Hi Everyone,
David Lahey wrote:Here are two sets of

TY250 twinshock engine mounting bolts.
Today I am doing an engine swap between two twinshock TY250s and noticed the difference in the bolts. One set has hollowed heads and waisted middles. Both of these things are standard weight reduction methods found on many bikes.
My question is (and I don't know the answer) which model TY250 had the lightened engine mount bolts as standard?
I've done way too much swapping around of TY250 frames and motors to remember which bolts originally came with which bike but I seem to remember that my TY250A which came to me in a very original state had hollowed head bolts here and there (on the handlebar clamps and the upper fork tube clamp bolts) so I'm leaning towards the lightened bolts being from an A model TY250.
Can anyone confirm this theory or provide an alternative answer?
Like you David, I am thinking the lightened bolts are from an "A" model, there are a few

TY 250 in my shed but I wouldn't call any of them unmolested.
Here are some photos of the custom bash plate on one of my "A" models, Alastair might recognize it?

- 1619039097893.jpg (110.3 KiB) Viewed 1821 times

- 1619038980782.jpg (94.85 KiB) Viewed 1821 times

- 1619039145689.jpg (96.98 KiB) Viewed 1821 times
It certainly does the job well when you consider the gouging and the deformation under the gear lever, then look at the casings. Not sure what grade of alooooominium was used but I think it must be 5005 which is fairly pure and soft. It always makes me laugh when components like this are offered for sale new and a grade is
NOT stated as it pretty much means melted down Pots and Pans!
Recycling alooooominium is important as it take five times the amount of energy to make alooooominium out of raw materials than it takes to reuse. However if you are melting down Pots and Pans, you are only going to end up with Pots and Pans strength.
Here is a blast from the past as this is the "A" model with that bash plate that Donna rode at SHATTER. What a top weekend, we all need weekends like that one, thank you Alastair.

- 1619040614227.jpg (291.9 KiB) Viewed 1821 times