Bicycle thread

Discussion in 'Sports' started by Zodiac, Jul 10, 2006.

  1. Aurelius

    Aurelius Long timer

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    Downshifting, as in shifting to a lower (larger diameter) gear.

    Ideally, I shift gears just before I need to so that I'm not pressing hard on the pedals when the chain moves from one gear to another. But on unfamiliar trails, I'll sometimes come around a blind turn and be confronted by a steep climb or a rooty/rocky section of trail. In those instances I have no choice but to shift as I'm pedaling hard. I hate having to do that, since it makes a nasty grinding sound, which can't be good for the chain and gears.

    Not me personally, but I've had it checked by half a dozen bicycle mechanics over the past few months. Wouldn't they have noticed something like that?

    No. I only bought the bike in late March of this year, so I wouldn't expect the cables and/or housings to be worn out. :dunno

    I just spoke with another bicycle mechanic who thinks it may be caused by a bit of slack in the cable as the rear suspension is compressed. The loss of tension in the cable would explain why it only happens when I'm riding the bike, and why it only occurs when downshifting and not when up-shifting. He suggested turning the barrel adjuster the next time I'm out on the trail to see if the problem goes away.
  2. Gummee!

    Gummee! That's MR. Toothless

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    If you ride off-road, cables and housings should be on at least a 1x/year replacement schedule. 2x/year if you're off-road frequently. To save $ run the old rear cable as the 'new' front cable. Front shifting's not nearly as finicky as rear shifting.

    You can still let off for an instant as you shift, but it takes practice. Push hard with your dominant foot, ease thru with the off-side, then hard again on the dominant foot after the chain's shifted. Among other things, it'll help your stuff last longer.

    Your suspension activating *shouldn't* affect your shifting. ...unless there's a burr or something similar in one of the cable stops on the frame that grabs your cable. One other thing to try is put the bike on a trainer, sit on the saddle and have em adjust the rear derailleur as you're on the bike. That way, the suspension's compressed as you're adjusting things. :dunno

    My 'over the innerwebs' diagnosis is cable issues. Change em and see.

    M
  3. Aurelius

    Aurelius Long timer

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    I've got Trek's 'Red Shield' five year maintenance coverage. It's supposed to include even wear items like brake pads. I'll ask them if they'll replace the brake cables and housings. :deal

    I definitely need to work on technique. I've gotten so fast lately that all I'm concentrating on is climbing higher on the Strava leader boards :evil rather than working on my basic skillz.

    Putting the bike on a trainer sounds like an excellent idea. I'll mention it the next time I'm in there. The mechanic I spoke with says that because of the way the cable is routed, compressing the rear suspension rotates the swingarm upward, giving the cable a bit more slack than it has when no one is sitting on the bike. That extra slack, he thinks, is causing the derailleur not to move over as far as it should when I downshift. It might explain why the problem never occurs when the bike is up on a stand. :dunno
  4. ducnut

    ducnut Long timer

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    That Defy would be nice bike, for anyone starting out. Yeah, a little better drivetrain would be nice, but, you can always upgrade, later, as that's a really good frame to build upon. The price is excellent.

    I'd suggest working out a deal where they can swap on the largest tires that'll fit. A larger volume tire will ride better and provide additional protection against rim dings and pinch flats. That's important for a heavier rider. I believe a 28mm will fit that bike.

    I'd skip mailorder. As a novice, you're going to need the support of your LBS. The guy seems genuinely nice and wants your business. It would be in your best interest to have him behind you. Plus, you'll get a no-hassle warranty and tune-up support. At the minimum, you'll need wheel truing.

    I'm not sure on the size he's suggesting. At 6'3" and only 32" inseam, it appears you're of a longer torso. If so, I'd suggest looking at an XL, for comparison. The toptube seems a little short for someone of your proportions. Just ask him about it, to be sure.

    I'd keep your Crosstrail. You're not into that bike for a lot of money and it'll be handy to have around for other types of riding, like rail-trails.
  5. ducnut

    ducnut Long timer

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    I've been through this same scenario with my MTB partner's bike. He never does any preventive maintenance (only lube on the chain, but, never cleaning). He shifts under power. He's ~250lbs. We replaced the chain and cassette, because he'd torn up the originals. We adjusted numerous times, but, still couldn't get it to shift right. Turns out, the cables were dragging. Why? They'd never been cleaned or lubed. I suggested replacing them, but, he didn't want to. OK, fine. But, you're going to have problems again and soon. Most likely we'll be doing another chain and cassette. I don't get it.

    Given where you ride, you'll need a lot more maintenance than normal. When I got home from just 2 days (~90 miles of riding) at Santos, I pulled everything apart. There was sand in everything. We don't have that type of intrusion, up here. So, at the minum, I'd suggest replacing your shift cables (lube them, upon assembly-I'd suggest Gore cables), disassembling, cleaning, and lubing your shifters, chain, and derailluers. This will give you a fresh foundation to start from. And, you'll need stay on top of your barrel adjusters. Just a 1/2 turn will make all the difference in shift quality.
  6. Ridge

    Ridge Jitenshado

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    147 votes just before I posted this. He should be elbows deep into eating crow and throwing money at your charity by now...:lol3
  7. k7

    k7 Ancien cyclist

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    :nod

    He's not real thrilled by my use of ...uh... social media....but he'll be paying up. I decided since I pulled a fast one, I'll make the same donation so now, the Alzheimer Association will see a total of $200 from us. win/win!
  8. ducnut

    ducnut Long timer

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    :clap
  9. Craiger

    Craiger Been here awhile

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    Mail order for me is out of the question at this time. I must now correct myself having looked at so many different bikes Saturday, I confused myself on the bike that was marked down. The bike is not a 2012 it is a 2011 left over. The bike that is marked down is a 2011 Defy Advanced 4 if that makes a difference. I am going to test ride it Wed with an open mind about the size and comfort. I also am 95% sure I am keeping my Cross Trail. Does this new and correct information change anything?????? <?xml:namespace prefix = o ns = "urn:schemas-microsoft-com:eek:ffice:eek:ffice" /><o:p></o:p>
    <o:p></o:p>

    http://www.giant-bicycles.com/en-us/bikes/model/defy.advanced.4/7316/44046/
  10. YakSpout

    YakSpout Obstacle Allusion

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    :clap

    Oh yeah. That bike is one year older. You can't possibly get any style points when you pedal up to Starbucks on an '11. Sheesh. :puke1

    :rofl

    Just kidding. That looks like a great platform to start out on. Tiagra stuff is pretty solid and doesn't require the tuning/maintenance of the gruppos higher up on the chain. (Ultegra/Dura-Ace)

    I don't know what your area is like, but as a fellow Clyde, check your brakes. One area that discount bikes will try to save a few pennies on is the brakes and if you're hauling downhill, you'll need all the power you can get to slow you down. I found Tektro brakes to be nearly suicidal for long, high-speed downhills. You can upgrade the calipers to better Shimano model or there are other brands that will work as well. OTOH, if it's flat where you are, ride on. :lol3
  11. ducnut

    ducnut Long timer

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    The differences I see are the '11 is a 9spd and the '12 is a 10spd; the '11 has a 25T low gear and the '12 has a 28T low gear (you can swap cassettes on the '11, up to a 28T, if you need lower gearing); and there are subtle geometry difference. These aren't huge differences, especially, if you decide to upgrade the drivetrain, at a later date. I think the price is fair enough, provided it fits you. It's still a great bicycle. I still stand by my previous post, on the rest.
  12. pierce

    pierce Aven'Tourer

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    9 speed chains are both cheaper and more durable than 10 speed chains. Ditto the chain rings, the 10 speed chain rings are really thin and more prone to wear.
  13. ducnut

    ducnut Long timer

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    Oh, c'mon! The difference is negligible. :rolleyes

    I'm over 5K miles on the same complete 10spd Apex drivetrain and the chain (PC1071) is still within spec. Maintenance is the key to making anything last. :deal
  14. DougZ73

    DougZ73 Fading off.........

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    This may be a silly question. I have a GT MTB..and it has three gears in front and IIRC, 8 in back. BUT, I almost feel like I can not really use all of them, because if I have it on the inside gear in front, and try to use the outside most gear on the rear wheel, it feels like the chain is almost too cocked? Does this make sense.

    When I first noticed this, I thought the crank bearings on my new bike were bad right outta the box...but then when riding more, kinda figured out that it was the way the chain was rubbing against the front derailer.

    Can that be adjusted out by shop?

    FWIW...shifts with no issues.
  15. GP640

    GP640 Long timer

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    They all do that:lol3

    No, really, the drive train is not set up to run small/small or large/large on most mtbs.
    Ther is a combination of chain length and chain line that makes these combinations
    tough on components.

    You have enough duplication of ratios to prevent these situations.
  16. pierce

    pierce Aven'Tourer

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    I would ONLY use the small front ring with the biggest 3-4 back rings. Use the middle ring until you need a lower gear than small front to middle back on up to the biggest back.

    and don't use the biggest 2-3 rear cogs with the big back cog, either. like, for example if the front cogs are L,M,H (L is smallest, H is biggest), and the rear cogs are 1-8 (1 is largest, 8 is smallest), shift something like L1, L2, L3, L4, M2-M7, H4-H8

    give or take. this gives you maybe 16-18 usable gears instead of the theoretical 24. The M and H ranges probably overlap and there may well be evenly spaced gear ratios that require double shifting (say, M6 to H4 to M7 to H5 to H6-7-8 or whatever...)
  17. DougZ73

    DougZ73 Fading off.........

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    OK, thanks for the quick replies guys. "useable" gears..key point I suppose. Just glad to know there is nothing wrong with bike and I am not going nuts. :D
  18. Gummee!

    Gummee! That's MR. Toothless

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    The 'I've got all this Gore Tex cycling stuff, fuck it let's ride' ride.

    So Sandy's sticking around the area and I'm going stir-crazy cause I ain't ridden in a day.

    So I went riding! Gore jacket. Gore gloves (BMW Summer Rains :thumb). Gore booties. Only thing that wasn't Gore were my tights. ...and that's cause they don't make em 'cycling tight.' :nah

    There's been a few trees knocked over. There's at least one power line down. LOTS of debris on the roads.

    Only reason I was chilly was I was overdressed under the jacket. Got sweaty, then chilly. I was going hard enough to not get cold, but not so hard to stay warm.

    All-in-all :ricky

    M

    edited to add: fenders rawk!
  19. YakSpout

    YakSpout Obstacle Allusion

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    Definitely following Rule #5. :clap

    I, on the other hand, forgot my shoes for Sunday's ride, stayed in and played with the baby while my wife and f-in-law hit the road. Well, I did give my bike a thorough cleaning while the YakSprout was sleeping.

    I'll also take the easy way out on tomorrow's ride with the club and drive over to it rather than ride 13mi to the meeting point, do the ride and then ride 6mi to work. Too damn dark at 5:30am to try riding over. Next week should be better after the time change.

    Solvang Prelude Metric is on Saturday, though, and we've got a group together to ride that. Lunch after at Firestone Brewery. :freaky
  20. RxZ

    RxZ Legal Drug Dealer

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    Well, the sun is setting at about 1830 now, and starting next week it will be 1730 :cry

    Not enough time for me to get a ride in after work.

    So I just ordered a MagicShine MJ-808 headlight :D

    Some local semi-pro racers are putting on a MTB skills clinic this Sunday as well. Should be fun, and very educational since I can tell while riding that I am doing stuff probably not the best way :lol3