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.
mtn. biking 101
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.
Results 1 to 13 of 13

Thread: Tuning my EX8

  1. #1
    mtbr member
    Reputation:
    Join Date
    Apr 2009
    Posts
    11

    Upset Tuning my EX8

    Because I'm a cocky ass, I decided that I knew enough to try to start tuning my bike. Long story short, when I'm in the middle front ring and shift all the way down, the chain hits the side of the front derailler. When I shift all the way up, the chain hits the other side of the derailler. How do I fix this? Do I need to just go to the shop and have them shake their head at me?

    Thanks.

  2. #2
    mtbr member
    Reputation:
    Join Date
    Jun 2006
    Posts
    991
    I think you're alright - that's pretty much how it is. There's only so far you can swing the chain side to side with the rear derailleur before it's going to rub on the front cage. Certain gear combinations are just going to do that.

    Shifting technique helps - say you're in your easiest gear, small ring-large cog. You shift the rear for the first 3-4 gears, then, rather than going to the 5th in the back, you'll want to shift up to the middle in the front and drop back down a gear or so in the back. Your overall ratio will still be right, but you'll be keeping a straighter chainline, which works better (and quieter). Your middle ring will run smoothest the closer to the center of the cog you're using in the rear. Same concept for the big ring.

    Personally, I like to use my middle ring and easiest cog, so when I adjust the front derailleur, I set it a little inboard so I don't get rubbing in that gear. Trade-off is that I end up with more pronounced rubbing the highest gear, but I rarely use it anyway.

  3. #3
    mtbr member
    Reputation:
    Join Date
    Apr 2009
    Posts
    11
    OK, good. I was expecting more, "no matter where you shift, you won't get that rub." Can't say that I won't sit down with someone more experienced, and have them give me some pointers (over a six pack, of course) next time.

    I spend most of my time in the middle ring too, and the mid-line+a couple in either direction has good clearance, so I should be ok. Thanks for the advice.

  4. #4
    mtbr member
    Reputation:
    Join Date
    Jun 2013
    Posts
    68
    I have two chain rings in front and if I am cross chaining I get slight rub as well. If I attempt to go Small front small rear the chain actually rubs the front derailleur at the bottom. I tend to use the middle gears and switch the front chain ring more.

  5. #5
    mtbr member
    Reputation:
    Join Date
    Jun 2006
    Posts
    991
    Quote Originally Posted by tajar66 View Post
    I have two chain rings in front and if I am cross chaining I get slight rub as well. If I attempt to go Small front small rear the chain actually rubs the front derailleur at the bottom. I tend to use the middle gears and switch the front chain ring more.
    Small front - small rear is a combo you never want to use. Forget that it even exists.

    In general, you want to try to spend as little time in the granny ring as possible - save it for challenging climbs and try to push the middle ring as much as possible everywhere else. I guarantee if you make a point of doing this, your riding will improve by leaps and bounds. Not to take anything away from granny gear - I'm no stranger to mine.

  6. #6
    mtbr member
    Reputation:
    Join Date
    Apr 2009
    Posts
    11
    I've been running pretty much middle-middleish, and that's been working fine. Don't know why I felt the need to tinker. If it ain't broke, right?
    Stay off the granny gear as much as possible. Working on confidence building now. I know I have ok technique. Just need to feel confident enough to start raising my speed.

  7. #7
    Fat-tired Roadie
    Reputation: AndrwSwitch's Avatar
    Join Date
    Nov 2007
    Posts
    12,302
    I love people who try to stay out of their grannies. Especially on FS bikes. I have nothing to prove about my gear combinations. I spin by 'em while they bob on the bottom of the climbs.

    You paid a lot of money for that bike. Use all the gears. Only power output matters. If you can't spin at 90 rpm on road climbs, learn.
    "Don't buy upgrades; ride up grades." -Eddy Merckx

  8. #8
    mtbr member
    Reputation:
    Join Date
    Sep 2012
    Posts
    223
    I run the granny any time I need it as well, if it rubs then it rubs.

  9. #9
    mtbr member
    Reputation:
    Join Date
    Jun 2006
    Posts
    991
    Quote Originally Posted by AndrwSwitch View Post
    I love people who try to stay out of their grannies. Especially on FS bikes. I have nothing to prove about my gear combinations. I spin by 'em while they bob on the bottom of the climbs.

    You paid a lot of money for that bike. Use all the gears. Only power output matters. If you can't spin at 90 rpm on road climbs, learn.
    It's not about having something to prove. If I thought I had something to prove, I'd be racer. And I definitely spend good time in my granny, but once you get to a point you can increment up to the middle ring smoothly, it makes sense to do so. For the same (or very similar) end ratio, the middle ring is going to give you a better chainline and more tension on your derailleur spring. Things run smoother and tighter. Also, while spinning a high cadence makes sense on smoother terrain or climbs (which may be what you spend a lot of time riding), it's not so great for more technical riding. On a rocky, rooty trail (which is what we have for the most part), you're better off having something to push hard against. I've seen a lot of people's bike handling skills benefit substantially once they try riding a little higher gear (which translates pretty quickly into them being smoother and faster riders overall).

  10. #10
    mtbr member
    Reputation: tigris99's Avatar
    Join Date
    Aug 2012
    Posts
    520
    Rubbing mostly is a "your doing it wrong" matter. Everything i have learned says middle ring should clr entire cassette with minimal most 0 rubbing. 10s setup for example granny ring I can clr 1-7 but never exceed 1-6, usually1-4 before going to middle ring. Middle ring 1-10 where ever as needed. outer ring, 6-10 only, till I removed it and replaced for bash cause i only used it a couple times on a big long paved downhill.

    If it rubs badly (slight almost unnoticable rub isnt world ending) your cross chaining, going to eat chains and hard on cassettes/chainrings. no reason to do it anyway as ratios you need are easy achieved in proper ring/cog combos. If you get some ever so slight rub in one combo that shouldnt be cross chaining, check your FD alignment cause a slight outta place can create rubbing where it shouldnt be.
    Trek Marlin 29er

    Like It, Love It, Want Some More Of It!

  11. #11
    Fat-tired Roadie
    Reputation: AndrwSwitch's Avatar
    Join Date
    Nov 2007
    Posts
    12,302

    Re: Tuning my EX8

    Quote Originally Posted by slapheadmofo View Post
    Also, while spinning a high cadence makes sense on smoother terrain or climbs (which may be what you spend a lot of time riding), it's not so great for more technical riding. On a rocky, rooty trail (which is what we have for the most part), you're better off having something to push hard against. I've seen a lot of people's bike handling skills benefit substantially once they try riding a little higher gear (which translates pretty quickly into them being smoother and faster riders overall).
    I meant to write a reply the other day and got sidetracked...

    I don't really want to contradict you because I think we might be having another semantics thing, not a real difference of approach.

    I like to pedal a low enough gear that I don't translate a lot of movement above my waist. I like to pedal a high enough gear not to have to catch up with my freewheel, and not to have problems controlling my stroke.

    One of the problems with the Internet is that while I can drive down the road, see a cyclist for a second or two, and say "this guy knows how to ride a bike," "this guy doesn't know how to pedal," or "this guy's bike is set up for someone else," I can't see anyone on the Internet. Being able to quantify things like cadence becomes useful. I think there's also no downside to adding tools to the set, which is really all stretching out one's power band is.

    Anyway, I don't use a crank sensor on my mountain bikes, so I only have my perception. But, I don't perceive that I select gears any differently off-road than on the road, and I also don't have any problem picking up my front wheel or managing traction. Ironically, long-time mountain bikers often have more developed pedaling technique than roadies because of the necessity of managing traction. On the road, I pedal 80-105 rpm, with the distribution centering around 95 for tempo-paced riding. So I assume my cadence follows a similar distribution off-road.

    Point being, I think everyone can benefit from practicing around the upper limit of their usable cadence ranges on the service road or whatever to the trail head, and anyone who's curious should actually measure their cadence. While JRA, count the number of times your right knee comes up in 15 seconds and multiply by four.
    "Don't buy upgrades; ride up grades." -Eddy Merckx

  12. #12
    mtbr member
    Reputation:
    Join Date
    Jun 2006
    Posts
    991
    Quote Originally Posted by AndrwSwitch View Post
    I meant to write a reply the other day and got sidetracked...

    I don't really want to contradict you because I think we might be having another semantics thing, not a real difference of approach.

    .
    I agree. There are a lot of times that a good spin is the best way to go for sure. I do find that when riding with beginners though, that many of them will have a lot of trouble with a couple areas that getting into a higher gear can help with. They can get into a mindset of staying in the granny ring too much of the time, and end up spinning out before reaching a speed that allows them to take advantage of any decent flow or momentum. I find that spending more time in the middle ring when at all possible gets them riding more smoothly overall; I've had a lot of people tell me it made a big difference to their riding. I know it helps me out quite a bit on technical or winding trails, and particularly on rolling terrain with a lot of shorter ups and downs, where it's better to mash a few pedal strokes on the descents to get up some good momentum for the climbs and just powering through a few hard cranks to get back up, instead of coasting down out of gear, then spinning wildly until you lose momentum enough momentum for your gear to be effective on the way back up, etc. I think this plays into exactly what you say about having a quiet upper body - you don't want to have to saw back and forth on the bars a bunch, but you also don't want to be bouncing around in your saddle trying to keep up with your legs and having to make exaggerated leg motions when you need a more stable platform to implement body english when required.

    Like anything, experience and experimentation will lead to finding what works best for each particular rider and type of situation. On 'average' terrain, I personally find more useful combinations in the middle ring than in the granny. I've had good intentions of developing a nice high-cadence spin for ages, but found that being a little more of a masher works better for me. Like they say, YMMV.

  13. #13
    mtbr member
    Reputation:
    Join Date
    Oct 2013
    Posts
    46
    Quoting from Sheldon Brown, "Front derailer adjustment is not an exact science. It requires a good eye and a bit of patience to get right." (article link)

    In my experience, it is difficult to completely get rid of chain rub for every cog/ring combo, and it can be normal to have a bit of rub when you are cross-chaining (which you shouldn't do anyway). Some road shifters even have "trim" capability which lets you fine tune the front mech tension on the fly to get rid of this. If you are getting unwanted rubbing in more than the worst 1-2 cross-chained positions you can play with the position and angle of the front derailleur. Chain rub will definitely be worse if your front mech isn't aligned optimally, or if you aren't using a combination of chain rings and front derailleur that were designed to work together.

    The article I linked should have all the information you need if you want to tinker some more.

Similar Threads

  1. Fox RP2 Tuning
    By ronbo613 in forum Shocks and Suspension
    Replies: 3
    Last Post: 04-29-2013, 11:22 AM
  2. Fox 34 CTD oil tuning
    By Mr.P in forum Shocks and Suspension
    Replies: 1
    Last Post: 03-02-2013, 10:27 AM
  3. PBR 130 tuning
    By sandwich in forum Cannondale
    Replies: 0
    Last Post: 12-04-2012, 01:21 PM
  4. Tuning help in 5.7
    By Rei_Ikari in forum Pivot Cycles
    Replies: 5
    Last Post: 07-22-2011, 01:57 PM
  5. 951 suspension tuning
    By ruralrider528 in forum Intense
    Replies: 10
    Last Post: 07-04-2011, 12:00 AM

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •