Leaperkim Lynx 2700wh: 151V, 20" tire, suspension, 89lb

[techyiam]

7 minutes ago, Skampster said:

The problem here is this, who correct with their torque values, you or him? This is the problem ……………

It gets worse.

Apparently, someone posted a small plastic bag of motor bolts from Leaper Kim with a label instructing 18 NM.

That tightening torque was for Grade 12.9 bolts going into steel, not aluminum alloy.

[fbhb]

2 hours ago, techyiam said:

That tightening torque was for Grade 12.9 bolts going into steel, not aluminum alloy

Worse still, it's not aluminium alloy it's "Cast Chineseium"

[WheelGoodTime]

I acknowledge that there is the presence of frame flex on Lynxes and quite possibly other LK wheels. The question we ought to be asking is, is this causing real-world problems? Very few people in the world are abusing their EUCs to the point of the frame flexing causing real-world problems. There might be a few racers out there who are doing this, but if light scuffs on the motor cover is the only "problem" to show for it, then I don't see the problem here. I'm not going to say that frame flex is "good" - but it doesn't seem to be causing any actual problems to any owners, so I personally see it as a minor issue, if an issue at all.

[Rawnei]

9 hours ago, Skampster said:

The problem here is this, who correct with their torque values, you or him? This is the problem ……………

edit, I don’t know why the video isn’t inserted  

 

https://youtu.be/KAp_q05uBWs?si=cKTXBJzF1NjFiTqA 
 

 

 

LeaperKim labels the bags containing replacement/spare screws they send out to customers with torque values, that is where I got my values from, i.e. from LeaperKim directly.

The motor screws I double checked on mine from factory they torqued them to 15 instead of 18 (the bag was labeled with 18Nm) so I adjusted my value to 15 to match what the factory was using.

In his video he says he talked to his friend and used some chart for reference.

Do with this information as you like.

9 hours ago, techyiam said:

It gets worse.

Apparently, someone posted a small plastic bag of motor bolts from Leaper Kim with a label instructing 18 NM.

That tightening torque was for Grade 12.9 bolts going into steel, not aluminum alloy.

That someone was me, that was screws sent to me (and others) directly by LeaperKim.

And guys me and my friends have been using these torque values on re-assembly many times on Sherman S, Patton and Lynx, these are the values people on Telegram use and have been reference values a long time since the Sherman S came out.

Edited August 3 by Rawnei

[Duster]

22 hours ago, daniel1234 said:

There are two sources I noticed during disassembly.  

- My shock seals are probably wearing off, some play is coming from there. 

- Clamp what hold shock doesn't fit perfectly. You can tighten it but it doesn't hold as well anymore.  I think I bent it via hammering while constantly pushing the wheel up/downstairs.

When I took one side down - it was noticeable that the wheel was loose on the suspension leg, in more than one direction (yes it should rotate one axis since it missing other leg but, but mine has play even elsewhere). 

These are some valuable details. Thanks for your thoughtful response.

So, here's my main point: everything wears down, which is why we call it "maintenance." Your problem seems fixable, and might not be an inherent problem with the wheel, but rather the consequences of hard riding.

You've noted play in the bushings and in the suspension clamps (which is metal under tension), both of which are common wear points for all vehicles (bicycles, motorcycles, cars, etc.). Every video I watch about proper upkeep of off-road vehicles, or any vehicle that goes through intense g-forces, say that you should re-tighten every screw after each intense session, as intense sessions knock things loose way faster than calm, casual use. The videos also note that intense use wears down materials faster, so reinforced materials are suggested for certain weak points. And even then some parts need to be replaced. One crazy example is that the wheels of the fastest production cars like the Bugattis and the Koenigseggs need to be replaced after EVERY top speed run, as they are designed to not fall apart under all the stress of going hundreds of miles per hour, but their rigidity becomes unreliable after one run.

Taking this all into consideration (with the caveat that I don't fully know your use of your Lynx), it only makes sense to me that your Lynx is experiencing this accelerated wear. This is not me trying to normalize quick wear of parts, but from the sounds of it, your wheel experiences more intense forces than my Sherman S, which after 1500 miles (2400+km) has no significant play or motor wear.  I have replaced the seals/bushings on both suspension struts, which feels acceptable considering this is a common wear point that shock oil companies target by saying "our oil prolongs the life of your seals!" The clamps are still quite tight. However, since mine was a second batch wheel, I received the milled(?) aluminum outer clamp to replace the original cast clamp. This suggests that Leaperkim knows the improved reliability of making the outer clamp milled, but they do not yet feel the need to upgrade the wheel-mounted clamp, as they must have determined it sufficient for common, non-extreme use. The teardown post on the Sherman L thread mentions a third-party milled part for the motor-mounted clamp, I think. They even suggested that the upgrade provides better fitment and thus less play than the cast piece it replaces. This is where one could upgrade to a somewhat 'reinforced' part, considering the milled part will be stronger than the aluminum. This statement might motivate a "why do we have to spend even more money to make our wheels work off-road when we spent so much on them?" question, which I get and kinda agree with. However, plenty of vehicles are sold with parts that are only sufficient for normal-intensity use. If Leaperkim is following this, then that may explain why I can't recall any Lynx or Sherman L marketing videos showing as intense riding as they did with the Patton (save for the videos of going up stairs). Maybe they are trying not to market super-intense use, which would be smart, considering the cast motor mounts.

From what it seems, those having issues with looseness need to replace the seals on their suspension struts, and replace their motor clamps, possibly upgrading to milled third-party options.

And if the complaint is how this system is "terribly unreliable," then we need only look at complaints about the Begode Falcon's suspension not holding up to light trail riding, or the complaints about linkage suspension either breaking too soon (think WrongWay and the King Song S22) or the air leaking from the shock. Every solution to suspension has its flaws. Every part is a consumable and needs replacing. Every wheel needs maintenance of different mechanisms at different time intervals. Every rider will have a varied experience based on their weight, their local riding conditions, and their riding style. Therefore, there should be a reasonable solution for each rider, even if each solution doesn't feel fair because it isn't the exact same.

[daniel1234]

Maybe this is better way how to monitor it in time, if anybody has same issue.
I have aprox 1,5 mm flex to each side after tightening all and glueing it up with loctite -> 

I would be surprised if others have less than 1 mm. It really depend on force you use. Until you hit the battery case edge with the tyre it is ridable. Of course if I go easy it is not visible and not noticeable.  Especially since it is not in same axis wheel spins.

I see problem when you crash or hit rim from side on curb. 

I would be happy if they sell reinforced shock clamps for "people like me who abuse theirs wheel" ... at worst case I can still sell it and get something else next year.

Edited August 3 by daniel1234

[Duster]

1 hour ago, daniel1234 said:

Maybe this is better way how to monitor it in time, if anybody has same issue.
I have aprox 1,5 mm flex to each side after tightening all and glueing it up with loctite -> 

I would be surprised if others have less than 1 mm. It really depend on force you use. Until you hit the battery case edge with the tyre it is ridable. Of course if I go easy it is not visible and not noticeable.  Especially since it is not in same axis wheel spins.

I see problem when you crash or hit rim from side on curb. 

I would be happy if they sell reinforced shock clamps for "people like me who abuse theirs wheel" ... at worst case I can still sell it and get something else next year.

So, rewind a little bit. From the way you described your Lynx and fretted about play and wear, one would be led to think that your wheel is just as worn as Brian Dilliard's, from Dawn's video. However, if the wheel pictured in this embedded video is yours, you have nowhere near as much play as Brian's wheel, and you don't even have the scoring along the side of the motor casing. Your wheel has no signs of current or future failure... It's not even something a company would honor a warranty claim for if they covered issues with tolerances. No offense, but I think the focus on your wheel's play is a little perfectionistic. I'm no expert at reading the tool you used, but 1.5mm sounds like very little play (Brian's wheel was on a factor of cm, not mm), and people who have had play as little as yours have had no stability issues, at low and high speeds, so if anything your situation is being overblown or any problems you suggest are present are qualitatively different in some unique, unrelated way (which could be hard to diagnose without comparing your Lynx directly to someone else's Lynx). I mean, in many mechanical scenarios, 1.5mm is negligible. And like I've said, think about how much your tire deflects from side to side, giving way to the resistance of the street and your momentum changes. Why would a tolerance that minimal mean so much when a tire makes so much more difference?

I made mention that I saw the Sherman L teardown from our Russian(?) members suggest that there are third-party, milled motor clamps and mounts that improve tolerances. Now, I don't know how available they are in different regions, but if 1.5mm of play and a lack of motor-to-body contact really upsets you that much, then investing in those aftermarket upgrades may make you somewhat happier. But to be so fixated on one subjective and tiny aspect of your wheel that you'd want to sell it is wild, but it's completely your right. Just don't be surprised when people disagree with your choice and reasoning, as it is our right too.

[Standard4130]

I know these have been posted before but I thought I’d bring it back up…. Maybe these would remove some play & add rigidity.

[Rawnei]

10 minutes ago, Standard4130 said:

I know these have been posted before but I thought I’d bring it back up…. Maybe these would remove some play & add rigidity.

Waste of money if you don't have a problem IMO.

[Duster]

2 hours ago, Standard4130 said:

I know these have been posted before but I thought I’d bring it back up…. Maybe these would remove some play & add rigidity.

Yes, these! Thanks for posting a photo! Judging by the "B/D" are these by Beidou?

Also, for anyone wondering why these are just the motor mounts, Leaperkim ready upgraded the outer clamp to CNC aluminum.

2 hours ago, Rawnei said:

Waste of money if you don't have a problem IMO.

I'm currently in no need of them. Should my wheel someday have play as a result of heavy wear, then I might buy these for longevity, but I have no need for them so who knows. I remember when I had hobby-level RC cars, though, and upgrading to anodized aluminum parts made me feel so confident. I figure if it makes riders feel more confident in their wheels, they can enjoy the ride better. That's money well spent in my book!

[onkeldanuel]

One Guy ftom German tg group had exactly this amount of flex and i asked for the source of it and he disassembled and his Motorscrews (Suspension Base) were loose and bent , so as expectet 

[Skampster]

There are many a mountain for moles to enjoy. 

[Anthraksi]

16 hours ago, Rawnei said:

And guys me and my friends have been using these torque values on re-assembly many times on Sherman S, Patton and Lynx, these are the values people on Telegram use and have been reference values a long time since the Sherman S came out.

Was about to ask if these torque spec's can be used as is on the Sherman S, but apparently they can? They use pretty much the same parts anyway but I thought I'd verify before saving these and using them in the future when I have to take the suspension brackets off for the first time during a tire change.

[Gabe_]

21 hours ago, WheelGoodTime said:

I acknowledge that there is the presence of frame flex on Lynxes and quite possibly other LK wheels. The question we ought to be asking is, is this causing real-world problems? Very few people in the world are abusing their EUCs to the point of the frame flexing causing real-world problems. There might be a few racers out there who are doing this, but if light scuffs on the motor cover is the only "problem" to show for it, then I don't see the problem here. I'm not going to say that frame flex is "good" - but it doesn't seem to be causing any actual problems to any owners, so I personally see it as a minor issue, if an issue at all.

As far as I'm concerned, the answer is a solid no.

[Rawnei]

7 hours ago, Anthraksi said:

Was about to ask if these torque spec's can be used as is on the Sherman S, but apparently they can? They use pretty much the same parts anyway but I thought I'd verify before saving these and using them in the future when I have to take the suspension brackets off for the first time during a tire change.

They originate from the Sherman S, that's what they sent out replacement parts for early batches (new clamps, pedals, trolley, screws in bags marked with torque values), then the parts are pretty much the same across the wheels with minor improvements, for example on the Sherman L (if you look closely at the ecodrift teardown) you can see that they added nuts to the clamps instead, most likely in an effort to minimize the risk of de-threading them. Some of the design changes on the Lynx they even backported to the Sherman S, for instance if you order a replacement motor today the axle will have a slot for the bracket so optimally you would also need new brackets and new mudguard holders + mudguard (although you can mount your old  brackets if you want also), source: My friend got a replacement motor for his Sherman S recently and it was an updated one same design as Lynx.

[Rawnei]

Fresh prime example, two very experienced senior community members not using a torque wrench during re-assembly, hate to call you out @Marty Backe but this is why screws come loose for riders! If you like that tire you should probably torque those clamp screws and the battery case screws or you will risk them coming loose.

Unfortunately people will mimic this and other similar tire change videos and do the same mistake not torquing the bolts and run into problems later, yet I'm being bashed on for suggesting that this is why some riders experience loose parts.

Edited August 4 by Rawnei

[Marty Backe]

10 hours ago, Rawnei said:

Fresh prime example, two very experienced senior community members not using a torque wrench during re-assembly, hate to call you out @Marty Backe but this is why screws come loose for riders! If you like that tire you should probably torque those clamp screws and the battery case screws or you will risk them coming loose.

Unfortunately people will mimic this and other similar tire change videos and do the same mistake not torquing the bolts and run into problems later, yet I'm being bashed on for suggesting that this is why some riders experience loose parts.

I can tell by the amount of energy you spend commenting about our crappy techniques that you have a lot passion for this subject. I commend you.

In my little place on the planet, how we work on our EUC's gets the job done and we have fun riding our EUC's and most importantly they aren't falling apart. Screws that might loosen are easily tightened.

[Rawnei]

1 minute ago, Marty Backe said:

I can tell by the amount of energy you spend commenting about our crappy techniques that you have a lot passion for this subject. I commend you.

In my little place on the planet, how we work on our EUC's gets the job done and we have fun riding our EUC's and most importantly they aren't falling apart. Screws that might loosen are easily tightened.

Well there is context in this thread if you read it, there was a discussion regarding some riders feeling looseness and flex in their LeaperKim wheels some claiming that it's a design flaw.

[Marty Backe]

50 minutes ago, Rawnei said:

Well there is context in this thread if you read it, there was a discussion regarding some riders feeling looseness and flex in their LeaperKim wheels some claiming that it's a design flaw.

Well, locals have commented on the Lynx flex, on their Brand New Wheels. So if it's due to improper screw torque than maybe Leaperkim isn't following their own instructions ?

The L seems stiffer - maybe because of the larger battery packs?

[Rawnei]

7 minutes ago, Marty Backe said:

Well, locals have commented on the Lynx flex, on their Brand New Wheels. So if it's due to improper screw torque than maybe Leaperkim isn't following their own instructions ?

The L seems stiffer - maybe because of the larger battery packs?

I see a lot of people doing tire change the first thing they do when they receive their wheel and usually people who swapped tires are complaining from what I see, no local riders over here have any flex in their wheels (maybe around 15 LeaperKim suspension wheels locally).

[techyiam]

49 minutes ago, Marty Backe said:

Well, locals have commented on the Lynx flex, on their Brand New Wheels.

Interesting, if the Lynx flex is widespread when new with no work done to it.

[Anthraksi]

Well then, it seems that there is no common consensus on the issue.

Don't really think arguing about it is going to make any difference. If someone has flex on their wheel, they should tear it down and follow the torque specs on the bolts and see if it persists. If it doesn't there is no issue, it is either user error due to not torquing the bolts enough if you have tore down the wheel or then it came under torqued from the factory if you havent taken it apart. If the problem persists after making sure they are properly torqued to spec, then there is an issue. But it still raises the question of why it only affects some wheels and not all of them.

[The Brahan Seer]

Even if this issue is due to torque specs no other wheel has experienced this 'problem' regardless of how the wheel was put together. So it is important to be aware of this shortfall of the wheels design. You could argue that other wheels may experience this but no one has highlighted it as an issue before. Its up to you if that is important or not or makes a difference to your ride. But is still worth noting.

[Marty Backe]

4 minutes ago, The Brahan Seer said:

Even if this issue is due to torque specs no other wheel has experienced this 'problem' regardless of how the wheel was put together. So it is important to be aware of this shortfall of the wheels design. You could argue that other wheels may experience this but no one has highlighted it as an issue before. Its up to you if that is important or not or makes a difference to your ride. But is still worth noting.

I think plenty of suspension EUC's have flex but there's enough space between the tire and the "shell" that the flex isn't an issue. Apparently the Lynx tolerances are tighter.

What flex exists is not an issue for the vast majority of riders. I've seen how some riders (who have complained about flex) ride and their carving is extreme, and I can see where they would have a problem.

[Rawnei]

44 minutes ago, The Brahan Seer said:

Even if this issue is due to torque specs no other wheel has experienced this 'problem' regardless of how the wheel was put together. So it is important to be aware of this shortfall of the wheels design. You could argue that other wheels may experience this but no one has highlighted it as an issue before. Its up to you if that is important or not or makes a difference to your ride. But is still worth noting.

That is not true at all, plenty of Begode wheels have the motor bolts becoming loose.