Mountain Biking - New bottom bracket for 2000 Rockhopper A1 Pro

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The best replacement I can find for the current Shimano BB-UN40 bottom bracket is the Shimano BB-UN54 but it comes in several sizes and the only way to find out is take it off and read the label on the old one, but I'd like to buy the BBT32 tool and bottom bracket at the same place to save shipping.
blamp28
01-13-10, 06:59 AM
email to Specialized for tech advice or look on thier web site.
email to Specialized for tech advice or look on thier web site.
Specialized representative told me to go to my local bike shop, the thing I've been dreading because I don't know how they work. Do I roll my bike into the shop? Do I ask someone at the service counter to come out to my car? If I ask for a specific Park Tool BBT-22 will they try to sell me a generic brand tool or think I'm some kind of snob to want only Park Tools? How will they know what part fits my bike when Specialized doesn't?
reptilezs
01-13-10, 11:04 AM
if you have a crank puller you can pull the crank and measure the spindle length. bb shell width is 68 or 73.
bikinfool
01-13-10, 01:52 PM
Specialized representative told me to go to my local bike shop, the thing I've been dreading because I don't know how they work. Do I roll my bike into the shop? Do I ask someone at the service counter to come out to my car? If I ask for a specific Park Tool BBT-22 will they try to sell me a generic brand tool or think I'm some kind of snob to want only Park Tools? How will they know what part fits my bike when Specialized doesn't?
It'd be a strange bike shop you couldn't roll your bike in for them to work on. If they try to sell you something you don't want, don't buy it. OTOH not sure how a shop is going to confirm what bb spindle length you're currently using by just looking at it, they may need to pull it apart if you want the same spindle length. In any case your crank really determines the bb details other than shell width (which you can easily measure), so what crank is on the bike? Might be able to determine the correct spindle length that way. Surprised Specialized couldn't tell you but perhaps they spec'd the bike with different crank/bb setups that year.
^^ Don't most of those square-tapers have the same amount of spindle beyond the face of the cups?
urbanknight
01-13-10, 02:48 PM
^^ Don't most of those square-tapers have the same amount of spindle beyond the face of the cups?
I don't think so, but since this is a mountain bike with a triple, I'd be surprised if it wasn't a 113mm spindle. Bikepedia confirms that it's a 68mm shell width.
Specialized should have records of the specs. I can't believe the person you got is too lazy to just look it up for you.
well biked
01-13-10, 03:13 PM
^^ Don't most of those square-tapers have the same amount of spindle beyond the face of the cups?
No. As already mentioned, the length of the spindle is largely determined by the design of the crankset, and to a lesser degree the frame. For any square taper crankset, the crankset manufacturer will have recommended spindle length(s), usually giving a couple of different lengths.
Also, as already mentioned, 113mm is common for mountain bikes with square taper cranks, but it will vary between about 110mm and can need to be as long as 120+ (121, 127 aren't very common anymore, but they're out there). 118mm is common, too.
urbanknight
01-13-10, 03:51 PM
Since I have little better to do while students filter through to take their instruments home, I poked around a little and although I can't find references to a 2000, I found the specs for the 2003 Rockhoppers, which are also A1 frames, so there's a really good chance it's the same (113mm).
http://www.specialized.com/us/en/bc/SBCBkModel.jsp?arc=2003&spid=20993&menuItemId=0
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