How to check straightness of bike when looking at a used one

Hi Guys,

I am looking at a used R6 tomorrow. It's been down, but it's "rideable." I want to check basics - forks arent bent, frame is ok, etc. I have been searching for hours and cannot find information that does not require me to disassemble the bike. Any tips/measurements I can take to check on this stuff? Bonus: All of the side fairings are removed.

Thanks!

 

Look for the article on-line about using a string to check/align a bike's wheels. The same method will tell you about lateral alignment of the bike.
I think Nick I wrote it, so check Cycle World.

 

Wouldnt have expected to see you hereJK

 

No matter what else, I am a bike junkie.

I do read other forums than the Dungeon.

 

easy check:
put another bike in front of it and see if it gets a boner

 

The bike or the rider?

 

For what it's worth. When my son yard saled his R6, 2x in one weekend at Willow Springs, it bent the swing arm and the triples. The bike flipped multiple times, wiping out the tank, subframe, bodywork, front cluster, fairing stay, etc. The forks didn't get bent or if they did, very slightly. Put on the spares and had to race it that way at the AMA Barber round the next weekend.

Afterwards I took it to the frame straightener, as it had a noticeable crease/bend where the left clip on came around and creased the frame. He said the new modern frames almost never bend and it checked out straight. He straightened the triples and the swingarm.

We later realized the forks were fubared. Put it on a front pin stand, and grab at the bottom of the forks, then try to move it forward and backward. Ours would move and make a slight clunking sound. We discovered that at the Laguna Seca round. It wasn't obvious as the suspension was looked over by multiple knowledgeable industry people. Once we replaced the upper tubes, most of his chatter problems went away, too bad it took a few race weekends to figure that out.

 

the r6 is amazingly resilient as far as crashes go.. i honestly can i can't think of anyone i know that races em, that i know of for certain that bent a frame, but didn't break it (frame that is). And i thought about it for a bit prior to posting ... forks bend, swingarm will get a ding where a rearset pushes in (as Rob noted above). Swingarm can get a bit bent, subframes bent a little before breaking .. but those are all relatively inexpensive.

 

First thing you do is get a 2x4...

 

but one from lowes that is dry already, cuz the home depot ones are never straight in the first place

(from a guy who's building a deck right now and now that all the wood is dry, it's bending in all directions. great!)