spinningmagnets
100 TW
I certainly want to encourage anyone who wants to develop a new product for the ebike market, in order to fill an under-served niche, but...be aware that this can prove to be a fairly difficult challenge to overcome.
Strong freewheeling crankset
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Ecyclist
10 kW
SM, are there posts about unsuccessful attempts of that type? ES threads? It would be very helpful to read about them so I don't make the same mistakes. I'm sure there are plenty of new ones I can make.spinningmagnets said:
Here is interesting design by Japanese company that might do the trick. https://www.youtube.com/watch?v=0SlaeTYGicU
This is a heavy duty design and it needs to be half assed for a bike application.
Ecyclist
10 kW
So I did some research on freewheels and put a little thought to it. I figured that making a freewheel from A2 tool steel with wire EDM machine would cost an arm and a leg (at least a couple hundred a piece) and it is not worth pursuing. I looked for reasonably priced good quality freewheel and came across one made by Excess. I bought 22T from Dan's Comp and inspected it today. It was very difficult to open and I made a couple half ass tools to help me out. That freewheel is not bad at all. The ball bearings are in cages and axial run out at 3" dia. is only .001" After removing single .004 shim and putting it all together, the slap was only .005" total. It was not filled with grease but lubricated with oil and still very quiet.
Other really cheap freewheels have three shims (two .010" and one .005") This tells me that Excess freewheel with only one shim is made to very tight tolerance. I think that with proper spider attachment this freewheel is a very good choice for a e-bike crank. That is what I will use for my second build.
Other really cheap freewheels have three shims (two .010" and one .005") This tells me that Excess freewheel with only one shim is made to very tight tolerance. I think that with proper spider attachment this freewheel is a very good choice for a e-bike crank. That is what I will use for my second build.
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Ecyclist
10 kW
Different freewheel - different results. ACS Southpaw Freewheel, Left Hand Drive 20t 3/32" from Amazon. The good news is that I was able to use the same tools to open this freewheel and this wheel was lubricated with oil. The bad news is that ACS freewheel is much lower quality than Excess freewheel. It is better than $7 no brand name freewheel but not by much. Two .008" shims are used to set correct slap of .006". The axial run out at 2.5" dia. is .005". The wheel is noisy and three paws are not engaging at the same time. That means that paws are not 120 deg. equally spaced. This can be a major problem under heavy load.
These observations are based on two kinds of a single sample of a freewheel, and as you know, Chinese products are inconsistent if comes to quality. So take it with grain of salt. I will use first 22T Excess wheel for my crank and get a second Excess freewheel and with proper attachment use it as a left hand drive. No biggie...
These observations are based on two kinds of a single sample of a freewheel, and as you know, Chinese products are inconsistent if comes to quality. So take it with grain of salt. I will use first 22T Excess wheel for my crank and get a second Excess freewheel and with proper attachment use it as a left hand drive. No biggie...
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Chalo
100 TW
spinningmagnets said:
While it's cool that somebody did it, I wonder why use a BCD that doesn't correspond to any standard bicycle chainring? Normal 4 hole rings are 104/64mm, and commercially available 5 hole rings come in 144, 135, 130, 110, 94, 74, 58, 56, and 50.8mm BCD.
What does 68mm offer that 74mm doesn't? Or maybe it's a mistake and they actually mean 64mm?
For what it's worth, it would be a simple adapter plate that steps up the pattern on this freewheel to 110x5 or 106x4, or anything bigger.
Ecyclist
10 kW
64 BCD will not fit. If they made arms flush with outside wall and drill and tap for chain ring bolts, then we could fit a small chain ring without extra parts. But, I wonder why Luna freewheel is not made to accept 104 BCD. Maybe, they didn't think about it or maybe they just machined teeth off and drilled four holes from a standard 1.375x24 freewheel. I hope that the main body is not made of brass. It kind of looks like it.
Chalo
100 TW
Ecyclist said:
I doubt it. It looks like yellow zinc chromate to me, like what's on Grade 8 bolts.
A shame--if they had just left the full circle of metal on there, anyone with other numbers of holes could have easily redrilled it to work with their stuff, as long as it was the same diameter.
Doing it the way they did means less people can use it (without making a whole adapter ring/plate), so less customers to buy it, and probably weakens the structure, too (the full ring would better resist twisting loads from off-center chains, etc.
(crossposted from here https://endless-sphere.com/forums/viewtopic.php?f=28&t=7641&p=1250111#p1249690 since the ad was also crossposted)
If I was making such a product, I would have made it to accept "standard" chainrings, and if making my own chainrings too, I would have made *them* "standard" as well so they could also be used with other people's existing parts, and not force potential customers away just because they coudln't use the parts they already had or liked, or else force them to buy all-new stuff from me just to use the one part they needed.
I know some places do this sort of thing to ensure compatibility, or to solve some other problem that came up, but there are other ways to do that, most of the time.
In my limited experiences, when non-standard stuff is done, it's usually in an attempt to make more money, and sometimes backfires.
Doing it the way they did means less people can use it (without making a whole adapter ring/plate), so less customers to buy it, and probably weakens the structure, too (the full ring would better resist twisting loads from off-center chains, etc.
(crossposted from here https://endless-sphere.com/forums/viewtopic.php?f=28&t=7641&p=1250111#p1249690 since the ad was also crossposted)
spinningmagnets said:
Using a non-standard size means that you can't use stuff with it that you didnt' also buy from the same place. It's something that some companies choose to do, for whatever reason. I don't know if that's why it was done in this case, but I don't see any technical or other reason to have done it.Chalo said:
If I was making such a product, I would have made it to accept "standard" chainrings, and if making my own chainrings too, I would have made *them* "standard" as well so they could also be used with other people's existing parts, and not force potential customers away just because they coudln't use the parts they already had or liked, or else force them to buy all-new stuff from me just to use the one part they needed.
I know some places do this sort of thing to ensure compatibility, or to solve some other problem that came up, but there are other ways to do that, most of the time.
In my limited experiences, when non-standard stuff is done, it's usually in an attempt to make more money, and sometimes backfires.
panurge
10 kW
Dunno where at Luna they get their 4Arms freewheels, but I've managed to get quotes from the 2 Taiwanese manufacturers I know about with these kind of frewheels in their catalog 2 years ago, exactly for 64mm bcd arms and sorted out that a 64 PCD would not give the required room for the bolts, the main FW body being 54mm.
68PCD was an old and really faulty standard from shimano mtb. I guess an orignal SHimano xtr M952 spider/ring combo would be perfect for these 68mm freewheels
was a 68-112 BCD spider with a 46t ring... And 112 is actually the new campagnolo standard for 2x11 in the range of 30-40t
After a lathe out in the splined bore till 54mm of diameter (or a rude cut-out around the holes) it should work perfectly
68PCD was an old and really faulty standard from shimano mtb. I guess an orignal SHimano xtr M952 spider/ring combo would be perfect for these 68mm freewheels
was a 68-112 BCD spider with a 46t ring... And 112 is actually the new campagnolo standard for 2x11 in the range of 30-40t
After a lathe out in the splined bore till 54mm of diameter (or a rude cut-out around the holes) it should work perfectly
recumpence
1 GW
They already sell them. I bought one 4 months ago. Kind of expensive at $110, but worth it.Pablo said:
panurge
10 kW
Hey Matt!
Are you talking about the UHD freewheel made by WI for SBP? is that unit equipped with double sealed bearing support?
Pablo seems to point at a different price, though.
Are you talking about the UHD freewheel made by WI for SBP? is that unit equipped with double sealed bearing support?
Pablo seems to point at a different price, though.
Perhaps a different unit....?recumpence said:
recumpence
1 GW
Yes, that is the one.panurge said:
briangv99
1 kW
Pablo said:
Hi Pablo, the UHD White freewheel is listed as sold out, are you doing another production run of them?
You do know there is a rule against spamming ads outside the for-sale sections, right?
I asked Pablo to create a new topic in the For Sale section where he can describe the freewheels he has.
Hummina Shadeeba
10 MW
With sickbikeparts no longer having square taper freewheeling cranks is there anywhere in usa that sells them besides the ridiculously priced Luna? I see some for trials but they’re so short and I’d like at least 160mm
Hummina Shadeeba
10 MW
Thanks Pablo. Yes got them from them
https://www.cyclone-tw.com/product/13
$25 and shipping to usa it’s $54. Not bad.
https://www.cyclone-tw.com/product/13
$25 and shipping to usa it’s $54. Not bad.
Chalo
100 TW
Hummina Shadeeba said:
You reckon you'll be pedaling much without e-assist? Once you exceed about 2kW of motor power, it isn't really a pedal vehicle anymore, even if it has pedals.
The shorter the crank, the faster you can spin before pedaling gets jerky/bouncy. I switched from the stock 170mm on my BBS02 to 152mm so I could pedal along at a crank speed that put the motor in a more efficient range.
I switched from 185mm to 170mm on a hub motor bike, to increase the speed range I could pedal in without changing up the bike's gearing.
Here are threaded trials cranks in 165mm and 175mm, from a USA online shop:
https://www.webcyclery.com/product/trialtech-race-forged-cranks-6437.htm
Hummina Shadeeba
10 MW
Thanks for the help but they’re Isis and I need square taper. I already ordered and they’re a sure thing for a good chainline and what I have already. Making three bikes for some reason.
I don’t plan to pedal at all and the freewheel I had made has no ratchet and needs a bolt added to enable pedaling. With the 54x21 gear ratio I wonder if ever be worth pedaling especially with it being a fixed gear.
i went w square taper as there’s so many more bb spindle lengths and could get a better chainline
I don’t plan to pedal at all and the freewheel I had made has no ratchet and needs a bolt added to enable pedaling. With the 54x21 gear ratio I wonder if ever be worth pedaling especially with it being a fixed gear.
i went w square taper as there’s so many more bb spindle lengths and could get a better chainline
DanGT86
100 kW
Just came across this FW bottom bracket on amazon. Anybody try this one? Looks like it's based on a csk bearing clutch. Also appears to be a slip fit in one side and thread on the other similar to the way a BBS02 installs in the BB. Wonder what the long term effect on the BB threads are.
https://www.amazon.com/dp/B085RXNS5R/?coliid=I13K5AT1WFHOWJ&colid=JUK41FZ9RE06&ref_=lv_ov_lig_dp_it&th=1
https://www.amazon.com/dp/B085RXNS5R/?coliid=I13K5AT1WFHOWJ&colid=JUK41FZ9RE06&ref_=lv_ov_lig_dp_it&th=1
Ecyclist
10 kW
This freewheel actually looks interesting. Nice find. :thumb:
DanGT86
100 kW
Seems like for the price it would be worth getting something thats proven already like the UHD white ind unit. But the bearing clutch is nice and probably very reliable and quiet.
Hopefully someone will try it and report back to us.
Hopefully someone will try it and report back to us.
Chalo
100 TW
CSK clutch bearings have to be really big to withstand all the pedal torque a strong rider can develop. Reviewing their ratings, I find that a CSK 35 world work for a typical cyclist but I'd need a CSK 40 to be able to stand on the forward pedal (even without pulling on the handlebar for more force).
CSK 35 is 72mm in diameter, 17mm thick, and weighs 317 grams. It would be feasible but not easy to package into a crank spider. The Amazon freewheeling bottom bracket definitely doesn't contain one that size.
CSK 40 is 80mm in diameter, 22mm thick, and weighs 500 grams. It would make for a very bulky crank.
CSK 35 is 72mm in diameter, 17mm thick, and weighs 317 grams. It would be feasible but not easy to package into a crank spider. The Amazon freewheeling bottom bracket definitely doesn't contain one that size.
CSK 40 is 80mm in diameter, 22mm thick, and weighs 500 grams. It would make for a very bulky crank.
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