Timing belt tension rollers - how should they feel if they’re OK?

yellowfever · 06-09-2024, 03:26 AM

OK I appreciate checking belt rollers by hand is something of a dark art, acquired through experience. Or a waste of time unless really egregiously worn according to some. And trying to describe how something should ‘feel’ in a post is perhaps even more difficult.

But anyway here goes nothing, any thoughts appreciated!

How freely should they turn? Are new ones stiffer to start with? Background below…

Whilst belts off to investigate oil leak on my 2006 S2R 1000 I’ve been checking the belts and rollers. Belts will be going back on as they look fine at 1.5 years old and I’ll be swapping them for new at big service next year anyway.

On rollers the horizontal fixed and mobile rollers were both replaced in 2016 and the vertical mobile roller was replaced in 2014 and they all feel fine, rotating freely enough without any slop, noises or notchiness.

The vertical fixed roller is still the original from 2006 complete with the weird special 10mm across flats bolt holding it in place. It also has no slop and turns OK but is noticeably stiffer than the others. I had thought I might replace it at some point as it’s the only original roller still left. I’ve been told it may only have been left in situ when the others were changed previously by pro mechanics as it still turns alright and because between the threadlock and weird bolt and difficult access they’re apparently not that easy to remove, so tend to get left in place unless they’ve obviously gone bad.

I’d had the foresight to get a new OEM fixed roller from MSP as I expect I’ll need to replace it at some point. So I thought a useful cross check as I’m new to feeling belt rollers would be to see how freely the new one turned. Surprisingly it’s very stiff - more so than any of the rollers on the engine now including the fixed vertical one that I was thinking of replacing! it’s meant to be Ducati OEM and was €51, though it didn’t come with any Ducati packaging. Anyone got any idea if this is normal? Are new rollers stiffer at first? Or have I got a dodgy part I should return?

Thanks in advance for any thoughts…

06-09-2024, 03:26 AM	#1
yellowfever Bronze Member Join Date: Mar 2006 Location: London Bike: S2r 1000 Posts: 251	Timing belt tension rollers - how should they feel if they’re OK? OK I appreciate checking belt rollers by hand is something of a dark art, acquired through experience. Or a waste of time unless really egregiously worn according to some. And trying to describe how something should ‘feel’ in a post is perhaps even more difficult. But anyway here goes nothing, any thoughts appreciated! How freely should they turn? Are new ones stiffer to start with? Background below… Whilst belts off to investigate oil leak on my 2006 S2R 1000 I’ve been checking the belts and rollers. Belts will be going back on as they look fine at 1.5 years old and I’ll be swapping them for new at big service next year anyway. On rollers the horizontal fixed and mobile rollers were both replaced in 2016 and the vertical mobile roller was replaced in 2014 and they all feel fine, rotating freely enough without any slop, noises or notchiness. The vertical fixed roller is still the original from 2006 complete with the weird special 10mm across flats bolt holding it in place. It also has no slop and turns OK but is noticeably stiffer than the others. I had thought I might replace it at some point as it’s the only original roller still left. I’ve been told it may only have been left in situ when the others were changed previously by pro mechanics as it still turns alright and because between the threadlock and weird bolt and difficult access they’re apparently not that easy to remove, so tend to get left in place unless they’ve obviously gone bad. I’d had the foresight to get a new OEM fixed roller from MSP as I expect I’ll need to replace it at some point. So I thought a useful cross check as I’m new to feeling belt rollers would be to see how freely the new one turned. Surprisingly it’s very stiff - more so than any of the rollers on the engine now including the fixed vertical one that I was thinking of replacing! it’s meant to be Ducati OEM and was €51, though it didn’t come with any Ducati packaging. Anyone got any idea if this is normal? Are new rollers stiffer at first? Or have I got a dodgy part I should return? Thanks in advance for any thoughts… Last edited by yellowfever; 06-09-2024 at 03:29 AM..