Advertise on Bikeforums.net



User Tag List

Results 1 to 14 of 14
  1. #1
    Building a better Strida
    Join Date
    Apr 2008
    Location
    toronto, canada
    My Bikes
    bianchi brava 1988. fuji track 2007, 2006 Bianchi Pista, 1987 Miele and a strida knock off
    Posts
    1,108
    Mentioned
    0 Post(s)
    Tagged
    0 Thread(s)

    bike nerding - first build - fuji track 2007 chainline + chainrings...?

    hey guys, ok so I am building up the drivetrain of a fuji track 2007.

    got a few questions tho when i was digging up info on the chainline.

    I need a flat normal chainring, as I didn't get one with the frame and stock 165mm cranks. It looks like the stock formula hub is some skinny formula that works OK with the stock bb and crankset.
    However, should i upgrade the wheelset to something built on formula high-flange hubs, the chainline to the rear spaces itself out proper to 42mm (ideally)
    Apparently tho, the stock bb/crankset doesn't appear to be compatible with this since its some road setup running at 46+mm on the outer chainring....

    [EDIT]
    I JUST CONFIRMED THIS LAST NIGHT. the stock crankset and 103mm bb run around 46mm. as some may know.. the stock fuji issued chainring is dished or flanged on an angle. so at 130mm bcd, it mounts to the outside of the crank, but the chainring is bent so that the chainline falls somewhere above or behind the crank's chainline center.


    is there a way that doesn't require me to dish the rear wheel to compensate for a 46mm chainline? is there a bb that would swap in? I COULD RUN a flat normal chainring on the inside of the crank and get a 41mm chainline as well...?


    soooo.. is there any non-expensive fix that can be applied so i don't have to purchase any new parts? ie, i don't want to buy a new crank or bb... or can i get away with the stock noodle crank/chainring but use a longer bb? can the stock bb be spaced out properly?

    [edit] yes, respace the rear hub and then dish the wheel to compensate. i am looking at about 4-5mm to the left.... right?

    thanks!

  2. #2
    Building a better Strida
    Join Date
    Apr 2008
    Location
    toronto, canada
    My Bikes
    bianchi brava 1988. fuji track 2007, 2006 Bianchi Pista, 1987 Miele and a strida knock off
    Posts
    1,108
    Mentioned
    0 Post(s)
    Tagged
    0 Thread(s)
    also, what makes the FUJI TRACK 2007 stock FSA road cranks different from the sugino RD crankset?

    I understand the sugino RD to be a road-double hence have road double chainline spacing? how come it is advertised to have a 42mm chainline with a 103mm bb?

    thanks!

  3. #3
    Senior Member DannoXYZ's Avatar
    Join Date
    Jul 2005
    Location
    Saratoga, CA
    Posts
    11,495
    Mentioned
    0 Post(s)
    Tagged
    0 Thread(s)
    You have a 120mm rear-wheel? Can you put the chainring on the inside of the crank spider-arms?

  4. #4
    cab horn
    Join Date
    Jun 2004
    Location
    Toronto
    My Bikes
    1987 Bianchi Campione
    Posts
    28,295
    Mentioned
    0 Post(s)
    Tagged
    0 Thread(s)
    Quote Originally Posted by trueno92 View Post
    I understand the sugino RD to be a road-double hence have road double chainline spacing? how come it is advertised to have a 42mm chainline with a 103mm bb?

    thanks!
    It doesn't.

    It has a 45mm chainline with a 103bb. That's why that crankset is a piece of crap and also why it's so cheap. There's no way of getting the chainline in further as 103 is the smallest length square taper bb you can buy.

    You're overthinking this a bit much. You have two options

    1) Dish the wheel over to get the 45mm with your formula hub setup
    2) Get a 42mm crankset/bb combo
    3) Put the chainring on the inside and get a longer bb

    Spacing your bb out 2-3mm is pushing out. So don't do it.

    The RD is basically a glorified double crank with horrible chainilne characteristics marketed to the fixed gear crowd as one of many crank options. Seems to be quite popular as well. For no good reason.
    Last edited by operator; 11-08-08 at 07:28 AM.
    Mes compaingnons cui j'amoie et cui j'aim,... Me di, chanson.

  5. #5
    cab horn
    Join Date
    Jun 2004
    Location
    Toronto
    My Bikes
    1987 Bianchi Campione
    Posts
    28,295
    Mentioned
    0 Post(s)
    Tagged
    0 Thread(s)
    Quote Originally Posted by trueno92 View Post
    as some may know.. the stock fuji issued chainring is dished or flanged on an angle. so at 130mm bcd, it mounts to the outside of the crank, but the chainring is bent so that the chainline falls somewhere above or behind the crank's chainline center.
    There is no such thing. This is utter nonsense.
    Mes compaingnons cui j'amoie et cui j'aim,... Me di, chanson.

  6. #6
    Senior Member Retro Grouch's Avatar
    Join Date
    Feb 2004
    Location
    St Peters, Missouri
    My Bikes
    Rans Enduro Sport, Hase Kettweisel Tandem, Merin Bear Valley beater bike
    Posts
    23,830
    Mentioned
    0 Post(s)
    Tagged
    0 Thread(s)
    Quote Originally Posted by DannoXYZ View Post
    You have a 120mm rear-wheel? Can you put the chainring on the inside of the crank spider-arms?
    That's what I was thinking too. Should give him roughly 5mm difference. 46-5=41. That's close enough.

  7. #7
    surly old man jgedwa's Avatar
    Join Date
    Sep 2006
    Location
    Carlisle, PA
    My Bikes
    IRO Mark V, Karate Monkey half fat, Trek 620 IGH, Cannondale 26/24 MTB, Amp Research B3, and more.
    Posts
    3,287
    Mentioned
    1 Post(s)
    Tagged
    0 Thread(s)
    There is a lot of confusion floating around about chainline issues.

    -The over-nut dimension of the rear axle and/or chainstay spread has nothing to do with chainline. Nothing. Chainline is measure from the center of the bike. The distance between the stays is precisely irrelevant.

    -The Sugino RD crank, with a 103 mm BB with ring on the outside of the spider will give 45. I have always loved Sugino products; not sure what their rationale for this is. If you mount the ring on the inside of the spider (which is fine, but a little uglier) it will be 42mm. I would much rather do this than respace/redish a rear wheel. Bear in mind that if you respace it, it will not really be a flip-flop anymore.

    jim
    Cross Check Nexus7, IRO Mark V, Trek 620 Nexus7, Karate Monkey half fat, IRO Model 19 fixed, Amp Research B3, Surly 1x1 half fat fixed, and more...
    --------------------------
    SB forever

  8. #8
    Senior Member Retro Grouch's Avatar
    Join Date
    Feb 2004
    Location
    St Peters, Missouri
    My Bikes
    Rans Enduro Sport, Hase Kettweisel Tandem, Merin Bear Valley beater bike
    Posts
    23,830
    Mentioned
    0 Post(s)
    Tagged
    0 Thread(s)
    Quote Originally Posted by jgedwa View Post
    There is a lot of confusion floating around about chainline issues.

    -The over-nut dimension of the rear axle and/or chainstay spread has nothing to do with chainline. Nothing. Chainline is measure from the center of the bike. The distance between the stays is precisely irrelevant.
    I absolutely agree with your first statement. The proof is your second statement.

    It doesn't matter where you measure from, what matters is that the chain is parallel with the bike's main frame.

  9. #9
    Senior Member
    Join Date
    Nov 2008
    Location
    Brooklyn Zoo via 61ooo
    Posts
    136
    Mentioned
    0 Post(s)
    Tagged
    0 Thread(s)
    another thing you may want to consider:

    the stock issue fuji chain ring is a road chain ring that is slightly elliptical. this is not something you want on a fixed gear setup. you want a track specific chain ring that is a perfect circle. otherwise, you're going to weaken your chain, wear your cogs out, possibly loosen your components, and basically get some wear that won't be fun. not to mention, you won't get the stiffness you want for a track setup. get a new non-fuji chain ring.

    this was true about three years ago but I haven't done any research recently to see if fuji has corrected the problem. check it out for yourself, or anyone else want to chime in?

  10. #10
    Senior Member Retro Grouch's Avatar
    Join Date
    Feb 2004
    Location
    St Peters, Missouri
    My Bikes
    Rans Enduro Sport, Hase Kettweisel Tandem, Merin Bear Valley beater bike
    Posts
    23,830
    Mentioned
    0 Post(s)
    Tagged
    0 Thread(s)
    Quote Originally Posted by yahnming View Post
    the stock issue fuji chain ring is a road chain ring that is slightly elliptical. this is not something you want on a fixed gear setup. you want a track specific chain ring that is a perfect circle.

    this was true about three years ago but I haven't done any research recently to see if fuji has corrected the problem. check it out for yourself, or anyone else want to chime in?
    I really doubt the issue is elliptical chainrings so much as the chainring not being concentric with the crank spindle.

  11. #11
    Senior Member
    Join Date
    Nov 2008
    Location
    Brooklyn Zoo via 61ooo
    Posts
    136
    Mentioned
    0 Post(s)
    Tagged
    0 Thread(s)
    i agree with the grouch for your particular problem, but it's another thing to consider.

  12. #12
    surly old man jgedwa's Avatar
    Join Date
    Sep 2006
    Location
    Carlisle, PA
    My Bikes
    IRO Mark V, Karate Monkey half fat, Trek 620 IGH, Cannondale 26/24 MTB, Amp Research B3, and more.
    Posts
    3,287
    Mentioned
    1 Post(s)
    Tagged
    0 Thread(s)
    Quote Originally Posted by Retro Grouch View Post
    I absolutely agree with your first statement. The proof is your second statement.

    It doesn't matter where you measure from, what matters is that the chain is parallel with the bike's main frame.

    It matters very much where you measure from: one measures from the centerline of the bike. No other dimension is at all relevant for chainline.

    I suppose it is right that the chain is supposed to be parallel to the frame of the bike. In fact, you could interpret "centerline of the bike" to mean just that. But using your language suggests a rather coarse measurement is all that is needed here. I am not overly doctrinaire about perfect chainlines, but just a few mm's can make a difference in noise. A few mm's more make a difference in wear and efficiency. Therefore, one has to measure (or at least eyeball) from the center of the hub to the cog teeth and compare that to the center of the BB shell to the chain teeth.

    The over-locknut to locknut measurement of the hub has nothing to do with this. Consider, for a moment, that if you stretch a 126 frame to fit a 130 hub, the chainline is not effected one bit. And, if you compress a 130 frame to fit a 126 hub, chainline is again not effected one bit.

    To put it numerically, if you are going for a 42mm (from center) chainline, it makes no difference what happens beyond those 42mm's. Does the axle keep on going to 65mm (for a 130) or only to 63mm (for a 126)? Does not matter at all. Those extra 23mm or 21mm (respectively) are not within the scope of the center to cog measurement. Instead that extra distance is the difference between cog and the inside of the chainstays. As you will notice, chainstays are not parallel to the main frame of the bike. And, so by your own reckoning, it is not relevant.

    jim
    Cross Check Nexus7, IRO Mark V, Trek 620 Nexus7, Karate Monkey half fat, IRO Model 19 fixed, Amp Research B3, Surly 1x1 half fat fixed, and more...
    --------------------------
    SB forever

  13. #13
    Senior Member Retro Grouch's Avatar
    Join Date
    Feb 2004
    Location
    St Peters, Missouri
    My Bikes
    Rans Enduro Sport, Hase Kettweisel Tandem, Merin Bear Valley beater bike
    Posts
    23,830
    Mentioned
    0 Post(s)
    Tagged
    0 Thread(s)
    Quote Originally Posted by jgedwa View Post
    The over-locknut to locknut measurement of the hub has nothing to do with this. Consider, for a moment, that if you stretch a 126 frame to fit a 130 hub, the chainline is not effected one bit. And, if you compress a 130 frame to fit a 126 hub, chainline is again not effected one bit.
    OK, let me try one more time with a real life example.

    On a typical Shimano octalink triple, with 130mm dropouts the bottom bracket spindle is 118mm in order to keep the chain parallel with the main frame when in the middle of the cassette.

    I also own a tandem with a dishless rear wheel and 160mm dropouts. The bottom bracket spindle for that bike has to be 129mm in order to get the chain line correct because the cassette is way out to the right.

  14. #14
    surly old man jgedwa's Avatar
    Join Date
    Sep 2006
    Location
    Carlisle, PA
    My Bikes
    IRO Mark V, Karate Monkey half fat, Trek 620 IGH, Cannondale 26/24 MTB, Amp Research B3, and more.
    Posts
    3,287
    Mentioned
    1 Post(s)
    Tagged
    0 Thread(s)
    I strongly suspect that we both have the same concept of chainline in mind, and a discussion at this level is not needed. It is true that wider stays typically go with wider hubs (or at least more dished hubs), and therefore wider chainlines, so there is some indirect reason to link the two measurements.

    But, the jerk in me has to try to get the last word in. So, thanks for your patience with me.

    The tandem you have has a wider chainline because of (I would guess) a wider hub. Not wider stays. Your own numbers show this. The difference of half of each stay width in your examples is 15mm. The difference of half of each spindle length in your examples is 5.5. If OLD had anything to do with chainline then this would suggest that one of bikes had a chainline that was about 10mm (15mm-5.5mm) off. I bet both are much closer to straight than that.

    This is a bit oversimplified, since different cranks sit on those spindles in different ways; a triple compared to a double for example. And it is a bit presumptious of me to assume that one of the two bikes in your example has a straight chainline, which therefore means that the other would have to be off by 10mm if OLD was relevant; each could be off 5mm in opposite directions which could spread the difference acceptably between both bikes.

    jim
    Last edited by jgedwa; 11-09-08 at 06:14 AM.
    Cross Check Nexus7, IRO Mark V, Trek 620 Nexus7, Karate Monkey half fat, IRO Model 19 fixed, Amp Research B3, Surly 1x1 half fat fixed, and more...
    --------------------------
    SB forever

Posting Permissions

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