LightningRods mid drive kit

[r3volved]

It really sounds like there are a lo of users out there who have a misunderstanding that the upper adjustment (jackshaft) is to tension the belt and the chain...the upper adjuster is for BELT tension only!
The lower adjusters are for adjusting the chain.

If you're only using the upper adjustment and trying to tighten both chain and belt with it, then nothing will ever be squared and there will always be alignment problems...

 

[eTrailster]

It really sounds like there are a lo of users out there who have a misunderstanding that the upper adjustment (jackshaft) is to tension the belt and the chain...the upper adjuster is for BELT tension only!
The lower adjusters are for adjusting the chain.

If you're only using the upper adjustment and trying to tighten both chain and belt with it, then nothing will ever be squared and there will always be alignment problems...

So, to tighten your chain, you loosen your bottom assembly and motor push bolts? Not me. Usually a 1/2 tern of the chain-side bolt will tighten or loosen the chain without any issues whatsoever and with no effect upon the belt. When your chain was new and stretching, you must have done that 30 times. No wonder why they won't remain tight. I simply worked the chain side bolt on the upper tensioner until I ran out of ability to tighten it. Then I reworked the lower assembly adjustment to realign the jackshaft. Now, I have been slowly tightening it again and it finally seems to have stopped stretching. Now, I'm going to rework the lowers and realign the jackshaft. Hopefully for only the second, but also the last time.

I may be doing something wrong, but I haven't had any problems as a result.

 

[r3volved]

Every time you adjust one side of the jack shaft, you have to adjust the other side as well or you're JS becomes crooked and out of square with the kit

 

[eTrailster]

Ok, not sure if it has been too compressed. But on the full quality video, you can clearly see that the offset axis is causing the chain tension issues.

http://vid1248.photobucket.com/albums/hh484/Robbie260z/20150902_171437_zpsttngc0rl.mp4

I just checked my bike and I have the same issue. My wobble actually seems much worse than yours. Now, I would like to try to figure this out as well.

 

[Archer]

Anyone have a good way of locking out their upper adjusters (jack shaft)? I've got over 1000km so far and over the last few days (~60Km) I've noticed my adjustment nuts have been coming loose...should I be locktighting with removable?

I tried doubling up the nuts but they both seemed to vibrate loose. Any ideas?

r3,

A few E-Bike riders here on ES have had great results using Nord Lock Washers.This after numerous failures with loosening nuts.Just an FYI.

Happy Happy!

Tim.

 

[Ozziebike]

Ok, not sure if it has been too compressed. But on the full quality video, you can clearly see that the offset axis is causing the chain tension issues.

http://vid1248.photobucket.com/albums/hh484/Robbie260z/20150902_171437_zpsttngc0rl.mp4

I just checked my bike and I have the same issue. My wobble actually seems much worse than yours. Now, I would like to try to figure this out as well.

Question is, is this causing you chain to tighten and loosen at different points in the rotation? The chain noise that I get when riding is horrendous! (because I have to accommodate for the taught part of the rotation).

Hey someone mentioned that the chain will stretch in a bit when new! How many times on average would one need to retighten things before the chain settles in?

 

[eTrailster]

Ok, not sure if it has been too compressed. But on the full quality video, you can clearly see that the offset axis is causing the chain tension issues.

http://vid1248.photobucket.com/albums/hh484/Robbie260z/20150902_171437_zpsttngc0rl.mp4

I just checked my bike and I have the same issue. My wobble actually seems much worse than yours. Now, I would like to try to figure this out as well.

Question is, is this causing you chain to tighten and loosen at different points in the rotation? The chain noise that I get when riding is horrendous! (because I have to accommodate for the taught part of the rotation).

Hey someone mentioned that the chain will stretch in a bit when new! How many times on average would one need to retighten things before the chain settles in?

It seems the wobble is in the cranks, like mike suggested. There isn't much that can be done about it. It's only there when I peddle, not when motor powered. Therefore, I'm not going to worry about it. I think you may have something else going on as well. I don't have any chain noise, even with my jackshaft out of parallel. The system seems to be able to accommodate a reasonable amount of misalignment. Are you keeping your chain well dry-lubed? Big noise reduction with a little chain wax .

As for chain stretch. Mine stretched enough that I ran out of adjustment room and had to remove a link. Now, I am getting to the point that I may have to do it again, but it seemed to have stopped stretching. This is common and well documented by others. It takes many adjustments to get to 2 chainlink length.

I'm beating the shat out of my bike and motor. Everything is holding up extremely well. I'm surprised. I don't know if anyone has killed a SB motor yet, but I'm on a mission. It doesn't even get moderately warm.

 

[r3volved]

Anyone using any other controllers with this kit besides the lyen?

 

[r3volved]

I'd put money on the wobble being caused by the freewheel in the chainwheel setup. Both of my BMXs have a slight wobble in their free wheels...it's not as noticeable but scaled up to the size of your crank it would scale up the wobble. My chainwheel has a very slight wobble but it's very very slight and not causing any tension problems.

It seems to be the way they're seated to the bearings....
If I peddle forward giving the wheel motion, there's no wobble. If I peddle reverse freewheeling, there's no wobble. If I peddle forward and then stop my peddles and let the wheels momentum freewheel, it wobbles.

Both BMXs do that. I haven't tried the chainwheel.

 

[LightningRods]

I think we're on the right track. It's the freewheel and/or the pedal cranks. I'm not convinced that the lateral (side to side) wobble is doing much to affect chain tension. It's possible that the users with chain tension fluctuations have some axial (offset, like a camshaft lobe) wobble as well. This is usually caused by the 219 driven sprocket not being attached to the adapter plate properly. Look at the sprocket from both end and side views. I'm pretty sure that the issue causing lateral wobble is not the same as the one causing axial wobble.

I have an order of 20 of the new tensioners in at the laser cutter along with a bunch of other new stuff. It will fit any standard length lower bracket (non stretch) small block. The standard length big block will also work once I work out the side to side spacing. There is less room for the tensioner because of the width of the motor. The stretch brackets will require a completely new mount because of the different angle on the chain line. I do plan to offer tensioners for the stretch lower brackets. If anything they need the tensioner more than the standard mid drive.

I'm also considering developing a typical spring loaded arm tensioner for my mid drive. Rather than getting entrenched on one side of a manual-is-better-than-spring-loaded-tensioner debate I'll offer both. It will be a solid, quality piece and not the kind of flimsy crap that comes with the Chinese mid drives. No red plastic sprockets with springs requiring a piece of added inner tube immediately.

There will be a bit of a crunch getting retrofit tensioners out to customers who already have mid drives, but I'll ramp up the production as soon as I know how many are wanted. I should be able to make a new batch every two weeks.

What do you think? Do you want the spring loaded tensioner available as well?

 

[r3volved]

I am the type who prefers the spring tension. Any slack is picked up that way even if there is some imbalance in there. I did like the spring tension of the chain on my gng1.1 after I replaced that stupid plastic cog.

 

[LightningRods]

Yeah, I think I'm headed towards offering both types of tensioners.

Regarding the discussion about using the upper tensioner to adjust the secondary chain, no that is not my intention. The left side bolt of the upper tensioner tensions the primary drive. The right side bolt is not a tensioner for the secondary chain but a tracking adjuster. If your primary belt is walking off of the end of the large driven pulley you need to lower the jackshaft on the right side. The nut under the upper adjuster plate pushes against the plate and forces the jackshaft down. If your primary belt is grinding against the flange on the large pulley you need to raise the jackshaft on the right side. The jackshaft should be level with an equal amount of adjuster bolt showing on the top on both sides.

The secondary chain should be adjusted after the primary belt is adjusted.

 

[Ozziebike]

Hey, crazy suggestion... but why not create a tensioner with a spring that can be locked out? So you are only making one unit, but people can choose what they want with a few turns of a screw...

 

[Ozziebike]

Hey guys, just a quick side point, I have switched to a single front gear (2 is SOOOO superfluous) but now I am getting the odd chain drop (even with my clutched rear derailleur). This unfortunately lead me to munch my chain. So, new chain on order, but what do you think is the best way to deal with stopping chain dropping.. I am looking into single speed front chainring, but they are quite pricey especially when you get up near 44T (and I cerainly don't want to go slower, I barely use 1st and second gear as is!).

 

[spinningmagnets]

A chainguide will solve the chain-dropping issue. Even downhillers with no electric motor have had this problem. When you hit a lot of bumps, The chain bounces around.

 

[r3volved]

I used my old front dereilleur as a chain guide for a long time with success. I use a spring loaded rear tensioner at in place of a rear dereleur and it's worked will so far...only one chain drop so far (two weeks ago actually...recent) and it only jumped to my smaller chainring. It was a strange lame drop off a curb that caused it...I've had a couple feet of air off jumps though with no prob.
Right now I do not use a front dérailleur or a chain guide.

 

[John Bozi]

Hey guys, just a quick side point, I have switched to a single front gear (2 is SOOOO superfluous) but now I am getting the odd chain drop (even with my clutched rear derailleur). This unfortunately lead me to munch my chain. So, new chain on order, but what do you think is the best way to deal with stopping chain dropping.. I am looking into single speed front chainring, but they are quite pricey especially when you get up near 44T (and I cerainly don't want to go slower, I barely use 1st and second gear as is!).

Would something like this work with the LR or your BB area?

More pics in the link: http://forums.mtbr.com/singlespeed/yess-products-etr-b-tensioner-product-review-408510.html

It's spring loaded.

 

[Ozziebike]

I don't know if i need a tensioner as I have a clutched rear derailleur, i just need something to prevent it moving from side to side as I've had drops in both directions... I'm just not sure what will fin into the limited area that the LR kit provides...

 

[John Bozi]

if there are no stock guides that will fit with the LR then there must be homemade custom ones. In a minute of google found some cheap ideas:

http://singletrackworld.com/forum/topic/1x9-chain-guide-device

http://putz-v.blogspot.com.au/2014/03/business-up-front-party-in-back-here-is.html

a thin piece of alu with a tube clamp should do it. Or maybe a couple of discs if possible to fit in with the bolts on the chainring?

 

[LightningRods]

I could put a tab for a chain guide or chain guides on my lower bracket. I'd be happy to do it if people can give me some kind of clear direction on what they want. The only real downside I see is that it's one more protrusion to cause conflicts on some of the bikes out here. Is this mostly an off road issue?

 

[John Bozi]

I was planning to use the 3 holes I have for some sort of guide since I will only be using my bike for off road rough stuff.

If the kit goes over one or all of them, possibly drill holes into it. Correct me if I am wrong but I dont think 1 or even 3 holes in this position will compromise the strength of the kit.

OFF topic: This pic however shows that I don't have a good point for the torque brace. I believe the shaft will be below the top pivot bolt which is I believe not in the right spot....

On topic: I doubt stock dh tensioners would fit between two chain rings but believe that a custom solution shouldn't be that hard.

I was more wondering if something a bit like a widgit might be possible with the bicycle drive train chainring.

This is my carbon hard tail which I put the widgit on years before the narrow wide race face chainrings came out. I never had a chain drop on any thing.

 

[LightningRods]

I've been thinking about something like this:

It would have a guide plate on either side (inside and outside) of the chain as well as upper and lower idler sprockets. It should be pretty impossible for the chain to come off. I was originally playing around with this as a way to move the pivot point of the chainline back next to the swingarm pivot point.

 

[John Bozi]

Could we still choose the size of chainring we want to run?

 

[LightningRods]

If it's slotted to be adjustable for different sizes of chain rings it will be less secure, but sure we can make it adjustable.

 

[John Bozi]

The bottom is cool.

First thing comes to mind still is there should be a straight line from the top of the chainring to the top of the rear sprocket. Here there is massive stress added to yet another part.

I played around with my mc tensioner for ages, all over the swing arm on the bottom of the chain and the top of the chain. It is possibly to to have that extra dip in the top of the chain where the main power is transefered as long as it is spring loaded. It probably wastes a small bit of power but the funny thing I discovered was that there was no nasty first engagement CLACK on the palls as the tension on the chain got pulled in gradually.

I think the top one will get messy for a kit meant for a variety of frames.

Although this is the opposite, where the angle in the chain is pushed up instead of down, it gives an idea of adding stress to parts (in this picture the sag of rider will get a straight line.

LMX

EDIT

Pardon my photoshop skills please.

The chain at top should only touch the guide and the bottom would be much better if it could both be adjusted and tension it with a spring = chainwrap increase.