Popular Post Ben Kim Posted November 18, 2020 Popular Post Share Posted November 18, 2020 Hi, starting this thread to discuss permanent fixes to the premature bearing failures. Would like to know why they fail, if it’s common, and what can be done to fix this issue. Is it rain related? Figure this is pertinent to RS, EX and Monster Pro. 8 Quote Link to comment Share on other sites More sharing options...
bryon01 Posted November 18, 2020 Share Posted November 18, 2020 How many have failed? I saw one post on here of a failed from the factory bearing. Looked like the seal had come off and dirt got in. In general the larger size means they are much stronger than smaller bearings, but countered by the fact that they are being sourced in China as cheap as possible. A European bearing of that size would be a couple hundred Euro. I'm sure these are $30 max. 1 Quote Link to comment Share on other sites More sharing options...
EMA Posted November 18, 2020 Share Posted November 18, 2020 (edited) 25 minutes ago, bryon01 said: How many have failed? i think only a few has gone bad, and i think more on v11 than RS RS episode: https://www.facebook.com/groups/GotWay/permalink/3616752958383000 Edited November 18, 2020 by EMA 1 Quote Link to comment Share on other sites More sharing options...
Popular Post Asphalt Posted November 18, 2020 Popular Post Share Posted November 18, 2020 (edited) Hollow bore/centreless/hubless motors will always wear out faster than traditional axle motors, given the same bearing material for the following reasons: Being further away from the centre, each ball bearing has to travel further and faster for every rotation of the wheel More ball bearings are required as you increase the bearing distance from the the centre of the wheel. Increasing the number of required ball bearings increases the likelihood of one of them failing. With the bearing being located closer to the tire, there is a greater likelihood of water and debris entering the bearings - don't go through puddles deeper than your tire [EDIT - this should have said "don't go through puddles deeper than your bearing"] Let's calculate how far a ball bearing in the EX has to travel each wheel rotation assuming a bearing diameter of 180 mm (halfway between the 160 mm inner diameter and 200 mm outer diameter): C=2πr C=2*3.1415*0.090 m C=0.5655m Now how far a ball bearing in the MSP has to travel each wheel rotation assuming a diameter of 57.2mm (halfway between the 17 mm inner diameter and 40 mm outer diameter): Edit: Apparently I can't do math. (17mm + 40mm)/2 = 28.5mm not 57.2mm! C=2πr C=2*3.1415*0.0286 m (2*3.1415*0.01425 m) C=0.1797m (0.0895m) The EX is spec'd with a wheel diameter of 508 mm: C=2πr C=2*3.1415*0.254m C=1.5959m The MSP is spec'd with a wheel diameter of 482 mm: C=2πr C=2*3.1415*0.241m C=1.514m The EX is spec'd with a no load speed of 86 km/h: rpm = speed / C rpm = (1433 m/min) / 1.5959 m rpm = 898 The MSP is spec'd with a no load speed of 80 km/h: rpm = speed / C rpm = (1333 m/min) / 1.514 m rpm = 880 Each ball bearing in the EX will be moving at: 898 rpm * 0.5655m 507.9 m/min 8.465 m/s = 30.5 km/h = 18.9 mph Each ball bearing in the MSP will be moving at: 880 rpm * 0.1797m (880 rpm * 0.0895m) 158.1 m/min (78.8 m/min) 2.636 m/s = 9.5 km/h = 5.9 mph (1.313 m/s = 4.7 km/h = 2.9 mph) So the ball bearings in the EX have to move more than 3 times the speed and distance (6.5 times) compared to ball bearings in the MSP. The MSP uses the 6203-2RS bearing with 8 balls:https://www.nationalprecision.com/ball-bearings/6000-series/6200_light/detail/6203-2RS/ The EX uses the 6832-2RS bearing with 9 balls (this can't be right - need someone to open up EX bearings):https://www.bearingscanada.com/6832-Bearing-Deep-Groove-6832-Ball-Bearings-p/6832-deep-groove-6832-ball.htm Possible Fixes: Improve bearing quality - bearing quality can vary widely. The ABEC rating system for machine parts doesn't necessarily mean it's a good fit for EUCs. Check out this article by Bones Bearings, a company revered in the skateboarding world.https://bonesbearings.com/support/abec/#:~:text=The ABEC rating system includes,at 20 to 30%2C000 RPM. Improve bearing material - ceramic bearings, used in racing bikes, are faster, lighter and more durable. They are also more expensive and more prone to debris contamination due to lighter seals.https://www.cyclingweekly.com/news/latest-news/do-you-need-ceramic-bearings-in-your-wheels-197145#:~:text=They are more corrosion-resistant,less friction is a bonus. Double the rows - The 6832-2RS bearing used on the EX is a single-row bearing, meaning that there is one row of ball bearings around the circumference of the bearing. A double-row bearing would distribute the load across more bearings and be able to bear radial and axial loads in both directions. The drawback is that they need better alignment than single-row bearings. You're also doubling the chance of a single ball bearing failure. EX specs: MSP specs:http://www.begode.com/productinfo/406993.html Edited November 23, 2020 by Asphalt Correct statement about going through water deeper than tire. Fixed calculation for MSP because I originally used the incorrect bearing diameter. 16 Quote Link to comment Share on other sites More sharing options...
Popular Post Asphalt Posted November 18, 2020 Popular Post Share Posted November 18, 2020 On the EX the circumference of the bearing is 566 mm. On the MSP the circumference of the bearing is 180 mm. So the EX bearing has ~3 times the area in which debris can enter and is ~70 mm closer to the ground. The 6832-2RS bearing that the EX is using, already has two rubber seals - one on each side of the bearing. Perhaps an improvement could be made to the seals, like on these triple sealed waterproof, dustproof bearings: https://www.nsk.com/common/data/ctrgPdf/e1234a.pdf Overall, there's no quick, cheap solution to this issue. The manufacturers are going to have to pay for higher-quality bearings, the cost of which they'll happily pass onto consumers. 4 Quote Link to comment Share on other sites More sharing options...
Ben Kim Posted November 19, 2020 Author Share Posted November 19, 2020 (edited) 14 hours ago, Asphalt said: Hollow bore/centreless/hubless motors will always wear out faster than traditional axle motors, given the same bearing material for the following reasons: Being further away from the centre, each ball bearing has to travel further and faster for every rotation of the wheel More ball bearings are required as you increase the bearing distance from the the centre of the wheel. Increasing the number of required ball bearings increases the likelihood of one of them failing. With the bearing being located closer to the tire, there is a greater likelihood of water and debris entering the bearings - don't go through puddles deeper than your tire [EDIT - this should have said "don't go through puddles deeper than your bearing"] Let's calculate how far a ball bearing in the EX has to travel each wheel rotation assuming a bearing diameter of 180 mm (halfway between the 160 mm inner diameter and 200 mm outer diameter): C=2πr C=2*3.1415*0.090 m C=0.5655m Now how far a ball bearing in the MSP has to travel each wheel rotation assuming a diameter of 57.2mm (halfway between the 17 mm inner diameter and 40 mm outer diameter): C=2πr C=2*3.1415*0.0286 m C=0.1797m The EX is spec'd with a wheel diameter of 508 mm: C=2πr C=2*3.1415*0.254m C=1.5959m The MSP is spec'd with a wheel diameter of 482 mm: C=2πr C=2*3.1415*0.241m C=1.514m The EX is spec'd with a no load speed of 86 km/h: rpm = speed / C rpm = (1433 m/min) / 1.5959 m rpm = 898 The MSP is spec'd with a no load speed of 80 km/h: rpm = speed / C rpm = (1333 m/min) / 1.514 m rpm = 880 Each ball bearing in the EX will be moving at: 898 rpm * 0.5655m 507.9 m/min 8.465 m/s = 30.5 km/h = 18.9 mph Each ball bearing in the MSP will be moving at: 880 rpm * 0.1797m 158.1 m/min 2.636 m/s = 9.5 km/h = 5.9 mph So the ball bearings in the EX have to move more than 3 times the speed and distance compared to ball bearings in the MSP. The MSP uses the 6203-2RS bearing with 8 balls:https://www.nationalprecision.com/ball-bearings/6000-series/6200_light/detail/6203-2RS/ The EX uses the 6832-2RS bearing with 9 balls:https://www.bearingscanada.com/6832-Bearing-Deep-Groove-6832-Ball-Bearings-p/6832-deep-groove-6832-ball.htm Possible Fixes: Improve bearing quality - bearing quality can vary widely. The ABEC rating system for machine parts doesn't necessarily mean it's a good fit for EUCs. Check out this article by Bones Bearings, a company revered in the skateboarding world.https://bonesbearings.com/support/abec/#:~:text=The ABEC rating system includes,at 20 to 30%2C000 RPM. Improve bearing material - ceramic bearings, used in racing bikes, are faster, lighter and more durable. They are also more expensive and more prone to debris contamination due to lighter seals.https://www.cyclingweekly.com/news/latest-news/do-you-need-ceramic-bearings-in-your-wheels-197145#:~:text=They are more corrosion-resistant,less friction is a bonus. Double the rows - The 6832-2RS bearing used on the EX is a single-row bearing, meaning that there is one row of ball bearings around the circumference of the bearing. A double-row bearing would distribute the load across more bearings and be able to bear radial and axial loads in both directions. The drawback is that they need better alignment than single-row bearings. You're also doubling the chance of a single ball bearing failure. EX specs: MSP specs:http://www.begode.com/productinfo/406993.html Great post! Here is my next question then, assuming no factory defects, on average, how long do these bearings last before they need a replacement in other applications? 10000 miles? Less? Given a broken axle on the old style EUC motors means you are basically getting a new motor, One would surmise replacing the bearings would be a cheaper (and easier) undertaking than replacing a whole motor. Also some links/discussion relating to suitable bearing replacements for these motors would also be greatly appreciated! Your feedback is invaluable! Edited November 19, 2020 by Ben Kim 2 Quote Link to comment Share on other sites More sharing options...
Popular Post xiiijojjo Posted November 19, 2020 Popular Post Share Posted November 19, 2020 (edited) Repair video Edited November 19, 2020 by xiiijojjo 5 Quote Link to comment Share on other sites More sharing options...
..... Posted November 19, 2020 Share Posted November 19, 2020 (edited) 11 minutes ago, xiiijojjo said: Repair video Nice vid! I dont even own an RS, but had to watch. I am SHOCKED that they put the circuit boards on the bottom and he has puddles in there. WTF were they thinking? I'd be drilling me some tiny drain holes! Edited November 19, 2020 by ShanesPlanet 2 Quote Link to comment Share on other sites More sharing options...
Popular Post BFE Duke Posted November 20, 2020 Popular Post Share Posted November 20, 2020 A 61824 bearing is rated for like 6000 lbf of load and 130 mph continuously lol. It's specced more for size/fitment and well beyond the needs of the device, and a decent bearing should last well beyond the life of any EUC. Can anyone with a failed bearing take a pick and pop off one of the side seals and see how much grease is inside? I'm curious if they were just too lazy to pack enough grease in there from the get-go. 4 Quote Link to comment Share on other sites More sharing options...
brockj Posted November 21, 2020 Share Posted November 21, 2020 (edited) Edit: lol oops @xiiijojjo posted the same one. ---------- This looks like a pretty good video that walks through the bearing replacement process from a couple of guys in the Seattle crew. (Btw lots of good offroading vids on this channel too.) Edited November 21, 2020 by brockj 2 Quote Link to comment Share on other sites More sharing options...
Simply_Striking Posted November 23, 2020 Share Posted November 23, 2020 On 11/19/2020 at 2:43 AM, ShanesPlanet said: Nice vid! I dont even own an RS, but had to watch. I am SHOCKED that they put the circuit boards on the bottom and he has puddles in there. WTF were they thinking? I'd be drilling me some tiny drain holes! Same, I put my trust in the weather man this weekend and went out for a 30 mile ride. Got rained on, not heavy, but def more than a drizzle. When I got home I put and air mover aimed at it for 30 min. When I opened it there was small puddles inside. There is a appears to be a vent on the case as well that may allow water in. 1 Quote Link to comment Share on other sites More sharing options...
RagingGrandpa Posted November 23, 2020 Share Posted November 23, 2020 16 minutes ago, Kingsong Russia said: RS after 4 days of snow in Moscow 2 Quote Link to comment Share on other sites More sharing options...
Asphalt Posted November 24, 2020 Share Posted November 24, 2020 Thanks for posting the teardown of the bearings. It's crazy the conditions of those bearings AFTER the EcoDrift waterproofing service - standard Begode bearings stand no chance. From this picture we can see that there are 24 ball/cylinder bearings (or groups of double-bearings, it's hard to see through all that grease). No wonder these bearings are so expensive! It also looks like the bearings were already sealed (or at least shielded): I'm not sure there's much that can be done to remedy the situation. I'm hoping that there's a bearing manufacturer out there who've found a robust way to seal them, but it's going to be a challenge with high speed moving parts and pressure fluctuations due to motor thermals, as mentioned by EcoDrift. If possible, it will be an expensive solution. While I love the idea of hollow bore motors, I think there's a reason they're not more common. 2 Quote Link to comment Share on other sites More sharing options...
bryon01 Posted November 24, 2020 Share Posted November 24, 2020 11 hours ago, Asphalt said: Thanks for posting the teardown of the bearings. It's crazy the conditions of those bearings AFTER the EcoDrift waterproofing service - standard Begode bearings stand no chance. From this picture we can see that there are 24 ball/cylinder bearings (or groups of double-bearings, it's hard to see through all that grease). No wonder these bearings are so expensive! Deep groove ball. 2 Quote Link to comment Share on other sites More sharing options...
null Posted November 24, 2020 Share Posted November 24, 2020 (edited) Could switching to ceramic bearings help with the issue? There is still the long gap to be sealed but at least it shouldn't rust.. Edited November 24, 2020 by null Quote Link to comment Share on other sites More sharing options...
RagingGrandpa Posted November 24, 2020 Share Posted November 24, 2020 34 minutes ago, null said: Could switching to ceramic bearings help with the issue? Bearings are designed to run with clean lubricant, or run clean and dry (special ceramic applications). But here, they can't stay clean. And ceramic is a bit of a false choice here: it would be relevant if a commercial ceramic product were offered in this bearing size at an affordable price... today, there isn't. Quote Link to comment Share on other sites More sharing options...
Flying W Posted December 8, 2020 Share Posted December 8, 2020 Any failure in dry conditions yet? Quote Link to comment Share on other sites More sharing options...
Waulnut Posted December 9, 2020 Share Posted December 9, 2020 4 hours ago, Flying W said: Any failure in dry conditions yet? ~400 miles here in dry SoCal. Mostly pavement, minor offroading. No issues. Quote Link to comment Share on other sites More sharing options...
Flying W Posted December 9, 2020 Share Posted December 9, 2020 6 hours ago, Waulnut said: ~400 miles here in dry SoCal. Mostly pavement, minor offroading. No issues. That makes me feel better, I'm in so cal too. Mission viejo area. Quote Link to comment Share on other sites More sharing options...
tumbla.jr Posted December 28, 2020 Share Posted December 28, 2020 Brand new wheel after 240 miles... Zero rain riding. 2 Quote Link to comment Share on other sites More sharing options...
Flying W Posted December 28, 2020 Share Posted December 28, 2020 @tumbla.jr where did you buy the wheel and is your seller going to make it right? Quote Link to comment Share on other sites More sharing options...
tumbla.jr Posted December 28, 2020 Share Posted December 28, 2020 1 minute ago, Flying W said: @tumbla.jr where did you buy the wheel and is your seller going to make it right? I purchased it from AliExpress. Specially Green Fashion. From what I was told the design of the bearings is now different and is less susceptible to moisture. I’ll compare the new/old ones whenever they show up. 2 Quote Link to comment Share on other sites More sharing options...
Planemo Posted December 28, 2020 Share Posted December 28, 2020 12 hours ago, tumbla.jr said: Brand new wheel after 240 miles... Zero rain riding. I'm staggered that there can be rust in bearings that have never seen water, and even more surprised given there is grease present. What do these manufacturers do? Soak them in salt water before assembling the wheel? 1 Quote Link to comment Share on other sites More sharing options...
Tawpie Posted December 28, 2020 Share Posted December 28, 2020 (edited) Condensation happens. Could have easily happened in transit, or it could have been exposed to salt fog on the boat—nasty nasty nasty stuff that salt fog. Edited December 28, 2020 by Tawpie 1 Quote Link to comment Share on other sites More sharing options...
Flying W Posted December 28, 2020 Share Posted December 28, 2020 I wonder if the fix for this from gotway is really going to work out well or we should just plan on buying higher quality bearings and replacing them. 1 Quote Link to comment Share on other sites More sharing options...
Recommended Posts
Join the conversation
You can post now and register later. If you have an account, sign in now to post with your account.
Note: Your post will require moderator approval before it will be visible.