Bike shop having trouble. Need parts suggestions!

[Collwyn]

Help me out all, but I'm a noob, so please keep it simple

My local bike shop tells me that the original derailleurs and bottom bracket are no good for the conversion.
I'm converting an old Pacific 26" mountain bike.

1. The original bottom bracket I'm told, is too small for the new cruzbike shell.

2. The old rear derailleurs were of the style that hooked onto the bike frame, and the new triangle brackets
require a screw-in.

3. The front derailleur attachment is too small for the cruzbike front tube.

Have I given enough info for anyone to suggest the appropriate replacement parts?

 

[Doug Burton]

With an old Pacific MTB, all of this is quite possible. None of it is a show stopper.

You need an English thread bottom bracket, 68mm, with a 115 to 118mm axle:

http://store.nexternal.com/shared/StoreFront/default.asp?CS=icycles&StoreType=BtoC&Count1=120128810&Count2=37269234&CategoryID=42&Target=products.asp

You need a 34.9mm (1-3/8") band, top-pull front derailleur:

http://www.nashbar.com/profile.cfm?category=600083&subcategory=60001037&brand=&sku=13000&storetype=&estoreid=&pagename=Shop%20by%20Subcat%3A%20Front%20Derailleur

And you need a reasonable-quality rear derailleur:

http://store.nexternal.com/shared/StoreFront/default.asp?CS=icycles&StoreType=BtoC&Count1=434185206&Count2=351325631&CategoryID=75&Target=products.asp

Using this info, the shop should either be able to procure these or provide similar replacements.

Best,

 

[Collwyn]

Thank you for the help, Doug.

When purchasing the rear derailleur, should I make a distinction between the kind that hooks onto the frame rather than the type that screws in? That's why the shop said I couldn't use the originals.

 

[Doug Burton]

Most shops only supply the "screws-in" type. The type that came with your bike is generally OEM-only. If you have any doubts, just e-mail me with what you intend to buy and I'll check it for you.

Best of luck,

 

[Collwyn]

Doug, here are the first two components I was directed to by the good folks at Nashbar:

Bracket:
http://www.nashbar.com/profile.cfm?sku=12779

Front Derailleur
http://www.nashbar.com/profile.cfm?sku=18404

Still looking at rear derailleurs, but do these first two fit the bill?

 

[Doug Burton]

Neither one will work for you. I am increasingly dissapointed with the online help at Nashbar and Performance (the are the same company.)

The bottom bracket they recommended is an "ISIS" type,; you will have to replace your crankset to use it , because I'm positive your crankset is square-taper and the bb they recommend is for a crankset that uses a series of teeth to engage the crank (that's fine, but I don't think you were intending to replace your crankset.)

The derailleur they recommended is a bottom-pull derailleur. this would require you to route your FD cable around the bottom bracket shell and back up to the derailleur. It can be done, I did it with my red bike:

but you will need to buy a cable guide, drill a hole in the bb shell provided with the kit, tap the hole for 5mm/0.90 thread, and bolt the cable guide to the bb shell. I don't think you were planning on all that.

A top-pull derailleur makes all this unecessary:

(shown on a Freerider, but your conversion will do this minus the clamp-on cable stop.)

Would you like me to give you a list of parts to buy, and bring to your LBS?

Doug

 

[Collwyn]

Could you, Doug? I was hoping to keep things under $100, if possible. If not possible, I understand.
One thing, though. The front derailleur at Nashbar is available as a top or bottom pull. Still no good?

 

[Kamatu]

Collwyn wrote: Could you, Doug? I was hoping to keep things under $100, if possible. If not possible, I understand.
One thing, though. The front derailleur at Nashbar is available as a top or bottom pull. Still no good?

I did it that way too, but the price just keeps going up.