So I had teased this for a while, but delayed posting about this for a bit, not for any particular reason - those at the Northeast 4C Rally saw these in action...
Background
I have been working on coming up with magnesium wheels for a little over a year now and was finally able to get these where I wanted them, in terms of strength, longevity, and weight.
Having long been of the mind that the lighter a wheel on the 4C the better, I set out to see just how light this could be (and frankly I already could make these a little lighter). I did this design quickly since the original design I had in mind wasn't coming out the way I wanted aesthetically and have since played with the engineering more to take a bit more weight off them.
Magnesium is tricky because despite being a light and strong material, it's density is low relative to aluminum so some designs will work better than others.
The Solution
BSPK Magnesium wheels in 18"/19" fitment weigh 32 lbs less than the stock wheels. This represents a staggering 35%+ reduction in rotating mass.
![Image]()
Front wheel:
![Image]()
Rear Wheel:
![Image]()
I chose to fit these with 215/40/18 and 245/35/19 RE71RS, which are pretty heavy tires, so the overall weight comparison, mounted on the car, comes out as follows:
![Image]()
Still, accounting for the 14lbs of additional tire weight (I am sure I could have chosen a lighter tire but the RE71RS has been terrific so far) these still removed 18 lbs of mass from the wheel/tire assembly on the car.
Why does it matter?
I think everyone on this forum appreciates that lighter = better (that's the whole ethos of the 4C we know and love) but I wanted to try and put some tangible data behind this...
I will start by saying that I think this dramatically oversimplifies the impact. With over 2k miles on these wheels to date, I find the biggest improvements are actually in ride quality and turn in; however, to try and put some data to this, I used my draggy and did 60-100 runs (to try and eliminate as much traction impact as possible).
The lighter magnesium wheels reduced my car's 60-100mph time by 0.45 seconds (almost as much as I found a tune to reduce this same measurement years ago). Note that the magnesium wheels were tested in worse conditions than the OEM wheels (it was the next day but density altitude was substantially higher).
Suffice to say these offer a measurable performance improvement and represent the ultimate in 4C wheels (IMHO).
![Image]()
![Image]()
Pricing
These are naturally going to be somewhat expensive. It's worth contextualizing that the least expensive magnesium wheels on the market (before BSPK) come in around $9k per set (DM I can point you to the company).
These are true to the BSPK mission of offering products to the 4C community at a fraction of the normal "market price"; however, these still cost quite a bit to make, so the 4C sets will retail for $5,250. That price reflects the total cost delivered, taxes paid, to USA, UK, Canada, Australia, or the European Union.
Why am I able to price these so much less than the competition? Because I am one guy sitting at my dining room table asking my GF to make me Top Ramen, not a bloated corporation with employees, overhead, or any commercial acumen whatsoever. 🤣
Don't let that understate the level of service you can expect from BSPK Forged. With hundred of satisfied customers around the world, customer service and safety remain central to our identify. These are made at the same load rating as the OEM 4C wheels. I do not, and will never, lower the safety of my products to be able to market lighter wheels.
This was a product driven by my personal interest in enhancing the 4C experience, and I am delighted to be bringing it to market more broadly.
Lead Times
Most orders will take ~8 weeks from order to delivery (geography dependent).
Photos
![Image]()
![Image]()
![Image]()
![Image]()
Notes: These can be made for any vehicle and different styles are available. As I mentioned, some styles will work better than others so best to discuss your vision to determine what best balances aesthetics and weight.
Thank you for reading,
John
Background
I have been working on coming up with magnesium wheels for a little over a year now and was finally able to get these where I wanted them, in terms of strength, longevity, and weight.
Having long been of the mind that the lighter a wheel on the 4C the better, I set out to see just how light this could be (and frankly I already could make these a little lighter). I did this design quickly since the original design I had in mind wasn't coming out the way I wanted aesthetically and have since played with the engineering more to take a bit more weight off them.
Magnesium is tricky because despite being a light and strong material, it's density is low relative to aluminum so some designs will work better than others.
The Solution
BSPK Magnesium wheels in 18"/19" fitment weigh 32 lbs less than the stock wheels. This represents a staggering 35%+ reduction in rotating mass.
Front wheel:
Rear Wheel:
I chose to fit these with 215/40/18 and 245/35/19 RE71RS, which are pretty heavy tires, so the overall weight comparison, mounted on the car, comes out as follows:
Still, accounting for the 14lbs of additional tire weight (I am sure I could have chosen a lighter tire but the RE71RS has been terrific so far) these still removed 18 lbs of mass from the wheel/tire assembly on the car.
Why does it matter?
I think everyone on this forum appreciates that lighter = better (that's the whole ethos of the 4C we know and love) but I wanted to try and put some tangible data behind this...
I will start by saying that I think this dramatically oversimplifies the impact. With over 2k miles on these wheels to date, I find the biggest improvements are actually in ride quality and turn in; however, to try and put some data to this, I used my draggy and did 60-100 runs (to try and eliminate as much traction impact as possible).
The lighter magnesium wheels reduced my car's 60-100mph time by 0.45 seconds (almost as much as I found a tune to reduce this same measurement years ago). Note that the magnesium wheels were tested in worse conditions than the OEM wheels (it was the next day but density altitude was substantially higher).
Suffice to say these offer a measurable performance improvement and represent the ultimate in 4C wheels (IMHO).
Pricing
These are naturally going to be somewhat expensive. It's worth contextualizing that the least expensive magnesium wheels on the market (before BSPK) come in around $9k per set (DM I can point you to the company).
These are true to the BSPK mission of offering products to the 4C community at a fraction of the normal "market price"; however, these still cost quite a bit to make, so the 4C sets will retail for $5,250. That price reflects the total cost delivered, taxes paid, to USA, UK, Canada, Australia, or the European Union.
Why am I able to price these so much less than the competition? Because I am one guy sitting at my dining room table asking my GF to make me Top Ramen, not a bloated corporation with employees, overhead, or any commercial acumen whatsoever. 🤣
Don't let that understate the level of service you can expect from BSPK Forged. With hundred of satisfied customers around the world, customer service and safety remain central to our identify. These are made at the same load rating as the OEM 4C wheels. I do not, and will never, lower the safety of my products to be able to market lighter wheels.
This was a product driven by my personal interest in enhancing the 4C experience, and I am delighted to be bringing it to market more broadly.
Lead Times
Most orders will take ~8 weeks from order to delivery (geography dependent).
Photos
Notes: These can be made for any vehicle and different styles are available. As I mentioned, some styles will work better than others so best to discuss your vision to determine what best balances aesthetics and weight.
Thank you for reading,
John
