Four wheel disk brakes on earlier GEM

Finally Got my Gem Done… Check out the disk Brakes on the rear How cool is this.


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more detail , please

What a cool looking Gem:
I agree with Mike please give us all the detail I would love to hear what you used. And how did you do the parking brake?

So I used 1997 Acura Integra parts front and back. Had a buddy make some brackets to hang the Calipers. Had to machine the center hole on the rotors to fit the gem hub and drill the stud holes. The parking drake was sure luck. The bracket from the Gem needed a little trimming with a grinder bolted right up. So far everything works like a charm. I think it frees up the drag you get from the drums. Less resistance is a good thing. As far as money I bought my parts from local auto parts place approximately 600.00 then gave my buddy 100. He used some scrape he had laying around. I found them a lot cheaper on rock auto. Like 1/2. Thanks for the comments took me a month to paint it.


How did you balance braking force front to back? Do you have trouble with the rear locking up? I tried using front brake cylinders on the rear and under hard braking the rear would lock up and the cart wanted to swap ends.

Guess I would have to say luck again. Using the stock master cylinder The only time I can lock the brakes is with the E-brake. Sounds like I got lucky

Also still using 6 big trojan battery’s so my car is still pretty heavy.

Really nice GEM! Great paint job!

are you using 4 or 5 lug wheels? got any closer pictures of the homemade brackets for the calipers?

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Here are some pics. The larger bracket is the front. The stock hubs are 4 on 4 inch patten. The new rotors are 4 x 100 mm you have to drill out the new rotor to fit. The center hole is also to small so you have to enlarge it to fit the stock hub. I had to buy adapters to run 4x100 wheels. There are 4 on 4 wheels I just didn’t like them. Hope this helps just reach out if you need something else.

Thanks! I’m running 4 lug Mazda Miata wheels on my Gem car. I’m going to the local pullapart junkyard in the next few days to look at Honda car disk brake setups.

Well I had went to local auto parts store and bought rotors for a civic. Found that the inner part of the rotor would not clear the most outer part of the Gem hub. Plus I wanted 4 wheel disc and the older civic’s did not come that way. Someone had made mention that a VW rotor would fit a gem hub I never checked. Good luck keep in touch with your progress.

This morning I got a set of disk front and rear brake calipers from a 2001 Acura Integra for $60 and Rockauto had new rotors cheaper than pullaparts so I ordered them $63 shipped to my house… I have a friend that can build anything from metal,I’ll do a write up on the swap after I have all of the pieces together.

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Are the caliper brackets made from 1/2 inch aluminum? Do you think your buddy would want to make another set? Also did you have get an adapter on the brake line to go from the Acura lines to the Gem car lines?


4 wheel disks on a GEM could be a dangerous proposition. To prevent swapping ends rear brake effort is MUCH less than front. This is why disk brake kits are not available for rear of GEM cars. You would have to include an equalizing valve in the system to get the right brake bias front to rear. Present systems utilize different size wheel cylinders to achieve proper bias.

I tried a set of front cylinders on the rear of a 2 seater. The first time I leaned on the brakes the rears locked up hard and I got sideways instantly…


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Yes I believe it was a 1/2 “ piece of aluminum. The last time we talked about making them for sale there just was not enough money to be made. I used the factory gem brake lines in the front they fit just fine. I used the Acura front lines for the rear just because they were longer. I had to lengthen the gem steel line. But they fit with no problem.
To touch on the Old Houseboater’s comment. Everyone has a opinion. I can tell you that my E4 will not lock up the wheels no matter how hard I apply the pressure. I can get them to lock up with the Hand parking brake but it’s tough. Me not being a engineer has an opinion that maybe because the calipers are so large that the stock master cylinder can not deliver enough pressure to lock up the wheels. The larger wheels probably have something to do with that as well. That rotating mass thing. That being said my cart stops like a dream compared to the stock drum brakes.
Guessing that I will never put 50,000 miles on my gem. I should never need brakes again. The 2500 miles on the stock ones were junk! Plus I have way less brake drag. My wheels spin forever off the ground. Sometimes you just have to brake the rules to have success. I’m just saying. I think it’s pretty f’n cool to have 4 wheel disk brakes. I’m just saying
Good luck to all.

To be sure check your cart out on wet pavement. Just to be sure you aren’t surprised. My drum brakes will lock up the rears. However I only have 21" wheels. I moved the pedal pivot point so I have 20% more pressure. Makes a big difference with drum brakes.

Thanks, I will, my cart is a 4 seater and with 4 adults on it the brakes are weak…

On the NEV kit the “bow tie” plate to attach the caliper is 1/2” steel.

looks amazing very good job