Conference noted::bicycle

	On a mountain bike; should the spindle that goes through the 
bottom bracket be centered? or offset?

>	On my bike I noticed that with the crank extended horizontally 
>parallel to the chainstays, that there is about 1/8" clearance on the
>left side and when I rotate the chainside crank back to the horizontal
>position parallel to the chainstay it shows over 1/2" clearance. 
    
    Interesting.
    
>	Can the spindle be adjusted side-to-side??
    
    Typically not.  The spindle's races must be oriented with respect to the
    BB cups.
    
    Further commentary from MTB-equipment experts?
    
    -john

    I would have thought that the spindle would be adjusted for the best
    chain line...

>    I would have thought that the spindle would be adjusted for the best
>    chain line...

at least on road bikes, the following applies: One arm of the spindle is 
typically longer (race to end of spindle, sometimes QUITE subtle). The 
long side is the chainwheel side. In the 'classic' configuration of BB, 
one side of the BB assembly was a 'fixed' cup. This meant that your 
spindle always ended up at the same distance out. If it didn't give the 
right chainline, tough (have seen spacers used to get the spindle out 
further occasionally). Many of the more recent BB's have adjustable cups 
on both sides, and by adjusting one in and the other out, you can affect 
chainline, crankarm->frame clearance, etc. Was that the question? :-)
                                      ken

    	What brand name is the ATB?
    
    	Is it a factory configuration?
    	If so, are you saying the manufacturer doesn't know what they're
    	doing? What line/level of components are on the bike? What is the
    	crankarm length? 175 mm?
    
    	Crank arm clearance is generally irrelevant with triple chainring
    	configurations. The critical clearance point(s) are the three
    	chainrings. It is difficult to build a frame that handles fat
    	tires, and allows for optimal alignment of the chainrings with
    	the rear cogset, be it a standard freewheel or a cassette freehub.
    	Elevated chainstays solve that particular problem, but that's
    	another story altogether.
    
    	With regard to crankarm clearance: as of late, the measurement to
    	check is the Q-factor, or overall distance between the left and
    	right crankarm. The larger the Q-factor, the more spread apart
    	your feet are. It is inherent that triple-chainring cranksets have
    	greater Q-factors than double-chainring, simply because of the
    	extra chainring.
    
    	If you buy a replacement bottom bracket, verify the application
    	thoroughly: with regard to overall axle width, chainstay clearance,
    	and compatibility with your existing transmission.

    
    	I just installed a Suntour greaseguard BB (see Cannondale note).
    You force grease in thru a hole in the spindle and spindle bolt.
    The Shimano is a good BB (note .0). The chainringside is usually a
    little longer and BB's are not usually adjustable and the chainring
    side is the fixed side and the Q factor is dependent mostly on the
    cranks used. Take the BB apart (requires tools or ingenuity) check
    the races and ball bearings for damage, grease it and put it back
    together. Pound on the crank when installing it then crank down the
    bolt.
    	Most BB's supplied with most bikes including "top of the line"
    models are not very high quality and replacement will always be an
    upgrade. Check the next DX or even XT grupppo you look at on a bike
    and see what I mean. It probably won't have a DX or XT BB.
    	Regards

      <<< Note 2375.4 by NQOPS::CLELAND "Nothin' special, it's just me" >>>
                           -< Elevated chainstays? >-

>    	What brand name is the ATB?
    
>    	Is it a factory configuration?
>    	If so, are you saying the manufacturer doesn't know what they're
>    	doing? What line/level of components are on the bike? What is the
>    	crankarm length? 175 mm?
    

	It's a Raleigh Crest- factory configured-unmodifed. It has Shimano
	400LX/200GS mix of components. I don't recall saying that the 
	manufacturer doesn't know what they're doing; I did say that the 
	crankarm-to-chainstay clearances were different on each side of the
	bike (which may be fine-or not; that's what I was trying to find out). 
	In the bike books I have seen so far, I haven't seen this mentioned
	one way or the other. 

                       <<< Note 2375.5 by PIPPER::GOOD >>>

    
>    	I just installed a Suntour greaseguard BB (see Cannondale note).
>    You force grease in thru a hole in the spindle and spindle bolt.


	Thanks!! This sounds like a good setup because you can re-grease
	periodically without tearing the BB apart. I think I'd go with this
	when the time comes. A bike mechanic I spoke with earlier (after I
	entered the basenote) also mentioned the Suntour greasegard due
	to the additional fact that squeezing new grease in forces the old
	grease and grit out. I ride in a lot of dirt, sand, mud and water
	so this sounds like it was made for where I ride. He also mentioned
	that there are adjustments to center the spindle and he tries to
	get it balanced. He's going to take a look at it tommorrow and let
	me know for sure if it's right/wrong/adjustable or what. Thanks again!

			Regards- mike

    You can also buy just the BB spindle for about $4.00 in different
    lengths.  For example, if you have a bike with a double chainring and
    are installing a triple you may need to move the chainring set out
    further to get clearance for the inner ring.  The local shops here in
    Mpls carry spindles where the length from bearing race to the end of
    the taper on the chainring side changes in 4-5 mm increments.  I
    recently converted a bike to a triple, and replaced the original
    spindle with one approximately 5 mm longer to get the right clearance
    and chain line.

    
    Well, I removed the cranks and opened up the bottom bracket and just as
    I suspected, nasty, swampy water came out. The bearings didn't look too
    bad though, but I figured that as long as I had it open, might as well
    check out an upgrade. The mechanic showed me the Suntour grease guard
    and the Shimano sealed unit. The Suntour was $46 and the Shimano was
    $17. I know I hit a lot of puddles and mud, and they both looked like
    they would solve the problem , but I went with the Shimano sealed unit
    because it's completely sealed (so I can clean the bike with the high
    pressure hose once in a while), and it's nonadjustable and expected to
    last about 5 years; but even if I only get 2 years, it's only $17 to
    replace and was pretty quick to install (if you have a splined BB
    tool). I also replaced the stock stem with a longer (135mm) stem- much
    more comfortable to ride now. Thanks again for all the advice!