Upgrading a Lafree Twist

[flecc]

The low cadence is the major thing John, but as Steve has said, anything that can impede the natural settling of the knee into it's most comfortable position is to be avoided.
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[derrick7]

Second thoughts

The one thing that makes me nervous about spending money on my Lafree Twist viz. the Shimano 8 speed hub gear, which would (guess) cost me about £200 including a new wheel, is if the main circuit board packed up, or parts that can only be obtained from Giant, the cost of these parts, or whether they can be got anymore!
I would hate to spend this amount of money only to find it completely wasted.
Perhaps it would be better to put it towards a new bike, where spares are readily available & cheaper than Giants outrageous prices. But I do like my present bike!

Derrick - Llanberis

 

[flecc]

No motor unit spares are available from Giant UK any more Derrick. Until recently they had some of the 14 tooth motor sprockets, once about £6, and at £30 lately, but recently they've said no more. Batteries are £250 (6.5 Ah). The 14 tooth sprockets are still available in mainland Europe at 81 euros (over £56), a staggering price.

The circuit board has never been available, simply because it's encapsulated and sealed into the RH alloy side casing with silicone rubber, and Panasonic have never made other parts available as far as can be seen.

The only answers to most failed parts are scavenging from another Twist, or buying a complete replacement unit at £450 plus fitting.

For that reason I've been warning for some while that second hand Lafree twist series bikes are a risky buy. There's further details on the repairs pages of my site.
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[prState]

The only answers to most failed parts are scavenging from another Twist, or buying a complete replacement unit at £450 plus fitting.
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Can something like the 14 tooth motor sprocket be custom made by a laser lathe? I would have to contact a third party, but I've seen ads for custom work if you send details of what you need. I'm sure it's probably not cheap though.

I seem to remember when Schwinn, manufactured their bolts and stuff with unique thread patterns. You couldnt just pick up a replacement anywhere -- very aggravating. Of course, i guess they were trying to lock in customers at the time.

Also, have any guess how long the original sproket should last on average?

 

[flecc]

It would be very difficult prState, due to the quite small shaft diameter it sits on and it's internal splines. The outer part of the sprocket would be easier. The lowest cost way would be to have the centre splined area cut out and the outer of any 14 tooth sprocket welded on. A laser lathe could easily do that cutting of course.

The sprocket is the fastest wearing part of the unit, but it's life depends on how well the chain is lubricated. The teeth reach the end of life at anything from 3000 to 6000 miles usually, and the chain starts jumping then.

A temporary fix that can last a very long time is to remove it's securing circlip and turn the sprocket round to use the reverse of the tooth faces. Doing that makes it impossible to replace the circlip, but the sprocket is kept on by the chain coming straight off the secure chainwheel position.

Thanks to Senior Member Leonardo's invaluable help in using his much greater language skills on my behalf, we've been scouring Europe for spares and can get the sprockets at the moment, but at that hefty price reported above. However, any repair method would probably be at least as expensive.

Unfortunately Panasonic's latest unit appears to use much smaller sprockets of between 8, 9 or 11 teeth, depending on the bike wheel size of course.

I'll be updating the Repairs section of my site shortly with the latest information and will add to that from time to time as any changes occur.
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[oznog]

I think a 16 tooth without offset will run ok on the SRAM P5 hub John, though I'm not certain. A 14 tooth definitely won't.

There's nothing else you can do on the Twist/Comfort, since the cowlings prevent chainwheel change, though an SRAM 7 speed will give a higher gear.

With that your 16.4 mph would become 18.1 mph, all other things being equal.

A.

so is it best to get a flat, or offset sprocket for a sram p5 hub?

 

[flecc]

Offsets are the safest bet oznog, though in larger sizes the straight ones are ok.

It's just a question of the chain riding on the side wall of the hub with the smaller diameter ones, the offset displacing the chain outwards a little to avoid that.

Normally this is never a problem with bikes, since the chainring can be changed to allow the larger rear sprockets for all gearing needs.

It's just on the Lafree Twist series that it's a problem since that is restricted to a non standard and small 37 tooth chainwheel, so small rear sprockets are needed for higher gearing.
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[artslim]

Lafree Sizes.

Is there any markings on the Lafree as to the size of the bike. If not, how do you know what size it is? Cheers.

 

[JohnInStockie]

Normally on the downtube (under the seat) near the top, there will be a label, usually either M (medium) or L (Large). Ive got an M non-strep thru and I'm 5'11", but thats with the seat up high too.

John

 

[artslim]

Thanks John.