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  1. #1
    SVO
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    Pain in my ENO- Crank options?

    My beautiful new custom Ti 29er has a problem- not enough Q factor, or too wide of chainstays. Actually, both. With a Phil BB, even a super long spindle would not clear with the ENO cranks (180mm). So the frame builder cut a couple of little slices out of the chainstays and welded on plates to create more clearance. But with lots of spindle and 200-lb me on the bike, there is enough flex that the canks still hit the chainstays under power.

    So, I need an option for a bomb-proof crank with more Q. Silver strongly preferred so dingers don't show so much and ideally square taper so I can use the install-it-and-leave-it Phil BB.

    Any ideas? I need hard specs on Q- not suggestions that X or Y might work.

    Or should I just demand that the frame be rebuilt with more S-bend in the chainstays (very little now) as it shoud have been done?

    X-Type cranks fit the frame fine, but I go thorugh those bearings in a few weeks. Cheers,

    JD

  2. #2
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    If you go through X-type bearings in a few weeks, you're either not installing them properly or riding through saltwater on a regular basis. Probably either too loose or (more likely) too tight. It's easy to do wrong. Anyway, if you think you're doing it right, try one with ceramic bearings. They last forever (if you install the system properly) and spin better, too. On a flexy frame, the external-type cranks will improve your bb stiffness, as well due to the wider stance of the bearings.
    A hardtail is forever

  3. #3
    breathing helium
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    I have some Enos on my SS but will be changing to XT outboard cranks so I can have a wider Q factor. I find that the external bearings are great, no trouble here so far.

  4. #4
    meh... whatever
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    Quote Originally Posted by Hardtailforever
    If you go through X-type bearings in a few weeks, you're either not installing them properly or riding through saltwater on a regular basis. Probably either too loose or (more likely) too tight. It's easy to do wrong. Anyway, if you think you're doing it right, try one with ceramic bearings. They last forever (if you install the system properly) and spin better, too. On a flexy frame, the external-type cranks will improve your bb stiffness, as well due to the wider stance of the bearings.
    ditto.

    my bikes suffer a great deal of abuse at my hands and ive had no trouble with outboard bearing cranks. have a raceface and an xt and both have given years of trouble free service.
    "Knowledge is good." ~ Emil Faber

  5. #5
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    I too feel the need for a greater q-factor for my q-zone. Does anyone think attaching tuvative, non-howitzer style cranks to a howitzer external bearing, isis-drive BB would work? Probably a chainline nightmare.
    I'm covered in beer.

  6. #6
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    Quote Originally Posted by Hardtailforever
    If you go through X-type bearings in a few weeks, you're either not installing them properly or riding through saltwater on a regular basis. Probably either too loose or (more likely) too tight. It's easy to do wrong. Anyway, if you think you're doing it right, try one with ceramic bearings. They last forever (if you install the system properly) and spin better, too. On a flexy frame, the external-type cranks will improve your bb stiffness, as well due to the wider stance of the bearings.
    Or try the Phil bearings... I had the same problem with Race Face cranks, as their bearings would fuse within weeks to a few months (never had this issue with the Shimano cranks).

    bb

  7. #7
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    Quote Originally Posted by SVO
    ... even a super long spindle would not clear ...
    JD
    How long is "super long"? If a 122.5mm spindle won't allow the cranks to clear the stays, the frame is at fault. Personally I'd ask the builder to make it right.

    --Sparty
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  8. #8
    SVO
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    Thanks for advice

    Quote Originally Posted by b1umb0y
    Or try the Phil bearings... I had the same problem with Race Face cranks, as their bearings would fuse within weeks to a few months (never had this issue with the Shimano cranks).

    bb
    EXACTLY. I have been wrenching bikes since Carter was Pres., trust me, installation is not the issue. With my full-suss, I eneded up riding in a lot of wet conditions last year (including 8 1/2 hours of Moab) and the RaceFace bearings went in under 3 months. I now have Phil bearings in there, but I am skeptical about how long they will last- little room for true Phil seals. Besides, add-up a Deus SS crank and Phil bearings, let alone ceramic: Major coin. I am not a big fan of Shimano anything, save cassettes. I suppose I could go XT (XTR rings wear too fast) but this was to be a dream bike for me. My first Ti. XT just doesn't fit the bill for me.


    Quote Originally Posted by Sparticus
    How long is "super long"? If a 122.5mm spindle won't allow the cranks to clear the stays, the frame is at fault. Personally I'd ask the builder to make it right.

    --Sparty
    We got up to 119 and it didn't clear at rest, let alone under power. It really is a combination of the stays having too little bend AND the Eno having so little Q. I measured the spread of the chianstays, outside edges, and it is about 3/8 wider than other 29ers I compared it with. But the X-Types clear it fine.


  9. #9
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    Quote Originally Posted by SVO
    Or should I just demand that the frame be rebuilt with more S-bend in the chainstays (very little now) as it shoud have been done?
    It sounds like the CS clearance on the frame is smaller than normal, and clearly it is too small for the crank you want to use. Did you inform the builder that you wanted to use 180mm ENO's? Did the builder ask? If you did specify the crank you were going to use, its the builder's responsibility to deliver a frame that will accomodate it. If the builder didn't ask, I think the blame for the situation is shared, but the builder has no real responbility to remedy the situation, especially if the ENO crank is the only crank that won't work. If only out-board bearing cranks will work, I think the builder under-designed the frame and should at least correct it so that it is within normal spec (though at that point I'd hope that he or she would just go ahead and make the frame ENO compatible).

    Good luck.

  10. #10
    SVO
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    The builder got most of the build kit, including the cranks, for me. He's a friend (owner of a medium sized frame business) and gave me an employee price which comlicates the whole matter. A 29er which was requested to be able to run 2.3s just needs a good amount of bend in the chainstays to work, and these are nearly straight. And they knew my weight and its a custom frame so the amount of flex in the BB is another design flaw.

    I'm tempted to just sell it on Ebay and buy something else. But I'd have to tell him.

  11. #11
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    Bummer. I've known someone who was in a similar boat -- frame built for well below standard pricing but due to the builders error not built to spec, and no way to fix the problem without going back to the drawing board. Ultimately a compromise was reached that everyone was happy with, but not as happy as anyone would have wanted going into the deal.

    Sounds like the error was his. I take it he hasn't offered to correct the problem completely?

    How about a Phil Wood BB with a custom spindle?

  12. #12
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    Quote Originally Posted by SVO
    With my full-suss, I eneded up riding in a lot of wet conditions last year (including 8 1/2 hours of Moab) and the RaceFace bearings went in under 3 months.

    I don't know anyone who rode the "24hrs" of Moab last year and didn't have to replace half the shyte on their bikes. After riding my geared bike for only two laps (I switched to single) I ended up putting $200 into it after that race (not counting my trashed rims), and that's at dealer cost! Before you give up on your external bearings, give a Shimano or FSA bb a chance. They will work with your Race Face crankset and have way better bearings. Or just see how the Phil bearings work. I just replaced a set with the Enduro bearing kit (non-ceramic) and they seem pretty decent as well. Race Face just never got their bearing issues worked out in their X-Type system.

    Also, new XTR (970) has improved chainring durability. So far it is noticeable. Also, you can just replace them with whatever you want now that they are standard size.
    A hardtail is forever

  13. #13
    SVO
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    Been round and round- three different BB lengths, then cutting slices out of chanstays (see above). I think I'll have him mount an external BB/crank and hammer it- I'm guessing it may still hit under hard load (200-lb me /1 gear= torque). Then he'll probably offer to build me a new frame, and then I can wait a couple more months while more of the season passes. Grrrrr. Ordered this thing last December!

  14. #14
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    Quote Originally Posted by SVO
    Quote Originally Posted by sparty
    How long is "super long"? If a 122.5mm spindle won't allow the cranks to clear the stays, the frame is at fault. Personally I'd ask the builder to make it right.
    We got up to 119 and it didn't clear at rest, let alone under power. It really is a combination of the stays having too little bend AND the Eno having so little Q. I measured the spread of the chianstays, outside edges, and it is about 3/8 wider than other 29ers I compared it with. But the X-Types clear it fine.
    119mm is long-ish but not super-long... try a 122.5 or 125? As long as your hub can handle the chainline, I'd say go for it.

    Coincidentally, I just swapped a Phil 108 for a 111 because of the same issue... frame flex = hitting arms.

  15. #15
    SVO
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    There are diminishing returns here- a longer spindle will bend more itself, and also increases the leverage through the bottom bracket, both of which increase flex. Also, when you get a large rider on such a spindle, keeping the BB tight can become an ongoing headache. I spent over a decade on square tapers and I won't go any longer - in fact, I would not really accept 119.

  16. #16
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    Physics...

    Quote Originally Posted by SVO
    There are diminishing returns here- a longer spindle will bend more itself, and also increases the leverage through the bottom bracket, both of which increase flex. Also, when you get a large rider on such a spindle, keeping the BB tight can become an ongoing headache. I spent over a decade on square tapers and I won't go any longer - in fact, I would not really accept 119.
    I've been having a similar problem with a set of narrow Q-factor cranks. The idea of going to a longer spindle has crossed my mind but I too was concerned about the added torque. Rolling it over in my mind howeverI realized that it shouldn't matter where you are creating wider Q-factor (in terms of BB and frame torque/flex). What matters is how far your pedals are out. You either have a short spindle with wide-Q cranks or a long spindle with narrow-Q cranks; the effective "torque" or "leverage" arm is the same on the BB area. Thus you'll still have the same "off center" forces going through the BB area. Of course one could theorize that a longer spindle may have a greater propensity to "twist" on itself but then you could likely say the same about cranks flared out with a wide Q.

    What do you think?

  17. #17
    SVO
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    Doesn't apply here: I was talking about different lengths spindle with the SAME crank. Pushes total lever longer, increases torque at the BB. And experience tells me that flex in the BB spindle is generally more pronounced (and potentially troublesome) than in the crank arm, at least with a square taper. I had Sampson crank arms back in the day that were very light and flexy, but not a problem. So if the BB spindle is inherently less stiff than the crank arm, even if you keep the total lever length consistent, increasing spindle and decreasing Q results in more flex as the more flexy part will expereince more leverage. The X-Type BB manufacturers are proposing a new standard for BB shell diameter which makes all the sense in the world- just too late to help me

  18. #18
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    Yeah...

    Quote Originally Posted by SVO
    Doesn't apply here: I was talking about different lengths spindle with the SAME crank. Pushes total lever longer, increases torque at the BB. And experience tells me that flex in the BB spindle is generally more pronounced (and potentially troublesome) than in the crank arm, at least with a square taper. I had Sampson crank arms back in the day that were very light and flexy, but not a problem. So if the BB spindle is inherently less stiff than the crank arm, even if you keep the total lever length consistent, increasing spindle and decreasing Q results in more flex as the more flexy part will expereince more leverage. The X-Type BB manufacturers are proposing a new standard for BB shell diameter which makes all the sense in the world- just too late to help me

    I see what you are saying about keeping the crank a constant. But from a more practical standpoint ususally one is stuck with a give frame and crank, and the spindle can be change most easily from a cost perspective. I use to think that BB spindles could noticeably "twist" but the more I think about the physics of it I doubt that is likely. Anyone have hard data suggesting a spindle actually can "twist" (or spindle) under force. I'd be suprised if any could provide such info. The yield forces elsewhere along the drivetriain would most certainly yield much sooner. Now in regards to a wider Q resulting in more BB shell and overall frame flex, I totally agree with that.

    As a side point, I find that too often frames end up providing far too much tire clearance at the expense of keep an acceptable Q. With the move to 29" wheels the need for large-width tires is not quite as necesary on true xc style frames. I just bought a 29" SS frame and find it provides far too much tire clearance at the expense of being able to run a narrow Q. Sure you can go to fancy S bend chainstays but I'll trade that in for simplicity and stronger tubes.

  19. #19
    SVO
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    We are getting far too techie, but I think twist is rotation around the axis and bending perpendicular to the axis, or deflection, is the issue at hand. The tip of the spindle hanging slightly lower under power. Hard data unlikely, but there were once several manufacturers who had weight limits for hollow Ti BB spindles. At some point you take away enough material it will bend. What is not intuitive is that the extremely small diameter of a conventional BB spindle means you have to have a LOT of material to achieve strength. The BB shell in the frame, for example, is perhaps 5x the diameter and can achieve equal strength with a lot less material. Or the old cannandale frames that were very strong but built like a beer can.

    Annecdotally, I rode the first S-Works metal matrix hardtail, an extremely rigid, efficient bike. When I switched to a lighter Ti spindle on it I beleive there was more flex in it, but not objectively verifiable. Long rocky rides left me feeling less beat-up, though.

    Still, I'd bet most of the flex I am getting is in the frame. Still the builders fault, though.

  20. #20
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    You know, you can get a wider BB than 122.... My GT Zaskar required a 127.5 from the factory. It actually feels great to have a wide BB for the technical section of a ride. Pretty sure you can get into the 130's. Oh, I am discussing Square taper here, not sure about those other ones.

    http://www.sheldonbrown.com/bbsize.html this link might help.
    "When the end of the world comes, I want to be in Cincinnati because it's always 20 years behind the times." Twain

  21. #21
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    Phil Wood makes up to a 135mm in the stainless steel.

  22. #22
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    Holy smokes!

    Quote Originally Posted by cocheese
    Phil Wood makes up to a 135mm in the stainless steel.
    Looks like their may still be hope to get my cranks on that frame after all.

  23. #23
    Single Speed Junkie
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    Call Philwood and talk to Brent he will be able to fix your Q issues.

  24. #24
    SVO
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    Quote Originally Posted by crux
    Call Philwood and talk to Brent he will be able to fix your Q issues.
    You mean a longer spindle. Nope. Too much flex.

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