xs1100 turning into a trike

[MaximPhil]

I hate that dam camera, no matter what I do it seems to come out blurry.

Hi DCracer,
try pressing the button only halfway and pause while the camera sets the focus. autofocus is abit slow on many digi cameras.
Phil

[DCracer25]

build

Ok will try that with the camera, and thanks on the bronze nuts will check that out for sure. also got the rear end housing cut down today and will weld it back up tomorrow for sure and will also have pics as well. I got some more parts in today from another member on here today and thanks they are in excellent shape, now I can get more done so expect more pics to come as I get more done.

[DCracer25]

build

Got the rear welded together today.

[DCracer25]

more pics

I got alot done today, finished the drive shaft and welded it back together and had it balanced, I used 2 xs1100 ujoints and 2 drive shafts that was measured then cut to fit, welded them together and sleeved it and welded it for extra strenght. then I cut the axle down 5inches had it welded and balanced. local shop in my area did this for me. then I put everything together with new bearings in the swingarm, another dust boot from a member from here, then with the rearend bolted up I welded triangler pieces of metal to the rearend to help strenghten the plates I weled to the rear to bolt to the swingarm, I am now waiting on the shocks from a friend who said they would be here by friday.

[DCracer25]

build

Ok now I have the shocks mounted. I took two pieces of dom tubing and ran them through the old turn signals holes 1st 1 was 1" tubing 2nd 1 was just alittle bigger than 3/4" dom tubing. 2nd tubing 1/2" longer on each side, then cut the heads off 2 bolts and welded them in the tubing for the shocks to mount to. then welded a piece of tubing in between the rear frame rails to help strengthen and take the stress from the shocks, then I welded 2 pieces of 1 inch angle iron to the frame then to the shock tubing, then another piece of tubing was welded to the front to the frame to add more strentgh. Pics to follow.

[Mr.Bill]

Great work so far, looking forward to seeing this complete

[crazy steve]

Hate to be a wet blanket, but the stock upper frame rails behind the OEM shock mounts have been known to break from the weight of a set of bags and a trunk... I don't think they'll be up to supporting half of the bikes weight....

[TopCatGr58]

Hey Racer,

Steve's right regarding the strength of the rear fender frame struts! Regrettably, you've already done a bunch of welding. Some folks have taken the sections that broke off just behind the OEM shock mount and ran an inner smaller tube inside the oem strut tubing. That would be too much work now. But what you can do is add some extra struts from the frame at the swing arm pivot junction up to the new shock bar, triangles are strong and that extra strut(s) I would think would provide the needed extra strength for the tail/fender struts that are going to be supporting the rear end weight and suspension points!

T.C.

[fredintoon]

Hi 'racer,
angle iron? Stucturally sound perhaps, but Gawd, how ucking fugly.
Seems to me it's too late for the famous aircraft designer's adage:-
Simplificate and add lightness.
And I'm with the others, the frame rear extensions are too frail to hang a rear suspension from.
Here's another adage:-
Triangulate to add stiffness
Like T.C. sez, strut up from the frame's swingarm bearing area to the shock upper shock location.
Best pull the swingarm bearings first, the weld heat will cook them.

[DCracer25]

build

Thanks for the input, will try to figure out a way to to do what you guys said. As far as the angle iron goes it won't be seen once there is a body on it.
I was trying to add some strenght to the mount so it wouldn't bend upwards. Since this is my very first build I am open for all suggestions. I was trying to keep the shocks straight as possible and out a little wider to handle the rear end better. I have built a few different types of stockcars from the ground up and had very good success with them. but building a trike is a bit different. I do know if you get to much of an angle on your shocks then they don't work as good as they should.

[DCracer25]

trike build

Ok added another piece of tubing to help support the setup on both sides then added 1/8" plate steel to the frame rails to strengthen them so there will be little chance of them breaking off, Oh by the way there was a luggage rack and trunk and saddle bags on this bike from the factory and the frame rails where in very good shape. PICS

[Pat Kelly]

How heavy is this getting?

[DCracer25]

trike build

Hopefully not much more, been trying to get a super lite body for it, already picked up alum 16" wheels for it. I weighed up what I took off that I am not using anymore it was about a 100lbs. so between the swingarm and rearend and extra tubing and plate steel so far totals up to 125lbs so as of now I have 25 lbs over the natural weight of the bike not counting rims and tires and body.

[crazy steve]

How heavy is this getting?

The weight is the problem....

The stock wheel/tire/swingarm/etc (all the unsprung parts of the suspension) comes in at about 75 lbs. The wheel/tire/rotor is the lion's share at about 44 lbs, FD is under twenty, and the swingarm is under 10 (I went and weighed the individual parts). I'm reasonably sure that cast-iron-centersection rear axle weighs all of that, add in the brakes and new swingarm and 125 lbs is probably low. You're going to have a minimum of 70 lbs of wheels/tires (assuming 35 lbs each, if you can get it that low) and that puts the total unsprung weight up to almost 200 lbs at least.

So the stock unsprung weight is about 13% of total bike weight (a 'naked' XS weighs about 600 lbs 'wet'). The new total bike weight will be at least 750 lbs (adding in a few extra for frame bracing, bodywork, etc), but the unsprung percentage will increase to about 27% or a 100+% increase.

Controlling this will be a problem. It's a case of the tail wagging the dog; increasing spring rate won't help as your 'sprung' weight is still the same, and increasing damping (stiffer shocks) will simply transfer it to the rest of the bike. This is why most trikes you see are hardtailed; unless you work very hard at keeping unsprung weight down, it becomes impossible for the suspension to control the inertia of all that weight moving around, and you essentially end up with a hardtail, only with even more weight. You could increase the total 'sprung' weight by adding more weight to the bike, but you'll start running into issues of the frame being able to take it.

DC, I'm not trying to rain on your parade, but what works on a 3000 lb race car won't transfer very well to a motorcycle. Yes, you need strength, but you also have to watch weight much more than you would on a car...

[DCracer25]

trike build

Ok I understand all of what you said and I did weigh the stuff before putting it on, the rear end is a small rear out of a 71 plymouth cricket or in the uk its called hillman. the rear itself with everything on it weighed in after I shorten it and the axle, at 75lbs and the new swing arm plus the tubing and stuff for the shock mount came up to 125lbs all together, and real lite weight alum rims from a mustang in the junk yard weighed in at 10lbs each, tires I don't know yet haven't bought any yet. and as far as what the bike weighed in at being a full dresser with fairing, bags and large lugaage rack and trunk, heavy duty rear shocks and air assist on front forks I don't know. amd as far as a racecar is concerned weight is a big factor in building one, you just don't throw it in any where you like. I know my swingarm tubing is alittle heavier than most people would use but I do understand the stress it will go through handling a larger rearend that weighs more than a bike rear setup. as far as racing goes I can get a road legal tire and lite weight rims that only weigh in at 10lbs per rim and tire if I have to.