Tweak more top speed on LMT'D?

[Bartman28]

View attachment 138724I replaced the front sprocket with a 52t, but the new shimano chain seems a little short in the largest rear cog

I also upgraded the front sprocket on mine, but only went up to a 48T. I think its much better, but I think I read the max is 50. I think you may have the sprocket on the outside of the cranks vs the inside if that makes sense. I did the same on mine and the chain seems to fall off much easier in the lower gears. I need to change this if this is true?

But yea I think your chain is way to short now for that 52T. Why did you choose 52?

52T feels really good. It gives a perfect gear range in my opinion. You are correct- I put the sprocket on the outside instead of the inside for a few reasons. First, there are no 52t size guards available to go on the outside, so it looks bad on the inside. Second, I was worried about the teeth hitting the wiring that is tucked there. Third, on the inside, the smallest cogs would be really out of alignment with the front sprocket. I went with the Shimano CN-HG71 116L chain. I'm considering purchasing a second one and two more links and adding on 4 to 6 more.

 

[Fast n' Furious]

I also upgraded the front sprocket on mine, but only went up to a 48T. I think its much better, but I think I read the max is 50. I think you may have the sprocket on the outside of the cranks vs the inside if that makes sense. I did the same on mine and the chain seems to fall off much easier in the lower gears. I need to change this if this is true?

But yea I think your chain is way to short now for that 52T. Why did you choose 52?

Yes. Definitely mounted incorrectly.
Here's my 46t to 48t conversion. I had doubts a 50t would fit. Perhaps the frame has changed, but a 52t was out for me.
And indeed, the chain-line should be on the center cog, or you'll have problems. Also, it's fine if it works, but of little benefit.
A mid-drive is the only real beneficiary of a larger ring. A rear hub reduces power per it's own rpm - regardless your pedaling speed, or the tooth count on the ring. At 28mph, essentially you're pedaling a xLbs eBike with no power.
GRIN has some good charts of various hub drives using various controllers. An essential study. Look at that plunge in power.
For a Mid Drive through a chain to a wheel, decreasing the final drive gear tooth count and or increasing the ring gear's actually turns the wheel faster with the motor, increasing the real top-end.
That having been said, the 48t ring is perfect for the Lm'td. I get to push myself more and safe city driving is all under 27mph.

It's been summed up that "the rule of thumb for changing total teeth count is add or subtract 1/2 of the tooth difference. For example, going from a 46T to a 50T chainring you should add 4/2=2 half-links. If the difference is an odd number go to the next even number since you can't add 1/2 of a link. The reason for adding only 1/2 of the difference is that the chain only wraps around 1/2 of the chainring or cog."
A 52t would require 3 additional half-links.
Fn'F

 

[Bartman28]

Yes. Definitely mounted incorrectly.
Here's my 46t to 48t conversion. I had doubts a 50t would fit. Perhaps the frame has changed, but a 52t was out for me.
And indeed, the chain-line should be on the center cog, or you'll have problems. Also, it's fine if it works, but of little benefit.
A mid-drive is the only real beneficiary of a larger ring. A rear hub reduces power per it's own rpm - regardless your pedaling speed, or the tooth count on the ring. At 28mph, essentially you're pedaling a xLbs eBike with no power.
GRIN has some good charts of various hub drives using various controllers. An essential study. Look at that plunge in power.
For a Mid Drive through a chain to a wheel, decreasing the final drive gear tooth count and or increasing the ring gear's actually turns the wheel faster with the motor, increasing the real top-end.
That having been said, the 48t ring is perfect for the Lm'td. I get to push myself more and safe city driving is all under 27mph.
View attachment 138726View attachment 138727View attachment 138728
It's been summed up that "the rule of thumb for changing total teeth count is add or subtract 1/2 of the tooth difference. For example, going from a 46T to a 50T chainring you should add 4/2=2 half-links. If the difference is an odd number go to the next even number since you can't add 1/2 of a link. The reason for adding only 1/2 of the difference is that the chain only wraps around 1/2 of the chainring or cog."
A 52t would require 3 additional half-links.
Fn'F

Thank you for the number of links help. Should I go with a 9 speed shimano ebike chain (CN-E6070-9) assuming it's longer, or should I simply add three quick links in a row to my 8 speed shimano chain? I wasn't sure if the 9 speed chains are actually longer, or if each link is a different dimension for an entirely different rear cog?

 

[Fast n' Furious]

Chains last forever on my Lm'td. Aluminum ring wears first, then chain, then steel cogs.
Rear hub drive wear on driveline is no more or less than any bicycle. I would simply add links.
Absent researching to be more precise (and some chains do vary in width), I stick with what works and improve it as needed.
As I remember, a 9sp is narrower chain. Your issue will be the chainline (and the lack of any protector to keep your pants out of that ring/ chain interface). Dropping your chain at all, you're out of whack and will mar your frame.
5mm additional offset is a lot to be small-cog biased, and even if it'll work will cause excessive wear to your cog and chain b'cuz you're two gears past the end of range and two gears shy of the upper range.
Cool you went there though. Very. Nice machine too. I soooo feel you, RE; finding a chain-guard. I had mine custom cut by a BMX Company that is now gone. It's for a 46t. A 50t works for a 52t ring, same clearance as in photos.
Jazzzed to see numerous Lm'td owners posting hands on work and improvements.
We picked the right machine for it. Upgrades are fairly easy and potential is perfect for a high performance, LEGAL Street Bike.
Ride1Up made the <56lb (w/ personal options), 100NM and internal frame battery starting point. Who else does that for under $2k?
Works for me !!!

Fn'F

 

[banshee28]

I'd missed this post. I've evolved my point of view a bit. Still think this MXUS will handle 25amps.
'Wiring issues', yes. The controller is 24awg (best I recollect). From there on it's all 28awg. I had problems with the incoming wires and their JST connectors where a real issue. I installed a Wuxing twist throttle. It ran well, but I had some intermittent issues w/ TS. That had to be the display wires or connector. So I replaced the 26awg with 22awg w/ factory installed JST's. They use them for LED lighting.
I changed the display 5 wire and the throttle 3 wire out for 22awg.
Big difference. No stutters. No off/on gremlin stuff. Power increased - most certainly with the throttle. I decreased the resistance right up to a couple inches from the display and throttle.
If you doubt this effect, research users of Domino throttles on big power bikes. I've seen it noted several times.
Set at 20amps will keep you from thermal overload better. I set controller for max and let the motor do the regulating. But - here's a can of worms - these machines synthesize 'thermal overload' data by extrapolating from other data. At least according to MXUS who told me they can either have TS or thermal overload sensing, not both. I hate to pass on bad info. That's how I read it.
The resistance issue is uber-common. Most Julets and JST's are 26/ 28awg. Increasing resistance 16fold can't be good.
A solder joint done correctly increases resistance in the milliohm range.
The Lm'td pulls more than 1000watts. I get +900 on throttle. The firmware provides up to 60% power on throttle.
How powerful am I ?
I'm selling my Lm'td and all the upgrades at a discount off my legacy costs. Just the Archer wireless shifting is now around $500.
It stays with bike for $200. All the same to me. I get better return parting it out. LOL. But less satisfaction than seeing someone else owning this correctly upgraded, completely reliable bike.
Interested parties should PM me for a parts list.
Love that bike, but I can only have one and I've expanded my horizon to a mid-drive WattWagons titanium CrossTour.
Hey, the Juiced is a nice machine, a bit heavier than a tricked out 56lb Lm'td.
Again, sorry for late response.

Fn'F

Thanks for the update! Interesting to hear your latest moves. Yea I just bought my LMT'D and so far pretty happy with it, esp. for the cost. Will keep tinkering with it, but pretty set now with the 48T up front. Prob wont mess with controller as I would prob be better off looking into another bike at that point. I don't recall much over 1000 watts but its still like new so will monitor it more as I move along.

 

[Fast n' Furious]

Thanks for the update! Interesting to hear your latest moves. Yea I just bought my LMT'D and so far pretty happy with it, esp. for the cost. Will keep tinkering with it, but pretty set now with the 48T up front. Prob wont mess with controller as I would prob be better off looking into another bike at that point. I don't recall much over 1000 watts but its still like new so will monitor it more as I move along.

Agreed. Our controller is great for this motor. 20 x 22amps rating seems accurate to me. Don't touch it unless needed. It's 24awg, just fine.
The JST plugs and wires pull out of (and stuff back in) the bottom of frame's battery compartment.
There's no issue with the controller, and the 'added resistance (from reduced wire gauge)' is actually no better, but usually even worse with the newer, more in style Julet (Bafang) connectors than the Lm'td's stock JST's.
Just to be accurate, there are higher (awg) quality Julet cables - if you can find them (please if anyone does, post it). My WattWagons uses them.
-
By decreasing resistance - as close as reasonable to the throttle (chop, stagger cuts; set shrink-fit/ solder 3 wires; shrink segments then - after testing - outer layer SF) - and plugging directly into the controller with higher gauge wire and grade JST, throttle performance increases markedly.
The 'wattage input range' spectrum and top speed both increased. Response became 'spicier' - best I can put it.
Throttle felt better able to communicate a command - than when previously shunted by an '18" of resistance wire x 2 bottleneck'.
Dare I say it? Just using throttle, even the motor had a somewhat different sound. More of a hum than the previous cackle.
-
Solder, shrink fit and $5 worth of LED wire, or (better) get fancy and use 2.3mm VW crimp-on Spade Connectors and shrink fit - to me, solder is just second nature. My connections add 10milliohms resistance, in toto. Stock adds several ohms in resistance for each grade of wire less than the source - both going from and coming to the throttle.
Replacing those wires actually reduces the stock wires resistance to 0.00000035 of it's previous values LOSS.
That's thirty-five millionths that couldn't be freed up, but that should be available isn't an increase from 'normal'.
The stock wiring is 4 magnitudes less in conductivity/ higher in resistance. In real world performance, when that bottleneck's removed it adds to performance.

 

[Bartman28]

Okay, ordering another Shimano cn-hg71 chain so I can take 3 links off it and add it to my existing hg71 chain. Also ordering the Shimano connecting pins. Quick question: I read some shimano chains can't be taken apart because the pins don't come out. Is that the case with this hg71 one?

 

[Fast n' Furious]

Easier to buy new chain, shorten to the length you need, then add the quick-link. Stock chain lasts forever absent dirt/ mud riding.
If your chain-line is correct, rear hub is no more wear and tear than a bicycle's.
The stock chain accommodates my 48t well, no link needed.
Build it your way. If it fails, do it better. Sure beats just accepting the mundane.
Naturally your Bikes will be awesome and better than knowing what does work, you'll know what doesn't.

 

[Bartman28]

Easier to buy new chain, shorten to the length you need, then add the quick-link. Stock chain lasts forever absent dirt/ mud riding.
If your chain-line is correct, rear hub is no more wear and tear than a bicycle's.
The stock chain accommodates my 48t well, no link needed.
Build it your way. If it fails, do it better. Sure beats just accepting the mundane.
Naturally your Bikes will be awesome and better than knowing what does work, you'll know what doesn't.

The problem is the stock chain is 116 links and I need 119. I thought it might make the chain a little rough if I add 3 quick links in a row. I was thinking the better way to do it might be to buy 2 chains and take three off the second one and add it to the first one?

 

[Bartman28]

How many speed is your bike? 8?
You can get something like this and cut it down to either 120 or 118 links.

KMC E8 EPT E-Bike chain | Bikeinn

Buy KMC E8 EPT E-Bike , Chains from Bike parts for only 21.99 $. Find bike deals in Bikeinn | Fast delivery

www.tradeinn.com

120 links sounds perfect. I kind of like the idea of having the Shimano hyperglide chain since it's a hybridglide cassette in the back. Yes, 8 speed and 52t front. Maybe it's my imagination, but it feels smoother to me than the stock chain did. Since I already bought one shimano chain, can I just buy another and remove four links from it and add them to the one I have?

 

[Fast n' Furious]

The chainring will have no factor on the accuracy of the speed. A workaround to get assist faster than 28 mph would be to change the wheel size or speed sensor setting in the display settings so that it reads a lower mph on the LCD than the actual speed, so the bike doesn't know it hits 28 mph and should continue to assist beyond that. I have a Ride1Up with the same display as the LMTD and tested to confirm that it affects that speed reading significantly, although I haven't tried to use assist at a higher speed as a result. I set mine back.

Thanks for the update! Interesting to hear your latest moves. Yea I just bought my LMT'D and so far pretty happy with it, esp. for the cost. Will keep tinkering with it, but pretty set now with the 48T up front. Prob wont mess with controller as I would prob be better off looking into another bike at that point. I don't recall much over 1000 watts but its still like new so will monitor it more as I move along.

Here's my new child.

Just getting it finished up - if such a place exists.

 

[Bartman28]

Update: I purchased a second shimano chain and lengthened it to 120 links from the factory 116. It now shifts perfectly smooth with the 52 tooth front sprocket and it feels amazing! Have no problem hitting top speed now without ghost pedaling. Super happy with this mod!

 

[Fast n' Furious]

Update: I purchased a second shimano chain and lengthened it to 120 links from the factory 116. It now shifts perfectly smooth with the 52 tooth front sprocket and it feels amazing! Have no problem hitting top speed now without ghost pedaling. Super happy with this mod!

If it works well, you're on to something. My chain lasted 4000miles. I only replaced because of the miles. Not at all worn out I could see.
They're cheap anyway.
Who cares if it eats the small cog if it'll stay in gear and doesn't dump the chain?
The advantage of having a 52t on the Lm'td are huge - for pedaling up to the 28mph'ish limit where the motor starts creating drag !!!!
Intermediate range, cruising at 20 - 25mph is a big winner.
A new cog-set's inexpensive and only a couple out of the ordinary tools you need to change.
But, you were having 'problem hitting top speed ... [with] ghost pedaling' before? Can't understand how you are happier 'without ghost pedaling', but great if that's an improvement !!!