Simplicity Broadmoor R/S Project

Tonight I didn't get really far, but avoided a potentially serious time wasting mistake. Previously I had roughly measured the angle of the king pins and thought there was a 1" difference between the upper and lower mounting points (when the wheel is straight up and down). As it turns out, it's only a 3/8" difference. To keep the wheels fairly straight, I need to make the lower arms longer than the top to account for the angle. Would have had some serious camber if I made them a full 1" longer...

Forward frame is flipped upside down and the "jig" is clamped in the new revised position for the lower control arms. I will double check tomorrow night before continuing. A minor difference is the thickness of the skid plate is now added in between the jig and frame. To be able to clamp the arm pieces straight during welding I will add a couple big washers at the ball joint end (bolt end of the jig) to account for it.


Also realized that Haspin is only about four months away. I've gotta really step things up to be anywhere close to done by then. I'll have a bit more time before the Top Tractor Challenge, but it would be best to be done for Haspin so I can do some testing and also fine tuning before the event in August. Besides that, I'd need to have some seat time on the thing to have a good feel for it.

To do some testing at haspin haha. I think the correct term may be thrashing? Hah maybe, maybe not.

Glad to see progress on it. Very neat project. Still haven’t decided if I want to make the drive to TTC, but we shall see. I’d love to see this thing in action when it’s all done

I hope it ends up being pretty nimble and I'll be able to throw it around pretty good. That's the plan anyway. Hopefully tonight I can get close to having the lower arms done. Then I can assemble the front end more or less and see how the spindles are gonna go. I have a bunch of shims and collars to line up so that will be easier once I have the arms on there and can measure things up.

Also snagged one of the front RFY ebay shocks off the Simplicity Adventure Edition to see how they will fit.

CraftsmanQuad19 wrote:

To do some testing at haspin haha. I think the correct term may be thrashing? Hah maybe, maybe not.

Glad to see progress on it. Very neat project. Still haven’t decided if I want to make the drive to TTC, but we shall see. I’d love to see this thing in action when it’s all done

You better make it. Who else am I gonna pick on all weekend

Doug wrote:

CraftsmanQuad19 wrote:

To do some testing at haspin haha. I think the correct term may be thrashing? Hah maybe, maybe not.

Glad to see progress on it. Very neat project. Still haven’t decided if I want to make the drive to TTC, but we shall see. I’d love to see this thing in action when it’s all done

You better make it. Who else am I gonna pick on all weekend

You and Sean have haspin for that

Tonight I welded all the inserts for the pivot/frame side of the lower arms. Then I realized I already used all ten foot of the 1" square steel I had. So I'm gonna need to buy more on saturday. I'll use that to finish the lower arms and also some more of the frame and rear swing arm will probably be made from that. The 7/8" weldable joints should be no problem to weld to the lower arms. Looks like the 1" steel will fit right over it if I notch the ends out. I plan on removing some steel from the bulky 7/8 joints to save some weight. They're a bit heavier than they need to be.

Alright, I have one of the RFY shocks off the #64 simplicity set in place to see how it fits the suspension.
From what I can see, I think I could use reservoir shocks like this one if they are flipped upside down. Looks like the steering shaft will be going over the top vs under the shock. I may go with non reservoir shocks. Found some that are roughly an inch shorter.

Bear in mind that the opposed will be fairly tall and the steering will need to clear the top edge of it anyway. So it may not effect things too much to go over the shock. Shorter shocks could be tucked in closer still to the frame making even more room. Some space needs to be left between the spring and steering shaft for suspension travel.

Looking really good

Left side control arm resting on the rack and pinion is a little concerning.  Will that be hitting when more complete?

Thanks! And naw it won't hit when it's assembled. It was just laying on it.

Set up to weld the lower arms


Removed a decent chunk out of the lower joints to save a little weight. They're way overkill anyway. Plus I could use a clear shot to weld the shock brackets on later.


Pic flipped sideways probably because my junk camera. One side done and test fitted. Looks slightly odd from the top since the upper and lower arms are at different angles.


Lower joints welded into the arms. One spot must have had something in the steel or some oil on it when I welded it. The rest of it turned out nice.


So at this point, both sets of upper and lower arms are together. I'll still need the shock brackets of course. Next thing is to order some shocks and a steering shaft. Also need some lock nuts for the heim joints and possibly some misalignment spacers. I'll have to figure out how the spindles/king pins are going to be bolted together. There's a lot of sleeves and things involved.

Some issues at Simplicity HQ... For those who enjoy reading and stories

I assembled the front suspension and bolted the front wheels on to see how everything lines up and check the steering. It would be nice to have a picture but I when I tried to use the camera I didn't have an sd card.

First of all, somehow my measurements were (possibly) slightly off and the arms ended up being very slightly shorter than they are supposed to be. Between 1/4"-1/2". (It's not easy to get exact measuring points on the center of bolts ect). If you recall, the main reason I was planning on 42" outside wheel width was so that I could have 45 degree steering and not have the tires contact the engine on a hard turn. So having the arms too short would be a bad thing...normally. But I don't think i'm going to be able to have full 45 degree steering, so it shouldn't effect anything. Also the spacing between the upper and lower ball joints seems fine (there's a lot of adjustability there too).

Also, it seems I measured the wheel width incorrectly by (at the most) 3/4". They are 3/4" narrower than anticipated. This is not an issue at all and is even helpful. Narrower wheels mean I don't get jammed between trees and can still have tight steering angles without the inside hitting anything. The reason I measured it wrong is either: One, I measured the old tires from doug's old golf cart which are marked as the same size but actually slightly different. Or two, I didn't measure the tires at all and drew the wheels on my blueprints based on tire size alone. I don't exactly remember. At any rate, it doesn't really matter.

There are a couple issues with the steering situation. First of all, the suspension arms have enough clearance without the ball joints binding up for almost 4" of travel. It would make sense to make use of as much of that as possible. But...the rack and pinion inner tie rod ends tend to bind up before you can move the suspension that far. Also when steering, the inner tie rod end on the outside of a turn will bind before the wheel can get to 45 degrees. The problem is that the rack and pinon is too wide. If the inner tie rod ends were closer to each other, the the tie rods could be longer and they wouldn't be at such a steep angle. There's no (easy) way to modify the rack to make that happen. So stop collars would have to be sleeved over the shaft of the rack and then I could weld them to the back of the inner tie rod ends to stop it before the ends bind.

The maximum steering that I can get with this setup is about the same as the #64 simplcity, which isn't horrible, but I already thought it was lacking a bit for the TTC. It's somewhere around 25-30 degrees. (I don't have the most accurate way to check angles either).

One other issue... The inner tie rod ends will also contact the lower control arm during a tight turn with the suspension at around 2" compressed. I could limit the suspension to roughly 2" but that wouldn't make a lot of sense. I could "washer" the rack and pinion up a bit and gain some more suspension travel, but then I think I run out of inner tie rod end travel at full suspension compression.

If I had a shorter rack and pinion, both problems would be solved and I could gain both steering and suspension travel. Except one more slight issue that I forgot about. I may have limited how far the steering can go by how far the control arms come straight out from the frame to clear the threads of the hiem joints. I didn't check that too closely yet but I don't think that will be as much of an issue as the rack and pinion.

I still need to double check everything, but if the current rack and pinion doesn't work out, I could do a couple different things:

-Use a bell crank where the rack is now and place the rack parallel with the frame, using only one side of the rack to move the bell crank. I could have much longer tie rods and they wouldn't have nearly as much angle. (Not sure if there is room between the engine and where the bell crank would have to be). In theory, I could even mount the rack straight up and down and still be able to steer it that way.

-Build a go kart type direct steer setup with a shaft going straight down between the forward frame rails. This wouldn't be too hard but I don't think it would work the best. My previous experience with direct steering hasn't been too great. Might be do-able but I don't know.

So, it's looking like the rack will be a problem and limit everything quite a bit more than I wanted. I've gotta do some more checking and then make some sort of decision pretty fast. The clock is ticking and this front end is taking a long time to sort out. Still have the whole rest of the machine to build.

MightyRaze wrote:

Left side control arm resting on the rack and pinion is a little concerning.  Will that be hitting when more complete?

So they did end up being an issue, just at the lower arm instead of the upper one. I didn't think they would be any where close.

I can get 2.5" of travel from the suspension (without hitting the inner tie rod ends) if I use a 1/4" spacer under the rack and pinion. Then the only issue is getting the steering to work without binding up. I may have to make something like this to be able to lengthen the tie rods.

what about some thing like a utv steering box like this one would it work https://www.gopowersports.com/steering-assembly/

That looks like it would be a nice unit to use.

mr.modified wrote:

I can get 2.5" of travel from the suspension (without hitting the inner tie rod ends) if I use a 1/4" spacer under the rack and pinion. Then the only issue is getting the steering to work without binding up. I may have to make something like this to be able to lengthen the tie rods.

I’m thinking about doing something like this on the mk2

Finally some pics! Viewed from the back. Bolted to table at 7" center ground clearance.


2-1/2" suspension travel (or whatever I said earlier) I was thinking that even though I originally planned on more, 2.5" really isn't too bad considering you only have 7" of clearance in the middle. How much suspension are you gonna use anyway on rough ground when the bottom is just going to end up smacking a rock or something. Still should be a usable amount to work with.


Steered out as in a left turn at full suspension depression. Note the clearance of the inner tie rod end to the lower arm. That's after spacing the rack up about 1/4", which is all the room you have with the upper arm at the bottom of the travel.


Front view


Top


I decided to weld up some ends and see how it works out. Turns out it will clear everything but it's very close. Also, I messed up the ackerman angle a bit because I couldn't find the proper info online and my cardboard mock up somehow showed me the wrong thing since I didn't have it figured out too well. Anyway, at this point, I think I'm just going to continue on from here and see how the rack holds up. If I have problems later on I will just re-do the front end. It's not horribly bad but kind of a shame that I messed it up. We shall see how it turns out. Time to buy some shocks and start adjusting things.

shame that rack is giving you issues, I like the rack to belcrank idea, might make your steering shaft super easy also, could use the belcrank from a suburban to speed up the fab work?

That might work yeah. I think it will be ok this way, just that it's an extremely tight fit. In the long run it will cause a bit more wear and tear on the tie rod ends and probably the rack too, but if it lasts awhile that would be ok. Might be best to experiment with this setup first anyway since I already made the frame to fit it.

Do I see Haspin pit fixes this year? Am I gonna have to bring the genny and the welder? lol

I’ll be bringing my new welder with me to haspin

Maybe, who knows. I think I'm gonna ignore the front end issues temporarily and work on the engine for a bit. I'll probably have to sort something else out. The ackerman angle isn't figured too good.

Took the side covers off both remaining opposed engines that I hadn't checked before. The one has stock rods which isn't so great. The other does have ARC rods and a decent cam which I will probably use. I'm going to order some gaskets and hopefully have the an engine ready to go fairly quick.

I'm a bit doubtful as to whether or not I can get this thing ready in time for haspin.

Both lower shock mounts welded up. I plan on having two or three different holes in the top ones for stiffer and softer suspension setup as needed.


These are some ebay shocks which are a bit shorter than the RFY shocks. 9.5" center to center and 750 lbs? They seem slightly cheaper than the RFY's so we'll see how they work out.

Progress on the RS program is getting behind a bit. Several weekends used up without much to show for it. This past weekend I managed to get a few things done. The front suspension has caused considerable frustration as stated earlier and it seems that the best option now is to not use the rack and pinion setup for steering. I have a rough idea to have a shaft mounted in the center of the front frame rails and run tie rods out from there. Maybe up near the steering wheel or somewhere along the shaft there will be some sort of gear reduction. For now I've installed all the lock nuts on the hiem joints and am ready to make final adjustments, tighten, and mark the arms in their respective locations in case I need to remove them for paint. The joints will stay in during painting later on. I had the arms fitting pretty well after welding, but after welding in the shock mounting brackets to the lower arms, I think the lower arms have distorted again slightly and I had to spread the one side with a scissor jack to get it to fit.  


Meanwhile in the engine dept. This is one of two stock engines that I had from doug. Older engines, both 42CI with the shorter crank shaft I need for the RS. The three race engines I bought have extended cranks and would be a problem to use. Originally, I planned on using one of the race blocks that had already been ported, but many of the manifold bolt holes are stripped or have messed up threads. Instead, I decided to use one of the Doug blocks and port it myself. One had been run out of oil at one point and had a scarred crank. This one had some cylinder wear but at least no gouging. The cylinders had a ridge but were smooth. I removed the ridge with a ridge reamer and gave the cylinders a quick hone.


The plan is to use one of the race cams from one of the race engines. It seems to be somewhat mild but more duration than stock. I'll try to get away with using new exhaust valve springs on all four valves to add some reliability. The race springs seemed to be hard on the valve stems and lifters in the race engines. Cleaned out all the manifold threads on this block and still need to port it. Having some trouble getting replacement parts online. The next step on the front end is to fab the upper shock mounts and weld them to the frame. The pretty much the steering is the only part left up there. To speed things along I think It might be best to bypass steering until the frame is mostly complete. At this point I would say Haspin with this thing is pretty much out of the question. I'm still going to attempt a push for the TTC though.

Ordered a 1" full keyed rear axle 40" length, gas and brake pedal, 6" diameter brake rotor, and 4 1" pillow block bearing for the rear end.
Did a crude check tonight of gear ratios of the 633a in 1-3 in high range.

633a transaxle, high range:
Gear 1-- 56 to 1
Gear 2-- 30.33 to 1
Gear 3-- 18.25 to 1

Now when I feel like it I can start working out some pulley and final drive sprocket sizes

Looking good mr moo. That suspension setup looks strong.

I think your making the right decision to give the front steering a break and work else ware. Love seeing a oppy go together