Cafe seat designs

[ray08pv]

I'm working on carving up a new seatpan mold for my bike (82 heritage special), i'm having trouble deciding what type of tail design i want to go with, so i took some screen caps from my Inventor models to get some opinions, if i had more time to work in the lab, i would have shelled the models to make them actually look like the pans, not just the mold block.

http://s35.photobucket.com/albums/d162/metalhead08/Seat%20Models/

I'd love to hear what you guys think, i'm leaning more toward the 2nd design, fully rounded, but longer than the first design, but i think the chamfered wedge would look cool as well

 

[bcware]

I have no qualm with "upgrading" as opposed to restoring an old bike, so my taste is much more modern. Are you going for something that is correct for the period or just aesthetically pleasing? When I do this I am going to do something more aerodynamic and tapered. I really like all of these designs:

 

[drewpy]

I'm for the rounded look and I've seen little round lamps in them which look cool too!

 

[ray08pv]

I think i'm going to go with the full rounded design, similar to your last pic bcware, though mine is a little taller. any tips for carving a quarter of a sphere out of a block? so far its been a painfully slow process.

once the plug is shaped, i'm going to take it to our composites lab at school to fiberglass it. i wish i could convince the professor to let me make it out of carbon fiber, but they're not too generous with that stuff.

 

[sharps09]

Check out wrenchmonkees web site their seats are nice, matches our square tanks.

 

[ray08pv]

i wish i had the square tank like in your pic, i have the more rounded looking one. from the later year xs's

 

[drewpy]

you can cheat and use part of a gas tank for the rear

 

[NewChurchMoto]

Check out newchurchmoto.com, we do all types of cafe seats, custom to the pan you choose!
Ginger

 

[ray08pv]

never thought of using the gas tank as part of the mold, i may do that if i can find another at the junkyard. I've also been eyeing a steel mixing bowl sitting in my kitchen, it might go under the knife soon if its a fit.

I appreciate the offer Ginger, but i'm more interested in the process involved in making the pan than the finished product, i'm a polymer engineering student, and our curriculum focuses more on thermoplastic processing than composites, so i'm using this opportunity and others to take in as much as i can on the subject.

 

[cafedan]

you can cheat and use part of a gas tank for the rear

here is a thread im following on another site that is doing just that. i really like what he has done so far.

http://www.dotheton.com/forum/index.php?topic=11919.msg244645#msg244645

 

[FUBAR]

i did one with my last project, it worked really well and was fairly easy to do.
materials:
fiberglass, resin, sand paper, bondo, cardboard, metal duct tape, pink foam board (for house insulation).

i can find a final picture but heres about 1/2 way..

cut the seat pan you want with cardboard, cut blocks out of the foam, shape the foam with a bread knife sand fiber glass and voila.

just a cheap way that looks good

 

[FUBAR]

oh and also its really easy to dremel out a spot for a light and dig out the foam if you want to tuck it in there nice

 

[NewChurchMoto]

Oh, I totally understand! That's why we don't actually make seat pans because most builders like to make their own. We just upholster the one that you make! I'd love to see your seat pan when you get done!
Ginger

 

[ray08pv]

I did some tinkering around today, finished the seatpans, tore the back half of the bike down, checked brakes, re-checked seat measurements, played around with turn signal mounting points, and figured about where i want to chop the frame off at.

I scrapped the idea of carving the spherical section out of foam, and instead took an old 3/4 shell helmet from my 3 wheeler gear (traded it for the yamaha) and took the dremel to it. i ended up with not one, but two useable bumpstop designs!

The turn signals i picked up i think will look good where i've mocked them up, on the top rear shock mounts. i also pulled the black metal covers off the shocks. if i hadnt forgot my spraypaint in my dorm i would have shot the springs quick.

In some of my pictures you can see two silver sharpie lines, i was toying with the idea of chopping the frame approximately there, maybe an inch farther back, i'm worried about compromising the structural integrity of the frame by doing that, and i dont want to get the sawzall out before i can get an opinion from someone whose done it before.

New pictures: http://s35.photobucket.com/albums/d162/metalhead08/xs400%2003052011/

 

[bcware]

It is important to maintain chassis stiffness. Realistically I don't foresee anything "breaking" unexpectedly, but performance in certain situations would be affected. It would take an experienced racer or engineer to say how much this particular part of the frame is contributing to structural integrity or handing. In general, just to be safe, I would re-connect the frame at some other point near the cut. This does not have to be a weld, but that may be the only reasonable solution. It should not be expensive to have done if you do not have the equipment.

I like the seat design with the cardboard taped on; the sloped one.

 

[jdmjimi]

I banged out a seat pan then grafted the rear half of my oe tank to make my all steel seat pan. Then i added a xs360 tank from 76' onto my xs400. Gets alot of looks, and belive it or not the seat isnt that uncomfortable. Check out my album.

 

[drewpy]

nice carb setup jdmjimi, what was those tubes front of the engine pre mods?

 

[jdmjimi]

Well they are some sort of balance pipes, Im not sure probably some sort of 1980's us emissions bs. haha. anyway sorry dont want to be a thread pirate.

 

[ray08pv]

I figured out that with the fitment of the longer seatpan, i'll be able to just cut the turn signal tabs off and not affect the rigidity of the frame. Once its on the road and out at college i'll take it to the weld shop and have a 180 degree section welded on thats aesthetically pleasing.

No more progress on the seatpans until i get back from break, as my friend has all the fiberglassing supplies.

I returned the bike to stock condition for now, i figured i may as well just to get it registered, inspected, and on the road.

Through some inspection i found that the front brake drum seems to be sticking, is this a common issue with the bikes? its a bit late, so i'll tear it open tomorrow and see what the situation is, any tips or precautions on the front rim? i've never done a bike with a speedo cable...or front drum before. my only other bike, my KX, has disk front and drum rear.

I'm sort of concerned about how small the aftermarket turn signals are that i purchased, so i think i'll take them back and either get larger, or brighter, led versions. While i'm at it i'm going to look for a new LED brake light to fit into the new seat.

probably taking a junkyard trip in the near future, so i'm going to look out for a few things:
clubman bars
older style boxy xs400 tank (will it direct fit?)
rear sets
cool lights from old cars
leather seat cover for upholstery

gotta love being 20 minutes from harry's u pull it and joe's ez pull (they've got a motorcycle section)

 

[jdmjimi]

i live in harrisburg. so there is a motorcycle pull it yard in hazelton?