Biologic freedrive chain cover

General cycling advice ( NOT technical ! )
rjb
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Biologic freedrive chain cover

Postby rjb » 5 Mar 2016, 3:03pm

Biologic freedrive chain cover.
Image

I thought about using something similar for the timing chain on the tandem. I have seen suggestions that it traps water but as we don't go out when its raining this may not be an issue and with 2 people the extra friction should be negligible.
I thought about using flexible cable conduit as i need almost 2 metres.

Any thoughts people.
At the last count:- Focus Variado, Peugeot 531 pro, Dawes Discovery Tandem, Dawes Kingpin, Raleigh 20, Falcon K2 MTB dropped bar tourer, Longstaff trike conversion on a Falcon corsa. :D

Brucey
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Re: Biologic freedrive chain cover

Postby Brucey » 5 Mar 2016, 5:43pm

it does indeed trap water (and anything else that gets thrown in there) but is otherwise a half-reasonable idea (that has been around in one way or another since the 1980s in fact...) .

Mind you a set of trouser clips works pretty well too.... :wink:

BTW cable conduit may or may not work; it may not fit, it may not clip together, it may not flex right, it may degrade with UV light.... if you do find something that works OK, I'm sure that others will be interested to hear what it is!

cheers
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greyingbeard
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Re: Biologic freedrive chain cover

Postby greyingbeard » 5 Mar 2016, 7:04pm

hosepipe with small holes to let water out ?

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Redvee
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Re: Biologic freedrive chain cover

Postby Redvee » 6 Mar 2016, 1:20am

Brucey wrote:that has been around in one way or another since the 1980s in fact.


Can remember seeing these in different colours on schoolfriends BMX's and wanting one on my geared bike but couldn't for obvious reasons.

rjb
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Re: Biologic freedrive chain cover

Postby rjb » 10 Mar 2016, 3:58pm

In town yesterday so called in to a motor factors to see what cable conduit they had. They were very helpful letting me into the warehouse to try a piece of chain I had brought with me. I purchased 2 metres of conduit 10 mm od, 7 mm id for the grand sum of £1.54 ! I really needed a slightly larger size, 10mm id was the next size up but unfortunately they didn't stock it but could order 50 metres for me at a cost of £30. I declined the offer and thought I would trial what I had just bought.
First impressions on fitting it to the 1/8 timing chain on the tandem. It's fiddly and messy to fit and not a five minute job. Anyhow having got it on we took it for a 45 mile test ride today. It was not at all draggy so the friction losses are negligible, it does make a "crinkling" noise for the first few revolutions but is then very quiet. Hopefully the extra rigidity will lesson the chances of an unshipped chain - I don't like to run it tight. The cover did not rotate at all on the test ride so all bodes well. The ends don't need to be secured as it all stays put. As you can see from the pics a slightly larger diameter would cover the chain better. Anyway I will update you all on progress in a couple of months. :D
BTW pics below were taken after the 45 mile test ride.

image.jpg
Split cable conduit on 3/32" chain


image.jpg
Split cable conduit on 1/8" tandem timing chain
Last edited by rjb on 10 Mar 2016, 4:15pm, edited 1 time in total.
At the last count:- Focus Variado, Peugeot 531 pro, Dawes Discovery Tandem, Dawes Kingpin, Raleigh 20, Falcon K2 MTB dropped bar tourer, Longstaff trike conversion on a Falcon corsa. :D

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Mick F
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Re: Biologic freedrive chain cover

Postby Mick F » 10 Mar 2016, 4:09pm

Excellent work! :D
Wonderful idea too.
Mick F. Cornwall

Brucey
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Re: Biologic freedrive chain cover

Postby Brucey » 11 Mar 2016, 9:25am

good work!

cheers
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~~~~~~~~~~~~~~~~~~~~~~Brucey~~~~~~~~~~~~~~~~~~~~~~~~

reohn2
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Re: Biologic freedrive chain cover

Postby reohn2 » 11 Mar 2016, 9:38am

Looks good,but what would concern me more than anything(leaving water aside which could be drained by a few holes on the outer edge) would be the inability of it to shed muck and dirt from the chain.As a chain by it's nature is an open structure which does shed a lot more muck than we realise IMO,and such a protector would do the opposite collecting it on the bottom run,which would then be captive and become a grinding paste being constantly recycled within the conduit.

My 2d's worth.

EDIT Thinks.... if the conduit closed totally on the free chain runs and was 'sliced' opened as the chain contacted the cog or chainrings,then it could practically 'close' the system.
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Brucey
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Re: Biologic freedrive chain cover

Postby Brucey » 11 Mar 2016, 10:00am

reohn2 wrote:....Thinks.... if the conduit closed totally on the free chain runs and was 'sliced' opened as the chain contacted the cog or chainrings,then it could practically 'close' the system.


I was wondering about the same kind of thing....

cheers
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~~~~~~~~~~~~~~~~~~~~~~Brucey~~~~~~~~~~~~~~~~~~~~~~~~

rjb
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Re: Biologic freedrive chain cover

Postby rjb » 11 Mar 2016, 1:34pm

Yes, that's why I wanted the 10 mm internal size but I didn't want 50 metres of it as an experiment. This is only an interim to test the theory. If anyone knows where the 10 mm stuff is widely available we could all try it. One thing that did surprise me was the amount of fine sandy dust on the cover after the first ride - at least the bulk of it isn't on the chain acting as grinding paste. Time will tell if its useful or not.
At the last count:- Focus Variado, Peugeot 531 pro, Dawes Discovery Tandem, Dawes Kingpin, Raleigh 20, Falcon K2 MTB dropped bar tourer, Longstaff trike conversion on a Falcon corsa. :D

rjb
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Joined: 11 Jan 2007, 10:25am
Location: Somerset (originally 60/70's Plymouth)

Re: Biologic freedrive chain cover

Postby rjb » 19 Apr 2016, 5:41pm

An update as i have completed just over 1000 miles with this cover. Impressions so far, it works well. the cover does get mucky on the outside from spray thrown up by the front wheel - at least its now kept off the chain. No problems with water but we don't go out if raining nor leave it stored out in all weathers. We have been caught out in the rain and some of the local roads are flooded due to high river levels and the chain is subjected to significant spray under these conditions. Lubing the chain involves a quick wipe over with a rag and then i spray a little chain oil over the exposed links while rotating the crank - takes a couple of minutes in total and i do this approx every 250 miles. I reckon i am using less than 1/2 the chain lube i used before fitting. As a timing chain cover it only revolves around a 38 tooth chainring, on a hub geared bike the sprocket will be much smaller so may cause problems with staying attached due to the tighter radius, dahon specify a 17 tooth minimum sprocket size. We have not had any problem with it coming detached on the tandem but it has shrank leaving a 3/8" gap between the ends. I may be able to stretch it a bit near the middle but its not really a problem. You just need to be aware of this when fitting it and try to compress it as much as possible. I saw one fitted to a Dahon folder which was supplied like it from new and that had a 1, 1/2" gap. :shock: whereas my cover was approx 7mm id it would cover better if you could get 9mm id. which is what i suspect is the internal diameter of the biologic cover.
so come on all you hub gear guys - give it a go and report back. :mrgreen:
At the last count:- Focus Variado, Peugeot 531 pro, Dawes Discovery Tandem, Dawes Kingpin, Raleigh 20, Falcon K2 MTB dropped bar tourer, Longstaff trike conversion on a Falcon corsa. :D

mercalia
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Re: Biologic freedrive chain cover

Postby mercalia » 19 Apr 2016, 10:10pm

Brucey wrote:it does indeed trap water (and anything else that gets thrown in there) but is otherwise a half-reasonable idea (that has been around in one way or another since the 1980s in fact...) .

Mind you a set of trouser clips works pretty well too.... :wink:

BTW cable conduit may or may not work; it may not fit, it may not clip together, it may not flex right, it may degrade with UV light.... if you do find something that works OK, I'm sure that others will be interested to hear what it is!

cheers


or easier tuck your trouser bottoms into your longish socks?, what I do. can you buy the clips any more?

Bmblbzzz
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Re: Biologic freedrive chain cover

Postby Bmblbzzz » 20 Apr 2016, 3:54pm

You certainly can buy clips, as well as slap wraps and velcro ties for your trouser cuffs.