Dave's 80:1 RC mid drive kit build log

Discussions related to motors other than hub motors.
This includes R/C motors, botttom bracket, roller and geared drives.
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Re: Dave's 80:1 RC mid drive kit build log

Post by Sloppy Floyd » Apr 14 2017 4:02pm

Can't wait to get mine! Building up the this steel FS frame for the motor
IMG_20170414_164503020 (1).jpg
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Re: Dave's 80:1 RC mid drive kit build log

Post by m4k3r » Apr 14 2017 4:27pm

Sloppy Floyd wrote:Can't wait to get mine! Building up the this steel FS frame for the motor
IMG_20170414_164503020%20(1).jpg
Looks nice! Is that a Brooks saddle on her? You going full throttle or PAS? You won't be disappointed! I can't wait to get back on mine this weekend. The sad thing is all this rain we had in Southern California has practically ruined all the best trails around my house. To the point were i can't commute to work on it at the moment. The brush/grass is taller than me and bee infestations around every corner, f*ck bees! I'll punch a bee in it's face....
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Re: Dave's 80:1 RC mid drive kit build log

Post by Sloppy Floyd » Apr 14 2017 5:10pm

m4k3r wrote:
Looks nice! Is that a Brooks saddle on her? You going full throttle or PAS? You won't be disappointed! I can't wait to get back on mine this weekend. The sad thing is all this rain we had in Southern California has practically ruined all the best trails around my house. To the point were i can't commute to work on it at the moment. The brush/grass is taller than me and bee infestations around every corner, f*ck bees! I'll punch a bee in it's face....
Thanks! It's a Velo Orange elkskin saddle. Not sure, but I think I'm going PAS (Thun) or both. I can do both right (imma big noob)? I went with 3215 and Phaserunner (that's it just behind the saddle), and plan on running 72v pack from Luna. 24 x 2.8 wheel/tires and Shimano Nexus 3 IGH. I run a Rohloff on my touring bike, and may go with a Rohloff in the long run after I have some time on it.

My commute also includes some single track with 2 creek/stream crossings (hard to believe in the DC Metro area) but this place is surprisingly covered in woods, bike paths and trails.

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Re: Dave's 80:1 RC mid drive kit build log

Post by tangentdave » Apr 14 2017 6:50pm

The 3215 is just a few mm's too long to fit the THUN torque sensing BB without higher offset cranks, like these:

http://sickbikeparts.com/cranks-high-offset/

Only the left side crank needs more offset for the 3215. Square taper interface. The cranks I use in the kit are 170mm long; those in the link are 152mm. We'll have to keep looking to fit the THUN and 3215 together. Of course, you did't buy a 4kW engine only for pedal assist....

You can always add the THUN later when we find the right cranks.


-dave
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Re: Dave's 80:1 RC mid drive kit build log

Post by Sloppy Floyd » Apr 14 2017 7:58pm

tangentdave wrote:...Of course, you did't buy a 4kW engine only for pedal assist...


-dave
Haha, nope! May need to look at getting a Domino throttle from you.

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Re: Dave's 80:1 RC mid drive kit build log

Post by morati » Apr 15 2017 4:33pm

So impressed with this system! I'll be a customer before the end of summer......Just trying to figure out which bike to put it on.

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Re: Dave's 80:1 RC mid drive kit build log

Post by BonesNis » Apr 15 2017 6:00pm

Dave...

I noticed your "store" on your website is locked. Does that mean changes are coming? Thanks.
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Re: Dave's 80:1 RC mid drive kit build log

Post by tangentdave » Apr 15 2017 8:49pm

Store is a strong term for that ugly webpage. Just redoing the page and kits with the PAS, trying to get caught up.
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Re: Dave's 80:1 RC mid drive kit build log

Post by ScooterMan101 » Apr 16 2017 12:05am

Going to design/make a crank/chainring freewheel for the Shimano Hollowtec II Cranks ? ( One design would work with both Mountain and Road Hollowtec II cranksets, by just using different BCD's for each.
Also
Would love to see a crank/chainring freewheel for BB30 Cranks .
BB30 bearings / cranksets are a pound or even more than a pound in weight savings over square taper designs . many bikes these days come with BB30/PF 30 / BB86/BB92 Bottom Bracket Shells.

>

="tangentdave"]I plan to replace that heavy ISIS crankset, the parts needed aren't difficult. Logistically, my plate is full of gearboxes right now but a complete custom kit is the goal.
175b.jpg
The Tangent mounting plates add 3mm to each side of the BB shell, our spindle and bearings need to accomodate this. The crankset also needs enough spindle stickout to accommodate the freewheel.[/quote]
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Re: Dave's 80:1 RC mid drive kit build log

Post by tangentdave » Apr 16 2017 9:41pm

Image

shimano fc-m7000-11

To be convenient, we'd have to get our freewheel or sprag clutch or one-way bearing or overrunning clutch outside the diameter of the spines so we don't add any width. To me, this idea is still simplest: Image

Different spindle lengths for the BB's. This design could also work with the PF frames I think, right? Just make the bearing/cups the right size. Different spiders bolt to the replaceable freewheel with the various chainring BCD's.
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Re: Dave's 80:1 RC mid drive kit build log

Post by ScooterMan101 » Apr 17 2017 1:47am

I just looked up , http://www.biketrialstatiion.com
and
google says " This site can not be reached, server DNS address could not be found "

I see you post a picture of an 11 speed crank from shimano,

I am wanting a clutch/ freewheel for the 3 speed/3 chainring shimano hollowtec II cranks, and FSA too. that way one of the chainrings can be taken off and the custom clutch/freewheel with one gear or two gears on it that can be put in its place. ( using the BCD bolt pattern of that particular crankset. ) ( FSA BB30 Cranksets typically only have 2 chainrings, so in that case perhaps the clutch/freewheel on the outer chainring ?

That leaves the other two chainrings, or one.
with a mid - drive RC motor what I am thinking of is to use the outer larger chainring 50 or 52 or 53 for direct connection to the motor , or the reduction gear , from the motor.
Then the other 1 chainring or two if two chainrings can be connected to the clutch/freewheel,

The industry is moving over to 11 speed because that way they can get rid of the front derailleur, put the lever for the dropper seat post where the front shift lever was, and only use one chainring up front.

But we are wanting gear reduction from the high spinning RC Drone Motors, so we want two chainrings up front, two if possible for even better hill climbing gearing.

And BTW , is there really a need for a gear reduction between the RC Drone Motor and the Front Outer Large 50 or more tooth chainring, since some of those motors spin much lower RPM's than the Astro's that have been used up until now ??
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Re: Dave's 80:1 RC mid drive kit build log

Post by briangv99 » Apr 17 2017 1:59am


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Re: Dave's 80:1 RC mid drive kit build log

Post by ScooterMan101 » Apr 17 2017 2:07am

Hmm, I got to see a RC Mid-Drive connected to that crank to see how it works, it looks to have only one freewheel, and a small at that, that would not give you much reduction at all , it being between a RC motor and the rear cassette .

So

I still see a need for Freewheels made for those of us that want to start using RC motors for Mid-Drives.

Freewheels that work with our existing cranksets. ( unless new crankests that have the spindle OD's that the BB30's have and the Hollowtec II's have. with outer 60 tooth or larger outer freewheel/chainrings connected directly to the newer slower RPM Drone motors, can be made ) . ...( there by eliminating the need for costly gear boxes connected to the RC motors / eliminating the costly gearboxes between the RC Motor and the Crankset ) .

briangv99 wrote:
typo in your URL http://www.biketrialstation.com/crank.html
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Re: Dave's 80:1 RC mid drive kit build log

Post by briangv99 » Apr 17 2017 2:19am

ScooterMan101 wrote:it looks to have only one freewheel, and a small at that, that would not give you much reduction at all
Just imagine that small freewheel with a chainring adapted to each side, motor chain on one side, output drive chain on the other :)

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Re: Dave's 80:1 RC mid drive kit build log

Post by ScooterMan101 » Apr 17 2017 10:25am

Yes that is what I am wanting to be sold, ... a freewheel with a chainring on each side,
with
different spiders for the three major bolt patterns for the three major cranksets, Shimano Hollowtec II cranks ( 130 BCD for road , and 104/62 BCD for their mountain cranksets ) and the 110 BCD for the FSA Cranksets .

So I do not understand why no one has made those parts yet ?

Make the freewheel that bolts up the crankset with the correct size BCD bolt pattern, have bolt holes so we can change chainring sizes.

( with such a freewheel/chainrings with the correct BCD spiders for the 3 most common used Cranks , and the other cranks as well that use the same BCD bolt pattern , so that we can use our better quality cranksets )

briangv99 wrote:
ScooterMan101 wrote:it looks to have only one freewheel, and a small at that, that would not give you much reduction at all
Just imagine that small freewheel with a chainring adapted to each side, motor chain on one side, output drive chain on the other :)
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Re: Dave's 80:1 RC mid drive kit build log

Post by tangentdave » Apr 17 2017 2:33pm

So I do not understand why no one has made those parts yet ?
Me neither. Maybe if you had a drawing showing how the freewheel will bolt to the FSA/Shimano crankset and decouple the rings from the spindle...I don't see it.
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Re: Dave's 80:1 RC mid drive kit build log

Post by ScooterMan101 » Apr 17 2017 3:39pm

Dave , What you do is unbolt one , or two of the chainrings from the crank ( Hollowtec II and BB30 and any Press Fit Crankset is 2 piece , meaning the spindle is connected to the right crank arm )
So
You unbolt the one or two chainrings right where they bolt onto the crank arm/spindle in the case of the Shimano Tiagra 3 speed FC-4603 crankset it has a BCD of 130 for the outer 2 chainrings, and a BCD of 92 for bolting on the inner / smallest chainring.

You just have made a thin freewheel that has a ... spider on side that bolts to either 130 mm or 92 mm then holes on either side of the freewheel , to bolt up a standard chainring made from the same company ( Shimano in this case )

http://bike-advisor.com/reviews/shimano ... -2012.html

http://www.shimanocycling.co.nz/media/t ... 746319.pdf

I use the Shimano Tiagra Crankset here because , it has a 50 tooth outerchainring, which can be changed to 52 tooth or 53 tooth . ( Can be done with any crankset, just get the right tooth size with the right BCD for that Crankset )
Road cranksets with their bigger chainring's are better for faster speeds.
Also
Less Reduction Drive needed when using a chain from RC motor to outter chainring on a road crankset. ( be sure to design around the newer slower speed / higher torque RC Drone Motors )
Attachments
IMG_1615.JPG
Shimano Tiagra FC-4603
IMG_1615.JPG (87.78 KiB) Viewed 1946 times
IMG_1616.JPG
Shimano Tiagra FC-46703 BCD Bolts and Crank Arm
IMG_1616.JPG (67.89 KiB) Viewed 1946 times
Last edited by ScooterMan101 on Apr 17 2017 3:52pm, edited 1 time in total.
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Re: Dave's 80:1 RC mid drive kit build log

Post by ScooterMan101 » Apr 17 2017 3:41pm

FSA BB30 2 speed Crankset.

What you do here is the same, make a thin freewheel, that has a spider that bolts to the 110mm BCD .
Attachments
IMG_1612.JPG
FSA BB30 with 110mm BCD
IMG_1612.JPG (86.47 KiB) Viewed 1946 times
IMG_1611.JPG
FSA BB 30 with 110mm BCD
IMG_1611.JPG (74.04 KiB) Viewed 1946 times
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Re: Dave's 80:1 RC mid drive kit build log

Post by ScooterMan101 » Apr 17 2017 3:50pm

Shimano Mountain Bike Crankset ( Hollowtec II )

Note with the Mountain Bike Cranksets there is a smaller BCD pattern.

Also

Note that when using a RC motor directly to the crank/freewheel/chainrings design that is much needed now, that ...

When riding off road / up steep hills / slower speeds, you will want to design / put the chain ring that will drive the chain to the rear cassette on the inside of the thin freewheel, in order to get a better chain line to the rear cog set.

and put the larger chain ring towards the outside for a larger reduction from the fast RPM RC motor . ( Still must look into and design around the newer slower speed / higher torque Drone RC Motors )
Attachments
IMG_1609.JPG
Shimano Hollowtec II Mountain Crankset 104/64 BCD
IMG_1609.JPG (94.24 KiB) Viewed 1942 times
IMG_1608.JPG
Shimano Hollowtec II Mountain Crankset 104/64 BCD
IMG_1608.JPG (95.73 KiB) Viewed 1942 times
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Re: Dave's 80:1 RC mid drive kit build log

Post by tangentdave » Apr 17 2017 4:01pm

A freewheel is not an easy thing to make, I'm definitely not going to attempt one. However, if someone were to design a way to convert existing cranksets like these to use a freewheel, I'd jump all over it.

I think you'd need a dual flanged freewheel, one flange being the center/input, the second on the opposite/outside side of the ratchet. Doubtful this arrangement would be as thin as two chainrings, meaning interference issues between freewheel and frame. Still need extra spindle length to accommodate the extra part (freewheel).

-dave
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Re: Dave's 80:1 RC mid drive kit build log

Post by ScooterMan101 » Apr 17 2017 4:16pm

Dave ,

I think you are forgetting that there is plenty of room once you get to / have a larger inside diameter of such a freewheel/spider , once you clear the Bottom Bracket Shell on the bike. You will see there is plenty of room.

Note : on my Mountain Bike there is 28 mm of space space between the frame ( downtube ) and the outer chain ring/chain . so in reality up to 25 mm of space to work with,
On my Road Bike there is about 17 mm of clearance.

Or to make it all fit, design so that the outer chainring, the one connected directly to the RC motor, is dished out a little . there is room to do that, look at where the pedal is connected and where the outer chain ring is on a regular crankset.
there is quite a bit of room there, by just designing a spider with dish on it it is doable .
A chain / bash guard would be helpful when doing this to save your pants/legs.

Perhaps take the thin-est freewheel on the market , grind down the teeth, bolt up the custom made spiders to one side ( different spiders for different BCD's ) and then bolt up the inner chain ring that drives the chain to the cogset on the rear, and you are good to go. not sure if a 4 bolt or 5 bolt pattern on the small freewheel will be good enough, testing will tell the answer.

and
Of course there are many smart people here on E.S. surly someone can easily ( for them ) design a thin freewheel that bolt up a chainring on one side and spider arms to bolt onto the crank on the other side, or even use the same bolts for both the chain ring and spider, so that one set of bolt holes are needed to bolt something onto each side of the freewheel.
tangentdave wrote:A freewheel is not an easy thing to make, I'm definitely not going to attempt one. However, if someone were to design a way to convert existing cranksets like these to use a freewheel, I'd jump all over it.

I think you'd need a dual flanged freewheel, one flange being the center/input, the second on the opposite/outside side of the ratchet. Doubtful this arrangement would be as thin as two chainrings, meaning interference issues between freewheel and frame. Still need extra spindle length to accommodate the extra part (freewheel).

-dave
Last edited by ScooterMan101 on Apr 17 2017 4:28pm, edited 1 time in total.
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Re: Dave's 80:1 RC mid drive kit build log

Post by tangentdave » Apr 17 2017 4:24pm

But I made a gearbox and mount system already that allows RC motors to power a bike. It works well.

How do the spiders attach to the freewheel so that they're decoupled from the cranks? Those Hollowtech spindles are 30mm I think, FW's use a 1.37x24TPI thread which has a minor diameter of about 34mm, not enough room for an adapter.
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Re: Dave's 80:1 RC mid drive kit build log

Post by ScooterMan101 » Apr 17 2017 4:38pm

I do not know the price of your gearbox, probably puts it out of my budget . Even though I know the advantages of gearboxes, ( I have a 6 speed gear Motorcycle )

What is the cost of your gear boxes ?

Hollowtec II spindles are 24 mm OD
and
BB30/PF 30 Crankset spindles are 30 mm OD

But , and Note here, you will not design around the spindle, on all these newer cranksets the crank buts up very close to the frame.

there is room between the spiders on a regular crankset and the frame of the bike. ( I edited the post 2 above ) here it is .. 25 mm on my Mountain Bike and 17 mm of room on the Road Bike. How wide are BMX freewheels ?

Don't you design the freewheel so that where the spider is bolted to the crank arm , is a different part that the chain ring is bolted to ?

Example : on a freewheel that goes on the back of a BMX bike ( I am guessing here as I have never owned a BMX bike )

One part of the Freewheel is connected to the hub, and the other part connected to the cog with the teeth on it ?

Would not the same design work for a bolt on to the BCD /s of a crankset do the same ?


tangentdave wrote:But I made a gearbox and mount system already that allows RC motors to power a bike. It works well.

How do the spiders attach to the freewheel so that they're decoupled from the cranks? Those Hollowtech spindles are 30mm I think, FW's use a 1.37x24TPI thread which has a minor diameter of about 34mm, not enough room for an adapter.
Last edited by ScooterMan101 on Apr 17 2017 4:45pm, edited 1 time in total.
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Re: Dave's 80:1 RC mid drive kit build log

Post by tangentdave » Apr 17 2017 4:44pm

The spider bolts to the FW flange. The flange is the outer side of the FW, the inside is the opposite end of the ratchet mechanism and screwed onto the cranks or rear axle if a BMX FW. The cranks need to attach to one side of the ratchet mechanism, the chainrings/spider the opposite side.

I sell the gearbox for $600. It allows a whole 'lotta awesome.
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Re: Dave's 80:1 RC mid drive kit build log

Post by ScooterMan101 » Apr 17 2017 4:54pm

Only 5 hours of sleep so not picturing this .

I am thinking there is a way to design around this .

For people like me who are new to looking into doing a mid drive,
Can you re post some pictures of your gear box / s and how the gear boxes and RC motors attach to the Bike Frame. ?

For me I would have to sell a whole lotta of stuff to get a $ 600 gear box, then there is the cost of the RC Motor ? Controller ? other items needed ? What total cost are we looking at.
Over 95 % -97 % of what I had in extra money, has gone to the Hub Motors / Batteries / and Road and Mountain bikes .

Although if I could sell one of my E-Bikes I could possibly do it . I do have a strong desire to get a much better performing E-Bike than what the Hub Motors are Providing . ( running my Mac 6T at up to 1200-1400 watts and it is still not not quite enough performance for me ... probably because I ride motorcycles )
tangentdave wrote:The spider bolts to the FW flange. The flange is the outer side of the FW, the inside is the opposite end of the ratchet mechanism and screwed onto the cranks or rear axle if a BMX FW. The cranks need to attach to one side of the ratchet mechanism, the chainrings/spider the opposite side.

I sell the gearbox for $600. It allows a whole 'lotta awesome.
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