Custom Backrest

After a few rides my girlfriend starting telling me that she felt a little insecure on the back--she always holds on tightly but said she was worried that if we hit a bump she might just bounce right off the back. We agreed that it seemed unlikely, but I want for her to feel as safe and secure as possible. I looked into aftermarket rear seats and wasn't too impressed with their bulkiness--both in design and expense.

I'm always up for a design challenge and have a good selection of random materials/tools in the garage, so I went for it. This is a more complex DIY than many, but certanly possible for those with the desire to do it! The collection of photos I have to show the process isn't the greatest. Sorry!

I jumped on ebay and picked up a used rear seat with torn vinyl for 40 bucks or so. I stripped it down, notched the back and reinforced the back portion (where the backrest would mount) with bondo. It conforms to the exact shape of the inside of the seat and is easy to work with and hardens like plastic. In it, I embedded two t-nuts for the mounting screws to eventually sink in to.



The backrest portion is made of a UHMD (ultra-high-molecular-density) plastic, available at many, but not all hardware stores. It's rigid, but with heat from heat gun or oven it becomes pliable. This allowed me to bend it to the right shape to give enough clearance for comfort but still allow it to fit into the stock location. On top of the UHMD is a layer of MDF (fiberboard), foam and the vinyl upholstery--the same vinyl I reupholstered the front seat in awhile back (GREAT STUFF)--available at Joanne's Fabric stores. I did the sewing myself, but I'm sure any upholstery shop could do the same for not too much $$.


(I later found better hardware and replaced the knobby allen screws here with ones you'll see later)

After hollowing out a bit of foam to leave space for the bondo applied to the sub-structure, I gave it a test fit. It fits perfectly within the same spot as the factory seat. This means it pops on and off in seconds and required no change whatsoever to the bike.



It all seemed to fit well so I upholstered it up, made a new grab handle to match the new vinyl and called it done! (also pictured is the red color-matched seat made the same weekend)



After our next ride, my girlfriend was quite pleased. She said she felt wayyy more comfortable and relaxed. Just having that little backrest to slide back against was enough to make a huge difference!

Thats awsome. Have you checked how strong it is? By that I mean try and push it away from the front of the seat like she was sliding off the back? That looks awsome and profesionally done.

Thanks--

About strength--yeah, that was the primary goal of the backrest, so we checked it out pretty well. The UHMD is 1/2" thick, so it's rather sturdy and the sort of stuff that bends rather than breaking. It flexes a little more than I had hoped for, but she tells me that when she's actually sitting against it, it doesn't feel like it flexes at all. I had her sit on it and apply the sort of pressure she feels like she puts on it when we ride while I stood to the side and watched and sure enough, it barely moved at all-- way less than when I yanked and tugged with my hand.

all in all, it probably cost $50 and is simple, clean, and most importantly, effective!

quote:

ORIGINAL: jerrad

Thats awsome. Have you checked how strong it is? By that I mean try and push it away from the front of the seat like she was sliding off the back? That looks awsome and profesionally done.

Just make sure you test this when bike is not in motion.

That's what I did.

You outta start making these. Have a person send you money with their back seat and just make them to order. If I can find a cheap back seat I might consider it.

I think I'd be open to that. Just a couple of concerns come to mind--

Matching the upholstery of the front seat. Unless you wanted me to upholster both or found matching material yourself, it would be difficult to have matching seats. Of course, this might be desirable for some.

My labor is free for me but I'd have to charge someone else. Perhaps if I had a few lined up I could save time on them, but doing them one at a time is a little more time consuming. Add to that the cost of buying an extra seat and the total might come to $100+... I'd have to see how long it actually takes to make one from start to finish to give you a better idea of what I'd have to charge.

Please let me know if you're interested!

Thanks!

That was awesome. Next time around can you post pics of the process of re-doning the foam and vinyl on the seat?

WOW! Very nice. Great write up and pictures. Thanks for sharing!
-D

If someone wants to commission me to make another for them I'd be happy to take more pictures. You know how it is when you get going on a project you just forget to take all the pictures. I wasn't really thinking of writing a how-to as I was doing it, so like I said, the collection wasn't the greatest.

Next time 'round I'll be sure to get a complete set and I'll insert them in the original post.

This may be something I'm interested in later. My wife is currently unavailable, but has told me that she wants to go riding. I have an 06 600RR and there isn't much for her to hold onto......except me. I think this would make her feel better about it too. Great job!

Thanks for another great write up!!! Very nice idea. My GF always puts her hands on my tank while riding. I hate it because I dont want her to scratch it, but the relief of her pushing on me when I stop and not holding on so tight is worth it. She sits back a little further, but not anything to put her in danger.

You think there is any way to do this to a 929 seat.

I've never looked closely enough at a 929 seat to know. I imagine it can be done with a similar process, though. If you're interested, you could take some pictures of it and measure the clearance between the seat and rear cowl and I could give you a better idea.

Nice work and it looks great!

That's a pretty sweet setup, nice work bro!

thats awesome man

Great idea. My Girlfriend freaks out about falling off too. Maybe I missed it, but where did you get the back rest? did you make it? was it the part you got off of ebay? I didn't quite understand that part. Also, I ride a f4i. Do you think I could just modify a back rest and mount it where the grab handle attaches? Thanks for the post

Beautiful job!

RdRage-- The entire seat, including the backrest part (with the exception of the plastic/foam underseat portions) was fabricated by me. The backrest is UHMD plastic, cut and bent to the right shape then upholstered with a vinyl-wrapped cushion mounted to it. The part from ebay was just the stock seat that I used as a base--I didn't want to tear up my stock seat and only have the backrest version. I wish I had gotten better pictures of it. If I have some time, I might disassemble it one of these days and add more pictures to clarify everything. Or if someone wants to send me their seat I'll make one for them and take lots of pictures! Even better! I'm assuming you mean you have the newer "bananna" seat F4i... sounds like a cool idea to use the grab handle as a mounting point for a backrest... I don't see why it couldn't be done... you could even find a used handle from someone who's done the split seat conversion and mount the backrest directly off of that...

Complete Genius! I could just weld a backrest to a new grab handle. Thanks for your ideas.

quote:

you could even find a used handle from someone who's done the split seat conversion and mount the backrest directly off of that...

huh? what? you can do that? I searched for a better explaination but I couldn't find one. could you point me in the right direction?

You're welcome for the ideas. Here's a couple of leads on tail conversions. I have an '01, so I don't think about them. I just know it's been done and someone who's done it might have a cheap grab handle for you to buy.

http://www.cbrforum.com/m_13417/tm.htm

http://www.cbrforum.com/m_92412/tm.htm