Resources

[comradegerry]

ENO free wheels Dos, 2 in one free wheel, had not seen that before, very cool looking and useful....

http://www.cambriabike.com/shopexd.asp?id=79692&page=WHITE+INDUSTRIES+DOS+ENO+FREEWHEEL

 

[jdcburg]

Hi folks – I have put together a table on what RPMs are required in a friction drive system to reach various speeds. Friction drive doesn’t care what size your tire is; the only thing that matters is what size the drive wheel is. As long as there is no slippage, the distance the surface of the drive wheel covers (usually on the top of the tire) is the same distance the bottom of the tire moves on the road. However the diameter of the drive wheel determines how many revolutions it must turn in order to cover a certain distance. A smaller diameter drive wheel will turn more times to cover the same distance, therefore it will need to turn at a higher RPM to maintain a certain speed. As with other mechanical situations, lower speeds means higher torque or power and higher speeds equals lower torque. Highest efficiency is achieved by balancing torque and speed and depends on the motor, etc. Hopefully the following chart will help people figure their needs. I am working on another series of tables to show motor rpms for various speeds for chain drive with different wheel sizes and sprocket sizes, but that’s a little more complicated. In chain drive, wheel size as well as sprocket ratios affect power and speed - jd

 

[graemebc]

http://www.csnstores.com/asp/show_detail.asp?sku=SK1502&catid=&stayAtCSN=1&country=AU

Found these pelican case copies. Price is 45 US each big enough to take a 36/10 PSI battery. Have not priced shipping to Au, free in the US I think.

 

[Miles]

Motor design/construction threads:

http://www.endless-sphere.com/forums/viewtopic.php?f=28&t=14484
http://www.endless-sphere.com/forums/viewtopic.php?f=28&t=14339
http://www.endless-sphere.com/forums/viewtopic.php?f=28&t=14800
http://www.endless-sphere.com/forums/viewtopic.php?f=28&t=13957
http://www.endless-sphere.com/forums/viewtopic.php?f=28&t=14134

 

[HAL9000v2.0]

freewheel cranks:

http://www.biketrialseller.com/category/cranks

 

[RWP]

Hi Guys,

Been working on a gear ratio calculator for a while and thought others may be interested.
The file format is Excel.

Enjoy,
Roy

Edit: Current version of Gear Ratio Calc:
View attachment ES_Gear-Ratio-Calculator_v.05.xls

 

[Solcar]

I have been thinking to substitute the IRFSL4010 in place of IRFIB4110 in my next project. I have heard mention that it is a logic level device, but the data sheet doesn't bear that out. The gate threashold voltage is a standard 2-4v. I think the "L" stands for leaded, as in leads having been added to a surface mount package.

I use clamps to mount my MOSFETs to the CPU cooling type heatsinks, so, not having the tab and mounting hole of the TO220 package wouldn't be a drawback for me. It is cheaper, though, than the IRFB4110, based on what I've been seeing out there.

The Newark catalog, in the product description, mentions drain-source breakdown voltage as 60v. However, the data sheet lists it as the correct 100v.

International Rectifier is running a banner ad that mentions e-bikes.

 

[MitchJi]

Hi,

Wide range of off the shelf and custom pulleys:
http://www.pfeiferindustries.com/capabilities.htm

Bourn & Koch CNC Gear Hobbing
~Hobs and tooth ranges currently available

• * 5mm HTD, (17 Tooth through 200 Tooth)
  * 5mm PowerGrip GT, (16 Tooth through 200 Tooth)
  * 8mm HTD, (14 Tooth through 140 Tooth)
  * 8mm PowerGrip GT2, (22 Tooth through 140 Tooth)
  * 8mm PolyChain GT, (14 Tooth through 140 Tooth)
  * Additional hobs available upon request

Excellent Belt Length and Center to Center Distance Calculator

Perform Calculations Using Known Belt Length:
Perform Calculations Using Known Center to Center Distance:
Perform Calculations Using Known Ratio and Known Center to Center Distance:
Perform Calculations Using Known Ratio and Known Belt Length:

Excellent Source of Timing Belt Technical Information here:
http://www.pfeiferindustries.com/technical.htm
Sections Covering the following:

• 
  Timing Pulleys
  Timing Belts
  Metric Timing Belt - Articles
  Trouble Shooting
  Installation
  Power Transmission Fundamentals
  Glossary

 

[Miles]

Here's a handy calculator for working out torque or power:

http://www.sensors.co.uk/home/pages/torquecalc.html

The formula for rotary power is:

Power (Watts) = Torque (Nm) x Angular Velocity (radians per sec)

Angular Velocity = 2pi * 60 * rpm

So:
Watts = torque (Nm) * rpm * 2pi/60 , or
Watts = torque (Nm) * rpm * 0.105

Solved for torque:
Nm = Watts * 60 / rpm / 2pi , or
Nm = 9.549 * Watts / rpm.

 

[spinningmagnets]

Many RC motors of the size used for E-bike builds have an 8mm shaft or a 10mm shaft. As chance would have it, high-RPM wood routers also use bits with 8mm and 10mm shafts. These split bushings allow an 8mm shaft to snugly be fitted to something that accepts a 10mm shaft. Prices for both are listed as less than $8.

Click on the lower pic on this link to find the list of sizes, its part # RB-110

http://routerbitworld.com/Amana-RB-120-Reduction-Bushing-1-2-To-10mm-p/amana rb-120.htm

And, an alternative source is SDP-SI part # A 7A30M100822

https://sdp-si.com/eStore/Direct.asp?GroupID=393

Also, since many available motors use a metric shaft, and many industrial machines use a 1/2" shaft, SDP-SI also carries "bore reducers" which allow an 8mm, 10mm, or 12mm shaft to be coupled to a 1/2" bore using a part listed under "couplings/rigid types".

https://sdp-si.com/eStore/Direct.asp?GroupID=273

 

[spinningmagnets]

Here's a wheel-diameter to RPM/speed chart for 20" 24" and 26" wheels, along with the formulas for calculating other diameters (such as a fat moped tire on a 20" rim). I am hopeful it will simplify the first step of calculating how much of a gear-down is needed to reach a goal top-speed from the available kV's of motor.

http://www.endless-sphere.com/forums/viewtopic.php?f=28&t=16114

Also, here is a great wheel-RPM to motor RPM calculator from Electric Scooter Parts (their customers often change the sprocket tooth-counts, and the voltage / Kv of the motor)

https://electricscooterparts.com/motorwheelgearratio.html

 

[spinningmagnets]

Here's a chart from jdcburg. This chart is already posted somewhere else, but this thread also seemed appropriate. One of the quirks of a friction-drive (where a roller presses against the tire) is that the roller RPM determines the ground speed, regardless of the wheel diameter. Sounds odd, but its true.

The most useful column is the 10-MPH one. If you move the RPM decimal point over to the left one digit, it provides the rpm's for 1-MPH, and from there you just multiply that RPM by the top MPH that is your goal.

Google "online conversions" and there will be another calculator to convert that to kilometers per hour, if you need that.

 

[Miles]

You could also use this spreadsheet calculator: http://www.endless-sphere.com/forums/viewtopic.php?p=312555#p312555

For friction drives, use the roller diameter in place of the wheel diameter and set the gearing to 1:1

 

[amberwolf]

I...am confused, about that roller diameter vs wheel diameter not making a difference to speed. Why would that not act as a gearing ratio in itself, exactly as with pulleys, gears, or sprockets?

Back when I was doing my friction drives on DGA, I first used the much larger fan blade cores on the motors, which were maybe 3.5" in diameter. Then I used roller skate wheels, which were less than 3", more like 2" or 2.25", and I got different speeds and different current draws. Was it just because of slip on them being different due to different surface materials, rather than their diameters?

I ask becuase I tried the same thing with a 24" tire and got yet different speeds and current draws, although I don't remember now what proportions any of these were in.

 

[Miles]

Amber,

You're driving the periphery of the wheel, directly. The linear velocity of a point on the wheel's periphery is the same as the velocity of the bike itself. So, it's the same as if you were using the roller directly on the ground. The diameter of the roller will make a difference to the bike's speed but the diameter of the wheel won't.

Does that make sense?

If you want to think about it in terms of gearing, the wheel is an idler gear between a pinion driver (the roller) and a rack (the ground).

 

[amberwolf]

OH! Light finally comes on. :lol:

Now I feel even dumber than I did, for not being able to see that myself.

I guess it must've been tire and surface differences causing the speed/current differences betweeen 24" and 26".

 

[spinningmagnets]

From Boostjuice.
8mm pulley/belt set from a Karting supplier, several tooth-counts available with the biggest being 90T : 14T (6.4:1 ratio). The link has an adapter plate that connects these pulley types to the ISO 6-hole bicycle disc brake interface.

http://endless-sphere.com/forums/viewtopic.php?f=28&t=26122&start=75#p395235

 

[spinningmagnets]

Fixed cogs that bolt to the ISO 6-hole disc brake mounts. These are useful for using a bicycle hub or a hub-motor as a jackshaft or a mid-drive. Various steel and aluminum styles with tooth-counts in some styles as low as 15T and as high as 22T. This site also has disc-brake spacers. from England, price at this time is 19-GBP

http://www.velosolo.co.uk/shopdisc.html

Here the similar "Tomicog" from the USA, which is originally designed to allow a rear wheel to be flip-flopped so the disc brake side becomes a fixed-gear with 16T/17T. Stainless steel, price is $35
http://tomicog.blogspot.com/

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A "track cog" can also be found that has a threaded bore, with a freewheel standard 1.38 X 24 threads, with tooth-counts from 12T-22T.
http://www.ebay.com/itm/Track-Cog-1...Cassettes_Freewheels_Cogs&hash=item3383bbcbb3

13T-20T threaded cogs are very easy to find from a variety of suppliers. 12T and 22T are rare but findable. I have only found a single supplier of 24T threaded cogs.

http://www.ebay.co.uk/itm/track-pista-cog-campagnolo-fixed-14t-15t-16t-17t-18t-19t-20t-21t-22t-24t-NEW-/221250241911?ssPageName=ADME:L:OU:US:3160

Surly has dual threaded cogs, with tooth-counts of 17T/19T, also 17T/20T, and 17T/21T.

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Individual cogs can be found with tooth-counts of 12T-22T with a bore that is splined for the common Shimano freehubs. If you pull sprockets off of a splined cassette cluster, the tooth-counts can be found as high as 36T.
http://www.wiggle.com/surly-13t-to-16t-cassette-cogs/

 

[spinningmagnets]

"Mounting TWO freewheels on one rear wheel hub"
http://www.endless-sphere.com/forums/viewtopic.php?f=28&t=13862

Jon Chan from GNG sells "side mount" kits for TNC style of motors. That kit includes a rear wheel with the adapters and dual freewheels, and in the past he has sold individual parts without the rest of the kit. http://www.gngebike.com/350w.htm

 

[spinningmagnets]

edit: the other two are out of stock this week, so I bought the SJS cycles part, arrived in a week, looks great!

From carl2.0, I'm not sure of all the things we could do with this, but it looks handy. I would prefer stainless steel, but it is aluminum for now, $13. edit: apparently some front forks are wide enough its difficult to get axles and wheels that fit, this adapter allows an inexpensive and common wide-axle rear wheel to have a brake disc attached to the FW threads, flipped around so FW-threads/disc are on the left, and used in the front fork.
It uses standard freewheel internal threads (1.37 X 24) and 6-hole ISO disk brake mount.

http://www.bicycledesigner.com/bike...sc-brake-adapter---free-or-flip-flip-hub.html

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and another: "DT Swiss - Arai to Disc Brake Adapter for 140 mm OLN 98 / TD" Internal threads are the common 1.37 x 24.
http://www.sjscycles.co.uk/dt-swiss-arai-to-disc-brake-adapter-for-140-mm-oln-98-td-prod29105/

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http://www.choppersus.com/store/product/308/Disc-Brake-Rotor-Converter/

Another supplier
http://www.myspace.com/broaklandbicycles

 

[spinningmagnets]

I was having trouble finding a die to cut threads on an aluminum slug to make a shaft-to-freewheel adapter for 19mm shaft and a 12mm shaft (Matt and Staton-inc make 1/2 inch shaft adapters). BSA threads are 1.37 X 24 TPI. It "looks like" a 1-3/8 X 24 is the same thing (1-3/8 is 1.375", and the die can have its tightness adjusted to make the cut looser or tighter, here is one axmple for $85. I would bolt one threaded item to the unthreaded slug, and slowly move the die from the threaded item onto the slug, to make sure the cut was perfectly perpendicular.

http://metalworking.mscdirect.com/CGI/NNSRITW?PMPXNO=1725443

 

[Miles]

Bottom bracket "standards".

View attachment Bottom_Bracket_Standards_Reference.pdf

edit: here's an article on bottom bracket standards from "bike radar", and I found it useful.

http://www.bikeradar.com/us/gear/article/complete-guide-to-bottom-brackets-36660/

 

[spinningmagnets]

$28 Freewheel spacer, may prove to be useful for other things
http://www.e-bikekit.com/shop/products/Freewheel_Spacer_1_Speed-162-15.html

 

[spinningmagnets]

From "Atomic Zombie", this $30 adapter allows the buyer to attach any disc with the ISO 6-hole disc brake interface to be mounted to a 3/4-inch (0.750") shaft and includes a keyway. It also alternatively allows a 1.375 X 24 freewheel to be mounted to the disc brake flange of a bicycle wheel. There is also a shorter version with no FW threads.

http://atomiczombie.com/DIY Parts.aspx

 

[jateureka]

Gomier trikes uses a part similar to that Atomic Zombie part (but without the flange for the disc brake), to mount the rear freewheel to the trike axle. The axle diameter is 15mm and the adapter is secured via a 4mm key and grub screw.
For Aussies, the part is available from bike shops that sell gomier trikes, or they could get their LBS to order it from bicycepartswholesale.com.au, p/n 93315 axle colar for freewheel.

Edit: similar item also available on eBay http://www.ebay.com/itm/ADULT-TRIKE-FREEWHEEL-ADAPTER-5-8-BICYCLE-PARTS-/390469084850#vi-content

You can also buy it as a fixed sprocket with the key and grub screw, which could be adapted so as to be able to mount a larger sprocket to it (or a disc brake per Atomic Zombie). The standard trike uses a 15mm axle and 20T sprocket, the industrial trike uses a 17mm axle and 20T sprocket suitable for single speed chain.