Kenevo Gen1 Creak City Chronicles: Lessons from a Snapped Motor Mount Bolt

[Hightower]

2020 Lenovo Kenevo here. It's been a solid bike overall—reliable, sturdy, no major complaints. Well, except for one: the Fusion Manic seat post decided to give up on life. Thanks for that, I guess.

Recently, though, my Kenevo has making a really loud creak. It's easy to replicate, especially when I'm stationary and put pressure on the left side. The noise seems to be coming from somewhere around the middle or rear, which narrows it down to...half the bike.

Naturally, I went through the usual suspects:

• Pulled the cranks, greased the spindle
• Loosened/tightened the rear axle
• Same with the shock bolt
• Gave the drivetrain some TLC

But nope, the creak was still loud and clear.

So, I took it to my local bike shop (LBS). The mechanics there are always super chill. One of the guys took a quick ride and confirmed—this thing was Creak City. He torqued a couple of bolts (shock bolt and some motor mount bolts), then hit me with, "We can figure this out for about $150... or you could do it yourself."

He suggested going through all the pivot bolts—remove, inspect, grease—and said not to worry about a torque wrench, since you can feel the stop when tightening. Cool, right?

Tonight, I rolled up my sleeves and got to work:

• Lower BB pivot? Squeak still there.
• Chainstay/rear pivots? Nope, still squeaking.
• All upper pivots? Yep, you guessed it—still creaking.

The mechanic had also mentioned retorquing the motor mounts, so I gave that a shot. And as soon as I started on the first one, barely any pressure, SNAP. The bolt broke like a toothpick. Apparently, motor mount bolts only need 160 inch-pounds of torque, whereas pivot bolts take 180. Who knew? I suppose I should have looked this up before I started on this fun little project.

Sooooo, FML. Moral of the story? Use a torque wrench, especially on those motor mount bolts! Don't learn the hard way like I did.

EDIT - changed foot lbs to inch pounds

 

[levity]

I assume that the creak gone now

 

[Hightower]

I assume that the creak gone now

Haha! No, it's still there. Think I can still ride it on just 3 out of 4 motor mount bolts?

 

[steve_sordy]

............. Think I can still ride it on just 3 out of 4 motor mount bolts?

Yes of course you can! You've only lost one, there is another three to go yet!
Let us all know how you get on with your next drop, jump or rocky descent.
There is nothing like learning from the mistakes of others.
I await your report.

 

[Hightower]

Yes of course you can! You've only lost one, there is another three to go yet!
Let us all know how you get on with your next drop, jump or rocky descent.
There is nothing like learning from the mistakes of others.
I await your report.

Wooosh! It was a joke. Guess it went over your head. Too many crashes in your youth?

The LBS - the ones who told me to told me not to worry about using a torque wrench - now wants to charge me $300USD to remove the motor to see what's up. Thanks for the sympathy dude.

 

[RebornRider]

I'm guessing this was intended to be a joke, too?

160 inch-pounds would be a more reasonable spec.

 

[Hightower]

Typo and meaningless as, again, the LBS told me don't worry about a torque wrench. I'm not blaming this all on the LBS but the guy flat out told me - for the pivot bolts and motor mounts - just forget about the torque wrench and do it by feel.

 

[steve_sordy]

Wooosh! It was a joke. Guess it went over your head. Too many crashes in your youth?

The LBS - the ones who told me to told me not to worry about using a torque wrench - now wants to charge me $300USD to remove the motor to see what's up. Thanks for the sympathy dude.

I suspected as much, but who knows these days, emoticons don't quite carry the same sense of meaning as a face-to-face chat would do.

You do have my sympathy! Shifting sheared bolts is a bastard. I assume that they are blind bolts, in which case a left-hand drill bit with an anti-clockwise rotation should remove it. The heat from the friction should destroy any thread lock and the bolt should unscrew. If you can see the bolt from the other side, just drill it out with a normal bit and drill. Again, the heat and friction should work. Use a small drill to start, don't try to drill out the whole core.

My sense of the correct torque to use was calibrated during my apprenticeship on steel and cast iron. I learned then that aluminium and its alloys was a whole other thing. I always use a torque wrench when tiny torques are required, anything less than 25Nm (most of the bike). For Bottom Bracket and cassette mountings at 40Nm, I still go by feel.

Mostly the size of the Allen key restricts the torque you can reasonably apply as long as you don't start adding pipes on to the end of the key, or hitting them with hammers. Those weird long-handled keys need to be treated with caution.

 

[Snrbrtsn]

To share my tale,
I chased a creak for a great many months, finally finding when I lost my back end.
My chain stay had cracked behind the chain guard, entirely invisible with chain guard in place though, once broke through it was easily evident

 

[#lazy]

I snapped the top bolt on my kenevo and was told the only fix is a new motor so plugged the hole with a rubber plug and it’s fine .