LightningRods mid drive kit

[LightningRods]

You probably do know the English word for bicycle gear changer. We use the French word "derailleur ".

You want the largest possible tooth count front and rear. Maximum spring pressure on the derailleur. Shortest possible chain as you said. As much wrap engaging as many teeth on the rear sprockets as possible.

I've been thinking about a second idler sprocket for the rear gears that could be engaged to hold the chain very tight in the small high speed gears and then disengaged to shift or when in the larger gears. There are three problems in the high gears: (1) The chain is too long for the small diameter sprocket and so makes the derailleur spring weak (2) The leverage on the sprocket is low because of the small sprocket diameter and (3) There are fewer teeth engaged in the chain. It's unfortunate that all of these problems happen at once. With a second idler we could effectively shorten the chain and increase derailleur spring pressure. If we could put the idler in the right place we could also increase the wrap on the sprocket and engage more teeth. A friction shifter could move the second idler in and out of position. Not perfect but better than a skipping chain in high gear.

Edit: I suppose it would actually be a third idler since the derailleur already has two.

 

[Föppel]

ah oke, its called derailleur, thanks

We ordered one of those for testing: http://www.bike-mailorder.de/index.php?cl=details&cnid=387&anid=201405141216JT1&fnc=logout
the distance of the pulley-wheel to the casette should stay the same while shifting (with this derailleur).

It could be a bit better than "standart one", but i think at 2500W you have to be very carefull with the 11T anyway. Like you say, to less tooth engaged for high torque, but still can use it on long flats when high speeds are reached.

where would you do this 3th idler? on the under site of the chain/sprockets, where the other 2 idler are?
Would be nice to have it on top of the chain, pushing downwards, that would give a maximum wrap engaging. Something like this:

http://www.sickbikeparts.com/catalog/images/IMG_0066.jpg

pushing frome both sides... If mounted at the idler-pully-wheel , it would move with your shifting... in theory

 

[LightningRods]

Or you might not even need another idler. Just another cable to apply additional pressure to the existing derailleur arm.

Check out the derailleur on one of your bikes. If you pull the cage plate up as shown by the red arrow in the picture below you can feel how much tighter the chain tension gets. There is normally a limit to how tight the chain tension can be or a derailleur won't shift. If there were an additional cable to apply more tension when you are in the gear you want and don't want to shift, it might prevent the chain from riding up over the sprocket teeth and skipping. The cable could be released when you want to shift gears and then the pressure reapplied after shifting. I think an old friction shifter would be the perfect way to pull that additional cable. Pulling up on the cage plate also causes the derailleur assembly to 'squat' and forces the jockey or upper pulley to wrap the chain around the cassette sprocket.

 

[amberwolf]

FWIW, taking enough links out of the chain can effectively do the same thing, depending on the lowest gear you want to be in.

 

[cheekybloke]

Or you might not even need another idler. Just another cable to apply additional pressure to the existing derailleur arm.

Check out the derailleur on one of your bikes. If you pull the cage plate up as shown by the red arrow in the picture below you can feel how much tighter the chain tension gets. There is normally a limit to how tight the chain tension can be or a derailleur won't shift. If there were an additional cable to apply more tension when you are in the gear you want and don't want to shift, it might prevent the chain from riding up over the sprocket teeth and skipping. The cable could be released when you want to shift gears and then the pressure reapplied after shifting. I think an old friction shifter would be the perfect way to pull that additional cable. Pulling up on the cage plate also causes the derailleur assembly to 'squat' and forces the jockey or upper pulley to wrap the chain around the cassette sprocket.

[/quote

http://www.ebay.co.uk/itm/Bullet-Brothers-Chain-Tensioner-/281404710231?pt=LH_DefaultDomain_0&hash=item4185071d57
one of these may help you Foppel
Darren

 

[Föppel]

i see, my idea with the pully-wheel pushing the chain from the upper side down may not be so clever.
Since motorforce is pulling the upper side of the chain, so the chain is maximum tensioned on this side.

i really like the ideas of giving more tension to the dereilleur-arm via cable/2nd shifter or with the spring-system darren found.

just for saying; this is not a problem of the kit, if you buy a LR-Kit and use it under 2500W, or say 2000W, you may not have this chain-slipping. If there would be other Kits having this brutal-torque, running on 3000W they would face the same "problem". its your Bicycle-Parts what have to be upgraded at this point.

Anyway, i checked the dereilleurs of the Bikes with the high power-setups, all 3 Bikes had the Shimano XT dereilleur... i think thats the problem.
I did some research in DH-Forums and talking to some DH-Riders i know.
Most what i heard was that the SRAM X01 is worth the money, should be the tensioner with the most tensioning-force. Yes its very much money for one part, and you need to use the (expensive) shift-lever that fits the X01 as well... they say you have to use Casette and Chain from the X01 as well, but i dont believe in that... We ordered the 7-speed version with a normal sram 7speed-casette, and normal 7-speed chain.
i will report when tested...

I have a Shimano XT (long arm- version) and a SRAM X9 (short arm, DH-type) here at the moment. the X9 have like double of the force the Shimano XT have.
Im currently building a YT-TUES bike, where i will test the SRAM x9 against the SRAM x01 on the Santacruz V10, both with around 3000W.
But first i have to order the fitting 83mm-lower sheets from Mike
If X9 fails, i will try Darrens spring-method (it seems to be a easy to do upgrade)

Here a Pic of the new Bike:




and look what else arrived

 

[LightningRods]

Darren's fix is a good one. The only disadvantage is that it's always on. It will be interesting to see how your bikes will shift with that mod. I think I'll play with the cable idea, just to see if I can make it work. It seems a lot like the idea of a lock up torque converter on an automatic transmission. My final design may be a cable pulling on a spring.

 

[electron bom]

Hammer geiles rad Foeppel!

 

[brixmitch]

I'm getting set up as an OEM supplier of the Cycle Analyst so that I can provide at least tier one tech support as well as to include them with my mid drive packages.

Interesting! I was just thinking of ordering one. How soon do you think this will happen?

Got my bonus, paid off some bills, ordered batteries, and am about ready to start the build.

 

[LightningRods]

As soon as I send their paperwork back to them. We've already sealed the deal.

 

[--freeride--]

i see, my idea with the pully-wheel pushing the chain from the upper side down may not be so clever.
Since motorforce is pulling the upper side of the chain, so the chain is maximum tensioned on this side.

i really like the ideas of giving more tension to the dereilleur-arm via cable/2nd shifter or with the spring-system darren found.

just for saying; this is not a problem of the kit, if you buy a LR-Kit and use it under 2500W, or say 2000W, you may not have this chain-slipping. If there would be other Kits having this brutal-torque, running on 3000W they would face the same "problem". its your Bicycle-Parts what have to be upgraded at this point.

Anyway, i checked the dereilleurs of the Bikes with the high power-setups, all 3 Bikes had the Shimano XT dereilleur... i think thats the problem.
I did some research in DH-Forums and talking to some DH-Riders i know.
Most what i heard was that the SRAM X01 is worth the money, should be the tensioner with the most tensioning-force. Yes its very much money for one part, and you need to use the (expensive) shift-lever that fits the X01 as well... they say you have to use Casette and Chain from the X01 as well, but i dont believe in that... We ordered the 7-speed version with a normal sram 7speed-casette, and normal 7-speed chain.
i will report when tested...

That is not going to work... the sram 7speed X01 is a 10 or 11speed Cassette, with only 7 gears on. So the spacing is 10 or 11 Speed. Safe the Money and send those parts back.

A normal 7 Speed Cassette does make sense, but you can not run it with the X01 derailleur!

My recommendation is:

10speed Shimano ZEE PLUS short Cage deraileur (damped and strong )40€
7speed SRAM grip shift 8€

That combination works perfekt with an old 7speed Cassette.
New shimano 10speed and old sram is 1:1 Ratio. The newer Sram 10speed/11Speed are 1:1 too, but they canged something, so they are not compatible any more!

If you want to run that much power through the gears, get bigger gears! and a good chainline
Run nothing smaller than 16T/15T in the Back and put a 48T or 50T up front and thats it. Live with the topspeed u have than, should be more that enough...

You can not put 3000W through a bike drivetrain with a 11T in the back... Even on the 250-600W Bosch bikes the chains and gears wear out super fast if you run 11T all the time. I don't want to change gears and chain every time I charge the Battery.
Sorry, but I have to say that:
Running 3000W with small gears is just dumb. Propably running 3000W through the gears at all is...

Best regards from Munich.

 

[LightningRods]

If you want to run that much power through the gears, get bigger gears! and a good chainline
Run nothing smaller than 16T/15T in the Back and put a 48T or 50T up front and thats it. Live with the topspeed u have than, should be more that enough...

I agree that it's best to start with as large a front sprocket as possible. I encourage customers to use a 48T when possible. Unfortunately some bikes have frame or suspension obstacles that prevent fitting a large front chainwheel. Many of the new fat bikes with wide chain stays are limited to 32T on the large chainring!

The hardest part is having good pedaling cadence with good top speed. The two ways to do that are high final drive gearing and large diameter tires. If you have done all you can in those areas and still want more speed you have to make the motor run faster with more voltage or use less reduction from the motor to the BB. Both of these will ruin your pedaling cadence but give you more top speed.

I'm going to play with the extra spring/cable to the derailleur. I've been told before that ideas wouldn't work out and they did.

 

[r3volved]

...Run nothing smaller than 16T/15T in the Back...

My experience is that 16T single speed is the smallest sprocket that I've found won't skip or shear at >=1500W.

The original 11T on my original cassette worked up to about 1000W and then pooched out real quick beyond that.

I tried a 14T single speed as well and it sheared off some teeth from the torque. Current 16T has been going strong for over 1000km (single speed though with BMX chain)

 

[LightningRods]

We may never make an 11T work above 1500W. My experiments will be to see how far we can push the envelope before there's nothing we can do to stop the skipping. If we can use a 13T instead of a 16T that would be worth the trouble.

 

[eTrailster]

Perhaps rear suspension is a problem as well? The rear flexes and the power side of the chain slacks and tightens reducing chain/cog friction and increasing the probability of a jump?

Also, acceleration being an exponential function, the greater your velocity, the more power you need to go faster. Therefore, it's not only the amount of power being put in the system, it's the speed you are traveling when you are applying that power (and aerodynamic drag). We can also consider the mass being accelerated. However, at a certain velocity, it seems wind resistance becomes the more significant variable working against chain/cog friction. We may be able to increase friction to gain additional speed, but again, it will begin to skip. This has nothing to do with the power source, but the fact that the bicycle system is unable to handle the additional power necessary to achieve greater velocity.

To this end, I find it interesting that Föppel is experimenting with the Sram XO. However, I'm disappointed he chose not to try the X-Sync cassette. The X-sync system allows Sram to use a 10T cog on these cassettes. Therefore, it seems reasonable to assume they have achieved greater friction to allow this. Although I don't think anyone has any hope of running 10T, I would think there may be less skipping on 14T than on traditional cassettes? I was considering trying this. However, it is very expensive and I'm not sure how well the Sram PG chains will hold up or if other chains can be used. Instead, I ordered Industry Nine hubs. The drive has like 120 points of engagement and is claimed to be able to handle 700 ft-lbs of torque.

 

[stonezone]

I suck at build logs....



All the alignment seems ok, and i'm finally about to take it for a spin with my toolbox. I won't really be finished until I do what everyone's talking about above and switch to single speed... speaking of, has anyone made any decisions on what's working best, rear sprocket size?

In the long run, I'm thinking about trying to cram 9 batteries in the frame instead of on my back. It's not the weight on my back that bothers me, it's the crash that's bound to happen... how long do i have to get that bomb off me before the lipos become the center of the sun?

This kit is the same one that I had fitted on my Nomad but Mike just sent me the wider bracket...I was a little worried since i'd managed to mangle (force to fit) a lot of the mounting hardware but Mike sent me everything I needed... The only thing I maybe seeing as an issue is slight twist from the drive torque that may slacken the chain, but I'll cross that hurdle when I get there. I cold always tack a bracket onto the frame if it's too much of an issue.. what could possibly go wrong?

All in All: Wicked Kit, great service and tons knowledge. Mike is doing it right, much respect to that guy.

Thanks,

SZ

 

[Archer]

Just watched a couple of videos linked from LR's site.Holy cow this mid-drive is kick ass! If you havnt seen the vids take a look,just awesome.

I have a couple of questions:

1.How well would LR's mid-drive work for street bike use? Any negatives if traveling for long periods at say 30 mph? I would like to get a bike to replace most of my car trips.
2.Just curious really,about how much does the small block kit weigh?

Thanks a bunch.

Tim

 

[LightningRods]

The only thing I maybe seeing as an issue is slight twist from the drive torque that may slacken the chain, but I'll cross that hurdle when I get there. I cold always tack a bracket onto the frame if it's too much of an issue..

Thanks so much for the kind words. I do the best that I can to take care of people.

If you're still having some flex issues due to the monstrous torque of the big block (remember, I fixed the flex issues for the small motor- now we're talking twice as much motor) the round lug on the top of the right upper sheet is for a torque brace. Attach a solid link between that lug and some solid point like the mounting point for the shock and there is just no way the sheets are twisting if your torque brace doesn't bend.

My advice for the rear cog on the single run is the smallest tooth count that will run without skipping. I'd start with a 14T and see how it does. A 14T track cog is going to take more power than a derailleur cog of the same tooth count. If you run a 1.37" freewheel cog, 16T is typically as small as they get.

 

[sascha2770]

The only thing I maybe seeing as an issue is slight twist from the drive torque that may slacken the chain, but I'll cross that hurdle when I get there. I cold always tack a bracket onto the frame if it's too much of an issue..

Thanks so much for the kind words. I do the best that I can to take care of people.

If you're still having some flex issues due to the monstrous torque of the big block (remember, I fixed the flex issues for the small motor- now we're talking twice as much motor) the round lug on the top of the right upper sheet is for a torque brace. Attach a solid link between that lug and some solid point like the mounting point for the shock and there is just no way the sheets are twisting if your torque brace doesn't bend.

My advice for the rear cog on the single run is the smallest tooth count that will run without skipping. I'd start with a 14T and see how it does. A 14T track cog is going to take more power than a derailleur cog of the same tooth count. If you run a 1.37" freewheel cog, 16T is typically as small as they get.

Hey Mike it's alex here who ordered some parts from you like the 12t 219 sprocket.

I wanted to ask if this 12t sprocket was specially designed for you. As you know I live in germany and the shipping takes a lt of time.
Do you know if someone in europe can supply me a 12t 219 with 12mm of inner diameter?

Asking because my sprocket is worn out, maybe it's from too much torque but I think I did a little mistake with the alignment.
Maybe there are sprockets from steel?

Alex

Edit: I'm using 75 phaseamps at 90V, install a torque arm to the driveside and you have one issue less.
(For those with bending problems)

 

[LightningRods]

I did have the 12T drivers made specifically for my mid drive. These sprockets typically have a .750" bore in them. Unfortunately there are very limited sources for #219 driver sprockets. Most of them have proprietary bores for specific types of kart engines.

I have replacement 12T 219 sprockets with 12mm bores and I'm happy to send you one. They're steel.

 

[KONAKID]

I suck at build logs....

View attachment 1

All the alignment seems ok, and i'm finally about to take it for a spin with my toolbox. I won't really be finished until I do what everyone's talking about above and switch to single speed... speaking of, has anyone made any decisions on what's working best, rear sprocket size?

In the long run, I'm thinking about trying to cram 9 batteries in the frame instead of on my back. It's not the weight on my back that bothers me, it's the crash that's bound to happen... how long do i have to get that bomb off me before the lipos become the center of the sun?

This kit is the same one that I had fitted on my Nomad but Mike just sent me the wider bracket...I was a little worried since i'd managed to mangle (force to fit) a lot of the mounting hardware but Mike sent me everything I needed... The only thing I maybe seeing as an issue is slight twist from the drive torque that may slacken the chain, but I'll cross that hurdle when I get there. I cold always tack a bracket onto the frame if it's too much of an issue.. what could possibly go wrong?

All in All: Wicked Kit, great service and tons knowledge. Mike is doing it right, much respect to that guy.

Thanks,

SZ

Hi SZ ..
Great looking build! i TOTALY agree with you about putting a bomb on my back... but like your frame - mine too (kona stinky) has almost no room inside the front triangle so thats why i too am going to build a battery box on my frame...like this:

its like a sadle bag out of sheetmetal - but it requires tools and equipment not everyone has access too.. but you could mke the same thing out of a strong tarp fabric.
in any case if you do go with the batts on your back - i would at least put them in one of these lipo safety pouches:
http://www.hobbyking.com/hobbyking/store/__41872__Super_Strong_Flame_Retardant_Silicone_Fiberglass_Bag_171x60x65mm_1pc_.html
or if you want to save money - or your batts are to big for the pouches - as in my case - get some of these lipo bags - the large size:
http://www.hobbyking.com/hobbyking/store/__4364__Lithium_Polymer_Charge_Pack_25x33cm_JUMBO_Sack.html
there cheaper - and each one can be cut into three and sown together to make three lipo pouches!
that way.. if one batt "blows" it will isolate it from the rest(and from you) long enough to get it off your back!
and tear it out of the pack before they all catch fire!... hopefully..
regards
Tim

 

[scorpionice]

Here's my take on the battery placement problem. Not yet done but the idea is to put 2 6s lipos each pvc downspout.

 

[sascha2770]

I did have the 12T drivers made specifically for my mid drive. These sprockets typically have a .750" bore in them. Unfortunately there are very limited sources for #219 driver sprockets. Most of them have proprietary bores for specific types of kart engines.

I have replacement 12T 219 sprockets with 12mm bores and I'm happy to send you one. They're steel.

I'll order them in some days from you. You don't have bigger ones? Like 13t,14t der 15t?

Greeetings Alex

 

[LightningRods]

You don't have bigger ones? Like 13t,14t der 15t?

I have 12T, 15T and 18T in stock. The 15T and 18T have the standard 3/4" bore and require an adaptor which I can provide. The 15T works well except that your pedaling cadence will be too fast. The 15T seems to give the highest top speed. The 18T is typically geared too high plus it's too large to work with the driver sprocket guard. I stock the 18T for other purposes. Your pedaling cadence will be about 116 rpm with the 15T @ 48V.

 

[KONAKID]

Here's my take on the battery placement problem. Not yet done but the idea is to put 2 6s lipos each pvc downspout.

Hey! Thats a great idea! i thought about using some kind of plastic... but couldnt find the right size...looks like it will be lighter than sheetmetal!?
so this is like plastic PVC downpipes for roof gutters?? will have to look for some..
Tim
P.S. if its PVC... maybe it can be bonded together with PVC pipe Glue? to make it stronger...just a thought..