Strong freewheeling crankset

[bee]

It was easily bent back with a hammer.

I'm glad to see that your Kona is working out well for you. Perhaps I should try and fix my old GNG BB spindle using the hammer method. :wink:

I wouldn't advise using a hammer, it's much easier to use a small bench vice to bend it back into the right position by taking the pedal off and slowly clamping the crank arm to the frame until it's straight.

 

[skyungjae]

It was easily bent back with a hammer.

I'm glad to see that your Kona is working out well for you. Perhaps I should try and fix my old GNG BB spindle using the hammer method. :wink:

I wouldn't advise using a hammer, it's much easier to use a small bench vice to bend it back into the right position by taking the pedal off and slowly clamping the crank arm to the frame until it's straight.

It's all good. I had no intention of ever using the GNG BB again. I actually have a brand new GNG BB, freewheel crank arm, & freewheel that I ordered after I bent the first one. By the time it got to me, I had already built a different chainring set. :lol:

 

[dustyearlobe]

I got my crank set from cyclone 148mm set ,just to throw my two cents in on this ,so much better than the standard square shaft ,still had to remove the thin spacer in the freewheel to tighten it up (and my god Paco this man will bend over backward to help ,so big shout out for trying to help with the dreeded import duty ,and customer service second to none)

 

[Kingwouldbe]

Hi Guys,


I was going to order the cyclone BB kit, looks good @ $117, but $117 for shipping is outrageous, I will not support.


@ $235 total to the USA, that opens up a lot more options to get high quality parts


Is there another option for the BB, can we get parts and build our own, better sprockets and better components for less.


If some have already done this, could you list your parts and where you got them

 

[skyungjae]

Hi Guys,


I was going to order the cyclone BB kit, looks good @ $117, but $117 for shipping is outrageous, I will not support.


@ $235 total to the USA, that opens up a lot more options to get high quality parts


Is there another option for the BB, can we get parts and build our own, better sprockets and better components for less.


If some have already done this, could you list your parts and where you got them

If you read through this thread, you'll see that you have to email Paco from Cyclone directly to get an accurate quote on shipping. :wink:

 

[Kingwouldbe]

Thanks skyungjae,

I sent him and email, so lets see what he does.

 

[Kingwouldbe]

I want to thank skyungjae, for telling me to PM Paco @ cyclone who responded right away to my concerns and we where able to make a deal.

So, hopefully I can go more than a block with out the chain flipping off.

Thanks everyone for your help

 

[DeathBlade]

I emailed paco and he still wanted $81 in shipping vs the original $117.

 

[DeathBlade]

Just picked up a ISIS crank from http://trialspads.com/ for $70 cheaper, its going to be more exspensive to buy all the parts piecemeal that buying from cyclone but $80 shipping....

Now I just need to find a 140-145mm BB, any good sources?

 

[skyungjae]

Just picked up a ISIS crank from http://trialspads.com/ for $70 cheaper, its going to be more exspensive to buy all the parts piecemeal that buying from cyclone but $80 shipping....

Now I just need to find a 140-145mm BB, any good sources?

Maybe you can order just the 148mm BB from Cyclone and negotiate more on shipping considering the packaging will be much smaller.

 

[bee]

make sure to ask for the optional steel chainrings on your cyclone crank if you plan on doing >2000w

my aluminum 48t chainring after ~50km:

 

[--freeride--]

Here something new:

There are several different wide Hollowtech II cranks.

I got LX crankset sitting here,that has a 46t or 48t big sprocket. They got a around 12mm wider shaft, than normal ones, to fit those big sprockets on normal frames.
People here used them for freewheel crank conversion to, what is realy nice as you can easily remove the cranks from the frame as often as you want to fit everything

The wider shaft of the LX crankset is compensatet with an plastik spacer on the right side. That shoud be easly removed.

I don't know if all 46/48t stock shimano cranks are coming with a wider axle but it could be.

http://www.pedelecforum.de/forum/showthread.php?4194-Noch-ein-Fully-mit-Kurbelantrieb

You can pull/ press the spider of the crankarm and turn the rest of the krankarm down and turn the normal freewheel thread on.

 

[Chalo]

make sure to ask for the optional steel chainrings on your cyclone crank if you plan on doing >2000w

my aluminum 48t chainring after ~50km:

More than a sign of the power level, that's a stronger indicator that your chain is completely worn out and elongated. So maybe you should lubricate, gauge and replace your chain more often at >2000W.

 

[boostjuice]

Right, here goes....
Despite having previously heralded the ACS Crossfire model of freewheel being a suitable candidate for duties in FW crank implementation, my recent discovery leads me to unfortunately revise that opinion to labelling them as unsuitable if requiring acceptable service life.

I today opened up one that had been in FW crank service for ~1500km. It was supposed to be to just routine maintenence to replace the bearing grease and check for bearing wear. I was disheartened to find that the ratchet teeth are badly indented and are nearing failure in one indexing position. I expected better of this FW model. The dimensional accuracy, fit & finish and metallurgy are clearly improved over the Dicta type 'cheapies', but obviously still not up to the torque demands of my modest 70kg (154lbs) mass on 170mm crank arms (~130Nm).





I'm concerned that their many not be ANY BMX/SS freewheel with dual angular contact bearings that provides enough torque capability that is required for FW crank duties when coupled with large chainrings. The 'Excess Pro' FW is a recently released model that boasts an 'industry leading' torque-hold rating of '550 LB/in' (62Nm) which is still far short of the required 130Nm for my body weight and crank-arm length, even disregarding shock loading. Unfortunately I can't find a published torque rating for the ACS Crossfire (or the single bearing White Industries ENO for that matter) to compare this to, but if the Excess Pro is above average then its still only half the strength of what I require, and this does not inspire hope of any others being up to the task.

Now you may be thinking, why do Trials bikes have less problems with FW crank related failures? Afterall, FW cranks for e-bike use are an adaptation of their successful use on Trials bikes.
I suspect the reason is that because Trials bikes with FW cranks are geared so low,the torque holding they are subjected to is far lower than in E-bikes with larger chainrings and therefore taller gearing. Because Trials bikes are geared to accelerate so rapidly, the rider can't apply as much loading on the FW in comparison with mid-drive e-bike riders who with wide ranging variable gearing are able to accidentally or deliberately pedal in a relatively tall gearing ratio for the incidental traveling speed. This allows far more FW torque loading than in Trials bike configurations.

If there is a Freewheel model out there that is potentially up to the long term torque holding durability that I require, it's likely to be the White Industries ENO. As far as I'm aware, no-one has reported undue ratchet teeth deformation when used in FW crank duties, however that could be because the run-out issues related to the single bearing in over-running operation lead to their replacement of a dual-bearing unit before significant service life elapses.

Unfortunately the need for a second support bearing requires quite involved fabrication and so I will reluctantly follow Miles'/Fullthrottle's example of how this is done.

 

[DrkAngel]

Right, here goes....

I today opened up one that had been in FW crank service for ~1500km. It was supposed to be to just routine maintenence to replace the bearing grease and check for bearing wear. I was disheartened to find that the ratchet teeth are badly indented and are nearing failure in one indexing position.

My understanding of how this damage occurs:
The ratchet teeth only come into pressure when pedaling.
Pressure while pedaling is minimal ... compared to the impact resultant from sprocket shifting.
Every shift, while applying pedal force, demonstrates as a "clunk" of impact as pedal speed alters.
Shifting to a higher speed sprocket produces an immediate pressure increase, while shifting to a lower speed produces a slack then impact as slack is "taken up".
This momentary impact at every shift is a greatly amplified amount of pressure on the ratchet teeth.

Solution? - improvement!
Buffering this shifting impact would greatly increase the service life of the FW crank as well as of the rear freewheel and the chain.
This could be accomplished by implementing a spring loaded idler pulley immediately behind the front chainring.
The force variance of every shift could be buffered over the length a chain link or so, rather than just the fraction of an inch of chain stretch.

Originally I considered using a roller skate wheel-assembly but then I found this little item.
Cheap w/dual sealed ball bearings looked ideal.

- $4.74 shipped

Some form of tension adjustment should be included, to increase or decrease spring tension.
Also advisable might be a travel limit adjustment?
Rear sprocket idler assembly will apply a "balancing tension".

 

[Chalo]

Now you may be thinking, why do Trials bikes have less problems with FW crank related failures? Afterall, FW cranks for e-bike use are an adaptation of their successful use on Trials bikes.

Trials riders bust freewheels all the time. They take it for granted. But their events are short in both distance and duration, so it's not that big a deal for them.

 

[Thud]

Well, that is disapointing news.......kinda hopeing the crossfire would be the answer.
goodbye ratchet & pawl freewheel.....hello CSK35.
http://www.vxb.com/page/bearings/PROD/Kit8183
says 140Nm of holding power.....

fixturing freewheel crank arms to get rid of the non-concetricity is kind of a pain.....as well as machining press fitting adapters for the sprockets.....

is there a freewheel crank for the splined shafts yet? (not ISIS or ST)

 

[Gab]

Boostjuice

Did you lubricate your ACS crossfire freewheel during the 1500km ? Or was this the first time you opened it to add grease to it ?

 

[speedmd]

Sure the power shifting didn't help either.

 

[bee]

My cyclone freewheel unscrewed itself partially (the crank arm stopped it from coming all the way out) and was giving me lots of chain dropping/snapping grief because of some sideways play it introduced to the crank sprockets. This thing will need a small spot weld or maybe some loctite for e-bike use.

 

[boostjuice]

Boostjuice

Did you lubricate your ACS crossfire freewheel during the 1500km ? Or was this the first time you opened it to add grease to it ?

First time I opened up this one. There was still plenty of grease where it needed to be, and it wasn't that dirty/gritty. I just wanted to freshen It up as I had the crank-set in pieces anyway for other reasons. In any case, a lack of lubrication would not have contributed to the severity or timeliness of the damage pictured.

 

[Thud]

My cyclone freewheel unscrewed itself partially (the crank arm stopped it from coming all the way out) and was giving me lots of chain dropping/snapping grief because of some sideways play it introduced to the crank sprockets. This thing will need a small spot weld or maybe some loctite for e-bike use.

Just re-assemble it with proper shimming & red lock tight will hold it.....Or get a new one.


I get a little puke in my mouth every time some hill-billy puts a tack weld onto a precision machined,hardened & tempered part.

 

[speedmd]

precision machined,hardened & tempered part

.......with pawls /teeth 1/4 the size / strength they need be.

 

[Thud]

Not for their designed purpose......

 

[speedmd]

Not for their designed purpose......

You right! Borderline passable for those little 60 pound kids on bmx bikes! :lol: :lol: :lol: