1 How whirr-ey is your gearbox Fri Oct 02, 2020 7:25 pm
stanthomas
Silver member
On my '91 K100RS 16V, 85k miles:
At idle, in neutral with clutch engaged, i.e. gearbox is spinning, there really seems to be a lot going on in that box. Just mechanical whirr, no knocks, rattles or rumbles. And nothing noticeable on the move. Now it's a long time since I had a bike that was this quiet, well silenced, no top-end clatter, no induction roar. But I can't remember the gearbox being as noticeable on, say, a CBR600. Goes away when clutch is pulled in so definitely down to those shafts a-spinning.
I'll add that it's had a new clutch, new seals, everything tight, splines greased etc. And yes, the gearbox has oil in it. There was a bit of water in the gear oil when I got it, and it had been standing for 4 years before that, but I've seen a lot worse. On the bench, rotating the input shaft by hand, you could definitely hear the gears turning but again, not really any different to other boxes.
So I'm just trying to gauge what I'm hearing. I am mindful of all those straight-cut gears spinning away on three shafts and it wouldn't suprise me if "they all sound like that". But confirmation would be appreciated.
At idle, in neutral with clutch engaged, i.e. gearbox is spinning, there really seems to be a lot going on in that box. Just mechanical whirr, no knocks, rattles or rumbles. And nothing noticeable on the move. Now it's a long time since I had a bike that was this quiet, well silenced, no top-end clatter, no induction roar. But I can't remember the gearbox being as noticeable on, say, a CBR600. Goes away when clutch is pulled in so definitely down to those shafts a-spinning.
I'll add that it's had a new clutch, new seals, everything tight, splines greased etc. And yes, the gearbox has oil in it. There was a bit of water in the gear oil when I got it, and it had been standing for 4 years before that, but I've seen a lot worse. On the bench, rotating the input shaft by hand, you could definitely hear the gears turning but again, not really any different to other boxes.
So I'm just trying to gauge what I'm hearing. I am mindful of all those straight-cut gears spinning away on three shafts and it wouldn't suprise me if "they all sound like that". But confirmation would be appreciated.