Bicycle Mechanics - Shimano XTR Crank & BB, Front & Rear Derailleur Questions

Hello,
I discovered this forum a few weeks ago and have been lurking ever since. I finally came up with a question that doesn't appear to have been addressed - at least I didn't find it in a search of the forum.

I am a 40 year old engineer and have been riding a Trek 8000LT for the past two years. I put around 150 miles per week on the bike split between 50% trails and 50% road. The trails aren't technical in nature. The biggest obstacle is sand and roots, followed by alligators. I am located in Florida.

I have been turning a wrench on my bikes all my adult life and am equipped with a good set of Park Tools and the Barnett Manual. I perform all the basic maintenance on my family's bikes. I simply don't have a bike shop locally that is reputable and trustworthy. In the past they have swapped superior parts for inferior internals on other bikes, assuming I wouldn't catch the theft. For major repairs I have to drive 30 miles, so I will be doing these upgrades myself.

Here are the questions by component - I will be using these with new model XTR shifters. I have Hayes brake levers. The bike is a 9 sprocket:

1. Shimano XTR Crank & BB
My Trek is using an Icon Onyx crank which I have never been too fond of. I originally was going to go with an XT crank, but have been considering the newer XTR. My bottom bracket spindle length is 113mm, but, the new XTR BB I will need to use is listed at 112.5mm. Will this slightly shorter length make a difference? Should it work ok? Should I upgrade the cassette to XTR for better drivetrain/chainline alignment? Current cassette is 11-32 HG70-9.

2. Shimano XTR Front Derailleur
Shimano has two basic models - the 953 and 952. Does one work better than the other? Which is recommended? What are the advantages and disadvantages of the two models?

3. Shimano XTR Rear Derailleur
Same question. Shimano has two basic models - the 953 and 952. Does one work better than the other? Which is recommended? What are the advantages and disadvantages of the two models? Yes, I will be using a long cage model.

Thanks in advance for your help.

Well this is a fun question. Thanks.
1) the 112.5 spindle will do just fine. Follow the directions for spacing that comes in the package. XTR is packaged to fit both 73 or 68 shell, so make sure all of the spacers are there.

2) The difference between the 952 and 953 front derailleur is where the clamp is in relation to the cage of the der. 952 is lower than the cage (top swing) and 953 is higher than the cage (bottom swing). This gets real important with some dual suspension bikes and with outside chainrings less that 46t but there is no issue the way you've described it. I would do the 952 because the inner plate of the derailleur cage moves differently than the outside cage plate. The inside plate lifts and ramps up to assist upshifts cleaner in normal gear pattern situations (i.e. stock XTR crankset gearing). The shifting degrades if you use a smaller chainring set (say xt) because the arc of the cage will fight the shift.

3) The difference in the rear derailleurs is 952 is a standard derailleur that you're used to, the 953 is "rapid rise". In other words, when the cable is slack on a 953, the rear der wants to go to the LOW or LARGEST cog in back. The 953 is supposed to be more efficient-- it was just clumsy trying to learn to both ride and adjust it.

4) Finally on cogsets, the XTR cogsets are light, but they wear out fast! and at about $150 a cogset, I can't see it. The XT level seems to last a little longer (M750) but I would wait until wearout.

Walt,
Those were the answers I needed. Thanks a bunch!

I went back to some of the online retailers and took a closer look at the thumbnails of the various derailleurs and see exactly what you mean.

The 952 series is definitely what I will need for the hardtail.

Again, thanks for the information.