How to mount sprocket to rear wheel

[BladeScraper]

Been looking for ages and have gotten nowhere... anyone know how to mount something like this to the left side of a wheel (so that I can still use the pedals if necessary)?


http://www.monsterscooterparts.com/25sp80to2moh.html

 

[Nobuo]

What is the motor do you have, you mean that there are not possibility to mount a freewheel in your build?

 

[spinningmagnets]

If you are using a wheel with the standard 6-hole mount for a disc brake, it is doable by a home enthusiast. I used the bottom of a frying pan from the thrift store (used items donated for charity). If a pan is made for an electric glsass-top stove, it will be thicker than normal and will be machined smooth.

Cut out the flat disc from the bottom of the pan and drill the center to match the disc brake mount. drill a tiny pilot hole in the center, and then do the lay-out for the rest of the holes. Don't drill the center hole larger till the very end. Then you cut out the center section of the sprocket and drill holes to bolt it to the adapter disc. Similar to this:

 

[BladeScraper]

What is the motor do you have, you mean that there are not possibility to mount a freewheel in your build?

I'm making a dual stage drive. Turnigy 6374-149Kv. First stage is 11/48t, second is 14/80t (both can be changed for higher speed)

If you are using a wheel with the standard 6-hole mount for a disc brake, it is doable by a home enthusiast. I used the bottom of a frying pan from the thrift store (used items donated for charity). If a pan is mafde for an electric glsass-top stove, it will be thicker than normal and will be machined smooth. Cut out the flat disc from the bottom of the pan and drill the center to match the disc brake mount. Then you cut out the center section of the sprocket and drill holes to bolt it to the adapter disc. Similar to this:

Unfortunately I already looked at doing that, but its a BMX 20 inch wheel with no 6 hole mount.

I found this, but it has 9 holes and is not (as far as I know) compatible with the 4 hole sprocket I linked.
http://www.bikeberry.com/sprocket-clamp-assembly.html

Something like that, but with 4 holes that line up with my sprocket, would be perfect.



Also another mostly unrelated question, will it be OK to run this without a freewheel? The motor would be spun by the wheel when I turned the throttle off. Will that burn my ESC if done too much or will it be fine?

If thats not Ok (and to be honest, I would rather have a freewheel), do you know where I can get a #25 1/2" bore freewheel sprocket with 14-18 teeth? (not a huge deal exactly how many teeth but preferably no more than 18t.

 

[BladeScraper]

Just had an idea for a freewheel:

I can use a one way bearing and a normal sprocket. The sprocket can be bored out to 3/4" (max bore is stated as 3/4")
http://www.surpluscenter.com/Power-Transmission/Sprockets/Finished-Bore-Sprockets/18T-1-2-BORE-25P-SPROCKET-1-2742-18-D.axd
then this one way needle bearing can be put inside the sprocket, and since it has a 1/2" ID, it will fit perfectly on the jackshaft (connection between primary and secondary drives) and the OD of 3/4" will fit perfectly in the sprocket (green loctite to hold it from spinning may be necessary)
http://www.vxb.com/page/bearings/PROD/Kit8651

So the question now is, will that one way handle the stress of up to 3Kw of electric power?

 

[nutnspecial]

I'm certainly curious if the one-way bearing works for that load. Doubtful, but curious.

Having no freewheel has no downside other than extra drag when pedaling.

Was the link to the sprocket adapter the type that bolts to/thru the spokes? that's what I was gonna recommend.

#35 chain may be more durable for the proposed torque.

There are plenty of freewheels that thread onto older style hubs. electricscooterparts is where I got mine. sickbikeparts makes a hd version. got the 35 sprockets and chain from amazon.

 

[BladeScraper]

I want to use #25 because surplus center has a MASSIVE selection of #25 sprockets. I especially like their 5/16 bore sizes. They have 11t through 23t and those would go on my motor (would have to slightly reduce shaft diameter from 8mm to 5/16" otherwise it won't fit in the sprocket) they also have 14t through 72t of 1/2" bore sprockets in #25 size. (Though I only plan to use 48t)



As for the one way, thinking about it I would imagine it would be fine if it's built to the standards of RC helicopter parts. A 12mm ID one way bearing goes in a 700 class rc helicopter (700mm blades) and is used to join the main shaft with the main gear, and they are pushed to peaks as high as 16.5Kw!! :O

 

[ferret]

I suggest that you simply replace the rear hub or the entire wheel to one with a disk brake mount.

Regarding one-way needle bearings, keep in mind that they need to run on a polished hardened steel shaft to get any sort of longevity. Also I doubt these bearings can handle high torque even if the can handle high power.

Avner.

 

[Dauntless]

http://endless-sphere.com/forums/viewtopic.php?f=10&t=51173&p=759216

I talk about this some there. This is without a freewheel, but you can put one on the motor instead. Another option is a jackshaft with a freewheel to merge the pedals and and the motor.

I've got some new links for parts.

http://www.kingsmotorbikes.com/Pineapple_Sprocket_Bushing_Kit.html
http://www.kingsmotorbikes.com/CNC-Pineapple-Sprocket-Bushing-Kit_4153_prd1.html
http://www.kingsmotorbikes.com/44-tooth-cnc-sprocket-adapter_4104_prd1.html
http://www.kingsmotorbikes.com/44-Tooth-Sprocket-Pineapple-Bushing-Kit.html
http://www.kingsmotorbikes.com/bike-motor-50-tooth-chain-sprocket.html

 

[BladeScraper]

I wanted to do that but I haven't been able to find a 20 inch wheel with disc brakes.

 

[BladeScraper]

Also I need a sprocket in the 60-80t range to get good gearing even with dual stage drive due to a high kv motor. If you can find a 20" bike wheel with disc brakes that doesn't cost a fortune and a 60-80t sprocket that has a 6 hole disc brake mounting pattern, that would be great

 

[BladeScraper]

Ok, I've got it, I'll be finding a 20" wheel with disc brake mount. (or making one)

So now the question is, where can I find a good selection of sprockets that will fit that mounting pattern and is either #25 or #35 chain?

 

[BladeScraper]

Ok, quick question:

Would this be able to connect to the threaded hub of a BMX bike and function like I want it to (freewheel when I turn off throttle)?
http://www.monsterscooterparts.com/freewheel-assembly.html

http://www.ebay.com/itm/201145431105?var=500307760954

Also one more small question, how do you attach a sprocket to it? I assume just normal nuts and bolts, but what size and length?

Thanks.

 

[ferret]

Here are some links you may find useful:

Disk brake to sprocket adapters:
http://shop.jakebike.com/The-Disc-Biscuit-rear-disc-drive-plate-28.htm
http://www.bicycledesigner.com/search?query=adapter&s=a&view=list&sort=releva&cid=&price=&price_low=&price_high=

#4x sprockets:
http://www.willardssmallengines.com/-41-pitch-axle-sprocket/-41-72t-high-strength-aluminum-.html
http://www.gokartgalaxy.com/racing_sprockets_for_larger_chain_sizes.htm
http://www.gokartgalaxy.com/sprocket_blanks.htm
http://www.motionindustries.com/taxonomy/Mechanical%20Power%20Transmission/Power%20Transmission%20Chain%20&%20Chain%20Sprockets/Roller%20Chain%20Sprockets/browse/en
http://gokartsusa.com/heavydutyhubandsprocketsfor1axles.aspx

#25 chain sprokets:
http://www.surpluscenter.com/Power-Transmission/Sprockets/Finished-Bore-Sprockets/?page_no=1&fq=ATR_PowerTransPitch:25&fq=ATR_Bore_Fractional:3/8\%22
http://www.robotmarketplace.com/products/sprockets_main_25.html
http://www.ebay.com/itm/Metal-Pilot-Motor-Gear-Roller-Chain-Drive-Sprocket-Pitch-6-35mm-9-525mm-12-7mm-/171591853809?pt=LH_DefaultDomain_0&var=&hash=item27f3abe6f1
http://www.vexrobotics.com/25-sprockets.html
http://www.aliexpress.com/item/74-Tooth-25H-26MM-Rear-Sprocket-Mini-Moto-ATV-Quad-Dirt-Pit-Pocket-Bike-Chopper-47CC/1991811570.html
http://www.aliexpress.com/item/72-Tooth-25H-26MM-Rear-Sprocket-Mini-Moto-ATV-Quad-Dirt-Pit-Pocket-Bike-Chopper-47CC/1991808606.html
http://www.staton-inc.com/store/catalog/30_25_Sprockets_Roller_Chain_1_4_x_1_8-45-1.html
http://www.electricscooterparts.com/sprockets25chain.html
http://tncscooters.com/index.php?route=product/search&keyword=sprocket&category_id=0

Left hand freewheels:
5 -hole:
http://www.staton-inc.com/store/products/5_Hole_Flange_1_37_x_24_LEFT_HAND_thread_freewheel-967-45.html
cog:
http://www.universalcycles.com/shopping/product_details.php?id=12218&category=403
http://www.bikeparts.com/productinfo/ACS-SouthPaw-16t-Left-Hand-Drive-freewheel-18-60381-52095.html
4 Hole:
https://electricscooterparts.com/freewheelclutches.html

#219 sprockets:
http://www.kartpartsdepot.com/SearchResults.asp?searching=Y&sort=13&search=219&show=150&page=1
http://www.pegasusautoracing.com/productselection.asp?Product=9806
http://www.gokartgalaxy.com/engine_sprockets1.htm
http://www.kart-master.com/Rotax_Leopard_PRD_Sprockets.html
http://www.zoomkarts.com/shop-for-kart-parts?productID=139#!/Chains-&-Sprockets/c/2132287/inview=category2288323&offset=0&sort=nameAsc
http://www.buller.net/index.php?sid=50fp37337nw768z8599eccekp3f30u12&app=ecom&ns=prodsearchp&ecom--prodsearch--string=219&SUBMIT=Go

http://gokartsusa.com/sprocket-gokart-small-engine-minibike.aspx
http://www.accelerationkarting.com/219sprockets.aspx
http://www.kart-master.com/Rotax_Leopard_PRD_Sprockets.html
http://www.gokartgalaxy.com/engine_sprockets1.htm


Hubs:
http://www.dmrbikes.com/products/hubs
http://www.bicycle-engines.com/Chain-Drive-System-4-Stroke/
http://www.jnmotorsbikes.com/product_p/jnm1145.htm
http://www.pistonbikes.com/product-p/gruhdak.htm
http://www.gasbike.net/bike-motor-engine-heavy-duty-axle-kit-free-wheel.htm
http://www.kingsmotorbikes.com/bike-motor-engine-heavy-duty-axle-kit-free-wheel.html
http://www.zone8cycling.com/Heavy-Duty-Axle-Kit-Free-Wheel-For-Pull-Start-Engines-Free-Shipping-p177.html http://www.bikeberry.com/catalog/product/view/id/427/s/free-wheel-heavy-duty-axle-kit/category/393/
http://spookytoothcycles.com/engine-kit-parts/view-all-parts/free-wheel-heavy-duty-axle-kit.html


Avner.

 

[litespeed]

Nice list!

Tom

 

[BladeScraper]

Dude... you are amazing 8)

This is exactly what I want
http://www.dmrbikes.com/products/hubs/single-speed-screw-on-freewheel


do you know what rim I should get? 20" bike.

 

[spinningmagnets]

do you know what rim I should get? 20" bike.

First measure how wide of a tire will fit. A while back, there was a bunch of builders who wanted to run a Pirelli ML75 moped tire (roughly 3-inches wide) and recumpence formed a group buy on double-walled 47mm wide rims with the correct number of spokes.

24mm (one inch) wide rims will properly seat a 2-inch wide tire very well, but the popular 2.5-inch wide size of wheel has often been mounted to a 32mm wide rim.