help: crash back o ring size?

[zoomzoombang]

Tried the search function but no size mentioned for the topcat's crash back o-rings. Does anyone know? Thanks.

[LurkingCAT]

Inner diameter: 22 mm; cross section: 2.5 mm - outer diameter 27 mm, obviously

[zoomzoombang]

Inner diameter: 22 mm; cross section: 2.5 mm - outer diameter 27 mm, obviously

thanks!

[GoMachV]

I converted that to inches and picked up a few, tried them on the bosscat....I'm assuming the 4wd cars use a different band cause it's very tight with only three on and they are a bear to stretch! Hahaha

[Incredible_Serious]

Both the TopCat and the ProCat / BossCat use the same part, U725Y, which is described in the ProCat manual as 21.6 x 2.4... what that measurement actually refers to, well, you've got me....

I got some tension bands a while back for my Nitro 4x4 (nitro Bosscat). They are VERY hard to put on.... but they do allow a small amount of crashback, whilst still keeping the front end firm, so I suppose they'll do for me!

Alex

[GoMachV]

Ahh they must be the right ones then
Since I don't have access to metric orings without ordering, the ones I sourced were 7/8"x3/32"

[LurkingCAT]

If you go metric or inches just make sure you get some new good quality nitrile ones. I have been very disappointed with some of the "New old Stock" U725Y floating around. Nitrile isn't ageing gracefully, especially if it has been exposed to light and you never know how they have been stored. So if racing them, go for new ones. If you "need" the originals for a genuine restore I'm sure we can help you out.