PSA: Don’t Ignore Strange Noises!

[jetpackjbd]

For a while now my eBike has had a loud clacking noise coming from the front wheel in random 1-5 second intervals and I couldn’t figure out what it was. I checked the spokes, brakes, and suspension but nothing seemed abnormal. The spokes were a little loose but adjustment didn’t yield any improvement. So I kept riding for a few months and ignored it.

Yesterday I noticed the noise was a bit more frequent so I pulled over to check everything again. Finally, I look down and:


I’m pretty sure the balls belong inside the bearing… I loosened the nut that was barely finger tight and try to shove it back in place but I couldn’t fix it without tools so I just rode it home another mile. After messing with the bearing I must’ve made it even worse as a new death wobble appeared. Drive Home

I take the wheel apart and find a ball had completely shattered at some point.

I spent a few hours trying to get the nut on the other side off so I could reinstall the seal but it wouldn’t move. Threads are all messed up and I couldn’t retread it all the way. So I reinstalled the seal incorrectly, cleaned up the metal shavings, and put in a spare ball I had. It works now and drives fine but definitely has more friction when you try to roll it by hand. I’ll probably need a new wheel in a few hundred miles.

Learn from my mistake, figure out the problem before it gets worse!

 

[jetpackjbd]

Video didn’t attach properly:

 

[neptronix]

I have a really bad story..

On my Cannondale recumbent ( currently ultra rare and expensive ), i had a chain come off while riding due to a new tensioner experiment, and it destroyed my rear swingarm.. I had headphones on so i didn't hear it.

..and good luck finding a rear swingarm for a 20 year old bike.

 

[jetpackjbd]

I have a really bad story..

On my Cannondale recumbent ( currently ultra rare and expensive ), i had a chain come off while riding due to a new tensioner experiment, and it destroyed my rear swingarm.. I had headphones on so i didn't hear it.

..and good luck finding a rear swingarm for a 20 year old bike.

Could it be welded back together or are other bits destroyed as well? I’d try to repair it seeing as it’s worth well over $1,000. A swing arm isn’t that complex from what I know

 

[neptronix]

The frame itself as a small gashes but nothing serious.

The gashes on the rear swingarm are severe and cut probably 80% of the way through the tube.

Given that on this bike, so much of the rider's weight is sitting rearward, i'd have a hard time trusting a repair of this damage, instead of swapping out the rear triangle.

It's possible that someday i'd be willing to pay an eye watering sum to have someone build a new rear from scratch.

 

[jetpackjbd]

The frame itself as a small gashes but nothing serious.

The gashes on the rear swingarm are severe and cut probably 80% of the way through the tube.

Given that on this bike, so much of the rider's weight is sitting rearward, i'd have a hard time trusting a repair of this damage, instead of swapping out the rear triangle.

It's possible that someday i'd be willing to pay an eye watering sum to have someone build a new rear from scratch.

View attachment 345766

If you had a professional do the welding (or if you’re a skilled welder) I’m sure it would hold up fine. The entire bike is welded together so another one shouldn’t be an issue, although it would probably be a good idea to support it by putting a smaller diameter pipe inside the bike frame. If you want to be really cheap you could buy a metal pipe from your local hardware store, cut a slot in your frame to about the size of the pipe, and create threads to secure the pipe in place.

 

[PaPaSteve]

The frame itself as a small gashes but nothing serious.

The gashes on the rear swingarm are severe and cut probably 80% of the way through the tube.

Given that on this bike, so much of the rider's weight is sitting rearward, i'd have a hard time trusting a repair of this damage, instead of swapping out the rear triangle.

It's possible that someday i'd be willing to pay an eye watering sum to have someone build a new rear from scratch.

My recommendation for a repair like this is a composite wrap.
A wrap can be done to look tidy and purposeful.

Warren Beauchamp at recumbents.com has done some nice write ups on this kind of repair.

Frame Repair

 

[Chalo]

I recently had to recenter and adjust the front linear pull brake on my cargo e-bike three times in about as many days. The third time, I noticed the fender was screwy. Then I noticed the right side fork tip was no longer attached to the fork. I had been riding a single sided hub motor wheel for a little while!

Oh well. Another project-- I could use some more of those in my substantial collection.

On the other hand, it motivated me to cook up yet another custom e-bike for myself. I started from a naked frame a couple days ago, and now it only needs electrics installed.

 

[neptronix]

If you had a professional do the welding (or if you’re a skilled welder) I’m sure it would hold up fine. The entire bike is welded together so another one shouldn’t be an issue, although it would probably be a good idea to support it by putting a smaller diameter pipe inside the bike frame. If you want to be really cheap you could buy a metal pipe from your local hardware store, cut a slot in your frame to about the size of the pipe, and create threads to secure the pipe in place.

I can't seem to find anyone locally who would be comfortable fixing it :/
So many people have told me to not fix it!

The shape of the chain stays are pretty irregular and swoopy. That's a problem for patching on strips of aluminum, or putting tubes inside.

My recommendation for a repair like this is a composite wrap.
A wrap can be done to look tidy and purposeful.
Warren Beauchamp at recumbents.com has done some nice write ups on this kind of repair.

Frame Repair

Interesting but i'd feel dramatically better doing a repair on the front of the bike ( in that example ) where 10% of the weight sits than the swingarm where 80% of the weight is resting on. I also sit further back than most, so i'm even more rear weight biased than usual.

 

[PaPaSteve]

I can't seem to find anyone locally who would be comfortable fixing it :/
So many people have told me to not fix it!

Interesting but i'd feel dramatically better doing a repair on the front of the bike ( in that example ) where 10% of the weight sits than the swingarm where 80% of the weight is resting on. I also sit further back than most, so i'm even more rear weight biased than usual.

Without doing a post heat treatment I would also not recommend a welding repair.
Welding aluminum without post heat treatment softens the parent material making the part weaker.
A wrap only adds strength, how much strength depends on how thick is the wrap.

Warren has chronicled several repairs on his web site.
Also study Calfee repair

 

[neptronix]

I'm told that a post heat treatment can sometimes weaken the welds.
This was the primary reason to not do it stated by a few welders.

Gotta love aluminum..

That's why i think rebuilding a new swingarm to the same dimensions or hopefully finding a replacement swingarm is the best option.

Interesting carbon bike repair site, too bad i have aluminum.. apparently the materials don't do a good job of bonding to each other, so i think that's non-applicable?

 

[PaPaSteve]

Knowing what the original alloy is part of the key.
Most modern bike frames built in volume will likely be 7005 alloy.
Whereas the local weld shop will be stocking 6061 tubes.
The two alloys can weld together but post treatment is very different for each alloy.

Official FAA approved method of bonding composite to aluminum is :
Alodine first then a layer of fiberglass before applying the carbon.
In the case of a aluminum bike frame :
Clean the repair area of the frame down to bare metal with 80 grit sandpaper
Wipe with isopropyl
Then use JB Weld Wrap
Many builders use Orthopedic Casting Tape with excellent results.
Long distance adventure motorcyclist's often carry a roll of Exhaust Weld as it make an excellent frame repair material.
For more resources search DIY Bamboo frame building.

 

[amberwolf]

Learn from my mistake, figure out the problem before it gets worse!

And...listen to your bike (or other mechanical stuff)...unusual sounds or feels are trying to tell you something.

FWIW, I had a similar failure in a rear wheel on CrazyBike2, but the failed bearing bits carved up the cup (part of the hub) as well as gouging all the other bearings. When i replaced the bearings (out of another old wheel), it still felt wrong, and shortly the cup collapsed into the hub and left the axle and cone riding on the remains of the cup...since I had the (powerchair middrive?) motor doing most of the work it took long enough for me to notice the problem (other than the feel of the ride) that it severely heated the entire assembly. By the time I was done I had replaced the whole wheel, axle and all.

Somewhere in the CB2 thread there should be some pictures of the damage, but I don't think theyr'e all still there after the various forum server moves and issues over the years.

Similar failure on a pedal bike long long before that was much easier to notice so I stopped immediately, but back then I had no idea how to work on these things; I think I ended up swapping the whole wheel out with a yardsale find (too long ago for me to remember).


As for the few hundred miles...you might have a lot less than that if the friction is very high--it could heat up enough to damage the bearings or cups or cones (you'll probably smell it--if mine had been the front wheel on CB2 instead of the rear, I'm sure I would have known about the problem long before it got as bad as it did).


Have had plenty of other serious mechanical failures that gave me plenty of warning, if I had paid attention to them instead of ignoring the signs.

 

[neptronix]

Liveforphysics recommended a kind of cast

Official FAA approved method of bonding composite to aluminum is :
Alodine first then a layer of fiberglass before applying the carbon.
In the case of a aluminum bike frame :
Clean the repair area of the frame down to bare metal with 80 grit sandpaper
Wipe with isopropyl
Then use JB Weld Wrap
Many builders use Orthopedic Casting Tape with excellent results.

The frame is supposedly 6061 T6 aluminum, glad to hear it's more common.

I'm surprised at that JB Weld Wrap's strength, if the video is true.

I don't need a ton of extra strength as i've only lost 1/4th of it at most, but i want to know 100% the repair won't be flaky and i'm not in for a surprise at 40mph.

The idea sounds feasible.
Are there any long term reports on bikes fixed/constructed with this and/or orthopedic casting tape?

I'm just wondering how it holds up to years of repeated vibration, 50F temperature variance, natural expansion/contraction of the metal, rain and dry conditions, etc..

 

[jetpackjbd]

And...listen to your bike (or other mechanical stuff)...unusual sounds or feels are trying to tell you something.

FWIW, I had a similar failure in a rear wheel on CrazyBike2, but the failed bearing bits carved up the cup (part of the hub) as well as gouging all the other bearings. When i replaced the bearings (out of another old wheel), it still felt wrong, and shortly the cup collapsed into the hub and left the axle and cone riding on the remains of the cup...since I had the (powerchair middrive?) motor doing most of the work it took long enough for me to notice the problem (other than the feel of the ride) that it severely heated the entire assembly. By the time I was done I had replaced the whole wheel, axle and all.

Somewhere in the CB2 thread there should be some pictures of the damage, but I don't think theyr'e all still there after the various forum server moves and issues over the years.

Similar failure on a pedal bike long long before that was much easier to notice so I stopped immediately, but back then I had no idea how to work on these things; I think I ended up swapping the whole wheel out with a yardsale find (too long ago for me to remember).


As for the few hundred miles...you might have a lot less than that if the friction is very high--it could heat up enough to damage the bearings or cups or cones (you'll probably smell it--if mine had been the front wheel on CB2 instead of the rear, I'm sure I would have known about the problem long before it got as bad as it did).


Have had plenty of other serious mechanical failures that gave me plenty of warning, if I had paid attention to them instead of ignoring the signs.

Jeez, that’s a pretty extreme failure. My bearing races seem fine right now although a bit of paint chipped off (why would they paint friction components?). The spare balls I threw in came from a rusty lawnmower transmission I found in the woods so I’m sure there’s going to be some uneven wear going on. The wheel feels cool after riding and it doesn’t seem to have too much friction so I think I’ll be alright? It’s the front wheel so there’s less load and it’s not the wheel with a motor.

I’m interested in your “powerchair middrive” build, there’s a guy who sells old mobility scooter parts in my town that I’ve considered buying from for electric projects.

 

[jetpackjbd]

K w

Liveforphysics recommended a kind of cast


The frame is supposedly 6061 T6 aluminum, glad to hear it's more common.

I'm surprised at that JB Weld Wrap's strength, if the video is true.

I don't need a ton of extra strength as i've only lost 1/4th of it at most, but i want to know 100% the repair won't be flaky and i'm not in for a surprise at 40mph.

The idea sounds feasible.
Are there any long term reports on bikes fixed/constructed with this and/or orthopedic casting tape?

I'm just wondering how it holds up to years of repeated vibration, 50F temperature variance, natural expansion/contraction of the metal, rain and dry conditions, etc..

I was going to suggest JB weld but figured real welding would be stronger. I’m not very familiar with aluminum welding though. JB weld seems to last but I don’t think it’s nearly as strong as real welds for a “bending stress”
component.

 

[AdR]

I recently had to recenter and adjust the front linear pull brake on my cargo e-bike three times in about as many days. The third time, I noticed the fender was screwy. Then I noticed the right side fork tip was no longer attached to the fork. I had been riding a single sided hub motor wheel for a little while!

Oh well. Another project-- I could use some more of those in my substantial collection.

On the other hand, it motivated me to cook up yet another custom e-bike for myself. I started from a naked frame a couple days ago, and now it only needs electrics installed.

View attachment 345773

@Chalo-where can I get a frame that large. Thanks

 

[neptronix]

That's why we use the wrap instead of regular JB weld.

There's an opportunity to borrow/add strength in that region.

 

[Chalo]

@Chalo-where can I get a frame that large. Thanks

1980 would be a good place to look! eBay might be your best time machine for that.

It's a 68cm or 27" sized frame, if that helps you find one. Usually you must be 6-1/2 feet or taller to stand over one.

 

[amberwolf]

Jeez, that’s a pretty extreme failure.

I specialize in those.

My bearing races seem fine right now although a bit of paint chipped off (why would they paint friction components?).

There's no paint on races. If something flaked off it is probably the hardened material that the bearings ride on, if that's different layer from the main body of the race. If true, that spot will wear faster than the rest and start making a divot, or begin flaking off the rest of the surface around it, or both, and also chip away at the bearings every time they pass the transition edge.

The spare balls I threw in came from a rusty lawnmower transmission I found in the woods so I’m sure there’s going to be some uneven wear going on. The wheel feels cool after riding and it doesn’t seem to have too much friction so I think I’ll be alright?

The wheel won't change temperature from the bearing friction; there's too much coolling between the wheel as a whole and the friction source.

But the races could heat up quite a bit; this will directly transfer to the hub and the axle (the tiny contact points of the balls in the bearing won't transfer all that much heat between them so there can be a temperature difference between axle and hub. QR skewer will probably be about the same temperature as the axle, but this will cool where these meet the fork/frame vs the part inside the hub where there is no direct airflow.

If the hub feels warm at the actual race/bearing area right after you stop riding, there may be significant friction in there. If not, then I wouldn't worry about the heating, just the wear from the damaged surfaces.

It’s the front wheel so there’s less load and it’s not the wheel with a motor.

But being the front wheel, if anything suddenly goes wrong, it's much more likely to leave your face smeared on the road, so I'd worry about it much more than the rear.

I’m interested in your “powerchair middrive” build, there’s a guy who sells old mobility scooter parts in my town that I’ve considered buying from for electric projects.

It's in the CrazyBike2 thread,

2WD Semi-Recumbent Recycled-Parts Cargo eBike: "CrazyBike2"

This is a project that's been in the works since the beginning of this year, based partly on previous projects, partly on web research, but mostly on whatever I happened to have on hand when I started it, and what I acquire as I go along. I already posted a series of pics including how it looks...

endless-sphere.com

for the variations I actually built and tested. They all use brushed motors with built in right angle gearboxes.

Torquey enough to bend the frame, destroy chainrings, wheels, etc., whenever misalignments in the chailine happened. (should be some nice destruction pics there).




The one I haven't built yet uses a brushless powerchair motor that is built into a single-sided-mount hubmotor. I only have one, but if I had a pair I would build a pair of wheels around them to use them on the SB Cruiser trike (or it's future version).

If the guy you know happens to have that kind of motor, and it would be cheap (and cheap to ship), I'd love to get a second one that matches what I have. There's a thread around here for Powerchair BLDC or Brushless motor that discusses that one.

Powerchair Direct Drive Brushless Motor (High-Torque)

A friend dropped by tonight with an interesting motor. It is from a powerchair, and the wheel bolts directly to it. Normally it would run at less than 200RPM, on 24V SLA, for a few MPH on a small-diameter wheel, but the manufacturers have apparently tested it up to 65MPH on the same size...

endless-sphere.com

Also, these particular motors also have available mounts for them that allow for suspension (though most chairs that use them don't have those, some do). So if he also had a pair of these mounts I'd be up for those too if they're cheap. If not, those can be made easily enough based on pictures I've found around the web of the existing types.

(the trike does not have any suspension at present, because rear suspension with axled hubmotors is just too complicated to build into the frame...but a single sided motor like these would make that much easier).

 

[jetpackjbd]

I specialize in those.




There's no paint on races. If something flaked off it is probably the hardened material that the bearings ride on, if that's different layer from the main body of the race. If true, that spot will wear faster than the rest and start making a divot, or begin flaking off the rest of the surface around it, or both, and also chip away at the bearings every time they pass the transition edge.


The wheel won't change temperature from the bearing friction; there's too much coolling between the wheel as a whole and the friction source.

But the races could heat up quite a bit; this will directly transfer to the hub and the axle (the tiny contact points of the balls in the bearing won't transfer all that much heat between them so there can be a temperature difference between axle and hub. QR skewer will probably be about the same temperature as the axle, but this will cool where these meet the fork/frame vs the part inside the hub where there is no direct airflow.

If the hub feels warm at the actual race/bearing area right after you stop riding, there may be significant friction in there. If not, then I wouldn't worry about the heating, just the wear from the damaged surfaces.


But being the front wheel, if anything suddenly goes wrong, it's much more likely to leave your face smeared on the road, so I'd worry about it much more than the rear.




It's in the CrazyBike2 thread,

2WD Semi-Recumbent Recycled-Parts Cargo eBike: "CrazyBike2"

This is a project that's been in the works since the beginning of this year, based partly on previous projects, partly on web research, but mostly on whatever I happened to have on hand when I started it, and what I acquire as I go along. I already posted a series of pics including how it looks...

endless-sphere.com

for the variations I actually built and tested. They all use brushed motors with built in right angle gearboxes.
View attachment 345808View attachment 345809View attachment 345810 View attachment 345812
Torquey enough to bend the frame, destroy chainrings, wheels, etc., whenever misalignments in the chailine happened. (should be some nice destruction pics there).
View attachment 345811



The one I haven't built yet uses a brushless powerchair motor that is built into a single-sided-mount hubmotor. I only have one, but if I had a pair I would build a pair of wheels around them to use them on the SB Cruiser trike (or it's future version).

If the guy you know happens to have that kind of motor, and it would be cheap (and cheap to ship), I'd love to get a second one that matches what I have. There's a thread around here for Powerchair BLDC or Brushless motor that discusses that one.

Powerchair Direct Drive Brushless Motor (High-Torque)

A friend dropped by tonight with an interesting motor. It is from a powerchair, and the wheel bolts directly to it. Normally it would run at less than 200RPM, on 24V SLA, for a few MPH on a small-diameter wheel, but the manufacturers have apparently tested it up to 65MPH on the same size...

endless-sphere.com

View attachment 345813

Also, these particular motors also have available mounts for them that allow for suspension (though most chairs that use them don't have those, some do). So if he also had a pair of these mounts I'd be up for those too if they're cheap. If not, those can be made easily enough based on pictures I've found around the web of the existing types.
View attachment 345815
(the trike does not have any suspension at present, because rear suspension with axled hubmotors is just too complicated to build into the frame...but a single sided motor like these would make that much easier).

Maybe it’s not paint then, it was just very black and I didn’t think hardened metal could look that way on its own. That CrazyBike is beautiful, that’s the kind of stuff I’d make if I had a welder

 

[classicalgas]

I can't seem to find anyone locally who would be comfortable fixing it :/
So many people have told me to not fix it!

The shape of the chain stays are pretty irregular and swoopy. That's a problem for patching on strips of aluminum, or putting tubes inside.



Interesting but i'd feel dramatically better doing a repair on the front of the bike ( in that example ) where 10% of the weight sits than the swingarm where 80% of the weight is resting on. I also sit further back than most, so i'm even more rear weight biased than usual.

Speaking from the point of view of a career TIG welder ( fifty years at this point ) the people telling you not to attempt a weld repair on that part are giving you good advice

Considering the unknown alloy, the depth of the damage, the area involved, and fact that you probably can't heat treat it post weld...all mean that failure later is almost assured.

I can't speak from personal experience about the carbon wrap option ( I'd b e concerned about stress risers at the ends of the wrap unless it was done very well, and de-bonding under flex ) but that solution seems much less likely to fail catastrophically than a weld repair there.

 

[amberwolf]

Maybe it’s not paint then, it was just very black and I didn’t think hardened metal could look that way on its own.

Depends on what they did to do the hardening, the alloy involved, etc. Also whether it was heated / discolored by the original problem.

They could have anodized the surface with a color, or plated, etc.

Paint, though...I just don't imagine any paint that would be useful inside a bearing.

That CrazyBike is beautiful, that’s the kind of stuff I’d make if I had a welder

You could bolt something like it together. It's initial build was done without welding. Not sure there's pics in that htread about it, but they might still be up on the old Electricle blogspot pages.

Dogman Dan built Bouncing Betty without welding, AFAICR;

Dogmans Full Suspension Longtail Frankenbike.

Just a concept for the moment, but more to come when I get time to build it. Starts with two steel framed bikes. One an old USPD currie frame. Cool for it's Electric logos, and geometry that is built for a 1-1/8 headset suspension fork. So that gets you front suspension, and I have semi...

endless-sphere.com

Or there's this that I didn't finish, started as bolt-together though

Amberwolf's Bolt-Together Semi-Recumbent Cargo Bike

The idea is not yet complete, but I was inspired to at least start physically putting stuff together after many weeks of trying to figure out what to do, when I knocked over a bunch of stuff in the back room trying to get the dogs out of there (they were playing around and not helping much...)...

endless-sphere.com

 

[neptronix]

Speaking from the point of view of a career TIG welder ( fifty years at this point ) the people telling you not to attempt a weld repair on that part are giving you good advice

Considering the unknown alloy, the depth of the damage, the area involved, and fact that you probably can't heat treat it post weld...all mean that failure later is almost assured.

I can't speak from personal experience about the carbon wrap option ( I'd b e concerned about stress risers at the ends of the wrap unless it was done very well, and de-bonding under flex ) but that solution seems much less likely to fail catastrophically than a weld repair there.

Thanks for your input; now your username makes a lot of sense