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Big Shocks Bonzi Shocks Review

Big Shocks has been around since 2009 and their long travel Bonzi edition shocks are extremely popular with the mud truck crowd due to their large available sizes, unique attributes, and affordable price.

Big Shocks Bonzi

Big Shocks is based out of Big Rapids, Michigan where they can be reached by phone at 231-679-0760. Their website is

Have Questions About Big Shocks Bonzi Shocks? Check Out The Comments Section Below!



In this review we will refer to these shocks as "Big Shocks" because we found the actual brand name "" too awkward to read in a sentence. Second, this particular model of shocks are called the "Bonzi Edition" which we have to assume is an alternative spelling of bonsai because the only thing that comes up when you Google "Bonzi" is an animated purple monkey that you can download on your desktop. Third, while their name implies that these shocks are big, they are the same size as every other coilover in this category.*

*For this review we are testing their 2.25" body Bonzi shocks because our requirements were 12" of travel and their 2.5" body Bonzi shocks start out at 14". We we're told that all of their shocks are built the same way (just with larger or smaller components) so this review should be accurate for their 2.5 and 3.0 body shocks as well.

The Ordering Process

We called Big Shocks anonymously and our call was answered on the second ring by someone that was driving at the time. The person we spoke with was extremely friendly and more than happy to answer our questions. He asked all of the right questions about our fictitious project and made recommendations that we found to be accurate and honest. We asked about custom valving and the call got dropped. We called again 1 minute, 5 minutes, and an hour later with no luck. We called the next day too but never got through or a call back. Based on information found on their website, it does not sound like custom valving is an option, however, replacement parts seem to be readily available. We ordered our coilover on their website and it shipped out a few days later.

Shipping and Delivery

We received our Big Shocks coilover 4 days after the order was placed via UPS. The shock was double boxed and padded with some craft paper and bubble wrap around the reservoir. It arrived in very good shape with no marks or scratches and there were a few extra freebies (koozies and decals) thrown in which is always a nice touch.

Shock Details: Big Shocks 2.25 x 12" Coilover, Remote Reservoir, No Springs
Manufacturers Price: $389.40 ($375.00 + $14.40 Shipping)
Typical Dealer Price: n/a
Date Ordered: April 10th.
Date Shipped: April 15th.
Packaging: Good
Reservoir Mounts: No
Pressurized Reservoir: Yes

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This Big Shocks Bonzi Shock Review is ©Copyright - Do not reproduce or repost without written approval.

Initial Impressions

The first thing we noticed about the Big Shocks Bonzi edition coilover is that it has several non-traditional design elements. The cylinder is not threaded and there are heim joints at each end instead of spherical bearings. The reservoir is marked "Max 100 PSI" which we find to be quite low for a performance shock and there was no rubber bump stop on the shaft. None of the components are anodized, painted, or coated, giving the shock a bit of a bland look other than the glossy reservoir decal that sticks out nicely in contrast.

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Despite the differences seen on the exterior of the coilover, the Bonzi shock opened up following standard performance shock servicing steps. The wiper cap is locked into place with a set screw that was tight but loosened up easily with a small tug. The wiper cap unscrewed easily by hand to expose the seal cap which moved down to release the retaining ring that holds it in place. The shaft assembly came out with moderate ease and the oil was poured into a clean container and showed no signs of any contaminants.

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Removing the top cap was surprisingly easy, it cracked loose with a slight pull on some large pliers and then unscrewed smoothly by hand. Looking inside revealed another unique design feature - an internal cap sits inside the top of the cylinder (sealed by an o-ring) and creates a large flat surface to seal against a rubber ring in the top cap. We did find it strange that no thread locker was used to keep the assembly tight.

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The use of heim joints instead of spherical bearings is an interesting decision. They are easier to replace, offer some coilover length/height adjustability, and make the shock significantly easier and cheaper to manufacture. Using the lower heim joint to attach the lower spring plate to the shaft would make changing springs a bit more of a hassle compared to traditional coilovers.

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The end caps on the reservoir are held in place with retaining rings that are exposed by pushing the end caps in from each side. With the end caps and internal floating piston removed, we again noticed a bunch of o-ring and no wear band. We removed the o-rings to check the fit of each component in the reservoir cylinder and found them to be very loose, which of course explains the need for such large o-rings.

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This Big Shocks Bonzi Shock Review is ©Copyright - Do not reproduce or repost without written approval.

Coilover Hardware

The coilover hardware on the Big Shocks Bonzi coilover is all extremely beefy. The top and bottom spring plates are machined from aluminum and have tight tolerances to the shock body and shock shaft. The slider is machined from a hard plastic (that almost feels like plexi-glass) and is also a very snug fit. Instead of a threaded body, Big Shocks uses 21 grooves spaced 1/4" apart to accept a retaining ring that holds the upper spring plate (coil nut). We found the ring difficult and awkward to remove and re-installing it in a new position required pliers and a hammer to push it into place. The ring only seems to cover about 2/3 of the circumference, which is a bit concerning, and we still can't understand why aluminum was used for the main cylinder.

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Shock Shaft and Piston Assembly

The shaft and piston assembly of the Big Shocks Bonzi coilover has most of the same components found in a traditional performance shock, however, it is clear that a lot of shortcuts have been taken to simplify production and reduce costs. The wiper cap and lower seal cap are solid and well made, although, between the two there are only two wiper seals and no o-ring or bushing to guide the shaft. A loose fitting ring of PVC pipe is used as the shaft spacer and the piston is very simplistic in design. Just like in the reservoir, o-rings are used instead of a wear band on the piston. Two identical shim stacks made up of only two 0.015" shims each are used for compression and rebound damping. Finally, the lower end of the shaft is internally treaded to accept the lower heim joint.

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Shock Valving

All Big Shocks shocks are pre-built and sold with the shim stack configuration listed below. We were unable to find the specifications of the oil but it appears to be medium weight shock oil. The recommended pressure for the reservoir is 100 PSI.

.015" x 1.421" OD .015" x 1.421" OD
.015" x 1.282" OD .015" x 1.282" OD

This Big Shocks Bonzi Shock Review is ©Copyright - Do not reproduce or repost without written approval.

Shock Details

The following is a list of component materials, dimensions, weights, finishes, and other important details as they pertain to each individual part. Each component was measured multiple times with a highly precise caliper and scale.

Complete Shock 11.0 lbs. Overall Dry Weight with Hardware
Shaft Assembly 2,090 grams of Moving Weight
Reservoir Assembly 805 grams Dry Weight Without Hose
Shock Oil Medium Weight | Gold / Yellow

Shock Cylinder 16.375" Long | 2.260" OD | 2.00" ID | 0.130" Wall | 567 grams | Aluminum | Bare
Top Cap 2.700" Tall | 2.465" OD | 5/8" x 1.50" Inner Thread | Aluminum | Bare
Top Coil Nut 1.640" Tall | 0.394" Spring Perch | 3.480" OD Spring Seat | 306 grams | Aluminum | Bare
Stop Nuts None
Slider 1.508" Tall | 3.618" OD | 2.277" ID | 0.371" Wide Spring Seat | 0.120" Wall | Plastic
Lower Spring Plate 1.176" Tall | 0.398" Thick Seat | 3.475" OD | Aluminum | Bare
Bearings Heim Joint | 0.625" ID | 0.748" Ball Width | 5/8" Shank | Chrome-Moly | Imported
Misalignment Spacers 1.749" Overall Width | 5/8" ID | Steel | Plated

Shock Shaft 16.00" Long | 0.999" OD | 1,531 grams | Steel | Chrome
Piston 0.836" Thick | 1.979" OD | 0.249" ID Ports | 81 grams | Aluminum | Bare
Valving Shims 0.408" ID | Various OD and Thickness | Steel | Bare
Shaft Spacer 0.882" Tall | 1.897" OD | 1.600" ID | 17 grams | PVC Pipe
Seal Cap / Guide 1.806" Tall | 1.980" OD | Wiper Seal Only | 154 grams | Aluminum | Bare
Wiper Cap 0.898" Tall | 0.553" Inset | Wiper | Aluminum | Bare
Bump Stop None
Lower Rod End None

Reservoir 11.00" Long | 2.260" OD | 2.000" ID | 0.130" Wall | 417 grams | Aluminum | Bare
Reservoir Valve End 1.981" OD | 0.919" Thick | Brass Schrader Valve | Aluminum | Bare
Reservoir Hose End 1.985" OD | 0.947" Thick | 0.450" Bore | 3/8" NPT Thread | Aluminum | Bare
Reservoir Piston 1.981" OD | 1.296" Thick | 0.210" Deep Hollow | 151 grams | Aluminum
Reservoir Hose 17.0" Long | .668" OD | 0.375" ID | 3,000 PSI | Steel Braided | 3/8" Fittings| Rubber

Summary / Conclusion

While we credit Big Shocks for doing things differently and building their shocks in the US, there are simply too many flaws with their Bonzi shocks to justify anything near their $390 price tag. We understand that labor and materials are more expensive in the US and that requires cutting corners to make a profit in this price range, however, removing the stop nuts and using a system that requires a spring compressor to preload your springs and set your ride height is simply unforgivable. For about $150 less, you could keep you money in the US economy and run an F-O-A coilover that is similar in quality but functions like a traditional coilover.

The Good Stuff The Bad Stuff
Fast shipping No custom valving option
Friendly customer service Aluminum shock cylinder
Low overall weight No stop nuts / secondary nuts
Replacement parts available Awkward preload adjustment system
Snug slider and spring plates Imported generic heim joint ends
Heavy duty wiper seals No wear bands on pistons
Simple and unique design No shaft guide bushing or o-ring seal
Very easy to service 100 PSI rated reservoir
Made in the USA Poor tolerances on reservoir components
No bump stop
PVC pipe used for shaft spacer
Shaft spacer makes contact with piston shims
No coatings on the aluminum components

The Final Word: We find Big Shocks to be an example of what happens when someone decides to reinvent the wheel. There is a reason why most performance coilovers happen to be very similar in their design and that is because off-road racers have refined that system over many decades. We commend them for their attempt at being different but in order to make Big Shocks a contender in the performance off-road shock market they will have to first catch up to the rest of the field.

Have Questions About Big Shocks Bonzi Shocks? Check Out The Comments Section Below!

Related Resources

Crawlpedia Shock Shootout
Shock Tuning Guide
Shock Valving Guide
How To Measure For Coilovers
Coilover Install and Setup Guide
ORI STX Struts Guide

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