A forum for owners of Yamaha TTR250 trail and enduro bikes!

TTRfan · Super Guru

Side panel foam lining

Cubber · Super Guru

I conclude that it is really unnecessary. hmm

My TTR originally had a vestigal foam lining - now it has none. disbelief

I presumed it was placed under the panel to deaden reverberations and absorb sound. confuse

The part number 4PT-21717-00 specifies it as "damper".

The bike will perform just as well with no foam lining as with twice as much. smile

Martyn

hanzo · Senior Member

Yes I would agree it does not really seem to be suitable for its application retaining moisture and dirt I assume its there to prevent rub marks to the frame .It would be better if it was of a different density it acts like a sponge when wet rubber gromits attached to the moulding would have been a better solution by yamaha

-- Edited by hanzo on Monday 7th of July 2014 02:40:47 PM

Markvan · Guru

Heres another view. Mr yamaha had the TTR motor in their work shop testing it in the 90s. Im thinking thier motors were blue printed. So ran way smoother than ours. They then place the motor in the bike frame and ran it again, also placing all the panels on. They also had an escape pipe for the exhaust fumes so it was safe for the mechanics. Doing this made the engineering room safe and quiet so they could see vibrations and hear echoes. Maybe they thought yes place the insulation on the exhaust side and foam on the air box side. Doing this helped with sound deadining but also stop the side panels vibrating . Maybe as long as it lasted for a few test rides selling the ttr new was enough. so my view is , it was placed there to stop the panels themselfs from vibrating. Thats my 2 bob worth.

TT-R250M · Super Guru

I agree with most.

My version is that it stops the vibration and also stops it rubbing through the plastic guard. It would also stop scratching to the airbox cover from vibrations. I cannot see how it would stop scratching to the frame as it does not contact the frame anywhere.

Jarrah

Padowan · Senior Member

If it's for vibration damping then it's resonance characteristics would change completely between being dry, wet and caked in mud. I wonder if it's there partly to make the panels feel less plasticky and more solid? I wonder if you could coat the back in truck-bed liner to provide some insulation/absorbtion - at least that wouldn't absorb ten times it's weight in mud!

LRJ · Senior Member

I don't think that my bike ever came with this foam lining of which you speak. Any other North American owners have foam padding under their (TTR) side panels?

TDVT · Senior Member

LRJ wrote:
I don't think that my bike ever came with this foam lining of which you speak. Any other North American owners have foam padding under their (TTR) side panels?

No foam here either, only the heavy foil on the exhaust side.

TD

petenz · Super Guru

none on mine either... but I did buy it used so may have been removed...

TT-R250M · Super Guru

The US models seem to only have a tiny little one that sits up against the airbox, which to me confirms my theory. See part number 20 HERE.

The Californian bikes have an extra one (part 19 in the link above) but not as big as the AU/UK etc. bikes.

Jarrah