Author Topic: Fitting a New Seat  (Read 3678 times)

Fitting a New Seat
« on: 03 December, 2016, 09:58:01 am »
I’ll be picking up my new carbon seat from Laid Back in Edinburgh next week and will be keen to get it on the bike.  David at Laid Back has been trying to contact Challenge for a while about obtaining the required fittings but so far they are unresponsive.  I certain that I could make the brackets myself using either aluminum or mild steel with rubber padding between seat and bracket however I’d really appreciate hearing/seeing how others have fitted none standard seats to their bents.

Tigerrr

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Re: Fitting a New Seat
« Reply #1 on: 03 December, 2016, 12:07:03 pm »
Good luck with that - the Carbon seat mounts on my fujin have been a source of grief over the years. Unfortunately I don't have your fettle skills or I would have rebuilt them from scratch, using harder material than the aluminium originals.
The front 'through-frame' mount relies on an aluminium machined grommet/inset washer that wears down because it under stress - a heavier machined steel or welded lug setup would be miles better. The rear adjustable setup puts all the stress through a tiny square hollow aluminium plug that is impossible to access to tighten fully with seat at lowest level - so sets up a wear/stress point by design. It also puts the dead weight bearing point right onto the rear frame junction, which is a weak spot. Not the best design.
That is of course just my opinion - but if you have access to machinery you could I am sure make much better mounts.
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andytheflyer

  • Andytheex-flyer.....
Re: Fitting a New Seat
« Reply #2 on: 03 December, 2016, 06:36:59 pm »
I’ll be picking up my new carbon seat from Laid Back in Edinburgh next week and will be keen to get it on the bike.  David at Laid Back has been trying to contact Challenge for a while about obtaining the required fittings but so far they are unresponsive.  I certain that I could make the brackets myself using either aluminum or mild steel with rubber padding between seat and bracket however I’d really appreciate hearing/seeing how others have fitted none standard seats to their bents.

I don't have knowledge of how Challenge mount the seat, and my 2 Performers have simple but effective seat mounts, but in another life I had to get new bushes made for mounting the mast on my 40 yo 26ft sailboat when the insurance surveyor said they were worn.  (it's irrelevant that the wear was minimal and in no way affected the structural integrity of the mast, but if you want to renew your insurance, you have to jump through a few irrelevant hoops).

Anyway, I designed up a mounting bush on paper (spares were long since extinct) and was fortunate to find a local one man band machine shop who made what I needed, to my drawings, at very reasonable cost, in only a few days.  They worked perfectly and the insurers were happy.  I was amazed at what British men in sheds can make.

Last week, and I don't know how I did this, I broke off the welded lug that mounts the side stand on my Performer Amigo, such that the lug tore out a section of the aluminium rear subframe/fork.  Rang a couple of firms on the local  industrial estate who professed to be able to weld aluminium.  One said it'd be expensive because he'd have to hire an aluminium welder (i.e. he had minimal experience...) and the second said he didn't touch bikes because of the liability....  Wimp....

Then, praise be, I fell over a local guy in a tiny industrial unit in the ar*e end of no-where who makes bespoke motorcycle frames.  Aly welding, bike, no problem.. Bring it round.  Friday ok?  Paint will suffer a bit though..... £30 OK?


Anyway, the point is, if you can work out a bracket design, there's a man in a shed somewhere nearby who'll make it for you, no matter how improbable it seems.  We Brits are really, really good at this.  Low volume, highly skilled and specialised engineering.  The challenge for those of us who ride recumbents is to find that shed.....  But they are there, just well hidden.....  Whatever you need, there's a man with a fag in a shed who can make it. 

Now, how about making me a pair of Amigo forks anyone?

So, Joe, all you need is paper, a sharp pencil, and the help of Inspector Morse, and new brackets can be yours in only a week or so.  I find it really satisfying to find that man in the shed.  It appeals to my 'beat the system', anti-throwaway society, planned obsolescence.  It's amazing what we can get mended if we put our minds to it.  Go for it Joe!




Re: Fitting a New Seat
« Reply #3 on: 03 December, 2016, 07:24:37 pm »
Thanks for the advice.  I had thought about mounting the seat with dome head bolts and nylon washers but some sort of sleeve or brush insert would seem to be a good idea.  The brackets themselves are easy to make at home but not owning a lathe is an obstetrical to doing DIY brush rings.  I've a feeling that the guys in the workshops at the naval dockyard I'm based at will do it for a modest amount of alcohol in return. 

andytheflyer

  • Andytheex-flyer.....
Re: Fitting a New Seat
« Reply #4 on: 03 December, 2016, 10:17:32 pm »
A bottle of malt will be small beer in comparison to the warm glow you'll get from knowing that you thought it through, sketched it out and saw it made.  And when it works to perfection, you'll know that you solved the problem, and got on with riding the bike.  Recumbents are full of life's little challenges, which is why they are so satisfying.

Re: Fitting a New Seat
« Reply #5 on: 04 December, 2016, 04:25:08 pm »

andytheflyer

  • Andytheex-flyer.....
Re: Fitting a New Seat
« Reply #6 on: 04 December, 2016, 07:50:08 pm »
Cheap enough to try out.  With some stainless bolts and washers that may do the job. The wall thickness may be a bit thin though, so you may need the washers to spread the load.  If it works for a while, at least you'll know what you need to get machined up.  There's a lot of load in a seat (well, my seat anyway....) and if it impinges on a small annular area around the bolt, you may get some wear as the seat moves a bit.  Try it.

Re: Fitting a New Seat
« Reply #7 on: 14 December, 2016, 09:37:46 am »
The new seat is now on. I've only had chance to ride round the block a few time so far but it feels ok, maybe a little higher and a tiny bit further forward than before but generally quite good.

At the moment it's held on with hex headed bolts but I'll be off to screwfix later for some dome headed alternatives. I'm not completely happy with the lower bracket and will probably re-fabricate at some point, the upper bracket is fine, I just need to swap the foam padding for something that will last longer.  My existing seat pad fits fine when turned round 180 degrees.

20161213_134038[1] by Joe.Audax, on Flickr

20161213_133217[1] by Joe.Audax, on Flickr

ElyDave

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Re: Fitting a New Seat
« Reply #8 on: 14 December, 2016, 10:54:27 am »
that looks almost exactly like the arrangement used on my M5 :thumbsup:
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andytheflyer

  • Andytheex-flyer.....
Re: Fitting a New Seat
« Reply #9 on: 14 December, 2016, 02:02:34 pm »
l
The new seat is now on. I've only had chance to ride round the block a few time so far but it feels ok, maybe a little higher and a tiny bit further forward than before but generally quite good.

At the moment it's held on with hex headed bolts but I'll be off to screwfix later for some dome headed alternatives.

Try these guys:

http://stores.ebay.co.uk/Falcon-Workshop-Supplies/About-Falcon-Workshop.html

I've bought loads nuts bolts etc. in stainless from them - cheap and quick.  You can get the length you need too!


Re: Fitting a New Seat
« Reply #10 on: 05 January, 2017, 07:55:01 pm »
Having ridden the bent very little over the festive period I’ve finally started getting out again this week for a few rides.
Overall I think that I’m happy with the new seat.  It’s certainly more comfortable for the bottom, (which was the aim of the whole enterprise)  however it is a bit wider between the shoulder blades which I’m less keen on.  Another negative is that propping myself up at junctions with my left leg seems to be more awkward than before as I don’t seem to be able to hold the position for as long.
Although I’ve mentioned a couple of negative points the fact that I’m no longer constantly sliding slowly off the front of the seat is a major improvement.   

Re: Fitting a New Seat
« Reply #11 on: 05 January, 2017, 11:30:23 pm »
I have a piece of polystyrene foam behind my ventasit pad at shoulder blade height.
This makes the seat a little bit convex there, which does make it a lot more comfortable for me as my arm harness pulls my shoulder back.
So it's fairly easy to mod the seat shape to fit you without cutting anything.

Re: Fitting a New Seat
« Reply #12 on: 07 January, 2017, 09:14:40 pm »
Good idea, can't try anything this weekend though as the bikes in Scotland while I'm in Newcastle.