SOHC.co.uk Forums > Anorak's Corner

Frame Alignment Checking

<< < (2/3) > >>

Bryanj:
I once read an article that said if a fork tube took enough of a hit to bend then the frame was stressed and probably bent.
The 750 book used to have the measurements for frame checking but never seen it for other models.
You idea with swing arm bar and headstock pointer(long threaded car with cones instead of races) will work for 95% and will only fail if the forks have bent the frame straight back which rarely happens.
Long ago i did an insurance job on a cx500 which when finished i had to slide the forks through the yokes by 1 inch to get the bike to stand on centre stand with a wheel off the ground. Wheels were perfectly in line and handling perfect, there was heavy front damage including both tubes, bottom yoke, one slider and wheel which with cosmetics made the bike very close to a write off.

Laverda Dave:
This is how the rat bike frame was checked at Hybrid motorcycles recently. Long bar with a pointer through the headstock. I had to fit the swing arm, rear shocks and slave crankcase prior to taking it to Hybrid. Frame was 100% in alignment, the first frame I have ever taken to be checked that was not out of alignment.

AshimotoK0:

--- Quote from: Laverda Dave on January 08, 2024, 04:43:24 PM ---This is how the rat bike frame was checked at Hybrid motorcycles recently. Long bar with a pointer through the headstock. I had to fit the swing arm, rear shocks and slave crankcase prior to taking it to Hybrid. Frame was 100% in alignment, the first frame I have ever taken to be checked that was not out of alignment.

--- End quote ---

Dave .. can you explain how that works please. What reference do they do to the rear wheel and how do they align the rear wheel? without the front end fitted?

andy120t:
I had my RD350LC checked after a crash years ago. The technique was the same - front end off but engine / swing arm and rear wheel etc in.

Would all dereference be taken from the back of the frame/ cranckcases....assuming they held it all square?

This isn't the company I used, but talks about the reference/alignment from swing arm pivot and headstock.

https://hbmotorcycles.co.uk/products-and-services/frame-alignment/

AshimotoK0:
Question for Dave .. but not sent  by p.m./email  in case of interest to others.

I am making a jig and the front bit is a long length of perfectly straight 16mm ground bar I borrowed from work mounted in two conical collets that pass through the head bearings. Question though is how was the rear wheel centralised in the jig at the place that checked your 400F frame?  .. did they just use the scribed line markings on the swinging arm? Also, is it best to have the tyre off the rear wheel?

Navigation

[0] Message Index

[#] Next page

[*] Previous page