Bicycle frame construction, selection, maintenance, and repair.

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Is it safe to ride with bent fork?

My bicycle went from this when I bought it: To this when I crashed (note the front fork bent where it attaches to the stem; front wheel almost touches the down tube): Update: Just looked at the ...
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1answer
196 views

How can I use a small Shimano BB on any frame?

I have a Shimano BB-ES25 bottom bracket and 45T crankset that was removed from a Giant-CRX City with an eccentric hub (it had Shimano Alfine internal hub gears). They have literally never been used, ...
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1answer
174 views

How bad is this damaged lug

I have noticed a little crack in one of the lugs of my gazelle steel frame. I hav not ridden it since, because I am worried it will break. Here are some pictures. The lug in question is the one ...
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4answers
9k 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 ...
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2answers
2k views

Am I better off buying a new bike, or upgrading my old bike?

Half a year ago I started to use again my old Schwinn Woodlands MTB for commuting. I didn't want to spend a fortune on a new bike, I wasn't certain that I would like to bike commute daily. Bike has ...
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2answers
695 views

Where can I go to change the vertical drop out for a horizontal drop out?

I have an aluminum road bike frame that I want to use to build a fixed gear. My problem with this frame is that it has vertical drop out and no derailleur hanger. Fr
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1answer
1k views

What difference does bike size make?

I am 6.2 feet tall, and I have a mountain bike that is 17 inches long. I know it looks bit small for me, but will I hurt myself by riding this bicycle? What should be the preferred bicycle length for ...
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1answer
1k views

How feasible is it to transfer modern (2010) components to a 90s frame (road bike)

My 2010 aluminum frame may be toast (stripped bottom bracket) and I was considering getting an older chro-mo frame and transferring the components to it. It's a racing/sport style with drop bars and ...
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1answer
315 views

Purpose of partially filled in rear drop out

I have an old MTB frame that has the drive side rear dropout partially filled in as if it was part of the original forging of the dropout. And, I have seen this on a few other frames -- even ...
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2answers
3k views

MIG Welds vs Brazing for simple bike hacks

Given that frames are generally brazed, not welded and given that MIG welding will work on simple bike hacks what are the downsides of MIG welding these hacks? For example, I would like to make a ...
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2answers
565 views

Why are bike frames getting so much bigger

This is just a general interest kind of question, but I've really been wondering about this lately. We've had a lot of advancements in bikes over the years, and people are always trying to make them ...
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2answers
766 views

How to choose between a race bike like a Madone and a classics bike like a Domane

I ride regularly for exercise in New York City but do not race. I currently ride on a steel frame that handles the rough roads easily. I want to buy a carbon bike and am torn between a "classics" bike ...
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5answers
4k views

Which type of frame is better for a touring bike, steel or aluminium?

I hear that a steel frame is more comfortable to ride for a long tour but that it is heavier and easier to rust than aluminum. Which material is better for a touring frame?
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1answer
967 views

How to avoid or reduce back-pain by adjusting the handlebar and seat of 19.5" MTB?

I'm 6' 3" long, having 45 inches of waist-Toe length. I bought Trek 3500, 19.5" sized frame bicycle two months ago. I've been experimenting with the handlebar and seat positions(Forward n Backward) to ...
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2answers
4k 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 ...
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1answer
339 views

34.9mm front derailleur on steel frame?

Can I fit a 34.9mm front Shimano derailleur on my steel frame? I understand that steel frames are narrower. However, is there some sort of adapter that I can use, or can I even wrap the frame around ...
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6answers
5k views

Fixie/Single speed frame information for beginner

I don't want to buy a ready made bike because singlespeed or fixed gear bikes are way expensive due to their popularity. I want to make my own bike, I haven't build a bike from scratch before. I want ...
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2answers
245 views

What frames fit these requirements?

I'm looking to build up a bike, and while I have certain characteristics in mind I'm not familiar enough with the frame market to know what to look at. This would be my daily commuter/grocery runner. ...
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2answers
2k 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 ...
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3answers
2k views

Can a (relative) beginner adjust spacing on a 501 cromo road frame?

Have acquired a cheap old Peugeot road bike from ebay; nice cromo frame, but it needs a new rear wheel and unfortunately I didn't check the dropout size before buying. It has an OLD of ~120mm, but I ...
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4answers
2k views

Is there a quality alternative to powder coating when it comes to repainting a steel frame?

I'm not a paint expert and want to make a choice that will last a few years. I know that powder coating will last a long time, but I'm restoring an older bike and don't want to spend too much. Maybe ...
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2answers
559 views

How to convert 17“ bike to 18” without changing frame

I bought Author Basic (2012) with 17" frame. But I have some back aches after 2 or more hours of cycling (just cycling or with little jumpings) and sometimes I feel little unsure while riding ...
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3answers
403 views

Skid on small frame

I bought a new, cheap and maybe nasty fixed gear bike. They were only in sizes 54cm and 56cm, so I had to go for 56cm, even though my road bike is 61cm and I'm 186cm. My first few skidding attempts ...
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4answers
6k views

What should a big guy look for when buying a road bike?

I'm 6ft 4" (1.8m) and 22st (139kg). I do a fair bit of cycling, mainly spinning and mountain biking. I would like to get into road riding so I'm looking to buy a road bike. I want to spend between ...
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5answers
4k 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, ...
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3answers
1k views

Is there any difference between professionally painting a car and a bike frame?

I'm getting ready to purchase a new bike which I love but I hate the color scheme. I can't find any custom bike paint shops in the area. Can I simply take it to a car paint shop and get a ...
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3answers
2k views

Difference between “Track Frame set” and a “TimeTrial/Triathalon frame set”

I am going to make a custom fixie bike (possibly with a front brake) that I will use to race on tracks and even commute with. I have been looking at a Planet X frame, and they seem to have very ...
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2answers
283 views

Can a tandem's front bottom bracket fail catastrophically?

Many tandems have a front bottom bracket that looks like this: The front bottom bracket is mounted off-centre in an aluminum shell called "the eccentric." When the pinch bolts shown in the ...
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2answers
17k views

Building my own full suspension MTB: How to I select a frame?

I've recently gotten back into mountain biking. I took my 5 year old Iron Horse full suspension out to the mountain with some friends that had recently purchased new bikes. I haven't ridden for a ...
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1answer
1k views

What does a good weld look like

Reading various questions and answers around here, I've heard a lot of people say you can tell the quality of the bicycle by looking at the welds. How do I know what a good weld looks like as opposed ...
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1answer
346 views

Gap between fork and frame

I removed the fork from my old racer because I was hit by a car. When I'm trying to put the new fork on the frame, I get a gap where the top bearing is situated. What should I do? Could I just remove ...
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5answers
2k views

51cm top tube too small for someone who normally cycles frame with 55cm top tube?

I'm looking to buy a second bike and have found a really nice frame. The bike I cycle at the moment, which fits me perfectly (I am 5'11" (180cm)), has a 55cm top tube. The frame I'm looking at has a ...
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1answer
377 views

Will a track wheel work with the dropouts on my frame?

I've got an old 7 speed steel frame. I've ordered a track wheel with a spacing of 120mm. My frame has correct drop outs for it, but does it have the correct spacing? If not, what are my options? ...
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2answers
345 views

Can missing cage mount screws cause the frame to rust?

I have a Cube Analog Disc 2012 bike, and recently discovered that I have no screws inserted in the bottle cage mounts. Is it possible for rust to form in this area? Also, is it possible for the water ...
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1answer
2k views

Why is the swingarm design uncommon / rare on full suspension bicycles?

While watching a snow biking video, I saw that some of the bikes use a true swingarm design, which matches most motorcycles (as does much of bicycle technology). While this looks rather interesting, ...
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5answers
799 views

What's a good second lock option for around the frame and wheel?

I've seen a few people, specially bike messengers that use a main lock to secure their bike to a post/fence/etc. but also have a second smaller one to lock the other wheel around the frame. Which is ...
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3answers
7k 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.
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2answers
819 views

Why does a bike frame have to be above 56 cm usually to fit 700c tires?

I first came across this when I was looking at the Surly LHT, but I started to see it everywhere. It seems to me they can just put on a longer fork or something, or is it more for the back wheel?
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3answers
2k views

How important is it to face the head tube?

I have a frame that I've built up and I'm having trouble getting the tension perfect on the headset, which is not usually something I have trouble with. A friend of mine who is much more knowledgeable ...
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1answer
462 views

How to grease a hub?

I have a question about hub, When should I grease my hub ? every 20000 km ? How do I know it needs new grease ? Because I can not see if the grease is dry or not...? Thanks
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2answers
2k views

Why don't frame manufacturers ream/face their frames?

Before building up a new frame, it's crucially important to ream/face the headtube and crown race seat (and the bottom bracket, if using press-fit cups). You should also ideally chase the threads of ...
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0answers
65 views

What's the different between ceramic and steel bearing [duplicate]

Possible Duplicate: Real measurable benefit to ceramic bearings? What's the different between ceramic and steel bearing ? On the bottom bracket, what do you feel when you change into ...
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3answers
1k views

Can I use normal grease for a car on the surface of carbon bike?

Helo Guys, I want to know your experience about carbon material and grease Can I use normal grease with carbon ? I want to put grease onto fork and stem.... Or WD-40 or silicone penetrant would be ...
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2answers
364 views

Carbon seatpost dip in?

Can I insert a carbon seatpost up to 20cm deep into seat tube? The seattube is carbon as well. Total length of the seatpost is 35cm. The shape of the seatpost is aero seatpost (tear drop shape). It's ...
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1answer
2k views

Clear lacquer on steel frame

I'm currently working on a steel frame that I got off ebay. I'm removing the existing paint using wire brush adapters for a drill (didn't want to get involved in nasty chemical baths). One result of ...
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2answers
830 views

FEM: How to Design weight-distribution in bike prototypes?

Inferio! No-one can understand this bloated question here, now more focussed. Suppose you are doing a new bike. How can you be certain that some critical point won't get too much force and the right ...
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2answers
519 views

Possible to repair a pushed in braze-on?

I have a Trek 7200 (Alpha aluminum frame) and it has two water bottle holder mountings, the top braze-on on the seat tube seems to have broken from over-tightening and has sunk into the frame. These ...
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1answer
444 views

Do kickstands damage the frame by being used?

I was told once that kickstands warp the frame when used, especially when the bike is laden down, and that some materials are more susceptible to this than others. Is there any truth to it?
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4answers
3k 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 ...
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2answers
2k 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 ...