Hello. I was riding my swyff minimax electric folding bicycle when suddenly the rim of my wheel popped open, resulting in a tear/split rim.
Its the back wheel, which also houses the motor. What are my options here? Im on a tight budget so i'd appreciate some insight and/or feedback.
The wheel itself, other then the gaping split, seems to be in fine order, other then a loose/bent spoke. Inner/outer tire seems fine too. Its a 20×2 wheel which is rated for 5 bar, tire is rated max 4,5, pressure was at 4.
Logically speaking, i'd imagine welding it would be the cheapest option, but im clueless whether thats even possible and safe.
Second best that comes to mind is buying a new wheel and spokes and transfer the working motor over to the new wheel, but i have been informed that that's pretty much impossible to do at worst or too risky/time consuming at best? Is that true?
Third that comes to mind is to toss the entire wheel motor and all and to purchase a new wheel with a new motor, which i simply cant afford right now.
Would appreciate any help/advice, as i use this for commuting.
Thank you
by Nekrosiz
14 Comments
Rim brake wore through the sidewall of the rim. Time to replace.
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Welding it is not an option. Most economical thing is to find an identical replacement rim (not just the 20″ size, but also how deep it is, and number of spokes), and basically transfer it onto the wheel by moving the spokes over one by one, then truing and tensioning the wheel. If you can’t find an identical rim you might need to replace the spokes as well, to be the right length.
It looks like maybe you had some debris in your brake pad that cut a groove into the braking surface until it was basically separated and the air pressure did the rest.
The rim is not repairable, it must be replaced. This is something your local shop can do, and will likely be cheaper than replacing the entire hub motor. I’d still expect it to cost $150-$200 in parts and labour, but that’s just what it takes.
Fwiw 4bar/58psi is still quite high for a 2” wide tire, the tire may be rated above that but the rim likely just couldn’t handle that much pressure. Somewhere around 35-40psi is normal for a 2” tire in a commuter style bike, and will be much less likely to wreck your rim again.
Jesus Christ. I’ve never seen a rim fail like that. Do you have a rim brake ? My only guess would be that the brake race was worn down.
As for your options :
-welding or otherwise repairing your rim : it’s not a thing. Not possible nor nearly economically viable. It’s aluminium alloy which can’t be easily welded (or at all), and it’s heat treated to be as stiff as it is, which would be ruined by the heat. And you’d need to unlace the wheel from the hub anyway.
-buying a replacement rim and lacing it to your hub : it’s the cheaper option by far if you do it yourself. It quite tedious but not in any way undoable. You’ll just need a spoke wrench, lots of patience, lots of time. Ask for help with spoke length, since the requirements length will be different for a different rim model.
You could also get someone to do it for you but I’m not sure it would cost less than a whole new wheelset.
If you can build wheels you can fix it for the price of an equivalent rim – Which means same or close ERD or Effective Rim Diameter. Many will recommend replacing the spokes as well, but I haven’t done that when my wheels wear out. I just tape the new rim to the old rim, move the spokes over, tighten, true, stress-relieve, and true. But yeah you need a new rim and it will take a few hours of labor so $200 is probably the minimum what it will cost you to have done.
I’m a tech at my LBS. I would strongly recommend replacing the rim! Any fix to that rim will be a bandaid fix and potential fail in the future. Any LBS should either have that rim, or be able to order one for you!
Rim brakes on an E-bike is horrifying to me. This isn’t what you want to hear but even if you find an affordable option to fix this issue an e-bike this poorly designed is just going to keep throwing mechanical issues at you and that’s going to keep costing you in the long run.
Too much commuting with rim brakes, i upgraded to disks because of the very same issue. A nice cheap solution to this expensive problem (replacing rims and spokes, doing all the lacing, and the brakepads wear out much faster too which means replacing them also cost more than disc brake pads).
I had this happen to a rim, only option was to replace, second time building a wheel I cheated and placed it next to replacement and moved spokes over one by one, got it trued up, only prob was valve placement was between 2 crossing over spokes and limits what pump I can attach to the valve.
“The wheel itself, other than the gaping split, appears to be in fine order, ther than a bent spoke.”
🤣
Get a new rim rated for E bikes and have it built to the hub.
So I read your description and read through the comments. First thing I will say is you definitely need to just have the rim replaced but on that note touching on the subject of it being worn through in 1000 km how much of the front brake are you using?
I had similar damage, rim brake pad came loose, jammed into the rim while braking and ripped it to shreds within seconds. It was a long walk back to the car in the woods with nothing to keep me company aside from the swarms of mosquitoes following as I ran.
You had me at Electric folding bike. I assume it’s an imported cheaper brand and therefore lower quality.
*The wheel itself, other then the gaping split, seems to be in fine order,*
That wheel is covered in gunk and grime.. It is very likely the gunk formed a grinding paste. Combined with the rim brakes it caused the rim failure.
The best fix is to replace the rim AND spokes. Take it to a bike shop. They will get you a nicer heavy duty rim and lace it to that hub. It will take a while to get it done, whilst they get the part and schedule it in their workshop.
Treat it as a learning opportunity.
Keep the bike cleaner, oil the chain, tyre pressure of 30 to 35 PSI is much more appropriate.