Building a quality 11t freewheel

[Jeremy Harris]

I've never seen a bike with 6 speeds. All mountain bikes since forever have been 7 to 9 on the rear.

There are literally millions of 6 speed freewheel equipped bikes around. I have two, both reasonably recent. The commonest freewheel used is the cheap Shimano MF-TZ30 - Google it, you'll get loads of hits.

The popularity of six speed comes from the budget bike market, all those tens of millions of cheap bikes sold in the Far East etc. Many just have 6 gears.

On an ebike I'd say that you don't need a lot of gears, or really any of the very low ratio gears, as you have the motor to help out. My electric folder stays in top gear most of the time and I don't think I've ever used the 28t gear.

Jeremy

[auraslip]

wow this is retarded http://cgi.ebay.com/NOS-Shimano-7-speed ... 256229e1bf

$110 with 3 days left for a freewheel that probably cost $20 ten years ago.

[neptronix]

Just shows how much of a demand there is for such an item..
23 bids... and with ~2 days left..

BTW guys, i am getting one of the 'beta test' 7 speed 11t-28t DNP freewheels and will give it 6 months of thrashing.
Fingers crossed that DNP has got the bugs worked out of this freewheel. If so, i will buy a baker's dozen and sell them as new old stock for a few hundred bucks too..

[auraslip]

Right... with prices this high, I'm surprised counterfeiters haven't gotten in on this action.

btw, does anyone here run 11t track freewheels?

[Ykick]

wow this is retarded http://cgi.ebay.com/NOS-Shimano-7-speed ... 256229e1bf

$110 with 3 days left for a freewheel that probably cost $20 ten years ago.

That's Nucking Futs!!!

[amberwolf]

Right... with prices this high, I'm surprised counterfeiters haven't gotten in on this action.

Maybe they have...and that's what you see on these auctions (artificially driven up by scam bidders, since you can't tell on ebay who's really bidding anymore).

[auraslip]

I doubt it amberwolf.... it's the only one I've ever seen for sale on ebay. their are plenty of the dnp 11t freewheels though.

[Mark_A_W]

It looks identical to my spare 11-34t shimano.

[Ykick]

Send that link to Shimano...

[motomech]

Just shows how much of a demand there is for such an item..
23 bids... and with ~2 days left..

BTW guys, i am getting one of the 'beta test' 7 speed 11t-28t DNP freewheels and will give it 6 months of thrashing.
Fingers crossed that DNP has got the bugs worked out of this freewheel. If so, i will buy a baker's dozen and sell them as new old stock for a few hundred bucks too..

Care to elaborate?

We were just talking about these things on your build thread, when I wondered out loud if there had been any recent develoments.
Let me guess, you took matters in hand, picked up thre phone and called them right then and there:)

At any rate, I, for one, eagerly await your report.

[neptronix]

well, thus far:

The freewheel was nickel plated.
It's heavier than the 13-28t Shimano that was removed.
Machining is not up to Shimano standards; looks like the metal is not cleaned up as well.
Does not freewheel as well as the Shimano, seems to have about 33% more resistance.
The freewheel clicking is louder than the Shimano; perhaps the mechanism is stronger? let's hope so!

Have yet to get it out on the road though, as it is raining like crazy. I will report back later.

[curious]

In my view 6sp freewheel with 11t cog is just fine *if* they had 7,8 and 9sp compatible spacing options so it can be used with any index system.

[auraslip]

I really like the idea of a freehub that screws on to the threads meant for the freewheel. There are so many options with cassettes.
I wonder how much it'd cost to have an adapter machined?

In my view 6sp freewheel with 11t cog is just fine *if* they had 7,8 and 9sp compatible spacing options so it can be used with any index system.

The spacing would be fine, you just have to limit the derailleur so it couldn't shift the last few gears and fall of the freewheel.

[curious]

The spacing would be fine, you just have to limit the derailleur so it couldn't shift the last few gears and fall of the freewheel.

It's been a while since I looked at the drawings but I thought spacing is different between 7,8,9sp systems and index shifting will not be reliable unless matched. Please correct me if I am wrong.

[Mark_A_W]

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

[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.