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Replacing a bottom bracket on a Dahon
#1
I'm new to bike repair and maintenance, and I'm using my Dahon Speed 7 as my guinea pig. So far I've managed to replace the rear wheel, remove the casette, replace the brake cable and adjust the derailleur.

My next project is to remove and replace the bottom bracket. I understand I need some tools to do this, but I'm not sure which ones. So, can anyone tell me which of the following I need?

Crank puller tool
bottom bracket tool
other miscellaneous tools

Here are the specs to my bike: Dahon Speed 7 Specs Page
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#2
(11-24-2011, 01:01 PM)coxen00 Wrote:  ........
My next project is to remove and replace the bottom bracket. I understand I need some tools to do this, but I'm not sure which ones. So, can anyone tell me which of the following I need?

Crank puller tool
bottom bracket tool
other miscellaneous tools

Here are the specs to my bike: Dahon Speed 7 Specs Page

Crank puller for sure, something like this:
http://www.amazon.com/IceToolz-Crank-Puller-Handle-Adapter/dp/B0028NEHGA/

The specific tool/tools for the bottom bracket will vary depending on the bottom bracket. If you provide a photo of the left side - preferably after removing the crank - we can help.
Nigel
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#3
This is a critical part and many things can go wrong for the beginner, I would not advise using a "good" bike to practice on.
Ask at your LBS if they have something scrap for you to try, you will probably find them helpful if you buy the tools you need from them.
  Reply
#4
(11-24-2011, 03:14 PM)nfmisso Wrote:  
(11-24-2011, 01:01 PM)coxen00 Wrote:  ........
My next project is to remove and replace the bottom bracket. I understand I need some tools to do this, but I'm not sure which ones. So, can anyone tell me which of the following I need?

Crank puller tool
bottom bracket tool
other miscellaneous tools

Here are the specs to my bike: Dahon Speed 7 Specs Page

Crank puller for sure, something like this:
http://www.amazon.com/IceToolz-Crank-Puller-Handle-Adapter/dp/B0028NEHGA/

The specific tool/tools for the bottom bracket will vary depending on the bottom bracket. If you provide a photo of the left side - preferably after removing the crank - we can help.


Thanks,

Here's an image of the bike. I can't take the crank off yet because I don't have the tool. I understand there are two types: square or splined. Can you tell me which mine is? Or can a I by a puller that has an adapter to do both?

http://www.flickr.com/photos/coxen00/6397604155/

http://www.flickr.com/photos/coxen00/6397604599/
  Reply
#5
You have a square tapered spindle, I recommend buying a crank puller that will do the square taper and the hollow type bottom brackets , the one in Nigel's link should work fine
There are two kinds of people in the world, "Those who help themselves to people, and those who help people!"
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#6
(11-25-2011, 02:12 AM)painkiller Wrote:  You have a square tapered spindle, I recommend buying a crank puller that will do the square taper and the hollow type bottom brackets , the one in Nigel's link should work fine

Great thanks, what about the new bottom bracket. How do I select one that fits and is good quality.

Dahon provides very little info and it's hard to find people who know anything about Dahon bikes.
  Reply
#7
The BB should have BSA threads (now the de-facto standard for square tapered BBs). Critical is the axle length: take off cranks and measure the axle length. Other way: find out type and make of the crankset and look at the table http://sheldonbrown.com/bbsize.html
I'd go for mid-range parts (Deore, maybe SLX?), too high end is built for low weight and not so much for reliability. Too low end is... well, low end. You can try to get last years parts, they should be quite inexpensive.
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#8
Thanks everyone to for your help. Let me summarize what I did.

I got curious so i just pulled the crank off with http://www.parktool.com/product/crank-puller-for-square-taper-cranks-ccp-22. I realized the bb had a lock ring, so I had to buy a http://www.parktool.com/product/crank-and-bottom-bracket-wrench-hcw-5. I removed the old BB and found it to be completely shot. So I replaced it with a squared tapered Shimano cartridge BB.

I also replaced the old Dahon derailleur, but I came to find out that the new dearailleur wasn't compatible with the old casette. So I had to remove/replace the 7 speed 13-30t for a 7 speed 14-28.

Also, replaced the brake cables and derailleur cable. Wow those SRAM grip shifts are a pain in the ass.

I have probably spent $200 in parts and tools and lost the better part of the last two weekends, but what I have lost in money and time, I had made up for in new knowledge and fun.
  Reply
#9
So can I ask what model of squared tapered Shimano cartridge BB did you use for replacement. I am trying to do the same.

(12-04-2011, 11:50 PM)coxen00 Wrote:  Thanks everyone to for your help.  Let me summarize what I did.

I got curious so i just pulled the crank off with http://www.parktool.com/product/crank-puller-for-square-taper-cranks-ccp-22.  I realized the bb had a lock ring, so I had to buy a http://www.parktool.com/product/crank-and-bottom-bracket-wrench-hcw-5.  I removed the old BB and found it to be completely shot.  So I replaced it with a squared tapered Shimano cartridge BB.

I also replaced the old Dahon derailleur, but I came to find out that the new dearailleur wasn't compatible with the old casette.  So I had to remove/replace the 7 speed 13-30t for a 7 speed 14-28.  

Also, replaced the brake cables and derailleur cable.  Wow those SRAM grip shifts are a pain in the ass.  

I have probably spent $200 in parts and tools and lost the better part of the last two weekends, but what I have lost in money and time, I had made up for in new knowledge and fun.
  Reply
#10
Shimano BB-un55 as long as it comes in the proper length you need. It has alloy cups. I do not like the plastic cup models. Most any brand makes a decent cartridge BB Let your wallet do the walking.
There are two kinds of people in the world, "Those who help themselves to people, and those who help people!"
  Reply


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