  • 1,059
2 votes
2 answers
580 views

What are the advantages of having a road bicycle frame with lower tyre clearance?

Say, I won't ever put tyres above 28mm and the frame allows upto 30mm vs a frame that has an allowance of upto 35mm. So, what are the advantages with a frame with lower tyre clearance or the ...
Rajesh Kharat's user avatar
0 votes
1 answer
122 views

How to adjust when i am 5'5 foot tall and having a 42 cm roadbike frame?

Im planning to buy a roadbike frameset in my local store but they say that the size of the frame is 42cm and i am 5'5 should i buy that frame?
Darlonapala's user avatar
9 votes
2 answers
3k views

Standard forces on a bike frame

Let's say I was going to design a bike frame for a specific size of individual. I'd start with some basic frame geometries, then I assume I'd calculate the necessary member sizes, stiffnesses, etc. by ...
DerekG's user avatar
  • 677
2 votes
1 answer
483 views

Why are bicycle tubing diameters often metric approximations of imperial measurements?

This is related to my previous question about seatposts and handlebars, but I’d like to generalize the question this time. The majority of bicycle tubes are metric equivalents of imperial sizes. The ...
MaplePanda's user avatar
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7 votes
7 answers
797 views

Spring frame in place of shocks?

Could a bike frame be springy like an athletes prosthetic spring leg instead of rigid? The frame would look like a bow, of a bow and arrow, open end ending at the tires. What problems may arise that I ...
Justintimeforfun's user avatar
0 votes
0 answers
249 views

Identify bike maker from frame number (DAXXXX)

I have a vintage lopro bike and would like to identify the frame maker, the serial stamped on bottom bracket starts with "DA" and is then 4 numeric digits, I was told it may have been used ...
user3129787's user avatar
-2 votes
1 answer
126 views

Santa Cruz but idk which model and year, please!

Hey can someone please tell me the model and year of this Santa Cruz frame I just bought... thanks!
Juan Manuel Cadena V's user avatar
3 votes
1 answer
163 views

my first frame jig - a customized one - which addons and features to add?

i am currently workin on the Bicycle-Frame-Building-Jig that is designed by tanner W at Instructables https://www.instructables.com/id/Bicycle-Frame-Building-Jig/ which bottom bracket assemblies ...
zero's user avatar
  • 143
10 votes
1 answer
4k views

How does brazing and welding not ruin the heat treat on steel tubes?

How does brazing and welding not ruin the heat treat on steel tubes? With such high temperatures, wouldn't the heat treat be ruined? Edit: Specifically in this video ...
justin's user avatar
  • 379
2 votes
1 answer
563 views

Dent on aluminium frame?

I have a Cube Stereo 120 2018. When I was driving today a car hit me. I'm fine but the bike has a dent in it made by the car door. Can it be fixed? Can I still ride it, and go MTB? Can I make a sort ...
Gleis Xheli's user avatar
1 vote
3 answers
3k views

How can I connect two pieces of square aluminum tubing together to make a bike trailer using n55 docs?

Me and a friend are trying to build a trailer using principles found here ... http://www.n55.dk/MANUALS/SPACEFRAMEVEHICLES/DIY.pdf They are using 25 mm aluminum square tubing with a 2mm thickness ...
jennifer's user avatar
  • 151
2 votes
0 answers
88 views

Any shared workspace in the DC Metro area where I can build/weld bike frames?

Anyone in the DC metro area know of a community workspace that I could join to learn to build bike frames? I'm not looking for any equipment or lessons, just a space where I can work. I've been ...
Daniel Patterson's user avatar
3 votes
2 answers
382 views

How is chainstay length defined for frames with horizontal dropouts?

Just reading our own definition of Chainstay Length in the terminology index. It is written currently as the distance between the centre of the chainring and the centre of the rear cog. This is ...
Swifty's user avatar
  • 12.8k
-6 votes
1 answer
301 views

How to get or build Superman Swimming bicycle? [closed]

Human body front area depending on pose in case it will be possible to ride in horizontal position drag must be way smaller as front area will be at least 5x smaller. Pardo face down HPV design. ...
Jan's user avatar
  • 346
11 votes
1 answer
4k views

How to attach cable mounting points to a bicycle frame?

I have a frame-building project that is near completion: An old 90ies steel MTB frame was cut, and converted into a frame for a cargo bike. In my enthusiasm, I have overlooked one detail: The ...
Donat Holzer's user avatar
5 votes
4 answers
2k views

Is it possible to rebuild a a steel bike frame (to make it lighter) by welding aluminum tubes

I have an old (80's I guess) road bike, it is heavy, I'd like to make lighter. is it posible to cut and replace the tubes on the frame by welding aluminum ones?
Victor Mendoza's user avatar
3 votes
2 answers
272 views

Why aren't vertical dropouts truly vertical?

Making some custom rear dropouts (vertical) for a project (nonstandard bike, they must be custom) and as I look to dropout examples, I notice that "vertical" dropouts never seem to have the slots ...
user avatar
1 vote
1 answer
254 views

Is there a non-proprietary standard for oval seat-tube/post?

I see Pinarello Dogma and Gan S frames have a proprietary seatpost/seattube combination, which don't have a circular section. An advantage of that design in my opinion is that it's impossible to have ...
Alessandro Cosentino's user avatar
4 votes
1 answer
491 views

How to evaluate different alloy types used for bicycle frames?

Only certain alloys are used for bicycle frames besides other materials like carbon fibres (at least for the mass market). I often stumble over aluminium alloy 6061 and 7005 (and I think I saw 8004 ...
Kalle Richter's user avatar
5 votes
2 answers
705 views

tall bike build

Hi everyone just a silly question. I have built a tall bike which is a wee project at the moment. I live in a hilly area in Scotland and having gone down a hill at 25 mpg (40 km/h) on the beast. I ...
robert45's user avatar
12 votes
2 answers
2k views

Feasibility of bike frame design by a layperson

I'm sure for many bike builders, their ultimate dream bike starts with a frame that they designed themselves. And herein lies the problem: it seems that modern means of frame production (e.g., ...
Dmitri Nesteruk's user avatar
1 vote
1 answer
502 views

Chain contact on rear triangle

Hi can anyone help with some advice. I have built up a 2007 specialized big hit 2 and fitted it with a 32t narrow wide chain ring as that is what I've been used to riding. It rides great it handles ...
user31395's user avatar
  • 123
7 votes
2 answers
4k views

Why almost every custom framebuilder builds steel bikes, but not many work with aluminum?

I know it's easier and cheaper to work with steel, but is it THAT MUCH easier and cheaper?
Emílio Dolgener Cantú's user avatar
2 votes
1 answer
463 views

Crankset fitting issues

May sound like a dumb question bit here goes. Is it possible to run a 68/83 hollowtech crankset on a frame designed for 68/73? I can see the crankset fitting without issue as the crank axle is the ...
user31395's user avatar
  • 123
7 votes
2 answers
4k views

Can I fit a modern internally geared hub on an old bike ?

I have an old Hercules frame that I have no use for but don't want to get rid of - I am in need of a new "town" bike for running around on, however I need something practical with a nice gear range... ...
Jon Williams's user avatar
2 votes
2 answers
304 views

Seat stay width issues

Hi I currently ride a decent spec 2003 mongoose full suspension but I find that the seat stay is slightly too narrow to run my maxxis high roller 2 2.3 tyre without it rubbing on the frame. In theory ...
Dave L's user avatar
  • 51
4 votes
1 answer
8k views

What are the differences between Columbus Tubings?

I'm just wondering why there are seven kinds of tube sets by Columbus (or Reynolds). There's XCr, Spirit, Life, Zona, Max, SL, and Cromor. I recently had a frame made using the Cromor tubeset; mainly ...
dork's user avatar
  • 827
2 votes
1 answer
475 views

Fork trail vs chainstay length in steering

Is fork trail or chainstay length is a bigger determinant in the overall steering of the bike? Consider an arbitrary frame that I think is steers too slowly. I'm going to rebuild it because I want a ...
ebrohman's user avatar
  • 5,518
6 votes
2 answers
1k views

Lugged carbon frame repair

In broad terms, I'm wondering if it is possible to repair a high quality lugged carbon frame, say a Colnago C60, that has been cracked in the top and/or down-tube. Normally once a carbon frame has a ...
ebrohman's user avatar
  • 5,518
0 votes
2 answers
998 views

What are the advantages of having a aluminium frame? [duplicate]

are there any advantages that an aluminium body brings to the tables over carbon frames?
letterhead's user avatar
1 vote
1 answer
170 views

DIY Bamboo bike? [duplicate]

I am wondering whether or not I can build my own bike. I was thinking of buying some steel lugs or maybe carbon ones or whatever off the internet, and a steerer tube too, and was hoping I could ...
Ben's user avatar
  • 573