Issue with my Pioneer Allroad

[jrb5j]

I was riding this weekend and noticed a quiet grinding sound with each turn of the crank. I thought it was the chain rubbing the front derailleur but that wasn't it. I put it on my stand and I can reproduce the sound but I see nothing rubbing. Then I noticed that I can get slight side-to-side movement if I pull my cranks. I know with a standard bike this should not happen. Is this normal with the motorized bottom bracket?

What should I do? I have very little experience with bottom bracket maintenance and my local bike shop is timid about working on an ebike.

 

[flymeaway]

Then I noticed that I can get slight side-to-side movement

Not having an exploded view of the drive assembly, just pictures of the drive, I'd say you have an issue with internal bearings that support the crank. If you have a failed or failing bearing the problem will get worse.

Court J.

PS.....any noise that seems to appear from nowhere isn't a good sign.

 

[flymeaway]

What should I do?

Note: your issue is probably related to one of the two radial bearings (text colored in blue) below. Either a bearing has become loose and the spindle is allowed more movement because the bearing has moved, or one of the bearings is failing allowing side load movement. In either case the problem will not correct itself. It would appear that bearing #44 is press fit into the housing and that bearing 46 is part of an assembly that is pressed and retained when the crank arm is attached.

Silly question....did you check to see if a crank arm might be loose?

Here's a link to a patent specific to the motor and bike in question:
http://www.google.com/patents/US6629574

Click on Fig. 3, see detail #44 and #46. These are radial bearings that support both ends of the crank shaft.

Motor assembly 28 includes a number of components which are coaxial with a main spindle 42. Further, main spindle 42 is also coaxial with the bottom bracket of the bicycle frame. Main spindle 42 which passes through the entire motor assembly, and is supported by left and right spindle bearings 44 and 46, respectively. (See FIG. 3.) The outside diameter of left spindle bearing 44 is mounted to a main housing 48. Main housing 48 is employed to house most of the components of the motor assembly and conveniently fits within the bottom bracket of the bicycle as previously described. Right spindle bearing 46 is mounted in an output driver 50. Coupled to main spindle 42 is a left crank arm 52 and a right crank arm 54. Crank arms 52 and 54 are coupled to spindle 42 with a tapered positive engagement and by the use of screws 56 which are screwed into threaded slots 58 in main spindle 42.

Motor assembly 28 further includes a motor rotor assembly 60 which is mounted to the outside diameter of rotor ball bearings 62. (See FIG. 3.) A motor magnet 64 is fixed to motor rotor assembly 60. The inner diameter of rotor ball bearings 62 are mounted on spindle 42. Motor rotor assembly 60 is free to rotate independent of spindle 42 as well as crank armns 52 and 54 which are mounted to spindle 42. A motor stator 66 is fixed to main housing 48. A plurality of motor control wires 68 exit through main housing 48. A circuit board 70 (see FIG. 3) having position sensing devices is mounted to a left side of main housing 48.

A first planet sun gear 72 is mounted directly to the right side of motor rotor assembly 60. The outer diameter of first planet sun gear 72 is meshed with three first planet gears 74. The three first planet gears 74 are mounted on ball bearings 76. The inner diameter of ball bearings 76 are mounted to shafts 78. The ends of shaft 78 are mounted to the flange of a second sun gear 80.

The outside diameter of second sun gear 80 is meshed with three second planet gears 82. Second sun gear 80 is supported on spindle 42 by bearings 84. The outer diameters of first planet gears 74 and second planet gears 82 are meshed with a ring gear 86. Ring gear 86 is machined directly into main housing 48. The inner diameters of the second planet gears 82 are mounted to ball bearings 88. (See FIG. 3.) The inner diameter of ball bearings 88 are mounted to shafts 90. Shafts 90 are attached to a motor output driver ring 92. Motor output driver ring 92 is supported by the inner diameter of bearing 94 as also shown in FIG. 4. The outer diameter of bearing 94 is mounted to a housing end cap 96.

 

[jrb5j]

Note: your issue is probably related to one of the two radial bearings (text colored in blue) below. Either a bearing has become loose and the spindle is allowed more movement because the bearing has moved, or one of the bearings is failing allowing side load movement. In either case the problem will not correct itself. It would appear that bearing #44 is press fit into the housing and that bearing 46 is part of an assembly that is pressed and retained when the crank arm is attached.

Silly question....did you check to see if a crank arm might be loose?

Here's a link to a patent specific to the motor and bike in question:
http://www.google.com/patents/US6629574

Click on Fig. 3, see detail #44 and #46. These are radial bearings that support both ends of the crank shaft.

Motor assembly 28 includes a number of components which are coaxial with a main spindle 42. Further, main spindle 42 is also coaxial with the bottom bracket of the bicycle frame. Main spindle 42 which passes through the entire motor assembly, and is supported by left and right spindle bearings 44 and 46, respectively. (See FIG. 3.) The outside diameter of left spindle bearing 44 is mounted to a main housing 48. Main housing 48 is employed to house most of the components of the motor assembly and conveniently fits within the bottom bracket of the bicycle as previously described. Right spindle bearing 46 is mounted in an output driver 50. Coupled to main spindle 42 is a left crank arm 52 and a right crank arm 54. Crank arms 52 and 54 are coupled to spindle 42 with a tapered positive engagement and by the use of screws 56 which are screwed into threaded slots 58 in main spindle 42.

Motor assembly 28 further includes a motor rotor assembly 60 which is mounted to the outside diameter of rotor ball bearings 62. (See FIG. 3.) A motor magnet 64 is fixed to motor rotor assembly 60. The inner diameter of rotor ball bearings 62 are mounted on spindle 42. Motor rotor assembly 60 is free to rotate independent of spindle 42 as well as crank armns 52 and 54 which are mounted to spindle 42. A motor stator 66 is fixed to main housing 48. A plurality of motor control wires 68 exit through main housing 48. A circuit board 70 (see FIG. 3) having position sensing devices is mounted to a left side of main housing 48.

A first planet sun gear 72 is mounted directly to the right side of motor rotor assembly 60. The outer diameter of first planet sun gear 72 is meshed with three first planet gears 74. The three first planet gears 74 are mounted on ball bearings 76. The inner diameter of ball bearings 76 are mounted to shafts 78. The ends of shaft 78 are mounted to the flange of a second sun gear 80.

The outside diameter of second sun gear 80 is meshed with three second planet gears 82. Second sun gear 80 is supported on spindle 42 by bearings 84. The outer diameters of first planet gears 74 and second planet gears 82 are meshed with a ring gear 86. Ring gear 86 is machined directly into main housing 48. The inner diameters of the second planet gears 82 are mounted to ball bearings 88. (See FIG. 3.) The inner diameter of ball bearings 88 are mounted to shafts 90. Shafts 90 are attached to a motor output driver ring 92. Motor output driver ring 92 is supported by the inner diameter of bearing 94 as also shown in FIG. 4. The outer diameter of bearing 94 is mounted to a housing end cap 96.

Crank arms are tight. I guess I bring it to my local shop and see if they will contact Optibike if necessary. Any thoughts @Optibike_Austen ?

 

[jrb5j]

Crank arms are tight. I guess I bring it to my local shop and see if they will contact Optibike if necessary. Any thoughts @Optibike_Austen ?

I've seen some videos of regular bikes with seemingly the same problem. The bottom bracket is just loose and can be tightened with a few specialty tools. Seems like that may be my problem, but I just don't know how this Motorized bottom bracket works.

 

[Optibike_Austen]

How much movement side to side does the axle have? I honestly couldn't say what the problem is without taking the motor apart and looking at it. If the side to side movement is minimal and there is no up and down movement, I would say its not a huge issue yet, but keep an eye on it in case anything gets worse.

 

[jrb5j]

How much movement side to side does the axle have? I honestly couldn't say what the problem is without taking the motor apart and looking at it. If the side to side movement is minimal and there is no up and down movement, I would say its not a huge issue yet, but keep an eye on it in case anything gets worse.

Side to side play is very minimal, but as I play with it, I am noticing separate movement/ wobbling if I move the chainrings. I am pretty sure the grinding sound is coming from behind the chainrings. Ugh. How do I go about getting this fixed? I am in Virginia, and the weather is just starting to get good for riding. I'm afraid my bike will be out of commission for a while.

 

[Optibike_Austen]

Side to side play is very minimal, but as I play with it, I am noticing separate movement/ wobbling if I move the chainrings. I am pretty sure the grinding sound is coming from behind the chainrings. Ugh. How do I go about getting this fixed? I am in Virginia, and the weather is just starting to get good for riding. I'm afraid my bike will be out of commission for a while.

If the chain rings are wobbling or rocking back and forth it could be the large spider nut has come loose, to check that you will need to remove the right crank arm which requires a crank arm remover, and a BBT-22 bottom bracket tool for the spider nut, but any bike shop should have those if you don't want to buy the tools yourself. If the nut is tight, its possible that the bearings on the output inside the motor are starting to wear out, it seems unlikely with the amount of miles you put on it but it is a possibility. If that's the case you could replace the parts yourself, but it would probably be best if you sent it in to us as there are some special tools needed to take the motor apart.

 

[jrb5j]

If the chain rings are wobbling or rocking back and forth it could be the large spider nut has come loose, to check that you will need to remove the right crank arm which requires a crank arm remover, and a BBT-22 bottom bracket tool for the spider nut, but any bike shop should have those if you don't want to buy the tools yourself. If the nut is tight, its possible that the bearings on the output inside the motor are starting to wear out, it seems unlikely with the amount of miles you put on it but it is a possibility. If that's the case you could replace the parts yourself, but it would probably be best if you sent it in to us as there are some special tools needed to take the motor apart.

So I bought some tools and took things apart. Spider nut seemed tight and I was getting discouraged. I went ahead and took the nut off and removed the chainrings and that's when I noticed that one of the bolts that holds the smallest chainring on (the ones you can't see with the chainrings in place) was very loose. It had backed out enough to to rub against the motor housing causing my grinding sound! I tightened that bolt ( the other 3 were somewhat loose as well) and put everything back together. Problem solved!

 

[Allroad Commuter]

That happened to me too. So I made sure to use Loctite on the bolts when I re-tightened.