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  1. #1
    Unhinged Aussie on a 29er
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    Surly Mr. Whirly crank failure

    I'm writing this after owning, and then breaking, three Surly Mr. Whirly spiders, none of which lasted longer than about 2 months. Right now there's sweet FA out there on the internet on the Surly Mr. Whirly crank in terms of failures, so it will be interesting to see if anyone else has the same experience as me. Apparently Surly do take the feedback from MTBR and similar forums, so hopefully this will result in improvements to future versions.

    TL;DR: If you pedal hard, pedal lots and/or are not obsessive-compulsive over your bike maintenance, strongly reconsider buying this crank and instead go for something else until Surly change the design.

    My Surly Mr. Whirly misadventure:
    If you look online for "Surly Ogre Rohloff" builds, one that comes up pretty quickly is the Monkey Lab build. It's a very nice setup, and everything looks right including chain line, which was my reason for going with a Mr. Whirly crank - especially when you're looking for the very, very short list of BCD 110mm 5 bolt cranks with a 54mm chainline and a Hollowtech II bottom bracket (BCD 110mm was desired as I wanted to run a Surly chainring, with something larger than a 36T - the largest size available in a 4 bolt pattern Surly Chainring). As far as I know, that list is very short: it's only 1 item long, and the only crank is the Mr. Whirly crank. I'm all ears if someone else has a suggestion to make.

    The instructions for Mr. Whirly are pretty comprehensive. Since I didn't know any of the torque specifications or how to set it up for a SS setup with a 54mm chainline with this specific crank, I took a look at the instructions. For the first install, I made sure I used my torque wrench, and set it as close to the specified torque settings as I could for my particular wrench, as per the instructions. As a disclaimer, the torque wrench is a Craftsman torque wrench, and is 2 years old and hasn't been calibrated in that time, however it is stored properly and does not see much use, so it should be approximately correct - I have used this on my motorcycle with great success and nothing has fallen off. After setting everything up, I took off, enjoyed the bike, rode it for a bit. Everything was pretty good and I was stoked to have what I thought was another solidly engineered Surly product.

    A long time ago I had some chainring issues, so I'm very OCD about checking all bolts related to the chainring - especially so after a new install - and this quickly made it on to the weekly inspection list. After 3 weeks of use, I noticed some unexpected deformation, and about 2 days later the spider broke on the way to work about a mile from my destination and warped the chainring enough that I could no longer pedal the bike, resulting in me being late to work. This was also a few days before a charity event I was doing that weekend on that bike, a 7500 ft elevation gain 100 mile ride. Some pictures of that failure are below.





    Looks kinda like a biopace chainring, only less awesome. You can see that once the spider deforms and breaks there's nothing holding it in position. This quickly causes the chainring to warp. Chainrings are very strong when the forces are in the same plane as the chainring - the instant the force is to either side, the chainring will warp and bend. Unfortunately, spindles do bend very slightly when force is exerted on them, and that is what consistently happened for me - the chainring would warp, bend, then throw the chain, and the bike would be unridable, unless some creativity with a set of pliers was used to temporarily keep going (and Surly chainrings are ~2.2 mm wide steel; they're pretty strong stuff).

    I ordered a replacement spider and chainring immediately with a rush on the delivery, accepted delivery Friday night, installed it, and did the event Saturday morning. Initially I thought I might have done something weird on the install, so I had a chat with Surly and sent them some photos, and their initial impression was that I didn't do anything wrong with the install (more on this later). For the second install, I did everything by hand, then verified it at least met the minimum torque specifications as per the instructions when I did the final inspection on the crank install (thus everything was at least as tight, or tighter than the specifications in the instructions).

    This time, it faired a little better. After a few weeks, the spider slowly started to warp again, but this time it was warping the spider and chainring more slowly than before. I placed a non-express order for parts through my local bike shop, and this time had them fit the spider for me, after explaining what had happened before. Their installation process was no different to mine other than they applied more torque than I did to the bolts. After this I started inspecting the bolts with greater frequency (twice a week, Sundays and Wednesday nights). I've been riding around 300 mi a week on this bike, so this is every 150 mi or so.

    Everything was going well until Friday. I was entering a roundabout; a car came from the left side & failed to yield right of way, and I cranked hard to get out of the way. I heard a loud *CRACK* noise, and pulled over immediately to see that the spider had failed once again, cracking at one of the mount points. I was about 8 miles from home without any SAG, so I limped home soft pedaling in 4th gear on the flattest route I could think of, and didn't deform the spider or chainring any more than I had to.

    Here's some photos of the latest failure:



    Final assessment:
    Despite my best efforts to love, cherish and take care of something that is marketed as, "Tour with it" on the Surly website, I've done everything right, taken all necessary precautions, and found that it doesn't live up to the marketing material. There are only a handful of failures I can think of more debilitating than a crank failure, and while I'm pretty creative with fixing mechanical issues on the road long enough to get home, this is one that has left me walking every time. It's not cheap either - every time the spider failed it warped the chainring as well, which meant I had to cough up the $63 for the spider, and the $40 for the chain for the MSRP prices.

    That other other thing - the warranty process:
    I mentioned "more on that later", and that was referring to the warranty process. Surly did warranty a chainring and a spider, which I thought was pretty cool. I was willing to eat the cost of one of the failures to date and accept that I, the rider and occasional mechanic, could have done something wrong because JRA failures on Surly products just don't happen all that often, and user error is far more probable.

    This post is long enough, so I'll spare you the miniscule details, but here's what you should know about Surly if you ever, EVER have to do a warranty deal with them:
    1) Order replacement parts through your LBS. Whatever you do, do NOT order it through someone that's not your LBS.
    2) Surly will credit your LBS's account directly by sending them a check for the wholesale price. This is the equivalent of what your LBS would be spending if they were to buy the part for you.
    3) Keep an eye on the entire returns process. If you didn't pay attention to my warning in #1, this will probably not go smoothly. This is my second return to Surly (the first being a Steamroller frame which cracked along a weld), and of my small sample size of 2 returns, neither has gone smoothly nor quickly.

    In this case, I first contacted customer service Feb 20, and the entire process was closed April 26; it wasn't the simplest of refunds since it involved an exchange of goods of equivalent value, but it wasn't exactly the most difficult either, and I got the general impression that they'd just forgotten about me in the day-to-day operations. Whether that's true or not, who knows, only Surly themselves can answer that question, but that's the perception I had. The irony was not lost to me that right around the time I was going through all of this, Surly had just posted their Customer Service (and Customer Service, again) blog posts - because it sure felt more like #1 than #2.

    The final word:
    As for what I'm going to do now about this crank, I don't know. I guess it could hold paper down, or I could figure out some way to turn it in to a bottle opener. Maybe turn it in to nunchucks. I've given up on the Mr. Whirly as a crank, and have lost all faith in it. I am replacing it with a Shimano XT FC-M780 crank, which should be pretty close to a 54mm chainline but with a 4 bolt BCD, and will have to use the 36T chain ring... or switch away from Surly Chainrings too.

    There is one upside to all of this. I received a Surly wool jersey as the "refund" for the crank, and it is some top notch sh*t. If you're looking for a sweet wool jersey but don't want to sell your first born to Rapha, the Surly ones are pretty nice.

  2. #2
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    Caution;  Merge;  Workers Ahead! Sad News

    Hi There
    You have had some bad luck with your Surly cranks.

    Have you looked at Middleburn Cranks? There new RS8 X-Type with Rohloff spider! yes its a 4 bolt But Middleburn make some very good rings too.
    Middleburn bicycle components, cranks, chainrings, hubs and accessories

    And Here is a Photo of the cranks

    RS8 crank set with new MONO spider and MONO ring | Middleburn Blog

    Pete


  3. #3
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    The failure looks like the same principle why we don't radial-lace rear wheels or hub/disc brake front wheels. The circular junction pieces between the spider legs don't do much to support the structure, they look just strong enough to hold things in place when you install the spider and that's it.

    Revising the spider design should eliminate further failures. The spider legs could be angled or the junctions reinforced.

    I have Mr. Whirlies on my Moonlander and I'm definitely not getting the spider, based on this post that verifies my doubts of the design.

    EDIT: yet another solution is to make (or have made) a 58 BCD chainring large enough to allow drilling additional holes for another chainring at a larger circle diameter. Much like the MWOD, but with a larger BCD.

  4. #4
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    I've had two sets of Whirly cranks and had issues with the spiders on both. When I contacted Surly, I was sent two thicker "prototype" spiders. I'd get in touch with Bob at Surly.

    Sadly, I still had no faith in the Whirly cranks and switched both to Deore, which have been absolutely perfect at 1/3 of the cost.

  5. #5
    Unhinged Aussie on a 29er
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    Quote Originally Posted by NZPeterG View Post
    Have you looked at Middleburn Cranks? There new RS8 X-Type with Rohloff spider! yes its a 4 bolt But Middleburn make some very good rings too.
    Middleburn bicycle components, cranks, chainrings, hubs and accessories
    Hi Pete, thanks for responding. After 3 spiders, I'm not so sure luck has much to do with it. I didn't consider the Middleburn cranks because I was looking for something to take a 110 BCD 5 bolt, with a Hollowtech bottom bracket. They are pretty cool though.

    What I found in my interwebz travels is that there is an abundance of 4 bolt "Trail" cranks with middle chainring chainline set at 47.5-50mm. The FC-M780's that I selected, for example, have 50mm chainline. The "standard" deviation between the chainline of the middle ring and the oute ring is ~5mm (with some variation based on chainring plate thickness, how the chainring is designed, etc.), so this puts most of those cranks well within reach.

    There's also an abundance of 5 bolt cranks that can be used on touring bikes, however they are not Hollowtech II - most of them are square taper. My frame can take both, but I am trying to avoid going back to the square taper route.

  6. #6
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    If the issue is with the 110 bcd spider specifically, I've got a 58/94 spider you could have for the cost of shipping. Warhawk makes 94 bcd chainrings up to 40t.
    Hey sexy mama, wanna kill all humans?

  7. #7
    Unhinged Aussie on a 29er
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    Quote Originally Posted by Saul Lumikko View Post
    The failure looks like the same principle why we don't radial-lace rear wheels or hub/disc brake front wheels. The circular junction pieces between the spider legs don't do much to support the structure, they look just strong enough to hold things in place when you install the spider and that's it.

    Revising the spider design should eliminate further failures. The spider legs could be angled or the junctions reinforced.

    I have Mr. Whirlies on my Moonlander and I'm definitely not getting the spider, based on this post that verifies my doubts of the design.

    EDIT: yet another solution is to make (or have made) a 58 BCD chainring large enough to allow drilling additional holes for another chainring at a larger circle diameter. Much like the MWOD, but with a larger BCD.
    From the physics perspective, the spider is a third order lever. The reason that this is failing is the lever is effectively bending around the point at which effort is applied. This represents one of three solutions for most applications:
    1. Decrease the load.
    2. Increase the distance between the fulcrum and effort (move the effort closer to the load)
    3. Increase the strength of the lever.
    4. We can add "changing the design around where the spider meets the crank to prevent rotation" to the list, due to the nature of the problem.

    Decreasing the load isn't really something any bike company wants to admit to, unless you build wheels or hubs. Definitely not cranks!

    Increasing the distance between the fulcrum and effort is a possibility. An additional mount point could be added along the crank arm. However, I think this would have limited success considering the power stroke of a regular rider, where most of the force is applied at an angle to the crank, not when the crank is at the 12 o'clock position. It also creates incompatibility between old style cranks and new style spiders.

    Increasing the strength of the lever is definitely a possibility. It will undoubtedly add weight and cost more to manufacture, but it's one of the more reasonable approaches. Adding a second rail and repositioning the two rails to provide maximum reinforcement, thickening the existing one, or just making it one solid hunk of metal are all possibilities. I suppose they could change the material too, but I don't see that happening. I don't think people will care all that much about the weight to be honest; if you're buying a Surly crank, chances are you're not a weight weenie. This is the approach I would use.

    Finally, redesigning the clamp between the crank arm and the spider to resist rotation is another option I would choose myself as a "what would I do after the stronger lever" approach. Adding a knurl, using the same approach as the mounts for road brake levers (serrated edge against the smooth frame surface) or redesigning the spider to "hug" existing crank mount points adds to manufacturing complexity and thus cost, but increases the resistance against rotation. This would primarily fail when the bolts are insufficiently tightened, but it would also give Surly some fuel for the, "You didn't keep those bolts tight" fire (they do have a special mention on all instruction manuals that if you did something stupid, own up to it & they'll see what they can do to help you out, so even if it was your fault it'd be worth chatting to them - in case you haven't noticed, I spend a lot of time reading documentation!!).

    Of course, all of this is moot if Surly can't find a willing manufacturer to make the changes (search for Moloko bars on the page), and since I'm not a mechanical engineer, it's just supposition. They are also a business: the cost benefit analysis of a single person having multiple failures when it works just fine for hundreds of other customers also might pan out to the whole, "not gonna do it" (given I have not found any other Mr. Whirly failures online).

    Still, it's better to be informed, and who knows, maybe there are other people out there who had failures but said nothing. I'm about 200 lbs, and a reasonably strong rider, so it's not impossible that someone stronger or heavier will push with equal or higher force than that which I put through my Mr. Whirly cranks.

  8. #8
    Unhinged Aussie on a 29er
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    Quote Originally Posted by solomon707 View Post
    If the issue is with the 110 bcd spider specifically, I've got a 58/94 spider you could have for the cost of shipping. Warhawk makes 94 bcd chainrings up to 40t.
    Thank you most kindly for your offer, but I will pass. Surly probably could do the same thing for me if they were to warranty it (ship a different BCD spider & chainring, or if I were to order it though my LBS, simply credit the LBS account for the same amount).

    The Warhawk chainrings information is useful. Any idea on whether they're typically steel or aluminum rings?

  9. #9
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    Quote Originally Posted by hunter006 View Post
    Thank you most kindly for your offer, but I will pass. Surly probably could do the same thing for me if they were to warranty it (ship a different BCD spider & chainring, or if I were to order it though my LBS, simply credit the LBS account for the same amount).

    The Warhawk chainrings information is useful. Any idea on whether they're typically steel or aluminum rings?
    Looks like they mostly do aluminum, but stainless and ti as well.
    Hey sexy mama, wanna kill all humans?

  10. #10
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    I've been using a 58/94 with a wolftooth 32t ring for the last few weeks. No problems, but thanks for the post. I'll definitely keep an eye on it.

    I think it'll be less of an issue with the smaller ring and BCD. Also, since it's a 4 bolt chainring, it connects differently and looks like it spreads the stress out more. I'm not a physics guy or anything, it's just a guess.


    Also I had fairly recent drive side knee surgery, so my weak leg might not be able to bend it.

  11. #11
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    Hi Hunter, due to reading about Thorn Nomads and their supposedly bullet proof nature with the build being an "expedition" bike, I opted for a 110mm bcd Thorn crank from SJS Cycles in the UK (in fact I found mine on Ebay but SJS is where they retail). I'm using the smallest available ring for that crank which I think is a 34T (again Thorn (reversible) and hauling a trailer. Let me know if you want a link. I only mention this due to your using a 110mm bcd. Ahh found them:

    http://www.sjscycles.co.uk/thorn-110...ack-prod11053/

    http://www.sjscycles.co.uk/thorn-110...lver-prod1673/

    A bottom bracket like:
    Shimano UN-73 Bottom Bracket > Components > Drivetrain > Bottom Brackets | Jenson USA Online Bike Shop
    would likely be best but a UN55 would do the trick.

    Quote Originally Posted by hunter006 View Post
    There's also an abundance of 5 bolt cranks that can be used on touring bikes, however they are not Hollowtech II - most of them are square taper. My frame can take both, but I am trying to avoid going back to the square taper route.
    Sorry - I just spotted this above.
    Last edited by rifraf; 05-28-2013 at 02:35 AM.

  12. #12
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    ... and if we just ... Hollowtech Cranks to use with a Rohloff Speedhub.

    Quote Originally Posted by hunter006 View Post
    Hi Pete, thanks for responding. After 3 spiders, I'm not so sure luck has much to do with it. I didn't consider the Middleburn cranks because I was looking for something to take a 110 BCD 5 bolt, with a Hollowtech bottom bracket. They are pretty cool though.

    What I found in my interwebz travels is that there is an abundance of 4 bolt "Trail" cranks with middle chainring chainline set at 47.5-50mm. The FC-M780's that I selected, for example, have 50mm chainline. The "standard" deviation between the chainline of the middle ring and the oute ring is ~5mm (with some variation based on chainring plate thickness, how the chainring is designed, etc.), so this puts most of those cranks well within reach.

    There's also an abundance of 5 bolt cranks that can be used on touring bikes, however they are not Hollowtech II - most of them are square taper. My frame can take both, but I am trying to avoid going back to the square taper route.
    Hi I know that your after a Crank with Hollowtech bottom bracket and that is why I said about Middleburn RS8 X-TYPE cranks and they make one for Rohloff Speedhub with 54mm chainline, But yes its only 4 Bolt.
    I have been Running Rohloff Hubs for over 8 year's and finding cranks has been a pain. I use Middleburn RS7 with square taper BB because I have my World Touring Thorn Nomad set up to go Cycling Touring offroad and back roads.

    All the best with you next set up.

    Pete

  13. #13
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    Quote Originally Posted by NZPeterG View Post
    I use Middleburn RS7 with square taper BB because I have my World Touring Thorn Nomad set up to go Cycling Touring offroad and back roads.

    All the best with you next set up.

    Pete
    Hi Pete,
    you dont favor the Thorn unit?

  14. #14
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    Wink No

    Quote Originally Posted by rifraf View Post
    Hi Pete,
    you dont favor the Thorn unit?
    Hi No its not as strong as a pair of Middleburn RS7.

    Pete

  15. #15
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    Quote Originally Posted by NZPeterG View Post
    Hi No its not as strong as a pair of Middleburn RS7.

    Pete
    Ahh, good to have a recommendation if I have a failure.
    I'll make a note of the Middleburn RS7.

    Cheers
    Aidan

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