No, there’s more on the horizon. I’ve still got to get the bed off and hack up the rear suspension to make it more independent. While the bed is off I’ll get the dents out and polish it up.
ARRL Field Day, a national Ham Radio event, is coming up the last full weekend in June and I’ve got to have the towing bar rigged up for the GEM by then. I plan to hook it over the frame in front of the rear axle pivot point and clamp it to the front of the motor/suspension sub frame then jack the front wheel off the ground and attach to the trailer hitch on the motor home. It should tow like a trailer with the weight carried on the tongue and the rear wheels.
We plan to use it to get around from the main street to the field in back of the high-school where we hold Field Day. It’s a decent hill and will make commuting from the front of the school to the back field much more convenient while saving gas and showing how “green” we are. The public information table will feature a “get on the air” radio station that’s solar powered and several GOTA coaches will be there to offer participants a chance to make real radio contacts all over North America and the world (if conditions are right). The GEM will get a lot of interest I’m sure. Pictures will follow of course.
Hey Bob, I’m new to this forum. I started out at the EV Trader which seems to be gone.
Don’t mean to sound dramatic but STOP what you are doing to your GEM. It will not survive. I have a 2002 EL with 17,000 miles on the meter, it had 8 when I bought it. I did what you are doing and propose to do. My suspension blew up. It turns out that these chassises are NOT heat treated and all aluminum should be. They can not tolerate the additional twisting moment that fewer shocks will cause. Put the shocks back on. Do not cut up the control arms. I HAVE TRIED and my GEM is a mess.
Now that I have scared you–sorry–I will tell what my experiences are.
I started–like you–thinking the suspension was too stiff. Not realizing that the EL model was a total after thought. ( I went to the same school that the original GEM designer / creator–Dan Sturges–believe or not it was a student project.) Being an after thought it was meant to be as cheap as possible. So the EL was given trailing arm suspension–just like a motorcycle–all that suspension can do and was intended to do was go up and down. After the second pair of shocks were removed the suspension was still intolerable. Thinking about I realized that Honda Goldwing’s weigh about as much. I bought a pair of very nice aftermarket air shocks, thinking that I would be running them at around max pressure. To my surprise I wound up using near minimum pressure–the EL is that light. After about 200 miles DISASTER struck. Pulling into the driveway–which is a simple low pan–the two outer control arms failed. One arm broke at the welds the other bent. Contacting GEM, they scolded me and sent me a replacement rear end. Only to find the out board tabs were crooked. Sent it back and got an other. Went back to the original shocks.
[B]Second Problem[/B]
The roads around my home are too rough. Putting in 17,000 miles has been a strain on the chassis. One day out on an errand. I realized that the bed in back was sagging. On closer inspection I found that one of the wings–at the top of the rear shocks–was tearing away from the chassis leaving a large hole. I stopped driving it. GEM told me it was my fault for overloading my EL. I told them I didn’t think so and that it was from the rough roads and the milage. At the time mine was one of the highest milage EL’s. GEM has a part / solution for this. It is called a “weldment” and they want $600 for it and your suspension will be good as new… [I]Yeah right[/I]. Figured I could design better suspension for less so that is what I am working on right now.
Thanks for the warning. I know the frame can’t take any extra twisting moment and that the original center mounting tabs will have to be replaced or added to for a new-style multi-link suspension. I haven’t done anything except take off the rear shocks and have very little mileage on the GEM this year (probably under 300 miles) so it’s holding together nicely.
I would like to re-do the rear suspension like the newer ones with the semi-independent operation with bushings at the 4 axle attachments. I may just spend the big bucks for the new parts had have the tabs welded onto the frame or maybe go for an add-on steel part that’s bolted in place to keep from further weakening the aluminum frame. In fact, that sounds like the best way to go - grind off the old tabs and plate over the frame member with steel angle that’s got the new tabs already welded in place. Maybe put a Nylon sheet between the aluminum and painted steel plates to head off galvanic corrosion and use stainless hardware to hold it all together.
I think GEM went to the round tubular parts so they could easily get the complex bends in the upper links and maybe for increased stiffness. That one inch square tube looks awfully flimsy to me. The upper shock mounts do look a little iffy to me too. The newer ones use shorter coil-over-shock units that attach to a cross-member instead of those welded-on pockets.
Well, the project is on hold till next spring anyway. Temps are frequently at or below freezing now here in Massachusetts and I’ve given up driving the GEM for errands in favor of the comfy, warm Prius V. Maybe if I get the garage cleaned out I can get the GEM inside and take the bed off to see what’s really going to be required. I’ll keep the forum up to date on my progress (if I make any).
That’s interesting. Kind of the same thoughts I’ve had.
My plan–and already have many of the parts–is to use the center axle connection, like you, but replace it with a Johnny Joint. Johnny Joints are a kind of rubber bushing / Heim Joint hybrid, that have a Zerk fitting, you can find them on the web.
Model 'T’s had a variation of this idea for front suspension. The rear axle will pivot around that center point.
I have designed and fabricated a crossmember that supports an articulated Watts linkage to keep the axle from moving side to side. One serious consideration was that the chassis is so narrow. Watts linkages work better if they are longer, that’s why I had to work out the articulation. Then the shocks will be mounted as you suggest, closer to the centerline. The big debate, in my mind now is, the position or angle of the shocks. I’m thinking that they should be straight up and down right to left. At an angle front to back. Shocks are stiffer straight up and down and more compliant when they lean a bit. They just need lean in the right direction so they don’t bind up.
Been thinking about taking some of weight out the Axle unit it’s very heavy. As you point out that it is one inch square tube and looks flimsy. It is very heavy with a think wall. But not very carefully made, that is the why of the flimsiness. I now have a three inch diameter, thinner wall, tube that I’m fiddling with. Larger diameters are naturally stronger and don’t need the heavier wall thickness. I’m currently focused on the shape and size of the of the bosses where the shocks and Watts linkage will connect.
You probably found this on your own but NEV Accessories sells for $185 a “GEM CAR REAR HEAVY DUTY SHOCK BRACKET SUPPORT” made of welded steel which bolts onto the aluminum frame and is intended to stiffen the rear shock mounting points. Of course it sounds like you’re fabrication skills are very good and probably don’t need this sort of hardware since you’d build your own anyway though someone else reading your posts might benefit.
Al
Bob,
Your story of registering your GEM reminds me of when I first tried to register mine.
Had a devil of a time convincing the local county deputy registrar that it was NOT just an oversized “golf cart” (which aren’t street legal in OH). Finally gave up and went to a different registrar’s office and found someone more sensible. Still had to prove it was legally a “Low Speed Vehicle” and not a “Golf Cart” but I could do that.
Next the Ohio EPA said it need an inspection for “pollution control”. Huh? It’s electric; there is no pollution!! Registrar said “No matter, it still needs inspection every two years”. Unfortunately the inspection stations were miles away and I would need to trailer the GEM back/forth. In the meantime I was fortunate to actually run into an EPA supervisor who had seen them before and knew GEMs and issued me a “permanent exemption”. That was a tense couple of days.
Al
[quote=ARandall;17396]You probably found this on your own but NEV Accessories sells for $185 a “GEM CAR REAR HEAVY DUTY SHOCK BRACKET SUPPORT” made of welded steel which bolts onto the aluminum frame and is intended to stiffen the rear shock mounting points. Of course it sounds like you’re fabrication skills are very good and probably don’t need this sort of hardware since you’d build your own anyway though someone else reading your posts might benefit.
Al[/quote]
Yes I am aware of it. When this first happened they wanted $600 for this ‘weldment’–their name, not mine–they likely reduced it to $185 to avoid a recall–a situation that prompted the first sale of GEM. The chassis is made of 6065-T6 Al that is reduced to T0 after welding and they don’t re-heat treat. That IMHO is a huge mistake. Their rational is likely that these are disposable vehicles and heat treating doesn’t matter. With heat treating they would last a very long time.
I suspect it’s most likely a cost-reduction decision on the part of GEM/Polaris to not re-heat treat the frames after welding. For niche market; low mileage vehicles that already are pushing the upper end of the cost/benefit curve, saving a few hundred dollars on each vehicle could make a big difference in how well they sell. I love mine (but then my wife says I’m a raving fanatic) and even I wouldn’t buy a new one for what they’re asking nowadays even without the additional cost of heat treating the frame. The marketplace DOES have an upper limit for a vehicle of this nature.
Frankly too I doubt if many GEMs ever really “wear out” given how few miles the average GEM is driven every year so NOT heat treating the frame after welding is understandable for the “average” user. Your 17,000 miles is I imagine considered very high mileage. I’d bet that most GEMs get only a few thousand miles before they’re “junked”. Hmmm, be interesting to know how many GEMs are still licensed and on the road versus the total sold.
Al
[quote=ARandall;17399]I suspect it’s most likely a cost-reduction decision on the part of GEM/Polaris to not re-heat treat the frames after welding. For niche market; low mileage vehicles that already are pushing the upper end of the cost/benefit curve, saving a few hundred dollars on each vehicle could make a big difference in how well they sell.
Al[/quote]
The cost control / reduction decision would have been implemented before the sale of GEM to Chrysler–well before the sale to Polaris. Look at Peterbuilt their chassis are heat treated aluminum, they get millions of miles out of them. By my experience, the motors and suspension / chassis are the weak points. The rest of my GEM looks and functions great. Would like lithium batteries.
Yep. But huge difference between the two types of vehicles you’ve noted in terms of performance, life-cycle expectations and initial and ongoing costs.
I too would like lithium batteries but the cost/performance isn’t warranted for me unless I keep the GEM for 10+ years.
Bob,
You mentioned removing the diamond aluminum plate and polishing it up. Have you done that and how did you polish the aluminum plate? Mine is dull as well and I’d like to shine it up but haven’t found anything that works well.
Al
I haven’t done it yet, but I watched a YouTube video on the subject and it looks like i’ll be getting covered with black polishing rouge for a while doing it. Might not be worth the trouble…
I watched a couple of videos as well and man it looks like a lot of work! My bed (the horizontal portion anyway) is pretty rough; scratched and dull. The vertical sections that don’t get abused are nice. Having polished by hand a number of aluminum motorcycle cases over the years, I KNOW it’s hard work and keeping it nice is tough too since aluminum oxidizes quickly.
Al
Guess I’m a bit jaded. All Al bicycle frames made here in the USA are heat treated–I live in that industry. There are even Al suspension bicycles with no pivots that rely on the modulus elasticity of 6065 T-6 for their range of motion. Begging the question, “what is GEM thinking and why?”
Isn’t it ultimately about the quality of the end user experience?
You ask the question [I]“Isn’t it ultimately about the quality of the end user experience?”[/I]. Unfortunately while I understand your concern and completely agree with your thought process, the answer is no. It’s about making a profit.
Obviously there was someone during the design, engineering or pre-production planning that looked at the pros/cons of re-heat treating after welding and for whatever reason (most certainly cost-containment) vs. benefit decided it wasn’t something they were going to do. For that matter it may be something that was changed with the later production years that wasn’t done in the early production period. To be fair they [U]have[/U] changed the basic design over time to address other areas of safety and/or concern.
The real question of course is what practical difference did that decision make? If it affected 1 in 10,000+ units and it’s not a “significant safety issue” resulting in lawsuits or recalls, it’s a non-issue since the cost to GEM is essentially “zero”. Especially if they can sell the consumer a $600 weldment “fix” for what we can call a design compromise. If on the other hand it affects only 1 in 100 (or less) and generates lawsuits and/or government recalls for safety issues, that’s a different matter entirely.
In the end these types of cost/benefit calculations are a fact-of-life in the capitalistic world in which we live. Happens all the time in all sorts of industries except perhaps in industries like aviation or manned space flight where the cost of failure is enormous and there is very low tolerance for failure.
Or another way to think of it is attributed to Voltaire [I]“The perfect is the enemy of the good”[/I].
Al
What’s GEM thinking? I’ll tell you what - they’re looking to get away from the classic GEM aluminum frame and rounded contours. How do I know? They sponsored a focus group a couple of weeks ago (thinly disguised - but still pretty obvious it was Polaris) to showcase the 3 possible styles - Original GEM, new electric utility from Polaris, and regular Polaris utility side-by-side with electric power. I was invited to the video conference so had all the questions and slides to view. I wasn’t really impressed.
This doesn’t bode well if Polaris wants to talk to electric vehicle owners about alternatives to the GEM’s styling and running gear. Admittedly, the GEM suspension is pretty awful compared to the various off-road side-by-side utility vehicles out there. But I’m concerned about eventual rust on a chrome-moly frame where the GEM’s aluminum one won’t have any.
Maybe if the GEM frame was heat-treated back to T-6 hardness after welding we wouldn’t be seeing frame failures and it would become a non-issue for Polaris. I get the feeling that a lot of the technical know-how didn’t get transferred to Polaris when they moved everything to Iowa…
More likely it was “We know more than those guys that designed it originally and we’ll do it our way so it will be cheaper”. And thus more profitable.
And in the end it’s all about profit. Which is easier and/or cheaper to make: an aluminum frame or a welded chrom-molly frame? After all the basic design has been around for at least 15 years and I’m sure Polaris is trying to cut costs and make more profit from each unit. They may sell it as “updating the design” but in the end, it will be about costs.
In fact they’d probably LOVE to be able to build the GEM on an already existing frame in their line (just look at the auto industry and how they put together vehicles on the same frames with different “skin”).
Fact of life: As much as we love our goofy, quirky, little GEM’s, in the end it’s got to make money for the owner or it’s going nowhere.
Al
Is it really?.. at the risk of sounding pedantic.
The dream of the electric car industry is to be more like the tech / electronics industry; exploit the economies of scale.
Apple truly focused on the quality side of the equation. It took longer and they had few misses. The profit happened anyway. Now they are the most valuable company in the US. For me there are serious lessons there. It seems like Tesla is getting close the “dream” by standing on Apple’s shoulders.
PS - You need to test drive a Tesla–forgive the plug–I don’t work for Tesla
At the risk of sounding cynical - yes 
Last I noticed, Apple was making money and hasn’t yet dropped the price of their products to the breakeven point.
Al
[quote=ARandall;17452]And in the end it’s all about profit… Is it really?.. At the risk of sounding cynical - yes 
Last I noticed, Apple was making money and hasn’t dropped the price of their products to the breakeven point. Al[/quote]
You make excellent points, don’t get me wrong. But they are currently giving away their Operating System… Don’t think that breaks even, I suspect it undermines it. The other lesson that comes of this is, “don’t pick a fight with someone whom has $100 billion cash in their checkbook.”