Replacement Giant Lafree motor sprockets

[flecc]

The supply of Lafree 14 tooth motor sprockets that A to B Magazine have arranged manufacture of are now ready for any owners or dealers requiring them.

These are precision CNC machined items, not the original pressed steel ones. When Giant last had spares they cost £30 each, but the prices from A to B Magazine are as follows:

£15 for one, £25 for two, or £35 for three, post free in the UK, and £1 postage on all orders overseas.

A to B Magazine, telephone 01305 259998, email atob@atob.org.uk

Here's a photo of one:

LafreeSprocket.jpg

[Teejay]

Does anyone know if these 14-tooth motor sprockets will fit the version of the panasonic motor on Agattus, etc?

If it does, this strikes me as potentially a splendid way round the power-fades-out-at-too-low-a-cadence thing. Would it work I wonder?

Any snags, disadvantages or no-no's in trying this anyone can think of?

[flecc]

No, it won't physically fit the newer unit. Firstly it's diameter is too great, secondly the spline structure is different, having a wide inner flange.

If it were possible, it would increase the cadence at the first step down from full power from 39 to 61, equal to the same 14 mph with standard bike gearing that the normal 9 tooth motor sprocket gives. The final power cut-off would be at 23 mph.

The downside would be a very large reduction in range.

There are three motor sprockets made for the newer Panasonic unit to suit different wheel sizes and bikes, 8, 9 and 11 tooth.

The 11 tooth on the Agattu etc would give full power to a 48 cadence with final cut-off at 18 mph, but there would still be a fairly large range loss, probably around 25 to 30%.

I don't think it's possible to buy those 11 tooth sprockets in the UK, but I know BikeTech of Switzerland who make the Flyer bikes have them. You'd need to find a BikeTech dealer in Europe to get one.
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[Teejay]

Thanks for that, Flecc. Saved me buying a pig-in-a-poke!

Will try and get an 11-tooth then, as I find one of the few downsides of these otherwise delightful and splendid machines is that it tends to hurt my knees a bit. I think any upping the cadence of fade-down will help.

[derrick7]

The one thing that bothered me about my Lafree (bought 2004) was the unavailability of spares, when you could have a perfect bike & not be able to use it because one component is worn out. No car owner after 5 years would tolerate that. 3 cheers for A to B!!

A company near me sells these - D Size 10,000mAh NiMH batteries @ £5.91 discounted price for 10+ (p + p incl) I have measured up the old cells off my Lafree & these new cells are same size (physically) @ £118.20 for the 20 I would need to make a new battery pack for my bike seems very reasonable to me. I haven't heard of the make before - VAPEX.

Go to Home if you want more info.

Derrick - Llanberis

[flecc]

These cells have end buttons Derrick, and that makes the fit in the case a problem. The existing packs are made of buttonless plain end cells with thin joining strips spot welded to make up the cell chain, and the resulting pack just squeezes into the case. I very much doubt the longer button end ones will squeeze in, especially once joining wires are soldered onto the ends.

Here's the sort of cells used for these packs:

Tagged end cells

and here's how the strip joined pack looks:


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[JohnInStockie]

I think these might be more suitable at £6.84 each.

1.2 V 9000 mAh D Ni-MH Industrial Flat Top Cell - Tagged CPS Batteries

John

[rog_london]

Originally Posted by JohnInStockie

I think these might be more suitable at £6.84 each.

1.2 V 9000 mAh D Ni-MH Industrial Flat Top Cell - Tagged CPS Batteries

John

It would be interesting to see what their lead time might be - they have a whole 11 volts worth in stock!

Rog.

[daniel.weck]

15 GBP:

Giant Lafree motor drive sprocket on eBay (end time 23-Nov-09 20:50:21 GMT)

[flecc]

That is the A to B one I posted about, and at the same price Dan. My guess is that it's A to B trying to shift some this way since they've had a disappointing response to making these available.
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