Getting my bike repaired without getting ripped
 

I am going to take my dahon to a shop to get the chainring and possibly crank arms replaced. I live in Taiwan and there is a sham that a lot of repair people use here - they will say "we don't know the sizes of xyz so we will have to take it apart and take a look at it", and then while your bike, computer, etc is in pieces on they table/floor they will quote a price that is too high, and most people will feel psychologically obligated to take it because the bike, etc is already in pieces.

Can someone tell me the sizes/materials, whatever that I need to ask for on my Dahon speed (w/ 7 speed rear cassette) so that they won't have to take anything apart? Also, is there a good post or link on materials and sizes for chain rings and cranks, crank arms? I have googled but get a lot of references that are mostly about the rear end.

Why don't you DIY, it's a simple undertaking. Search in youtube, you'll see how it is done. You need 15mm (thin wall) socket, 15mm bicycle wrench, and a simple puller. The chainring and crank arms come in a set. Bring your bike to the part store to make sure the parts would fit the BB axle on your bike. You can also search the net for the part such as in Taiwan: class.ruten.com.tw

There are steel rings (gear) and 7075 aluminum alloy gears, 48-tooth, 52T, and two and three-gear combinations such as 52-42-30. If your Dahon has single mid-gear and you want to put on a two or three-gear crank, you would have to buy shifting mechanism.

Explanation of chainring bolt patterns:
http://sheldonbrown.com/gloss_bo-z.html

List of common patterns:
http://sheldonbrown.com/cribsheet-bcd.html

Yeah, Dahon`s product description is missing the information you`d need for replacing the chainrings, and from the picture on their website, it doesn`t look standard. Somebody here will probably know exactly what you need. If nobody answers, call Thor- I`m sure he`ll know what it is and what your options are.

For replacing parts on your bike, you can do it yourself if you don`t have any real objections- some people don`t want to mess with it, and that`s fine. There are a few special tools required (such as for removing crank arms), but most are inexpensive. A set of allen wrenches will get you through probably 80% of the work you might do on a bike, add in a crank arm puller, a casettes ring or freewheel tool (depending on which your bike needs), thin wrenches for headset and pedals, and you`re up to 95 %.

Learn to do it yourself. The LBS I frequent is owned and operated by someone who is willing to teach me. Of course, I had to buy the bike there, but hey, he's in business. You get what you pay for, and have to pay for what you get.

If you find a shop that is willing to help you DIY, odds are good that it is a worthwhile place to take the bike for those things that are beyond your abilities.

Hi 朋友, I live in Taiwan too! Which city do you live in?

I completely understand what you mean with the scams and shams here. Lie, cheat, and steal, it's the Chinese way. I currently ride a Tern but only a demo model because the shop lied to me to get the sale.

Like car repair, it helps to educate yourself about the basics even if you don't plan on doing the work yourself. Nothing keeps mechanics more honest then being able to call them on their bs.

For starters, pick up Park Tool's Big Blue Book. http://www.parktool.com/product/big-...-edition-BBB-2

And spend some time poking around on the Sheldon Brown site. http://www.sheldonbrown.com/home.html

Both will give you a good start in arming yourself before heading to the shop. Like a lot of folder makers, Dahon uses a lot of off the shelf parts for things like crank assemblies, chainrings, hubs, brakes, etc. It's mostly the frame, handlepost, seatpost, and related bits, that are proprietary.

PS - If you have a 7 speed(D7?), it probably uses a freewheel, not a cassette/freehub. And if it has a Neos derailleur(probable), that is proprietary, and you would have to use an adaptor like Thor sells to put another type on it.

If you are not on tour and live in Taiwan you only need to find one reliable LBS. Ask around and someone will point you to one and then keep supporting it.

2010/11/12 D7 has Cassettes for sure. I've owned one.

If Local do a few observation visits, in various shops .