Three-speed fixed: They live!

[rogerzilla]

Wouldn't be any good for our "10" course (U48) - it's flat except for the first half mile, which is gently downhill (Jaded knows it now, after last night's dogging  ).

For that, you want something like 84" direct drive, with 90" for the very start.  With the ASC, you'd be condemning yourself to using the planetary geartrain for 96% of the time, and half a mile an hour in a time trial is a really big time difference.

[Treewheeler]

Rohlosphere...

I think that one may be a candidate for the 2010 edition of the Oxford Dictionary...

[Chris N]

My ideal fixed hub gear would be simple 2-speed design with no neutral, and no lossy planet gears, shiftable only when stationary.  Ratios maybe 70 and 60".  With the 70 as direct drive, and no backlash.  Like a TF

That would be just like turning the wheel round, but easier

Yes.

72'' and 81'' for me please.

The more I think about it, the more the Dingle makes sense.  40/19 and 42/17 for 57" and 67".

[Adrian]

The more I think about it, the more the Dingle makes sense.  40/19 and 42/17 for 57" and 67".

The trouble with that set up is that, whilst it works fine for two singlespeed gears, if the chain is to be taut enough for fixed the wheel would stil have to come out and be re-set each time you wanted to change the ratio.

[Chris N]

It's less hassle than flipping the wheel though, right?  And less to worry about than a fixed hub gear.

[Adrian]

I just hope they pitch it at an accessible "clubman" kind of price, and not up in the Rohlosphere. 

Did I mention that I held one at The Cycle Show? They were talking about the same sort of price as a "normal" 3 speed, ie around £90 including shifter, of which they anticipated a choice.

[rogerzilla]

The bad news is that any 3-speed weighs as much as a triple derailleur setup (that nice alloy case is almost full of case-hardened steel), so you have to look at the other advantages.

[Adrian]

The more I think about it, the more the Dingle makes sense.  40/19 and 42/17 for 57" and 67".

This set up from Londonfixie has an advantage over the Dingle in that you can chose from a wider range of cogs

[clarion]

A Dingle is simple & neat.  And I like the idea of the LF one above, but not sure about the spacing of the cogs...

[Chris N]

Yep, that's what I thought.  Lots of force on those screws.

[Pneumant]

Should not be a problem, motorbike rear sprockets are attached in that way.

[Chris N]

Using screws to attach a single sprocket should be fine, but it's the unsupported length of the screws when used to attach two sprockets that trouble me.  I can see bent bolts when you hoy it up a hill...

[Pneumant]

Thats a fair comment, unlike a motorbike sprocket carrier  the hub was designed to carry a disc which I would expect to have a lower torque loading than a sprocket under load.   Maybe the hub housing would / should fail first?

[border-rider]

The LeVeL system works like that - with bolts to hold the sprocket on - but the hub has bosses that stick out and its these that take the force

But I guess most disc hubs are pretty robust...I think I'd agree that bending the bolts is a bigger risk.

[oncemore]

With the bolt-on double I'd assume safety depends on the quality of the bolts and the spacer. The load is after all shared over six equally spaced points. To be fair, the LF comments are suitably qualified: "be it on your own responsibilty" I think.

[Adrian]

The bad news is that any 3-speed weighs as much as a triple derailleur setup (that nice alloy case is almost full of case-hardened steel), so you have to look at the other advantages.

How about "someone has to get one just so we can find out why they fell out of favour in the first place."

[clarion]

I gotta get one!

[Adrian]

We have a volunteer

[clarion]

A volunteer who is short of resources right now, but I'll review when the hubbly lovelies hit the market.

[Aidan]

I quite fancy one too. I enjoy riding fixed but I live on the edge of the Wolds , big hills one way flat the other way, would certailny save messing about changing cogs.

The novelty value would be attractive too

[rogerzilla]

The bad news is that any 3-speed weighs as much as a triple derailleur setup (that nice alloy case is almost full of case-hardened steel), so you have to look at the other advantages.

How about "someone has to get one just so we can find out why they fell out of favour in the first place."

I'd like to try one, but not to own one.  The gear jumps are too large for TTing and "normal" is the top gear when I'd like it to be the middle.  It's probably best for someone who really loves riding fixed and just wants a bit of help uphill - but experienced fixed riders will usually tell you the downhills are the problem.  You certainly want to spend 95% of your time in the "normal" gear for efficiency.

[clarion]

You're right about all of that, of course, but I imagine that to have normal in the middle, which I would definitely prefer, would mean lots more geary-type bits inside.

[oncemore]

The bad news is that any 3-speed weighs as much as a triple derailleur setup (that nice alloy case is almost full of case-hardened steel), so you have to look at the other advantages.

How about "someone has to get one just so we can find out why they fell out of favour in the first place."

Could run a raffle? "X" quid a ticket - winner has to install and test it? Anyone know/guestimate the price?

[rogerzilla]

About 90 quid, I'd guess.

[andygates]

And a tenner to get "Sheldon is my co-pilot" engraved on the shell before building it.

A project for when I'm out of this Northern Rock mortgage