Freewheel crank resources

[MitchJi]

Hi,

the more engagement points there are the less likely it is going to fail in this application because the pawls are not taking so much of a hammering when throttling up.

Except that the engagement points are smaller.

Industry9 freewheels use multiple teeth.
http://www.industrynine.net/Hubs

 

[Miles]

Except that the engagement points are smaller.

Hi Mitch,

No, that's not true in this case.

 

[MitchJi]

Hi Miles,

Except that the engagement points are smaller.

Hi Mitch,

No, that's not true in this case.

In the Trials FW with twice as many teeth in the same circumference the individual teeth are the same size?

Thats the main reason Industry Nine uses multiple teeth per pawl (because increasing the number of teeth for quicker engagement decreased the size of the individual teeth).

 

[Miles]

Hi Mitch,

It doesn't have twice as many teeth in the same circumference (or you would be correct). It has an extra set of 3 pawls, acting on the same teeth as the standard ENO freewheels. Because they are offset from the original set, they don't share the load, instead they increase the total number of potential engagement positions.

 

[MitchJi]

Hi Matt,

I installed my Echo FW cranks yesterday. I like them. However, the threads are not perfectly square on the crank arm. When rotating the cranks backward, the sprocket wobbles about 3 or 4mm (wobbling like a wheel out of true). It is not obtrusive, but looks weird on a $3000 bike.

Matt

Someone told me the White FW's are not very precise in terms of run-out. Is your problme the Echo Cranks or the White FW?

 

[boostjuice]

Hi Matt,

I installed my Echo FW cranks yesterday. I like them. However, the threads are not perfectly square on the crank arm. When rotating the cranks backward, the sprocket wobbles about 3 or 4mm (wobbling like a wheel out of true). It is not obtrusive, but looks weird on a $3000 bike.

Matt

Someone told me the White FW's are not very precise in terms of run-out. Is your problme the Echo Cranks or the White FW?

Well my 22T White FW does have a fair bit of 'slop' in its side to side movement about its rotational axis(=angular diversion?) however i figured out that in my case it is definately the threaded portion of the echo trials cranks that is not exactly perpendicualar to the bottom bracket spindle which is the major contributor to the noticable wobble in the large chainring.

Whilst the sealed cartridge bearing of the White freewheels would seem to be more durable, the fact that the sprocket load is supported on one side of the inner and outer rings only - when freewheeling - is not ideal when used under high freerunning loads such as in freewheel cranks when you are not pedal assisting the motor. This is because the ratchet and pawls occupy one side of the internal structure, whilst the sealed cartridge bearing occupies the other.
At least the cheaper loose-ballbearing freewheels have two bearing races, one on either side of the centrally mounted ratchet and pawls so uncentered radial loads are dealt with better. Basically Im finding the white freewheels are strong and durable, but only in the locked state. The over-running condition is only suppposed to support a slack chain of the rider pedalling backwards, not 270Nm of motor torque being tensioned off it with a slightly offset sprocket bolted onto the radial weightsaving cutout slots :lol:

 

[Miles]

This is a good point, boostjuice.

It didn't bother me because my set-up doesn't require the crank freewheel to transfer loads in the freewheeling state.

The Tensile is a good choice, if you want twin ballraces http://www.tartybikes.co.uk/product.php?product_id=398&category_id=16 they're not sealed cartridge, though...

 

[kfong]

Who make the best south pawl or left hand freewheel. I plan to use that on a ISIS freewheel crank that I will put on the left side for my ebike conversion. I assume I should be able to do this. Any good source on ISIS freewheel cranks as well? Everything I come across are the old square style cranks.

Kin

 

[Miles]

Kin,

Could you give more details of the drive layout you are aiming for?

I've never seen left-hand drive trials cranks anywhere.

Good selection of cranks here: http://www.tartybikes.co.uk/search.php?category_id=514

If you drive the left side of the cranks with a motor, you can use a normal right-side crank on the left with a normal RH freewheel, but only to allow you to pedal without the motor - you will probably need to use Loctite on the pedal threads, if you do this.

 

[kfong]

Miles,
There are left hand freewheels available. ASC is the only one I've heard of so far. I just want to start out with a good quality one so I won't need to replace it. My thinking is the theading on the left hand freewheel avoids any need for loctite and is a safer way to go. Since my crank arms are ISIS, I think left or right are interchangable. This is just my thoughts, I have not taken apart the cranks to verify this.

Kin

 

[Miles]

Hi Kin,

Sure, you can get left-hand freewheels, but you'll need a trials crank with a left-handed thread to put it on :wink:

What are you trying to achieve?

 

[kfong]

Hi Miles,

Basically I want to do the Stokemonkey design, http://endless-sphere.com/forums/viewtopic.php?f=28&t=9589
I was looking at the ISIS standard, and it looks like the left and right cranks are interchangable, so I figure all I need is a freewheel spinning in the correct direction. Which led me to the conclusion that there are left handed freewheels. I assume the lefthanded ones are threaded so they stay on the crank arm. Unless I also need a left handed freewheel crank arm. Something I have not seen. Maybe someone here that is a bike expert can enlighten us on the details. This would solve my problem of installing an RC motor setup. I can keep the 27 speed setup intact on my mountain bike, since I want to pedal as well.

Kin

 

[Miles]

Kin,

Ok, I understand.

You can do this with a RH freewheel and a RH (RH threaded) trials crank on the LH side, but you won't be able to isolate the pedals from the motor (run the motor without turning the cranks). The freewheel will allow you to pedal without back-driving the motor drive. With a LH drive set-up, like the Stokemonkey, there's no way to run the motor without turning the cranks.

All crank fittings are R/L interchangeable with regard to the fixing to the axle, but pedal threads may need to be Loctited to stop them unscrewing.

 

[kfong]

Thanks Miles, I see the problem now. Now if someone would produce some sort of double axial, so the gears are on one and pedals on another. Is there anything made in the tandem world that might be of use. So far that would of been the cleanest solution. Now I'm afraid I'm going back to a hub motor design for my mountain bike. I just don't see a good way to keep the original gearing, or at least most of it.

Kin

 

[MitchJi]

Hi Kin,

http://www.bike-elektro-antrieb.ch/home.htm

His prices are high but most of the parts are off the shelf.
Motor with 44t plus 44t+32t+22t chain rings:
You can navigate to the page with this image and quote by home -> shop -> kurbel-crank

Satz Deore Kettenblätter Motor z44 Rad z44-32-22 (siehe informationen/übersetzung)

One more image:

 

[boostjuice]

 

[TylerDurden]

Simply splendid, Boost.

Is there a drawing for the plate to share? (FWcrankadapter1.jpg)

 

[glv]

This just in!!! sickbikes now has these heavy duty free wheels from White industries for $64

http://sickbikeparts.com/catalog/product_info.php?products_id=62

Thanks for the link, this was perfect for my cyclone setup!

 

[gwhy!]

Not a good advert for tensile freewheels

A friend of mine was just about to do a gap on his trials bike when this happened,

 

[RWP]

Beautiful work boostjuice!!!

 

[kfong]

This is what I ended up doing. Found cheap bike parts from Allelectronics.com and used my CNC to mill out a spacer. http://www.endless-sphere.com/forums/viewtopic.php?f=6&t=11542

 

[gogo]

A new item over at Staton-inc:
BIMOTO MODIFIED Free Wheeling CRANK MECHANISM

Its a double freewheel crank drive.

Advantages:
1) Two bearings during motor use, a regular bearing in one of the freewheels and a cartridge bearing under the motor drive sprocket. This makes for a wide distribution of load.

2) The motor drive chain only turns during motor use.

Disadvantages: (maybe)
1) Seems wide and might be awkward for pedaling?

2) Price: $249

 

[picbuy]

 

[raysmith1971]

Hi all,
been looking at all this e-bike stuff and find it absolutely fascinating,regarding this freewheel crank thread Eclipse bikes in the uk sell complete cranks for £39.95,heres the link http://www.eclipsebikes.com/chainwheel-cranks-p-994.html . I've bought one recently so when it turns up I'll let you know what its like ,getting the 'toy' in my hands will also spur me on to do my own ebike!

 

[danoulz]

Hi all,
been looking at all this e-bike stuff and find it absolutely fascinating,regarding this freewheel crank thread Eclipse bikes in the uk sell complete cranks for £39.95,heres the link http://www.eclipsebikes.com/chainwheel-cranks-p-994.html . I've bought one recently so when it turns up I'll let you know what its like ,getting the 'toy' in my hands will also spur me on to do my own ebike!

Hello ! Did you purchase the updated 3-chainring version, or the old single-ring model ?
What is the third chainring for ? (44T/44T/32T) On the photos, the small ring looks unused.
They say that pedaling doesn't engage the motor (thus removing unnecessary drag). How does this work ?
I would need to upgrade the main driving ring to a 48T or 50T chainring for my application (I don't need a front derailleur), do you know if i can swap the original ring ?
Cheers, Daniel