Fitting Button head Allen bolts to CF base.

Unicycles and Equipment
1

Fitting button head allen bolts to your seat not only looks tidier than the usual bolts, but it’ll also save your finger tips being cut by catching them on the bolts. Working with a new base would be best, this would allow you to drill bigger holes and do less filing to fit the flange nuts into the base. If you are working with a base that has already been drilled and fitted with coach bolts, it is likely to take more time due to having to file the square holes out to fit the flange nuts.

What you’ll need.

Carbon Fibre seat base,
M6 flange nuts (10), in the pic below.
M6 x 12mm Button head allen bolts (6), in the pic below.
M6 x 16mm coach bolts (4),
M6 x 12mm washers.
Bumper and handles.
Tape, IE: Duct tape.

Small square file,
Marker pen.
If you have a new base, you will need a drill and drill bits (3, 6.5, and 8mm).

Working with a previously fitted base.

Firstly you’ll want to take the cover and foam off of your seat. Leave the coach bolts in the seat base, thread a 10mm nut (or one of the flange nuts, with the flange away from the base) on to each of the bolts for the handle and bumper. Draw around the nuts on the seat base, as pictured below.

Working with a new base.

If you have a new un-drilled base, I’d suggest following this guide, which can be found on municycle.com, up to and including the stage for drilling the holes. Put the button head bolts in the base, and thread a 10mm nut (or one of the flange nuts, with the flange away from the base) on to each of the bolts for the handle and bumper. Draw around the nuts on the seat base, as pictured below.

Working with a previously fitted base.

Remove the coach bolts, and file the square holes out to the outline of the nuts. You will want the nuts to be a tight fit in the base.

Working with a new base.

Remove the coach bolts and drill out the holes to 8mm, this should be just within the outline of the nuts, and now file the holes to the outline of the nuts. You will want the nuts to be a tight fit in the base.

With the holes for the handle and bumper filed out to fit the flange nuts, press the flange nuts in from the top of the seat base so that the flange is on top stopping the nuts going through the base.

And a pic from below.

Put a piece of tape across the top of each of the flange nuts, to hold them in the base, and re-fit the foam and cover on to your seat. The button head allen bolts will take a 4mm allen key, put a washer on each bolt and fit the handle and bumper to your seat.

Fit the seat to your unicycle, and now you’re done.

Yeah the pic’s and write up probably aren’t the best, but it’s better than nothing.

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2

Awesome write-up, thanks!

You might look into using some 2-part epoxy to hold the nuts in place… this is what SW does to secure his t-nuts. Not only does it make a semi-permanent bond between the bolts and base, it fills the gap between the bolt and the base that might pinch your air pillow, or tear your foam, after extended riding.

I’ll give this a try with some t-nuts, though. Looks great!

3

Thanks.

I’ll probably go with the epoxy on my next base, and put some on this one at the same time.

4

maybe you can replace the nuts with blind nuts

6

I did this conversion today, its realy worth the hasle just to loose the 10mm wrench in your backpack on rides.
But I did need to visit 4 stores the find some M6 flange nuts, and when I did found them I bought 3 bags of 15 nuts to have enough spares.
Anyways, the seat feels a bit stiffer now and the allen key is realy handy to tension the bolts at the post.
Great new way to build up a CF :sunglasses:

7

You changed the bolts for the seat post?

I thought about doing that too, but decided to keep the remaining 6 bolts for my next seat. I can always change them at a later date anyway.

8

Yep, all bolts are now imbus.
Feels realy stiff and strong :slight_smile:

9

I’m gonna have to do this to my SW when/if I get it.

10

SW will do it for you, for an additional charge… or at least he used to.

11

Sick! Thanks for that…

I’m going to do that soon… :D… as soon I get a CF for my spare uni ( I would not have any risks with my current base)…

Thanks!

12

Allen bolts at post still holding out fine, my rim is another thing.
Damn thing needs a re-true after 2 trial sessions.
Might be the lack of finesse after 6 months of non trials riding…

13

BUMP!
so i just got a CF base, and it came w/ a miata paper, great… i hope its not a miyata seatbase…
anyways, i was hoping someone could send me a copy of their template for the “KH style” seat base

i’m also going to get some “mighty putty” or similiar to epoxy in some T nuts, but i’m only planning on using one of the teeth. i’m going to drill out the circle and cut the tooth out w/ a jigsaw… if it ever breaks, i’ll just cut the other two grooves and run w/ it from there.

edit: i’m kind of disappointed in the construction of the seatbase, there are lots of bubbles in the resin, i’m pretty sure it would be strong enough if those were not there, but now i really don’t know… i guess we will see.

14

hi guys. I have a quick question. My CF base is on its way and i want to use this method to install it. Like you, Probailer2, i want all my bolts to be button head ones but i wondering about the bolt lengths for the seat post attachment. Would 16mm be too long if you kept the same method for the seat post as for the bumpers? Did you use 12mm bolts for your seat post attachment or longer probailer2? I am attaching it to a KH rail adapter- is the thickness of this comparable to a seat post top plate?
If you can help me out that would be great!
Cheers- and thanks to fraggle for a great idea and writeup!
Mark

15

thanks!

16

I also want to thanks to you and i agree with this user which saying i’ll probably go with the epoxy on my next base, and put some on this one at the same time.thanks again