Tall Fit drivers: It is fairly simple and cheap to move the driver's seat back a couple inches. It only took about $20-30 worth of parts, a few simple tools (although you'll be happier if you have some power tools), and a Saturday afternoon to make it happen.

I made no permanent alterations to my Fit; everything is 100% un-doable and can be returned to factory state. 2” is really the only distance you can move the seat without having to modify anything in your Fit. Less than 2” and the front feet won’t clear the new bolt; more than 2” and the back inside foot hits the center console. I found 2” adds more than enough room. I’ve actually got a couple “clicks” left on my seat now.

DISCLAIMER: I am not an automotive safety engineer and cannot make any guarantees about the safety of this modification. Do so at your own risk.

Parts:

The bolts, nuts, and washers I used are all class 10.9 steel, which is significantly stronger than class 8.8 steel you commonly see at the hardware store. Whether that's actually necessary, I don't know. But better safe than sorry! I suspect these bolts are stronger than the factory bolts.

4 - 10mm x 1.25mm x 25mm bolts
2 - 10mm x 1.25mm x 30mm bolts
2 - 10mm x 1.25mm x 40mm bolts
4 - 10mm x 1.25mm hex lock nut nylon insert
24 - 10mm washers

The flat bar I used (probably overkill again) is 1/4" thick, 1-1/2" wide ASTM A36 hot-rolled steel, suitable for structural use. I bought a 3' bar at Lowe's and cut my own pieces, but you can get pre-cut pieces from MetalsDepot.com: scroll down to "F214112, Hot Rolled A-36 Steel Flat, 1/4 X 1-1/2" and select "Cut to size", quantity 4. I cut my own pieces to be 4", but if I was going to do it again, I'd make them a little shorter. Neither Lowe's nor Hillman's website specifies exactly what kind of metal it is, but I called Hillman's customer service and they stated that it's A36-compliant without any prompting from me.

Tools:

Drill w/ 7/16” cobalt bit
Hacksaw w/ fresh metal-cutting blade
Clamps
17 mm wrench and socket
Metal files (optional)

Instructions:

Measure and mark 4 4” sections on the steel bar. Measure and mark two holes 2” apart and 1” from either end of the bar. (I'd probably make them 3/4" on either end if I did this again. Also, because of the angle of the attachment point on the rear feet, it probably would've been easier to install if the holes on the rear bars were slightly farther apart.)



Cut the pieces with a hacksaw or power saw if you have access to one. Additionally, you will need to cut a 45º angle on one side of one piece to fit the rear right foot so that it clears the center console. I did this on the 2 front bars as well for aesthetic reasons and so they wouldn’t hit the carpet, but this is optional.

Drill the 8 holes. Drill press highly recommended.



Optional but recommended is filing the edges. Even better if you've got a grinder.

Remove the factory bolts from the seat. The seat does not need to be removed from the car, nor does the electrical wiring need to be detached. You’ll need to lift up the seat and move it back and forth a few times throughout the process to get it out of the way.

Attach 2 bars to the front feet using 25 mm bolts inserted from the bottom and a washer on either side of the bar and the seat foot. Put the nut on top and tighten it enough to keep the bar in place, but not super tight yet.

Move the seat way up toward the steering wheel to access the rear attachment points. Put the remaining two 25 mm bolts through the rear bars from underneath with a washer; they just need to sit there loose while you attach the bars (recall the one on the inside needs an angle cut on it to clear the center console) to the floor using the 40 mm bolts. Put one washer on top of the bar and 6 washers underneath. These 6 washers are what lift the bar up off the floor far enough for the the other bolt to clear the carpet. (A fancier solution would be to actually bend the bars rather than using washers for spacing, but I have no facilities to bend 1/4" steel bar!) Don't tighten anything too far yet.

Move the seat into position: the rear feet will now have the upward-facing bolts running through them, while the front bars will now have their front holes aligned with the holes in the floor. Use the 30 mm bolts with a washer to attach the front bars to the floor. Don't tighten it down all the way yet. Put another washer and a nut on each of the rear feet. The seat is now reattached at all 4 points, but is not tightened down. You'll probably have to wiggle the holes and bolts around a bit to get everything to fit. The 7/16" drilled holes allow very little clearance for the 10 mm bolts, and getting your wrench underneath to tighten can be tricky, but it's worth it!

Tighten everything up fully and enjoy your additional legroom. Put your factory bolts somewhere safe in case you decide to undo this project.

My seat feels every bit as solid as it did before my alteration. My only complaint is that I wish the shifter (I have a manual transmission) was a tiny bit closer, but I'll take that slight stretch any day over cramped legs.

Also, I finished this project several months ago and am just now posting about it so some of the details are not fresh in my head anymore, sorry. Please post any questions and I'll do my best to answer.

Some more pics:

 

Thanks jefft. I appreciate the detailed write up. I'll be diving into this project in the coming week. I will post here if I have any questions. I'll also take pictures of my work and maybe can help with your write up if I encounter different problems/issues.

Thank you for taking the time to post this.

 

As someone with a 37" inseam, I find this thread helpful and interesting in the extreme. Do you see too much flexure in the the new metal bar mounts? Would it be worth putting more washers on the underside of the the bar, along with a longer bolt, to make the bolt head able to rest on the floor?

 

The 1/4" steel bar doesn't flex at all. The seat feels just as solid as before modification. If you use 6 washers as I did, the rear upward-facing bolts touch but don't fully rest on the carpet. But if you want them to (for stability?), all you would need to do is use fewer washers on the downward-facing bolts (lowering the whole bar). However, it would be pretty difficult to get a wrench under the bar to keep the bolt from spinning while you tighten the nut.

 

This is so sketchy. Why you'd buy a new car and make it unsafe is beyond me. Protip...buy a car you fit in.

 

Finally, something that's worth a try. My knees are hurting lately as I've been spending more time on the road.

jefft, do you think you could delight us with some follow-up pics? It would be nice to know if with a few months of driving the plates would bend. Maybe we can come up with a nice design. I am getting myself ready for this mod.

Many thanks!

 

I'll have to take some more pics, but my seat feels as solid as ever. Truly a "set it and forget it" kind of mod. I don't think you can overestimate the strength of 1/4" A36 bar and 10.9 bolts. They're way overqualified for this application. I'll caveat that statement with the ol' "I'm not an automotive engineer."

Good luck!

 

I've done something similar in several race cars, but I always use a 1 piece strap that runs from the front mount to the rear mount so there isn't any leverage on the part in the floor.
The issue you'll have with the style of mount is the leverage of the drivers weight will start the floor cracking around the mounts eventually..

I've seen his exact type of mod done with no issues but the cars were not driven that regularly or maybe as intensely?

In any case I'd make each side 1 piece..

 

Thank you for your critique. It's a lot more useful and thoughtful than mike410b's. This is my long-term concern.

In the front, the bars rest directly on the floor, so the stress point is on the bolt/nut connecting to the seat. You could fairly easily devise something to transfer weight directly down, but I'm hoping just checking the tightness on the bolts occasionally will be sufficient.

The stress on the rear bars can be mitigated by placing something (like washers) underneath so that the driver's weight is transferred directly to the floor, even though that's not where it's attached.

Also, am I wrong to think this is less critical than the seat belt?

 

Right after the seatbelt and airbag catch you, you get tossed back into the seat, I got rear ended a few years ago and tore the factory mounts out of the floor. ended up in the back seat.. Luckily I had a bunch of camping gear in the back and the sleeping bags caught me.. Dude hit me doing about 50.. I had zero injuries but the poor old Isuzu Trooper that I was driving, died on the operating table..

Think of that front brake as a bottle opener.. Its prying upward ever time you accelerate.

 

Performed this mod the other day. Made sure to loc-tite the bolts, too, try to help prevent anything from loosening. Very happy with it. This is a great discussion you guys are having here.

 

Thanks so much for the new responses. I finished mine yesterday. It involved extra work as my seats look a bit different from the ones here. I will post in the next few days some.
My car is a 2010 Honda Fit Sport. One of the front holes is at an angle. The extension I made was a total 2.5" further back.
Process followed for mine was to do the ones on the back first, then by placing just the plates on the original front holes I followed up by marking the new rail holes (while seating, my weight reduces the clearance from the rail and the plates; especially the one in an angle).
Pictures will make everything more clear, so you have a better idea.

 

Nice! I thought about painting the bars black but didn't. My bars are showing a tiny bit of oxidation, so I'd say painting them is a good idea even beyond aesthetics.

 

Wow, glad you didn't get hurt. Obviously, this is testament to the importance of the seat being securely attached. I'm going to check on my rear bars and see if I can't make some improvements. I still feel pretty confident in the strength of my design, but of course any modification adds some risk.

 

I'm not terribly familiar with the design of the previous generation Fit, but
I'm interested in seeing some pics. Glad this mod provided some inspiration for you, even if requiring some modification.

 

It definitely did inspire me. Pain in my knees is a big motivator as well lol.
Pictures coming soon. A moderator needs to approve that post. Have a nice weekend everyone.

 

This is a great idea. The other thing I was considering is that it would be better to drill and tap the bar itself to receive the stock fasteners. That would eliminate the stack of washers under the bar and allow the seat to be a bit lower for more headroom.

Now I have to look at my car and see if there is a straight shot between the front and rear attach points. If so, I'm in business!

 

Use a nut, Mild steel is not strong enough when threaded for this job.
Even on Chrome Moly roll cages you weld in a bung, run the bolt clear though the bar and nut it on the back side.. (Seatbelt mounts. )

 

We'll have to disagree.

A quarter inch of mild steel will easily handle the stress caused by tightening the bolts to spec, and that stress is an order of magnitude greater than any stress that might be applied to the bolts by crash loads. The stock welded-in nuts are, after all, mild steel, since you can't weld heat-treated nuts.

Roll cages are made of tubing much thinner than the bar we're talking about, generally 0.083 chromoly or 0.110 mild steel, and the boss welded through the tubing is designed to spread the load over enough of the thin tubing to prevent tear-out.

The weakest points in this seat relocation setup will still be the stamped steel seat base and the nuts welded to the body sheet metal.

And, before the inevitable question is asked, yes, I am an engineer.

 

Thank you ! Thank you ! Thank you !

What a great thread, just the plan I needed to relieve that cramped feeling from not enough legroom.

The driver side seat brackets on my 2013 Fit are a little different than the 2015 Fit seat brackets.
The adapter plates I made are basically the same as jefft's and I even mounted the adapter plates on both of my rear driver seat brackets the same as jefft's, but on my front driver seat brackets I mounted the adapter plates a little differently. (see photo)

This is the left front driver seat bracket.



This is the right front driver seat bracket.




The adapter plates are on top of both of the front seat brackest rather than below, so the seat did not lean back as far, which I found to be more comfortable for myself and was more comfortable for my wife with the seat slide forward.
The hole spacing of my front adapter plates are 2-3/8" apart, the hole spacing of my rear adapter plates are 2" apart.
On my 2013 Fit, the left front driver seat seat bracket mounts on the floor at a slight downward angle compared to the 2015 Fit, but the adapter plate still mounted ok, and everything worked out great. I now have more than enough legroom, in fact, if I'm driving in town, and doing a lot of manual gear shifting, it's more comfortable to slide the seat forward slightly (which is still further back than what I had in the stock rear most position). On the open road or interstate the seat is slide all the way back.

Thanks so much jefft for posting this modification,
I would like to thank hresendiz25 for his suggestions and help too.