Bizarre brake issue

About a week ago (about 30 miles of riding ago) I noticed a very slight ticking sound when I applied the brakes. I noticed no decrease in braking power. Very suddenly this past Saturday the slight infrequent ticking noise became a constant loud handle shaking noise and the braking was seriously diminished. It took a while to notice that all but one of the six bolts that hold the disk to the right wheel had fallen out. The one remaining bolt had become loose, so the disk was now offset and clunking into the brake housing. Bolts on the opposite side are nice and tight. It says a lot that just one bolt held the disk tightly enough that the missing bolts caused no problem. But how did all but one get loose and fall out when none have a problem on the other side?


  • What kind of terrain are you riding on?  How hard do you have to brake?
  • DIsc rotor bolts are notorious for coming loose especially when riding off road. Part of the regular maintenance for any bike trike requires a quick check on bolts now and then. Since brakes stop you most importantly them. You can get new bolts at most any bike shop or god hardware store and I use blue Loctite to make sure they stay put and can still be removed if need be. 
  • I ride mostly on a paved track, or fine gravel; no off roading. Generally, I do not brake hard. The mechanic was astounded. The manager had a look and was sure they should never have come loose. I'll know to look at these bolts regularly now and may carry a few, plus the right torx driver. Thanks!
  • Sounds like one more thing we all need to tighten occasionally.
  • Mine has done the same thing. I am just getting into the habit of checking them every week or two. I should probably try the loctite thing.
  • installed properly, the rotor bolts should never loosen. new bolts [i do not reuse] have all come with applied loctite. it is essential to use a torque wrench when installing new.

    if you do the above and any bolt loosens later on, time for a new wheel hub.
  • edited June 2017
    Any photos of these bolts on the disc for those of us that haven't had the issue (yet)?
    Is there a recommended torque for these bolts?

    Was unable to find anything detailed on the subject online. Can barely hold my eyes open... worked both jobs on 5 hours sleep.

    Where can one obtain an adjustable torque wrench with hex bits?

    ¬ ITL
  • edited June 2017
    During downtime went out to look at these bolts. Took a photo to see what type of heads these were. T-25
    Did you know the axle had a hole all the way through too??

    Tightened those puppies down using a Ryobi Impact Driver. Three that might is been working their way the other direction, only one of them was at a quarter of a turn loose.

    Saw a couple of mounting bolts for the brakes and questioned myself if I should see if these were tight. Looked it over, and used the impact driver on the two bolts on each side. Oddly this one was loose.
    The other side is too close to the tie rod bolt, did what I could. Seemed taught enough.

    Also had to tighten the seat bolts again too. If had the time would of took it off and used blue Loctite on it.

    ¬ ITL
  • you are setting up hubs and brakes for failure - only torque wrench tightening on these components! check out what avid and park tools say before doing.
  • edited June 2017
    Torque setting was on low, for 1/2" wood screws.
    Am looking for a decent, yet affordable hex/star torque wrench set.

    ¬ ITL
  • was under the impression that wood and aluminum had different properties. there is a specific lb-inch setting for brake components.
  • TerraTrike (@chonk) ought to post a torque specifications on their components, as only they know if theirs are different from other manufacturers. is a guide, although there differences in things like disc mounting bolts.

    ¬ ITL
  • For those of you who don't believe in torquing, there is I science to it. You actually stretch the bolt just enough to not lose it's elasticity and it is the bolt trying to spring back that holds it tight. If you tighten too much, the bolt will stretch past its elastic point and will not hold. If you do not tighten it enough it will vibrate loose. Each bolt class has its own torque requirement and you should also lubricate the threads and the underside of the bolt head to get an accurate torque. Dry threads have their own torque specs.
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