1. The most important thing about buying a new bike is to make sure it fits. The only way you'll know if the bike is right for you is to size up the bike and make sure that the bike's geometry matches your body's geometry. Ask questions and do some research.
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2. If possible, try to find a shop that will let you demo the bike on real dirt. Five minutes in a parking lot won't cut it. You wouldn't buy a car without a real world test drive, and a bike should be no different.
3. Don't belive the hype. Just because your favorite rider or best friend rides a certain bike, that doesn't mean that's the best one for you. Have an open mind and be realistic about your needs and ability.
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  1. #1
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    A few bike tuning questions

    Hi,

    I've just replaced most components on my bike; left it out rusting in the balcony for over a year . The bike "sort of" works, but since I'm a complete noob I'm worried I may have set things up incorrectly. Here are a few q's that I have:

    1) Rear derailleur pulley frequently hits largest sprocket
    - b-screw fully turned in; it helped a little
    - if I manually move the derailleur out and slowly let it move back in, it's ok
    - if I switch from a higher gear back to it, the two will occassionally hit; I can feel it if I turn the crankarm by hand

    2) Front derailleur shifting
    - when shifting from a smaller chainring to a larger chainring, I noticed that the deraileur actually pushes the chain against the side of the larger chainring. Is this normal?

    The last one is actually not about tuning. I just got my first pair of clipless shoes/pedals. The shoes are a pair of Shimano MT-40 mtb shoes. I found it a little weird that I need to stick a piece of sticker to the inside of the shoes for "water sealing". Doesn't feel very water resistant to me. Is this normal for a shoe in this price range (~$80)?

    Thanks!

  2. #2
    ride hard take risks
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  3. #3
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    hmmm

    Quote Originally Posted by SANdave
    Hi,

    I've just replaced most components on my bike; left it out rusting in the balcony for over a year . The bike "sort of" works, but since I'm a complete noob I'm worried I may have set things up incorrectly. Here are a few q's that I have:

    1) Rear derailleur pulley frequently hits largest sprocket
    - b-screw fully turned in; it helped a little
    - if I manually move the derailleur out and slowly let it move back in, it's ok
    - if I switch from a higher gear back to it, the two will occassionally hit; I can feel it if I turn the crankarm by hand

    2) Front derailleur shifting
    - when shifting from a smaller chainring to a larger chainring, I noticed that the deraileur actually pushes the chain against the side of the larger chainring. Is this normal?

    The last one is actually not about tuning. I just got my first pair of clipless shoes/pedals. The shoes are a pair of Shimano MT-40 mtb shoes. I found it a little weird that I need to stick a piece of sticker to the inside of the shoes for "water sealing". Doesn't feel very water resistant to me. Is this normal for a shoe in this price range (~$80)?

    Thanks!
    I don't know about your first problem. I think I'd have to see what you were talking about, the description isn't quite doing it for me. As for the second question, yes it is normal for the derailleur to push the chain into the side of the larger chainring. In fact, if you look closely at the inside of your chainring, you will see little machined ridges that are made to hook your chain and lift it onto the teeth. It's wierd, but untill someone comes up with a better system we're stuck with it.

  4. #4
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    Your feet are going to get wet. On hot summer days consider a water crossing a blessing, in the winter wear over booties if you so desire.

    Is your rear derailleur an older XTR? If so, the B tension screw is never quite long enough. Take it to Home Depot et al and get another that is a bit longer - or - put the screw in backwards (head in). That will give you about 3 mm more length but its a pain. One other thing, your chain is the proper length right? One too short would pull your RD forward a bit.

  5. #5
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    If I'm understanding your first problem correctly, it sounds like your chain is a few links too short. Try adding 2 or 3 links and see what happens.
    Most people don't realize that large pieces of coral, when attached to the skull with common wood screws, can a make a child look like a deer.

  6. #6
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    Thanks for all the info and suggestions.

    The rear derailer is a newer XT 760 long cage with 760 34T cassette. On the largest cog, the RD pulley will sometimes hit the cog lightly; ~3 times per crank revolution. If I paddle backwards, they will hit much more frequently. I'll try your suggestions of adding another chain link or two. What I have now is ~2.5 extra chains in addition to the big-big measurement from Shimano's instruction sheet/Zinn book (the inner/outter didn't match if I just use 2). This doesn't happen on the second largest cog.

    I was playing with it today, and think it may also be caused by stiff cable housing. I cut the new one to the old one's length, but the newer housing seem to "retain position". On a smaller cog (e.g. 11T), the clearance is higher. However, if I manually push the RD pulley against the cog and let it spring back, the clearance is significantly less. It is not nearly as far as before (via normal shifting).

    I think I'll try in order: 1) longer screw, 2) longer cable housing then 3) extra chains.

    Being a noob, I shouldn't have change everything at once. Now I lost a reference as to how things should be like.

    Agains, thinks for all the suggestions! I'll try them out and report back.

  7. #7
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    - If you did the big/big + 2.5 it is highly unlikely it is your chain.
    - I haven't heard of an XT needing a longer B Screw. It would be cheap and easy to find out if that is the problem tho...

    With the chain off, when you shift up to the granny in the rear how does your jockey wheel to cog clearance look?

  8. #8
    ride hard take risks
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    If you cant get it to adjust properly got to the LBS beffor it gets screwed up, it will be cheaper that way. I'm shure the LBS wont bite you to bad.

  9. #9
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    Good job! It works!

    Turns out I was very stupid indeed. I was working on my bike with it turned upside down! Flipped the bike over and the problem disappeared. I can push the RD pulley against the cog, and on first impact, the two will separate unlike when it was upside down. Now all front/rear shifts are very smooth.

    My whole bike is almost done pending minor brake adjustments. This is my first bike maintenance project. I've very proud!

    Thanks for all the ideas and suggestions!

    I may still head to my LBS at the end for a final inspection. Don't want it to fall apart while I'm riding.

  10. #10
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    Quote Originally Posted by SANdave
    Turns out I was very stupid indeed. I was working on my bike with it turned upside down! Flipped the bike over and the problem disappeared. I can push the RD pulley against the cog, and on first impact, the two will separate unlike when it was upside down. Now all front/rear shifts are very smooth.

    My whole bike is almost done pending minor brake adjustments. This is my first bike maintenance project. I've very proud!

    Thanks for all the ideas and suggestions!

    I may still head to my LBS at the end for a final inspection. Don't want it to fall apart while I'm riding.

    Congrats, and a lesson learned - whatever is happening on a stand will not necesarily happen when the bike is in actual motion - thats why it is so important to take it for a brief test ride before hitting the trails!

    Keep those other sites (park tool and sheldons) and you will have a massive amount of good quality information for all your needs. Pretty soon you will be building your own wheels (pretty much the most complicated part on a bike)

    TJ

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