Had a bad squeak in my Rebel

[ruffruff]

From day one, I had a squeak in my motor area when I pedaled.
It kept getting worse so I figured I'd better deal with it.

Motor was loose! You could wiggle it by grabbing the pedals and twisting them.

Took off the dust covers. Easy and straightforward. There are three bolts that hold the motor. Two in back are nylock and need to be torqued, I didn't even bother to check them.
The front bolt has a blind nut on one side, kinda weird...But it was loose!
I cranked it down. That was the problem!

Luckily, the cranks are incorporated into the motor so it couldn't do any bottom bracket damage. So if you are getting noises out of your crank area your motor might be loose!

While I had it on the stand, I gave everything a once over. Some bolts needed a little tightening!

 

[rich c]

It's accepted standard practice to check every fastener on a bicycle. Especially at the start of a season, and then critical fasteners every month.

 

[ruffruff]

It's accepted standard practice to check every fastener on a bicycle. Especially at the start of a season, and then critical fasteners every month.

i don't think removing dust covers to get at buried motor mount bolts on a bike right out of the box is standard practice.

 

[PineNut]

Thanks ruffruff for your post. By coincidence, I've seen a very similar issue on my 27.5 Rebel PW-X which started in just the last two days.

I got the bike in February this year and now have 500 miles on it (most riding was in the last two months after it got warmer outside). I've been very pleased with the bike.

I'm now getting a "squeak" or "screech" noise each time I push down on the pedal as I ride the bike. It's strange that I don't hear the problem while riding on dirt trails, even with steep climbs. As of now I'm just hearing it as I ride back home up hill on a paved road. The noise seems to be coming from around the crank/motor area.

Based on your post, I checked the bolts on my motor cover. Much to my surprise, all three motor cover bolts on the gear side of the crank were very loose and one bolt was missing entirely (I assume it previously fell out while riding). The two nyloc bolts on that side (each labeled "MAX 11Nm) were so loose that I could turn them with my fingers. I wonder where I can find a replacement bolt for the motor cover?

On the non-gear side of the crank the cover bolt was tight and the two nyloc bolts (labeled MAX 22Nm) were tight as well. There are three bolts holding the "Yamaha" labeled cover on the motor and they were also tight.

I haven't yet tried removing the motor covers to check the motor mount bolts. I don't yet notice any wiggle in the motor by moving the pedals as you observed but at this point (problem just started) it may require more pressure on the pedals than my arms can provide in order to hear that squeak or feel any wobble.

From your description, I guess you didn't need to remove the four nyloc bolts? I only have a 1/2" torque wrench (too big for this) so I guess I'll have to get a 1/4" with torque settings in the 11-22 Nm range or maybe a bicycle specific torque wrench (any suggestions)? Do you know what those bolts are for and why two of them would be so loose? I wonder it it requires a bike mechanic to torque them to the ideal setting? I see no mention of any of these bolts in the rather sparse BH manual that came with the bike.

I got my bike from Crazy Lenny's and they did the assembly although I assume the motor and motor cover bolts would have been assembled by BH. Bad me (and and maybe Crazy Lenny's) for not checking them earlier.

If you or anyone have any other suggestions before I take off the cover it would be appreciated.

 

[ruffruff]

HI Pinenut,

Take a picture of the bolts you are referring to.
The ones marked 11-22nm are the back motor mount bolts with the nylock on them. Mine were torqued to the bare minium spec. I cranked them to 22nm.
Don't remove them, just torque them to spec.
The other bolts that have the black ring with a spec Nm on them are the suspension bolts.



I picked up one of these for torquing the bolts. I have a regular torque wrench but this one is very convenient.

https://www.amazon.com/ACDelco-ARM602-3-Digital-Adapter-Audible/dp/B004VYUKTC/ref=sr_1_8?crid=HE3JBL6W2QBC&dchild=1&keywords=acdelco+torque+wrench&qid=1593109296&sprefix=acdelco+torq%2Caps%2C206&sr=8-8

I'm wondering what CrazyLenny does myself. It did this right out of the box.

 

[PineNut]

I missed the part where you said you had the squeak problem from the start. At least mine took 500 miles to show up!

I did remove the motor cover. On my bike, it appears the four nyloc bolts (two on each side of the motor) are what bolt the motor to the frame. That's much clearer to see once the cover was removed. I don't think I have the blind mounting nut you described, though I saw a nut I'll discuss later in this post.

Do we have the same model bike, you mentioned only three nyloc bolts? We both have a BH Rebel, and mine is the 2018 hard tail 27.5 Rebel PW-X with the PW-X Yamaha motor (very nice and strong motor!).

I did take some photos and can add them later if necessary.

I called Crazy Lenny's and spoke with the same person who sold me the bike (Gary). He's very knowledgeable and was helpful. He said the max torque values on the four mounting bolts are because we have steel bolts going into the mounting holes on the aluminum motor casing (is he correct the casing is aluminum and not steel?). Exceeding the max torque could strip the threads. I wonder if the nylon sleeves around the bolts are supposed to give way before that happens (not that I want to find out)? Anyway, lacking a torque wrench, he agreed that it's OK to just tighten the mounting bolts to the point where they feel tight enough to stay in place and DO NOT add another half turn or so to make sure it's even tighter. He also agreed a loose mounting bolt could cause the squeaking sound when I pedal.

By the way, that Delco digital torque meter you have looks very nice! I have a coupon for a cheap non-digital Harbor Freight 1/4" torque wrench for $12 (out of stock at my store), but I know the quality/accuracy of those is not the best.

As I mentioned earlier, the screws holding the plastic motor cover were all loose on the crank gear side of my bike and the two motor mount screws on that side were very loose as well. All screws were tight on the other side of the motor. I did have Crazy Lenny's put on a larger crank gear (from 38T to 42T) when I purchased the bike and that side has all the loose screws. Coincidence? However, I don't think they would have needed to remove those screws to change the crank gear.

There is one bolt I see on the side of the motor which is mostly blocked by the bike frame and I don't think I can get a wrench on it unless I pull the motor. It looks like the bolt is probably just to hold the motor case together and is not to mount the motor, but I could be wrong.

I didn't have time to put everything back together today so hopefully I can do that tomorrow and test that the squeak is gone. By the way, Gary said it would take time to find a replacement bolt at the store but he thought they are not custom and something similar (hopefully rust resistant) could be found at a hardware store. I'll look for one when I get a chance and if I can't find one I'll call Crazy Lenny's back. I think the plastic motor cover can be held in place OK even with the missing screw but I already see one of the screw holes has broken plastic (I glued it back, hope that works) and a missing screw could put more strain on the plastic around the other screws.

 

[FlatSix911]

From day one, I had a squeak in my motor area when I pedaled.
It kept getting worse so I figured I'd better deal with it.
Motor was loose! You could wiggle it by grabbing the pedals and twisting them.

Took off the dust covers. Easy and straightforward. There are three bolts that hold the motor. Two in back are nylock and need to be torqued, I didn't even bother to check them.
The front bolt has a blind nut on one side, kinda weird...But it was loose! I cranked it down. That was the problem!

Luckily, the cranks are incorporated into the motor so it couldn't do any bottom bracket damage. So if you are getting noises out of your crank area your motor might be loose!
While I had it on the stand, I gave everything a once over. Some bolts needed a little tightening!

I found the same squeak on my BH Rebel that required torquing the motor mounts.

Interesting to know that this was an issue from the factory... my BH Lynx spec was fine.

 

[FlatSix911]

Thanks ruffruff for your post. By coincidence, I've seen a very similar issue on my 27.5 Rebel PW-X which started in just the last two days.

I got the bike in February this year and now have 500 miles on it (most riding was in the last two months after it got warmer outside). I've been very pleased with the bike.

I'm now getting a "squeak" or "screech" noise each time I push down on the pedal as I ride the bike. It's strange that I don't hear the problem while riding on dirt trails, even with steep climbs. As of now I'm just hearing it as I ride back home up hill on a paved road. The noise seems to be coming from around the crank/motor area.

Based on your post, I checked the bolts on my motor cover. Much to my surprise, all three motor cover bolts on the gear side of the crank were very loose and one bolt was missing entirely (I assume it previously fell out while riding). The two nyloc bolts on that side (each labeled "MAX 11Nm) were so loose that I could turn them with my fingers. I wonder where I can find a replacement bolt for the motor cover?

On the non-gear side of the crank the cover bolt was tight and the two nyloc bolts (labeled MAX 22Nm) were tight as well. There are three bolts holding the "Yamaha" labeled cover on the motor and they were also tight.

I haven't yet tried removing the motor covers to check the motor mount bolts. I don't yet notice any wiggle in the motor by moving the pedals as you observed but at this point (problem just started) it may require more pressure on the pedals than my arms can provide in order to hear that squeak or feel any wobble.

From your description, I guess you didn't need to remove the four nyloc bolts? I only have a 1/2" torque wrench (too big for this) so I guess I'll have to get a 1/4" with torque settings in the 11-22 Nm range or maybe a bicycle specific torque wrench (any suggestions)? Do you know what those bolts are for and why two of them would be so loose? I wonder it it requires a bike mechanic to torque them to the ideal setting? I see no mention of any of these bolts in the rather sparse BH manual that came with the bike.

I got my bike from Crazy Lenny's and they did the assembly although I assume the motor and motor cover bolts would have been assembled by BH. Bad me (and and maybe Crazy Lenny's) for not checking them earlier.

If you or anyone have any other suggestions before I take off the cover it would be appreciated.

Welcome to EBR and thank you for a good first post... you will need to remove the cover to get access to one of the motor mounts.

 

[ruffruff]

If you read my other thread, you know my bike is in for repair at the LBS.
Got the call that the bike was done but the Tech added, "I checked everything over on your bike and ALL you suspension bolts were really loose!
DOOOH!

Check 'em all boys and girls! I guess the assumption is, even right out of the box, they need to be checked!

 

[PineNut]

I have a follow-up on the "squeak" (actually more of a creaking noise, like a worn door hinge) I'm getting on my BH Rebel 27.5 PW-X.

The creaking happens when I ride and put pressure on the pedals while pedaling. The noise seems to be coming from the crank area. When I coast downhill and stand up on the pedals and free spin the crank, I don't get any creaking.

Two of my Yamaha motor mounts (both labeled to torque to 11 nm) on one side of the motor were loose and I tightened them. It didn't help.

I had a Velofix guy come by to give the bike a 500 mile service. He lubed the crank and torqued all the bolts on the bike. The problem seemed to go away at first, but after about 5 miles on the trail the creak came back.

I turned the bike upside down to check things out. I held the rear wheel so it won't move and pushed down on each crank arm in the direction you would pedal. I notice a bit of movement in each crank arm when I do this, and each of them makes the creaking sound. I don't have to press down very hard (maybe 15 lbs) on the crank arm to hear the creaking. If I press down on both crank arms at the same time, there is little or no creaking. I also now notice that those two motor mounts are loose again. I've only ridden 25 miles since the bike was serviced and the bolts were tightened.

I'm wondering if the creaking might have something to do with the Yamaha torque sensor? I'm assuming the slight movement of the crank arms I notice is normal due to the torque sensor?

In another thread I see mention of the metal plate of the torque sensor on a Stromer ST1 cracking. However that issue caused the pedal assist to go bad and I haven't seen an issue with my pedal assist. Also that model has a rear hub drive instead of the mid-drive on my bike.

I don't know if this has anything to do with the creaking, but I did crash my bike a few weeks ago. However, I think that was a couple of weeks before I noticed the creaking. I had climbed a hill on a dirt trail and started coasting downhill. I made the mistake of locking my extended leg downwards while coasting about 15 MPH and my pedal got caught on a tree root which sent me flying. The bike actually ended up landing on top of me and I don't notice any visual damage to the bike. The bike was serviced after the crash.

Any ideas on what else I should check? If I need to check the torque sensor (is there just one?), any description of how to do that for a Yamaha PW-X (2018 model) would be appreciated.

 

[ruffruff]

Thanks Pinenut. You described my situation to a T!
I'm thinking about taking the chain ring off and looking at the lock ring.

 

[FlatSix911]

Here are the recommended torque values for the motor mounts and lock ring on the PW-X and PW-SE drive units.

The correct torque combined with a bit of Loctite fixed the noise issue on my bike. Hope this helps and good luck.

 

[ruffruff]

Thanks FlatSix911. I know these exploded view drawings aren't always up to date. It's interesting though that I have two other bolts to mount the motor that are not called out on either of those drawings.

BUT, next time I have to go in there, I' going to remove the bolts and clean them up if they are dirty, reinstall with a light coat of lube, tighten to spec with loctite and new nylock nuts.

 

[PineNut]

Thanks as well FlatSix911.

My PW-X motor has two of those 11 nm mounting bolts on one side and two 22 nm on the other side of the motor. I guess that diagram leaves out two of them in order to be less cluttered.

I'll try Loctite as you suggest. Looking at the Loctite website it seems Loctite Threadlocker Blue 242 (less permanent) is what I want instead of the Red 271 version (more permanent and requires heat to remove).

 

[FlatSix911]

Thanks FlatSix911. I know these exploded view drawings aren't always up to date. It's interesting though that I have two other bolts to mount the motor that are not called out on either of those drawings.

BUT, next time I have to go in there, I' going to remove the bolts and clean them up if they are dirty, reinstall with a light coat of lube, tighten to spec with Loctite and new Nylock nuts.

Thanks as well FlatSix911.

My PW-X motor has two of those 11 nm mounting bolts on one side and two 22 nm on the other side of the motor. I guess that diagram leaves out two of them in order to be less cluttered.

I'll try Loctite as you suggest. Looking at the Loctite website it seems Loctite Threadlocker Blue 242 (less permanent) is what I want instead of the Red 271 version (more permanent and requires heat to remove).

You're right, only one bolt of each type (M6 & M8) is shown to simplify the exploded view... you can see the correct quantities listed in the parts table.

I would recommend going with Blue 242 Loctite thread locker so you can remove bolts if needed... Red 271 is permanent and will require heat to remove.

http://wdarc.org/Loctite%20Guide.pdf

 

[ruffruff]

Yes, use Loctite blue. And for best results don't reuse nylock nuts if you take them off.