Building a quality 11t freewheel

[itselectric]

7 and 8 are the same spacing. 9 is different.

I am sorry, if I may make the correction. If we are talking about the DNP freewheel, the detail drawing was shown in the following topic:
viewtopic.php?f=2&t=18314&p=276120&hilit=dnp#p276120

7 speed freewheel space is 36mm 8 & 9 is 40mm

Ken

[curious]

Ken, I meant the spacing between gears (shift step) not the total freewheel height.

But I am even more confused after looking at DNP drawings you posted and comparing it to the reference here:
http://www.sheldonbrown.com/cribsheet-spacing.html
Shimano 7sp index step is 5mm, while DNP 7sp is 3.1+1.8 = 4.9mm
Shimano 8sp index step is 4.8mm, while DNP 8sp is still 4.9mm
AFAIK shimano 7sp and 8sp index shifters are not exactly step-compatible, 0.2mm is small for a single step, but over 6-7 spaces it accumulates to a ~1.3mm difference at one end or 0.65mm at both ends. It is probably OK from a practical standpoint but not perfect. It looks like DNP choose the midpoint so presumably it can work with both to some degree.

[neptronix]

OK, just went out for a ride with the DNP.

Front crank gear = 48t.
wheel / tire = 26" wheel, 1.95' tire @ 40PSI.

It was quite noisy ( grinding, clicking ) when i first installed it, after i took a ride it has quieted down some. I guess it needs to machine itself even, hehe. There was also a lot of wobble in the freewheel when first installed, that seems to be going away as well.

The downside is that it drags on the wheel more than the shimano. I hope this improves.
Perhaps it is not broken in. I will report back on that later.

The good news is that 11t is perfect for a fairly relaxed pedaling pace at 20-25mph. I hit 29mph, 1mph higher than my previous 10S lipo record. Cool.

I think i can get a higher top speed on 14s, probably a few mph higher.

This makes pedaling into the 30mph zone possible. At a frantic pace on a 26" wheel... but possible

[Doctorbass]

Here is my post about the very first SINGLE speed 11T freewheel for hub motor:

http://www.endless-sphere.com/forums/viewtopic.php?f=2&t=27108

Doc

[kudos]

Does anyone know of a UK/Euro supplier of 7 speed freewheels with a 11T cog?

You can get them from Grin and and ebikessf but with postage it works out expensive.

Crystalyte Europe only have a 9 speed with 11T.

Kudos

[miuan]

http://www.ebike-solutions.de/de/Shop/M ... -7-Ritzeln

[kudos]

http://www.ebike-solutions.de/de/Shop/Motoren/Schraubkraenze/Schraubkraenze-mit-7-Ritzeln

Thanks!

[hillzofvalp]

I CNC'ed a splined coupler that lets me mate a standard 11T or even 10T cassette cog to my White Industries freewheel. The two main reasons for making this were that I wanted to both avoid a derailleur because with horizontal dropouts it is redundant to have a derailleur AND to run a much smaller gear with a nice freewheel mechanism. It also let's me adjust chain alignment more easily and have arguably cheaper maintenance ($10 cog).

The reason the splines have rounded grooves is that the smallest endmill I had (1/8") would not get all the material if I didn't overcut. Worked out splendidly. Edit: too wide for cromotor. If Anyone wants one, let me know.

[Architectonic]

Looks like a work of art. What kind of price are we looking at for those?

[hillzofvalp]

Well, the above works, but it's only a prototype. I'm not sure what the spec is on the od of the white industries free wheels.. Also, i need to make a better design to hold the cog firmly against the splines. Fr the prototype I just used some button head screws to hold the cog down. Kind of stupid solution. A ring beneath that would've been better. A threaded piece tht requires a standard bike tool would be nice, but drives costs up

Making it all out of aluminum brings costs down, but I do not have the materials or mechanical knowledge to judge whether the splines woud hold up over time. It is a very snug fit, though.

If you are seriously interested, I can try to make a batch. I'd probably have someone else do it because using schools CNC machines it a privilege to not be abused. On that note, I'm not sure how much it would cost. Ifi had permission to run a dozen of them, I'd probably charge like $80-100usd.. But it really depends on if I can get the surface feet per minute up or not.

A bit of a catch is that whenever u want to take the freewheel off u have to take the aluminum off first.

[MAGICPIE3FOCUSPOWER]

I really don't like DNP Epoch 11T 8 speed freewheel.
To much play and noise (not even used).
And the price is way too high!

So I went back to Shimano 14T 7 speed freewheel, less play and noise.

[kfong]

It's hard for me to not use a freewheel with 11 tooth. Already gone thru one 9 speed DPN freewheel, had to throw it out after two seasons. my current DPN seems to be holding up, it seems to be better made. I recall epoch as the module number. One of the members found a bearing to fit the big gap. If you look at the design, there is just not enough support. It causes the higher gears to push hard aganst the opening. This increases the runout overtime. I plan to do the bearing mod when I get the chance.

[Kingfish]

It's hard for me to not use a freewheel with 11 tooth. Already gone thru one 9 speed DPN freewheel, had to throw it out after two seasons. my current DPN seems to be holding up, it seems to be better made. I recall epoch as the module number. One of the members found a bearing to fit the big gap. If you look at the design, there is just not enough support. It causes the higher gears to push hard aganst the opening. This increases the runout overtime. I plan to do the bearing mod when I get the chance.

I just replaced mine with a brand new unit and it is so much more quiet. The first one was a rattle-trap; I don't think it was well-greased. People would here the freewheel over the motor noise. Now - I only hear the motors, which also have new bearings

Although I'm with you and can't go back to a lower gear; I have several 13 and 14T Shimanos and they turn smoothly like silk.
Pity I can't use them KF

[MAGICPIE3FOCUSPOWER]

I don't trust them anymore.
The sprockets will worn out earlier then all other drivetrain.
And I don't like to replace whole drivetrain because of this weak DNP Epoch freewheel.

So my solution is a bigger chainring

[neptronix]

They do make 60T chainrings.. ;]

http://www.vueltausa.com/components/chainrings/se-flat-chainrings/se-chain-ring-130mm-38-60t-1.html

They sure look funny though, lol.

[MAGICPIE3FOCUSPOWER]

Looks great mate!

Thanks for the pictures.
But my cranks are 104mm and 4 arm
I have just ordered 48T chainring hopefully this enough with 14T freewheel.

[kfong]

Unfortunately modifying the drive gears or even the frame geometry was never an option for me. I use the ebike solely for single track. Performance and all gears are needed. I often push the ebike to empty. Try riding an ebike without power in the trails. Having a big front sprocket will get mashed up during use over log piles. My Ebikes have to ride as good as a quality mountain bike in the trails. I've put the current one through many crashes, jumps and hard climbs. It puts a smile on me every time I take it in the woods. Not much I would change on this setup. viewtopic.php?f=6&t=12654
Obviously riding only on street or commute would have different objectives.

[Kingfish]

They do make 60T chainrings.. ;]

Oh now you've done it and planted a seed and I can't stop thinking about it now

I'll have to check that out - thanks, KF

[hillzofvalp]

Slightly related.. I just made a 63T chainring for my 104mm 4 bolt MTB crank. Is turned out really nice. Running 1/8" chain with 15T white industries. Happy pedaling 25-35mph. I wheelie a lot more actually and my top end is better as u would expect. Cnced it out of 7075.

[MAGICPIE3FOCUSPOWER]

Waauww well done!

Too bad I don't have the opportunity/machines/skills to that

[rjoe]

Sorry, I didn't want to start a new thread just to say this:

I will never use anything other than a DNP freewheel on my bike

because the first time I tried to remove it, all the splines stripped and now it cannot be removed

[DrkAngel]

Sorry, I didn't want to start a new thread just to say this:

I will never use anything other than a DNP freewheel on my bike

because the first time I tried to remove it, all the splines stripped and now it cannot be removed

DNP 11T uses a special deep removal tool.
It will probably work with your damaged freewheel, if you can tap it in.

DNP tool.JPG (17.03 KiB) Viewed 290 times

DNP Epoch Freewheel Remover

[MAGICPIE3FOCUSPOWER]

Does anyone knows how I can remove Shimano bearing for maintenance?

Thanks

[DrkAngel]

Sorry, I didn't want to start a new thread just to say this:

I will never use anything other than a DNP freewheel on my bike

because the first time I tried to remove it, all the splines stripped and now it cannot be removed

DNP 11T uses a special deep removal tool.
It will probably work with your damaged freewheel, if you can tap it in.

DNP tool.JPG

DNP Epoch Freewheel Remover

Epoch and Long Yih seem to be the only produces of the DNP 11T freewheels.

Epoch 11T freewheels consistently available from NiagaraCycle.com

Long Yih 11T freewheels available (only?) from SDebike.com

See - EBikes Toolbox - Bargains! ?

[Chalo]

11t freewheels are an inherently bad solution to the problem of too-low gearing. They are not a terrible thing to have when the 11t sprocket is used appropriately, which is just once in a while.

The main issue is that chain wear and friction increase nonlinearly as a sprocket diminishes in size, becoming measurably higher with each increment below 21t, and becoming problematic below 13t. On pedal bikes, the problems are surmountable because the very top gears are only used occasionally. (Also, to the manufacturers of parts, things that wear out quickly are not necessarily seen as problems. Especially when those things are seen as desirable rather than just shoddy.)

Note that track racing bikes, which sometimes reach 40mph speeds without the use of power assist, have sprockets that only go as small as 13t. Below that size, the loss of efficiency makes the option of higher gearing with smaller, lighter sprockets not worth it. And those bikes are using sprockets with wide, tall teeth-- not the kind we are discussing, with skinny stumpy teeth to help them shift more cleanly.

With e-bikes, small sprockets become a problem because the bike is run in high gears much of the time. If you run in top gear very much, you'll just chew through a lot of chains and 11t freewheels, accelerating the wear on your chainrings as you do so.

So for e-bikes, a better technical approach is to use a larger chainring rather than a smaller driven sprocket. This is a winning method in several ways: The chain articulates through smaller angles, the load is carried by more teeth, wear is distributed over more teeth, and chain tension under load is lowered in proportion to the increase in chainring diameter.

If you're not already using a 53t or larger big ring, it's foolish to pursue higher gearing through the use of a smaller rear sprocket instead. 53t cranks are so common as to be ubiquitous. A 60t ring is no more exotic or difficult to get than a freewheel with 11t high gear. So step one should be a 53t stock crankset, and step two should be a 56-60t chainring for that crank. Only after these steps are taken should a sprocket smaller than 13t be considered as an option to raise the gear ratio further.