Building a quality 11t freewheel

[Mark_A_W]

My derailleur problem is a 9 speed derailleur doesn't expect a 34 tooth gear in position #4, so it doesn't clear the gear, but runs into the side of that gear. It would handle a 34t gear is position #1 just fine, it is designed for that. But the 6 gear freewheel is skipping the first three gear positions, effectively.

So that is one danger of making a 6 or 7 gear freewheel. The derailleur may not be opened up enough to clear the largest gear if it is made too large.

At least that has been my experience with mine.

Sounds like you need to adjust the tension screw to pull the derailleur away from the sprockets.


There really isn't a "9 speed" derailleur - they are agnostic.


Oh, and yes, the spacing for 6 and 7 speeds is the same. 7 speeds fits in almost all motors, I can't see the reason for going lower.

But a 7 speed with 9 speed spacing would be very handy.

[Alan B]

Thanks for the derailleur adjustment tip, I'll check on it.

I see no reason for seven speeds. Six is plenty for an ebike with three front chainrings. Seven speeds won't fit on many motors without a spacer, exceeding the 135mm design width of the frame and bending alloy frames is not wise.

It would be excellent to have both 6 and 7 speed freewheels, but if only one can be made the 6 would be the most universal choice.

Thanks!

[Mark_A_W]

I have one front chainring = 56t.


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

[Hyena]

All my bikes came with an 8 speed clusters and run fine with a 6 speed shimano 14-2x.
That said I ride it practically as a fixie and very rarely take it out of top gear so I don't know how smoothly it shifts through the gears...

[Mark_A_W]

Till it breaks...

I currently have 56t and 28t rear and it's almost unrideable when the electrics are broken...

[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