Sissy bar

[HarleyJay]

I bought a highway hawk sissy bar for my 125 dragstar off eBay, came nicely with instructions as to what side was what. I was trying to install today but the wouldn't go, my Allen bolts are just too small to go through the chrome stip and the metal brackets. Where so I get some longer ones from ?

[Noise]

Here you go. you will need to know what size it is (most likely an M10 or M12 if i remember correctly) and the length and the thread pitch.

http://www.custom-fasteners.co.uk/

Im sort of lucky as just around the corner from me is a shop that sells nuts and bolts and all sorts in stainless steel. Try having a look round your local area and see if there is any nick nack shops about.

[DirtyDT]

Modern jap bikes normally use metric nuts and bolts.

Bolts are the long bits with the threads, nuts are the bits with the hole in.

There are various heads (that's the bit on the top of the bolt that does not have any thread). These include: hex, counter sunk etc

They come in various metals and finishes such as: jappaned, high tensile, stainless etc

Bolts normally have 2 measurement and the description tells you what that is. Often this is something like: M6x20 or M12x50. Mostly sizes M4, M6, M8, M12 and M14 are used. Some bolts are special sizes. The M6, M12 etc is the measurement across the thread. M6 is smaller than M8 which is smaller than M10 etc. Often M6 size is used for crankcase cover bolts as a guide. the second part: 20, 50 etc is the length of the bolt measured from the BOTTOM of the head in mm.

This means that a:

M6x100 would be skinner than a M10x50 but would be twice as long in the threaded part.

A M8x45 and a M12x45 would be different thicknesses but the thread would be the same length.

if you get all that, the last part is the thread. The thread can be different although they normally work to a set standard. Threads can be described as fine, 1.00, 1,25 etc and often go up in increments of .25 Normally the size of the bolt defines the thread, but not always and this is why sometimes a loose nut you found does not fit on a bolt you have. Thread measurement is known as "pitch". The last thing about threads are the length they go up the bolt shaft, Some are threaded all the way, and some are not.

You can get gauges with holes in to measure the M8, M10 etc part and the thread pitch. An example is shown here LINKY

I think that is about it. I have to go and do some work now but you should now be able to work out what you have and what you need.

.

[Ttaskmaster]

The backrest should have come with longer bolts included already...

[Campaman]

Good information from DT there, bolts with the thread all the way are actually called set screws.

I work in the fastener industry, we actually make Steel/Stainless steel nuts so I have easy access to new Nuts, Bolts & Screws when needed.

If you cant find what you need locally let me know the size you need as I may have something laying around here.

[DirtyDT]

Cheers. I wish I had known you make them. I like to have a few jars of stainless nuts, bolts and washers hanging about and recently topped up with a couple of mega packs. Not cheap, I think the bits I brought came to about £60 and I always run out of the sizes I need. I could go for a tub of M6 in various lengths as these seem to be the most popular size on a Bike.

I know the set screw name but thought throwing things like japanned in was enough