Ask the Bicycle Mechanic

[QUOTE=Chasing Dreams]
I don’t get what goatheads are. Please explain.
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It’s a plant (Tribulus terrestrius) that produces sharp needle-like seeds, sharp enough to puncture tires.

There are MTBs with 700c wheels. Except in the MTB world it’s referred to as “29-inch” size. I don’t know how popular they are though.

Most modern hub dynamos have 2-wire connectors. The frame is not used for ground connection.

[QUOTE=DJ Motorbike]

I should have been more specific. Sorry.
[/QUOTE]

This Bianchi is close, except for the gear system.

[QUOTE=Chasing Dreams]
The fact that you have a tandem with independent pedaling should be a plus because your SO likely doesn’t have the exact same cadence you do.
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Actually, most tandems with independent pedaling don’t have independent gearing. One can pedal while the other coasts, but when both are pedaling, they are using the same gear.

By the way, DJ Motorbike, how’s this for a utility bike? :smiley:

(It’s my Pedersen replica, which I currently use as my commuting bike. That’s a Shimano 8-speed internal-gear hub on there, and I’ve since added a hub dynamo. I know, it still needs a good rack…)

(Goatheads: tire liners, thorn resistant tubes, and Slime ™. Start with Specialized Armadillo tires. Only solution)

Scr4: we are drooling over your Pedersen ride. Sweet. Is that one of the Amsterdam-made ones?

[QUOTE=capybara]
Sweet. Is that one of the Amsterdam-made ones?
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Thanks! It’s a modern replica made in Denmark, usually referred to as the “Copenhagen Pedersen.” It’s not exactly a performance bike, but it sure is fun. And very comfortable for an upright bike.

[QUOTE=scr4]

Most modern hub dynamos have 2-wire connectors. The frame is not used for ground connection.
[/QUOTE]

Right. I was attempting to mount one of those friction-driven dynamos that rub against the tire that ground to the frame. I was eventually able to get it to work by using the handlebar as a ground.

[QUOTE=scr4]
Thanks! It’s a modern replica made in Denmark, usually referred to as the “Copenhagen Pedersen.” It’s not exactly a performance bike, but it sure is fun. And very comfortable for an upright bike.
[/QUOTE]

Yeah, right on! I’ve seen one of these. It was Dutch made and had a 12! speed hub.

Very nice. Thank you.

[QUOTE=scr4]
Thanks! It’s a modern replica made in Denmark, usually referred to as the “Copenhagen Pedersen.” It’s not exactly a performance bike, but it sure is fun. And very comfortable for an upright bike.
[/QUOTE]

Is the rear brake on the hub on your Pedersen? I see that the front is a rim brake but I can’t see what it has in back. Tell me more!

[QUOTE=DJ Motorbike]
For one, mountain bikes don’t have an upright riding position which I think of as central to a bicycle useful for general commuting. Nobby tires have more rolling resistance. Granted different tires can be used, but nearly every mountian bike I’ve ever looked at has nobbys. Also, don’t most - if not all mountain bikes have 26" wheels? I want 700mm.

Second, mountain bikes generally lack fenders. Further, they often lack of any way to mount fenders. I’ve seen those plastic add-on jobs that mount to the rear seat-post, but I want full fenders around both tires. The mounting hardware should be integral to the dropouts, the fenders should be included as part of the design, not an after thought.

I want lighting options. Specifically, I want dynamo power! Extra points for hub dynamos. I’ve tried in the past with limited success to mount those cheap tire driven dynamos to mountain bikes. I have come across mountain bike frames that didn’t work as an adequate ground for the dynamo. What do they make these things out of, brass?

I also have strong feelings about internally geard hubs. They are superior to derailuer systems which seem to need constant adjustment and attention (when they work at all). A good internally geared hub should require next to no attention and adjusting it youself isn’t difficult to learn and usually require no specialized tools. Sturmey-Archer rules.

As far as luggage capacity I am aware that handlebar mounted baskets move the center of gravity dangerously closer to the top and fore and a heavy payload would severely affect handling. Panniers are okay but I was thinking more along the lines of this. A trailer, as you suggested, would be interesting as an additional accessory, when you really want to move stuff.

I should have been more specific. Sorry.
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I think this is everything that you dream of. Breezer Uptown

[QUOTE=DJ Motorbike]
Is the rear brake on the hub on your Pedersen?
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Yes - Shimano internal hubs can be fitted with roller brakes. It’s not as powerful as V-brakes, but so far it’s been reliable and maintenance-free.

[QUOTE=50million]
I think this is everything that you dream of. Breezer Uptown
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Yes, that hits the nail on the head. That is the bike I want.

What is a V-brake, scr4?

[QUOTE=DJ Motorbike]
What is a V-brake, scr4?
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Another name for a direct-pull brake. It’s extremely common on MTBs and hybrid bikes.

Acn you recommend a bike for someone that is going to try out some triathlons, but isn’t sure if it’s the sport for them, and therefore doesn’t want to spend TOO much.

What makes a derailleur lock up while downshifting? I have a 20+year old Schwinn Traveler with a tall man’s frame, and I’m ready to sell it, but it has a bad tendency to lock up (can’t turn the pedals) when I’m downshifting to come to a stop sign. I’m going to sell it cheap, so I don’t want to pay more to fix it than I’m selling it for. Can I honestly tell a buyer it just needs adjustment? It has 3 chainrings in the front, and 5 cogs on the back. The front shift is labeled Shimano, and the back one says Shimano 400.

I’m selling it because my hands can’t handle supporting my weight for several miles anymore (bad tendinitis.) I’m planning to get a recumbent after this one is sold.

I’m incredibly hard to fit (freakishly long legs) and that contributes to bicycle shopping being a nightmare. What I really need is a custom bike - but that’s out of my price range (or at least, the real custom bikes are. The fake custom “you get to choose the color,” is affordable. But the reason the bike doesn’t fit is not because it’s blue).

Last time I went looking and couldn’t find anything, I got a couple of “a friend of a friend of mine builds bikes in his basement. You could give him a call.” I ended up not going that route, because it sounded slightly unsafe. I ended up buying the best of the bad choices. While it doesn’t quite fit, I wasn’t worried about it falling apart on the road.

But were my fears unfounded? Next time I buy a bike (which will probably be soon), should I just call up the “friend” and trust what comes out of the basement? Do you ever see these come in to shops to get worked on? Do they seem as well constructed as known-name bicycles?

[QUOTE=amarinth]
I’m incredibly hard to fit (freakishly long legs) and that contributes to bicycle shopping being a nightmare. What I really need is a custom bike - but that’s out of my price range (or at least, the real custom bikes are. The fake custom “you get to choose the color,” is affordable. But the reason the bike doesn’t fit is not because it’s blue).

Last time I went looking and couldn’t find anything, I got a couple of “a friend of a friend of mine builds bikes in his basement. You could give him a call.” I ended up not going that route, because it sounded slightly unsafe. I ended up buying the best of the bad choices. While it doesn’t quite fit, I wasn’t worried about it falling apart on the road.

But were my fears unfounded? Next time I buy a bike (which will probably be soon), should I just call up the “friend” and trust what comes out of the basement? Do you ever see these come in to shops to get worked on? Do they seem as well constructed as known-name bicycles?
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Find a dealer that has a FitKit. I have long arms and legs and was able to buy a stock Cannondale frame and add the appropriate combination of crank arm length, stem length and rise, handlebar width, etc.

[QUOTE=Chasing Dreams]
I don’t get what goatheads are. Please explain.
[/QUOTE]
I see others have explained…you’re a lucky cyclist not to have made their acquaintance. If you have regular tires/tubes and you catch a goathead, you will get a flat. Sometimes just the tip of the thorn will embed itself, then it will gradually work it’s way through the layers, often causing a very slow leak. Other times, you’ll run over a patch of them, and end up with half a dozen punctures. The plants tend to favor patches of ground that have been cleared off…like the edges of roads and bike trails. I hate goatheads.

[QUOTE=Poysyn]
Acn you recommend a bike for someone that is going to try out some triathlons, but isn’t sure if it’s the sport for them, and therefore doesn’t want to spend TOO much.
[/QUOTE]

What kind of background do you having on a bicycle? How often do you ride? I can be more helpful if I know these things.

The best solution would be to borrow a friend’s road bike that is about your size and put some aero bars on it. You could also stop by your local bike shop and see if they have any customers interested in selling their bikes.

However, if you must purchase a bike, you should stay away from pure time trial / triathlon bikes because they are geared towards a very specific audience and thus relatively expensive. Look for a aluminum road bike with double chain rings and aluminum handlebars so you can attach some aerobars. A road bike won’t be as aerodynamic as a time trial / triathlon bike but it will suit a beginning triathlon just fine. Besides, the person is much more important than the bike if you are just beginning. Just look for a basic road bike.

I’m assuming that Tiagra components will be okay for you since I don’t know exactly how much you want to spend. Here are some specific bikes that you can buy and throw some aerobars on: Specialized Allez 24 , Giant OCR 2 , Trek 1200.

Be sure to buy some clipless pedal and shoes for your bike because they will make a world of difference to how much power you can generate.

[QUOTE=blondebear]
I see others have explained…you’re a lucky cyclist not to have made their acquaintance. If you have regular tires/tubes and you catch a goathead, you will get a flat. Sometimes just the tip of the thorn will embed itself, then it will gradually work it’s way through the layers, often causing a very slow leak. Other times, you’ll run over a patch of them, and end up with half a dozen punctures. The plants tend to favor patches of ground that have been cleared off…like the edges of roads and bike trails. I hate goatheads.
[/QUOTE]

Yeah, there isn’t anything like that around these parts. Actualy, I very lucky on the bike. I have never gotten a flat while riding. All my flats have occurred when my bike is locked up to a bike rack or in the garage.

If it is as bad as you say it is, then I can only add that you consider solid rubber tires or make the plant go extinct. :smiley: