Yet Another Cycling Forum

General Category => Freewheeling => The Dark Side => Topic started by: nobby on 15 December, 2008, 09:09:40 pm

Title: Tailboxes
Post by: nobby on 15 December, 2008, 09:09:40 pm
These here tailboxes on recumbents; are they to special scientifical dimensions or are they as wide as the back of the seat, as high as the space between top of rack and top of seat (unless you need a headrest) and as long as rack allows while finishing in a pointy bit?
I reckon I could bend one up from thin ply and stitch and glue it. It'd be handy for waterproofs and stuff but if it's scientifically worked out measurements I'll stick with the rack bag/saddlebag/bumbag combinations :D
Title: Re: Tailboxes
Post by: Torslanda on 15 December, 2008, 09:38:28 pm
Someone who is an aerodynamicist/Mike Burrows/all round clever git will be along soon to put everyone right but here goes.

Anything that reduces the drag (vortex behind the riders back) and allows the bike to exit the air with less turbulence is going to do some good.

Generally avoid a tailbox that is longer than the rear wheel, it could act like a sail in a crosswind. Remember a tailbox will hold less than a pair of good panniers, will also prevent the fitting of same and puts the weight higher on the back of the bike. A tailbox will make you pack sparingly and prevent you carrying tons of crap you don't need. A tailbox is a great place to mount rear lights and reflectors, batteries for Smart type lamps and even a stereo if you are so inclined.

By all means make one from ply but I think you would be better off making a traditional buck for fibreglass, taking a mould from it and using epoxy and bi-directional glassfibre cloth to produce the actual part.

Two reasons 1. It means that you can make another if you end up trashing it.
2. It will be somewhat lighter as  the made from ply option needs to be effectively waterproofed which means coating it in GRP.

luv'n'stuff

J
Title: Re: Tailboxes
Post by: nobby on 15 December, 2008, 10:39:21 pm
Someone who is an aerodynamicist/Mike Burrows/all round clever git will be along soon to put everyone right but here goes.

Anything that reduces the drag (vortex behind the riders back) and allows the bike to exit the air with less turbulance is going to do some good.

Generally avoid a tailbox that is longer than the rear wheel, it could act like a sail in a crosswind. Remember a tailbox will hold less than a pair of good panniers, will also prevent the fitting of same and puts the weight higher on the back of the bike. A tailbox will make you pack sparingly and prevent you carrying tons of crap you don't need. A tailbox is a great place to mount rear lights and reflectors, batteries for Smart type lamps and even a stereo if you are so inclined.

By all means make one from ply but I think you would be better off making a traditional buck for fibreglass, taking a mould from it and using epoxy and bi-directional glassfibre cloth to produce the actual part.

Two reasons 1. It means that you can make another if you end up trashing it.
2. It will be somewhat lighter as  the made from ply option needs to be effectively waterproofed which means coating it in GRP.

luv'n'stuff

J
Thanks for that.
I'm only interested in the storage aspect, I think. Camping is still going to need panniers.
I'd waterproof with resin; glass reinforcement isn't necessary. Twisting the ply into shape will give it sufficient strength.
cheers
Title: Re: Tailboxes
Post by: cycleman on 16 December, 2008, 08:46:46 am
you could aways tow a aero trailer instead nobby  ;D
Title: Re: Tailboxes
Post by: PhilO on 16 December, 2008, 09:04:44 am
You can usually go wider than the seat - the width of the rider's body will give more storage and better aerodynamics.

'Correx' or 'corroplast' seams to be used more than plywood. There are a few pages on the 'net which give guidance:

Lee Wakefield (http://leew.co.uk/tailbox1.html) has built a few, and most recently contructed a complete streamliner out of correx. IIRC, he 'stitches' the structure using zip ties, then seals and gussets using hot melt adhesive. He hangs out on the BHPC club site a lot, so you can always ask over there.

I've also found this (http://www.humboldt1.com/~mhp/tailbox.htm), and this. (http://home.comcast.net/~jeff_wills/tailbox/index.htm)
Title: Re: Tailboxes
Post by: Wendy on 16 December, 2008, 09:16:14 am
Remember a tailbox will hold less than a pair of good panniers, will also prevent the fitting of same and puts the weight higher on the back of the bike.

I guess that depends on the tailbox.  It's certainly not the case for my 55l Novosport lowriderbox, which can hold absolutely shed-loads of stuff.  Personally I can't recommend tailboxes more, they are the absolute dog's particulars.  They carry stuff better than panniers and can be made lockable, they look good, provide advertising space, and will make the bike slightly more aerodynamic.

(http://www.londonskaters.com/cycling/images/P9240425.JPG)

I'm currently waiting on my new VK tailbox, still being made at the moment.
Title: Re: Tailboxes
Post by: Tiger on 16 December, 2008, 10:01:40 am
If you go to BHPC site you can learn more than you would ever like to know about tailboxes. Mr Larrington of the parish is also very experienced in this area.
Homebuilds abound. Correx is definitely the material of choice for those who don't have advanced carbon/fibreglass modelling skills. Lee Wakefileds correx streamliner is indeed a work of art.
I knocked a correx  one up and it put my speeds on the track above 25mph avg for the time I had it on the speedmachine - 2 races a couple of years ago. I reckon a better built one would have given even more.
I am waiting on bentmikeys VK2 fujin  fit to copycat for for audax use.
Title: Re: Tailboxes
Post by: Torslanda on 16 December, 2008, 11:26:41 am
Quote
Someone who is an aerodynamicist/Mike Burrows/all round clever git will be along soon to put everyone right but here goes. . .

See. Told you. . .
Title: Re: Tailboxes
Post by: Tiger on 16 December, 2008, 12:34:41 pm
Nobby - what you want can be found by googling or linking from BHPC to MOAT (Mother of all Tailboxes) whcih is teh definitive guide to knocl=king up a correx box. It takes a couple of evenings - very easy to do and no special tools etc.
Title: Re: Tailboxes
Post by: nobby on 16 December, 2008, 06:21:02 pm
you could aways tow a aero trailer instead nobby  ;D

The only person I know that uses a trailer cycleman is seriously weird. I wouldn't want to be thought to sharing interests with them  ;D
Thinking about it, it's their fault that I am riding a 'bent. that's enough weirdness for most folk!
Title: Re: Tailboxes
Post by: Polar Bear on 16 December, 2008, 06:25:10 pm
(http://www.londonskaters.com/cycling/images/P9240425.JPG)

Hmm.  That looks like a Challenge Hurricane with a very practical, large tail box.   Where do I get one of them and how much please?   

<edit>  The tail box that is.  I have the Hurricane...  :thumbsup:  </edit>
Title: Re: Tailboxes
Post by: nobby on 16 December, 2008, 06:27:16 pm
Quote
Someone who is an aerodynamicist/Mike Burrows/all round clever git will be along soon to put everyone right but here goes. . .

See. Told you. . .
;D

Title: Re: Tailboxes
Post by: nobby on 16 December, 2008, 06:28:32 pm
Nobby - what you want can be found by googling or linking from BHPC to MOAT (Mother of all Tailboxes) whcih is teh definitive guide to knocl=king up a correx box. It takes a couple of evenings - very easy to do and no special tools etc.

Thanks for that. On my way over there now  ;)
Title: Re: Tailboxes
Post by: Wendy on 16 December, 2008, 07:54:50 pm
I got it from novosport.de - pretty good!  It's not that large at 55l internal capacity, some tailboxes can be *much* larger, especially the race fairings.
Title: Re: Tailboxes
Post by: Polar Bear on 16 December, 2008, 08:03:04 pm
I got it from novosport.de - pretty good!  It's not that large at 55l internal capacity, some tailboxes can be *much* larger, especially the race fairings.

Thanks.   A pressie for myself next year then  :thumbsup:
Title: Re: Tailboxes
Post by: LeeW on 16 December, 2008, 10:53:53 pm
My trice tailbox did not use a single zip-tie in it's construction.  All my fairings are joined using hot glue from a powerful gun.
Title: Re: Tailboxes
Post by: PhilO on 17 December, 2008, 08:51:55 am
My trice tailbox did not use a single zip-tie in it's construction.  All my fairings are joined using hot glue from a powerful gun.

Apologies - my memory playing tricks on me...

So you don't use any tempory fixing while gluing? Where do you hide your third hand when you're not using it?  ;)
Title: Re: Tailboxes
Post by: Tiger on 17 December, 2008, 09:40:43 am
Lee is the probably the worlds leading exponent of the correx aero artform.  What he says goes! 
Title: Re: Tailboxes
Post by: Wendy on 17 December, 2008, 09:53:16 am
I'm extremely impressed with Lee's correx skills!
Title: Re: Tailboxes
Post by: LeeW on 17 December, 2008, 01:51:17 pm
My trice tailbox did not use a single zip-tie in it's construction.  All my fairings are joined using hot glue from a powerful gun.

Apologies - my memory playing tricks on me...

So you don't use any tempory fixing while gluing? Where do you hide your third hand when you're not using it?  ;)

I sometimes used duct tape or electrical tape while the glue dried which I then pulled off.