Questions tagged [frames]

Bicycle frame construction, selection, maintenance, and repair.

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50 votes
3 answers
21k views

Why do men's bicycles have a top tube while women's bicycles don't?

Bicycles intended for men have a top tube that always hits me on that embrassing part when I brake. Conversely, women's bikes often don't have a top tube. Why is this?
37 votes
7 answers
40k views

What is the difference between a horizontal top tube and a sloped one?

Some comparable bicycles have a crossbar (top tube) that's horizontal: Others have one that's sloped: What are the reasons for either frame design? Is it merely style preferences? Or is there more ...
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36 votes
4 answers
36k views

How can you recognise a quality steel frame?

I'm looking to buy/build a road bike and I would like it to: last 100 years have a low environmental cost As I'm not interested in shedding grams (a diet would be more helpful for me), I'm leaning ...
35 votes
5 answers
7k views

How to choose a bike for a very tall and heavy person?

So I have wanted to ride a bike for a long time, I do strongman training, I am 6'6 (200cm) tall and kinda fluctuate between 440 - 480 pounds (200-220 kg) depending on what training I am on. We are ...
  • 423
33 votes
8 answers
141k views

What are the differences between men's and women's bike frames?

Why do women's bikes have a diagonal bar in the frame instead of a horizontal frame? Is this the only difference? Sorry if this has been asked (but I cannot find it by searching) and I also just ...
31 votes
6 answers
63k views

Why is carbon fiber inherently weak? Or is it?

This question got me to thinking: If it were possible for me to use a carbon frame, I would, but the expense and my riding style keep me using steel and aluminum. (I like hauling stuff on racks and I'...
30 votes
3 answers
7k views

Why Did Old Soviet City Bikes Have Longer Frames in General

Yesterday I got my hands on an old soviet city bike "Ukraine". It was produced in Kharkov velo factory, 1987. I could not help but notice that the bike frame has different geometry compared ...
  • 401
29 votes
5 answers
16k views

Explaining the effects of frame geometries

I asked about buying a bike here, and someone asked on my behalf about test-riding a bike before buying. My question is, what should I know, or should have known, about the sizing or 'geometry' of a ...
  • 11.8k
29 votes
2 answers
16k views

Road bike carbon fiber frame life span

I have read in several places that the carbon fiber has a shorter life span than the aluminium, and i was wondering just what would it be. I am not referring to accident related failures of the frame....
27 votes
5 answers
114k views

Should my foot be able to step flat on the ground, when I sit on a bike seat?

I was wondering, for a correctly sized mountain bike, or hybrid, should I be able to place my foot flat on the ground, when I sit on the bike seat?
25 votes
4 answers
3k views

Can road bumps excite frame eigen frequencies?

During my last bike holiday I have happened to ride downwhill on roads which had transversal stripes to mark the approaching of a turn. The stripes were made with road paint, and were slightly higher ...
  • 6,687
25 votes
8 answers
8k views

I keep breaking my road frames - why?

I've gone through four five frames in the last decade or so, all from different manufacturers, all steel but both lugged and welded both steel and aluminium. Every one of them has eventually developed ...
  • 1,515
24 votes
5 answers
34k views

Should or can I (car) wax my frame?

Having spent the whole summer taking a bike apart, painting it and now in the process of building it again, I was thinking about waxing it. I want the finish to last as long as possible, after all, I'...
  • 595
22 votes
18 answers
5k views

What different frame materials have been used?

In response to yet another frame materials question, I thought it might be useful to start with a more answerable question. One answer per material please, with an example of a bicycle frame using ...
22 votes
5 answers
80k views

DIY Painting a Bike Frame: Is it possible?

I have painted a couple bike frames (think really cheap garage-find rebuilds) with varying degrees of failure. Can you help me correct/fill in the missing pieces of my frame painting process? ...
  • 321
21 votes
9 answers
54k views

How many years an aluminium frame lasts in a touring bike?

How long does an aluminium frame lasts in a touring bike? [Removed extra questions to be clear.] Background So far I preferred aluminium vs. steel for many reasons, but if steel lasts significantly ...
  • 1,338
21 votes
2 answers
11k views

Dealing with rust on a steel frame

I have a small spot of rust on the bottom side of my steel frame's top tube (Columbus Niobium tubing). It's from abrasion during transport that I didn't notice until it was too late. The spot is ...
  • 10.7k
20 votes
11 answers
24k views

How does a bike's weight affect the overall experience of owning it?

Naturally, carrying a light bike up the stairs is much more enjoyable compared to a heavier bike. Are there any other aspects of a bike which are affected by its weight? For example, would the weight ...
19 votes
5 answers
4k views

Why the penny-farthing?

The penny-farthing was the standard until the diamond-frame "safety bike" was "invented" and revolutionalized the world of bikes. It seems to me strange to have to "invent" to put the same size of ...
  • 13.3k
19 votes
10 answers
32k views

Rear wheel slipping out under load

My commuting/cyclocross bike (a Surly Crosscheck) has a problem. If I tighten the quick release skewer to a normal level, sort of firm to close it, then if I step on the pedals hard at some point, ...
  • 4,346
19 votes
11 answers
28k views

Is there such a thing as frame failure?

Several general questions have been asked regarding how long a bike or bike frame will "last", and the gist of answers seems to be that a bike can last quite a while if the replaceable components are ...
  • 1,424
19 votes
2 answers
1k views

How to prepare a frame for a new paintjob

I want to have my bike frame repainted. What should I do before I give it to the paint shop? How would they like to have it prepared?
18 votes
6 answers
7k views

How is this damaged aluminium frame likely to fail?

I had an unplanned collision with a car yesterday (everyone is fine, thankfully) but my bike – a Giant Revolt 1 – now has a lovely new pair of dents. I cycled it home from the collision (~6km) and it ...
  • 290
17 votes
12 answers
126k views

What are the advantages and disadvantages of riding a smaller Mountain Bike frame?

I am 182cm (5' 11'') tall and am looking into buying a new frame for my mountain bike. Right now i have a 19'' frame and i found a good deal on a 17'' frame. The guy from the shop told me that it ...
16 votes
3 answers
3k views

Is it safe to ride an aluminium bike with a big top tube dent?

Someone tried to steal this bike - they damaged the top tube. The frame is designed with a wide flat top tube. Is this still safe to use?
  • 161
16 votes
10 answers
13k views

Removing Seat Post rusted into downtube

I have an old steel frame (Columbus Number 2 I think) that has the seat post (Suntour Superbe Pro - see, I said it was old!) rusted in. I have tried lots of WD-40 but it will not budge. Any tips on ...
  • 6,125
16 votes
5 answers
5k views

Why is it common for cheap bikes to have the frame sawn in half below the saddle?

These days cheap bikes often seem to come with the frame sawn in half below the saddle. What does the manufacturer gain from this design, and why is it associated mostly with cheap, low quality ...
  • 739
16 votes
5 answers
8k views

What is the purpose of a serial number?

It seems like pretty much everywhere I look, serial numbers can't do the things that it seems they should be able to do. They can't help people figure out what bike they have. They can't help at all ...
  • 5,630
16 votes
8 answers
59k views

Don't integrated headsets wear out, ruining the frame?

I came upon this marvelous explanation of headset types. However, this got me wondering. Isn't the role of the headset cups similar to that of the derauler hanged - to not waste the frame as soon as ...
  • 13.3k
16 votes
1 answer
1k views

What is this frame feature for?

I have a Kinesis Tripster ATR. The drive-side seat stay has a lug on it whose purpose I can't work out: There's no such feature on the other seat stay. What is it for?
  • 3,456
16 votes
2 answers
11k views

Bamboo bikes - the verdict?

I'm curiously interested in buying a bamboo bike for use as a Sunday road bike, and I'm just wondering whether they're suitable: Strength at high speed? I live near Parbold, which has nice hill for ...
  • 579
16 votes
3 answers
20k views

How do I measure the size of my bicycle frame?

From what point to where do I start measuring? I suspect the bike I'm trying to measure is a 56cm because I usually ride a 54 and this is slightly too big, but I want to be sure.
  • 263
16 votes
5 answers
12k views

How does stiffness in carbon frames increase speed?

I have a Specialized Roubaix with a 7r carbon frame; the Tarmac has 11r. Will I notice a speed change if I ride "exactly" under the same conditions? Does the additional 4r = more speed? I am thinking ...
15 votes
3 answers
4k views

Why do some triathlon seatposts go straight up and down instead of at an angle?

Why is it that some triathlon bikes have a seat post that adjusts straight up and down instead of the more standard axis that aims at the bottom bracket? This means that if you raise (or lower) the ...
  • 1,081
14 votes
3 answers
7k views

Can I glue this crack as a temporary solution?

I suddenly noticed a crack in my frame. Is it practical for me to use glue to seal it off as a temporary solution? Edit: Further information ...two incidents so far. Someone opened their driver ...
  • 243
14 votes
7 answers
6k views

Is it worth buying a high end light bike (8.5 kg) from 80' vs recent mid range bike (10kg)

I want to acquire my first road bike with a limited budget (~400€) but I'm faced with a lot of choices, found an old vitus 979 equiped with campagnolo chorus, a little rusty but really pretty and ...
  • 243
14 votes
5 answers
9k views

Can the top tube on a mens bike be cut off?

I want to cut the crossbar on a mens bike to make it easier to get on and off. Will it damage the bike?
  • 165
14 votes
3 answers
6k views

Why are all road bike frames now squashed parallelograms?

I am currently shopping for a road bike and have questions about current frame designs. My height is 6'3" and decade(s) ago I always liked frame designs for which the top of the seatstays joined ...
14 votes
3 answers
3k views

What is this spring between the fork and the frame?

Sometimes on a bike I see a short spring, most often covered in rubber, connecting the fork with the frame: What is the purpose of it? The only thing that comes to mind is stabilising the fork so it ...
  • 735
14 votes
3 answers
22k views

Repairing a bent bike frame, is it worth it?

I have a bike with an incredibly bent frame. The bike itself I have tried to replace with other inexpensive bixes, but this one just had a certain geometry that I keep wanting to resurrect it. It is ...
  • 938
14 votes
3 answers
6k views

What are the advantages of investment casting?

I'm starting to see more and more frames using investment casting for head tubes, drop outs, seat tubes, etc. Such as the new WTP c.r.e.a.m. frame . It looks nice, but I'm suspect on how much more ...
  • 885
13 votes
4 answers
6k views

Why would a bike feature a "carbon wrapped aluminum frame"?

I saw a link to what appeared to be a Carbon bike on amazon. The price was extremely lower than any carbon bike I had ever seen. After reading a bit, it seems that the bike frame is really made of "...
  • 21.5k
13 votes
4 answers
19k views

Why offset the rear rim to the hub and not the hub in the frame?

I'm currently reading The Bicycle Wheel by Jobst Brandt, and I'm reading all of the issues with offsetting the rear rim toward the drive side of the hub... Asymmetry in a rear wheel built for a ...
  • 3,893
13 votes
4 answers
16k views

Metal seat post with carbon fiber frame?

Is using a metal seat post on a carbon fiber frame advisable or not? I want to use a seat post mounted rack on my road bike (no regular rack mount points are on this bike), but I have been told that ...
  • 373
13 votes
3 answers
10k views

Name that frame! (Likely Japanese, likely made in 1986, with known serial number, likely a Bianchi)

(This post was substanically edited/updated on 5/8/14.) I have a bike frame of unknown lineage. What is known: The serial number under the bottom bracket is IS513786. This fits with the serial ...
  • 309
12 votes
7 answers
3k views

What are the most basic parts of a bicycle which cannot be upgraded over a period of time?

After reading this question: Cheap MTB with future upgrades v/s costly fully ready MTB, I myself had a question. What are the most fundamental parts of a bicycle? What are the things which we have to ...
12 votes
2 answers
32k views

Is it possible to repair a dent on an aluminium frame?

I have Centurion Cyclo Cross 4000 bike. Recently I got into an accident with a car door. As a result I have a significant dent on my frame(see the photos below). I have two questions: Is it possible ...
12 votes
4 answers
24k views

Attach bottle cage to frame w/o mount screws

I'm planning on getting a bottle cage for my bike, but my bike does not have the standard mount screws for one. As I understand it, there are two types of cages: bolted cages and clamped cages. I'd ...
11 votes
4 answers
2k views

I have a question regarding the structural integrity of my aluminum frame after its having... incurred damage;

Apologies if this has been covered previously, but I didn't see it if it had been, and at this point I'm at a loss. For context, the bike in question is this year's Haro Double Peak Sport 29 https://...
11 votes
4 answers
3k views

To Cold Set or Not To Cold Set?

I have a Trek 620 (Reynolds 531 lugged steel frame) from the mid-80s the rear dropouts are spaced at 126 mm. I'd like to be able to run an 8- or 9-speed cassette and I was wondering about the issues ...
  • 6,946

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