Bikes Front End

[Killer848]

Hi there,

Im wondering if there is anyone out there that knows of a simple way to check if the front end of a motorbike is straight????

Cheers
Chris

[Big Lunt]

I string lined mine from a central point off the frame if it the forks you are referring to

That was after I flipped it at EC and all was good? Flew straight

[Killer848]

yeah i wanna check if the forks are straight. I figured a stringline might be the answer im just quite sure how to go about it:confused1:

like if i string off the frame i just pick a central point and take the line along the bike and around the forks and back to the same point?? Or do i go wheel to wheel with the line??

[Big Lunt]

I went from a central point from the frame and then chose different points off the forks and clamps.

See how you go with the axle going through nice and easy as that can be a give away unless both are bent. Run a straight edge on the fork tubes as well

Good luck with it - can always take them out and get some to check them

[Terry Hay]

If you simply wish to check if the forks are straight here's an easy method. (usually it is the chrome tubes that bend)
Remove the front wheel and calipers. Now rotate the fork lowers and see if they are out of round. A good eye will usually pick 2 tenths of a mm. Sometimes even less. To check the uppers remove the fork and clamp the fork bottoms in a vise. (Soft jaws recommended) Now rotate the uppers. If you cant pick any "out of round" you will generally be ok. There is enough tolerance to accommodate small imperfections.
Terry

[Killer848]

Thanks terry,

The bikes been down on the right hand side and there is a light graze on the right side of the front rim and a little nick in the back of the right fork tube at the top.
The right clip on was completely torn off in the crash as well

I'm fairly confident that the fork tubes themselves are still straight however i will do a closer inspection on them.

Is there anyway the steering could be out as well?
or a posibility that the triple clamp set up could of been twisted or shifted in anyway?

[zenodamper]

I mostly see the weaker upper aluminium outer tubes bending/damaging with creases where the bottom clamp sits, or where the handlebars mount near the cap. As well as sometimes the triple clamps having tweaked angles between them as the most common "injury" with modern USD fork legs - running your hands up and down the tube will often see you feeling or spotting the crinkle, this is if you don't have V blocks and a dial gauge... though they work well too :)

[Killer848]

Cheers Zeno, I'll take a closer look 2moro and post my findings. From what i can tell it seems to have been only the right fork that has taken any impact, im just trying to determine if it was a front on blow or just from the top.

It looked as if another bike had driven over the top RHS of my bike.

To me the whole front end of the bike looks fine, but it has taken a knock and i just want to make sure as best i can that its all still straight before i go putting it all back together.

Thanks for all the input guys :ayyy: