Mountain Biking - Noob has a few questions.

I have some questions that I don't seem to be able to find the answers to. I've only been riding for a month or so and I'm trying to learn all that I can.

1) What kind of performance difference (if any) will I see by switching my cassette for an upgraded one?

2) How much of an upgrade would I need to see a difference if any? I have a sram pg-950 9spd now. Would a Shimano Xt cassette even be considered an upgrade or would I have to go even higher to see any benefit?

I have sram x7 trigger shifters and rear derailleur if that makes a difference.

3)I noticed yesterday that my large cog on the front is SLIGHTLY bent. Looking down on the chain, I can see a slight wobble to it when turning the pedals. Big deal? Don't worry about it? Change it asap?

4) My rims are wtb speed disc. It's spec's are 559x17 541 ERD. What do these numbers mean?

5) I have 2.14 49/52 wtb motoraptor tires. Would it be to my advantage to go to a wider tire? If so how wide could I go and what would the positive vs negatives be?

Most of my riding is xc. Nothing extreme at all. Logs and stuff but no actual jumping or drops.

I appreciate anyone taking the time to answer these questions or referring me to a link that answers them.

1) Hardly any at all. Biggest difference is weight!
2) Again, just weight. O.k., maybe slightly better shifting. Just wait until the one you have wears out and then upgrade.
3) Chances are it is. Cheap ones are usually not straight. Just get a bit creative with a vice and you should be able to straighten it.
4) No clue. Scary, I've been in the industry for 20+ years. I don't know, but I WILL find out.
5) Depends on the type of riding you are getting into. You said mostly XC. If however, you are doing more jumps or drops or really technical riding, a wider tire is better for traction, and more impact absorbtion. If you stick with XC it'll be too heavy and slow due to increased rolling resistance, (more drag due to a bigger contact patch.) you'll also have increased rotational weight.

L8R

Thanks a lot for your responses. Most of that is pretty much what I had figured, except for the tire stuff. I hadn't really thought about it being that much slower because of the weight and all.

Interesting about the rim measurements. I have also sent an email to wtb for clarification on it. If I get a response from them I will be sure and post it here.

Appreciate it.

Received the following from WTB.

The 559 x 17 is what is referred to as the ETRTO dimension. The represent
the inside width of the rim 17mm at the specified diameter of 559mm which
is the tire bead diameter for 26" tires. The 541 ERD refers to the
"effective rim diameter" in Millimeters. This is the distance from outside
eyelet to outside eyelet 180 degrees apart. This dimension is needed to
calculate spoke lengths.

Thanks,

Fred Falk
WTB

At least they responded. Better than most companies.

#3, they are called chainrings.
#5, is dictated by the 'tween the forks\bosses space, newer dh and like, have the space, older mtb no.
An interesting go> is run say -1.95 rear- 2.15 front. Bmx or even motocross does this, gets a little rotation weight down and you still have your 'bigwheel' to get over obs'- problem is finding treads to 'match' for xc cornering. Dh- it doesn't matter as much.

Oh...IMO :rolleyes: (except #3, they really are called chainrings.)