1100 Evo Rear Sprocket (again)

[makemdan]

Having decided to adopt the rear sprocket upgrade to 42 I managed to get a JT carrier but can't get a Renthal sprocket anywhere. Renthal have suspended their direct sales due to Covid but told me to try B&C express who do have a good selection of sprockets.....but not the 358A-525-42P-HA which is the one I need. I've plumped for a JT alloy for the moment but its not as "pretty" as the Renthal. I guess I'll have to wait post Covid for production to resume. The Renthal guy said production was not actually suspended indefinitely but scaled down atm.

What I have sourced via ebay is a 42 tooth Renthal but in 520 gauge. This may turn out to be useless to me but in my limited experience I can't see any reason why I can't convert front and rear sprockets and chain to a 525. I am very happy to be convinced I am wrong so please fire away!

[Darren69]

I think it may be a generic image but : -

https://www.ebay.co.uk/i/23310755414...EaAqvDEALw_wcB

[rollo22]

Here is the hard alloy one

https://www.motorcycleraceparts.co.u...-rear-sprocket

[slob]

Originally Posted by makemdan

... What I have sourced via ebay is a 42 tooth Renthal but in 520 gauge. This may turn out to be useless to me but in my limited experience I can't see any reason why I can't convert front and rear sprockets and chain to a 525. I am very happy to be convinced I am wrong so please fire away!

IMHO I’d seriously avoid that, the chain will be free to slide sideways on the sprocket, whilst this is not the primary direction of the forces involved any imbalance in the chain itself will promote this, as well as inertia caused by cornering. In the best case this is likely to promote wear, in the worst case, more immediate damage.

edit: I may have misunderstood what you’re suggesting, I’ve read it twice and I’m still not 100%

With regard to the above links, give the suppliers a call and see if you can confirm they actually have the right part in stock before ordering, rather than buying online and finding it’s on back order.

[makemdan]

Thanks for the leads, I'll give those suppliers a ring tomorrow

Regarding the 520 chain, as long as the clearance either side of the sprocket body is the same I think its may be OK. My S2r and 748 both ran on 520s, the 748 had more power than the Evo but made it in a different way. I've had a look at specs for other Ducatis and the Monster 821 uses 520 but the S4R and 1200 both use 525. There must be a reason for the difference so I'm cooling to the idea and I'm going to park the sprocket on the "needs more investigation" shelf where it can gather dust for a while. Or maybe look for a bike that uses a 520 chain.....hmmmm

[slob]

You should be able to run 520 or 525, I just meant they have to be matched parts, not a mixture.

[mickj]

Originally Posted by makemdan

Thanks for the leads, I'll give those suppliers a ring tomorrow

Regarding the 520 chain, as long as the clearance either side of the sprocket body is the same I think its may be OK. My S2r and 748 both ran on 520s, the 748 had more power than the Evo but made it in a different way. I've had a look at specs for other Ducatis and the Monster 821 uses 520 but the S4R and 1200 both use 525. There must be a reason for the difference so I'm cooling to the idea and I'm going to park the sprocket on the "needs more investigation" shelf where it can gather dust for a while. Or maybe look for a bike that uses a 520 chain.....hmmmm

Have a look at some Kawasaki's, I think they have a few running 520's

[Darkness]

Maximum Torque, weight of bike and rider, and number of teeth on the front sprocket all affect maximum chain tension in service.

A 520 chain and sprockets combo MAY be OK for strength, but is not likely to last so long as a 525 setup. The problem comes if you don’t clean, lubricate and re-tension it regularly, making it more prone to wear.

It also makes it more prone to snapping, with associated risk of punching a hole in the crankcase!
A 520 is standard fitment on some of the 750s, but not the 750R.

I wouldn’t chance one on an 1100 unless racing and checking/replacing the chain for each meeting.

[Mr Gazza]

What Darkness says and..
An L-twin will produce power pulses to a greater degree than a smooth in line 4.
I bought a chain for my first Monster many years ago but didn't fit it until I got the present Monster. I was told that I needed a special chain because of the Ducati power pulses. It was a really heavy Izumi thing.
It was fine when new but did need to be cock on for adjustment to avoid any vibration.
I didn't get a sensational mileage out of it before I couldn't stop the vibes with any amount of carful adjustment. When looking for a replacement I took advice on what to get and some were astounded at the heavy chain I was using.

I actually wrote to DID in Japan and they recommended a DID VX-2 520, which I had read was suitable for up to 750cc. In fact the power figures of the contemporary 750's are all higher than my M900, so I took their advice. It's been great, with much lower vibes, even when it's in need of adjustment now and then, due to it's much lighter weight than the previous. I think it's now covered more miles too.

The moral is too heavy is as bad as too light. The manufacturers worked out the Goldilocks chain before the bike went into production for good reason, so you will do very well to go with the chain type they specify.

Finally.. Get a case saver in there, before it's too late and sleep better. http://www.ukmonster.co.uk/monster/s...ad.php?t=49399

[Luddite]

Apropos of nothing, I see that the new V4 Superleggera and V4 SP are both equipped with a 520 chain.

Cue gratuitous photo of V4 SP

[chris.p]

Just to add my 2penneth, I used to race albeit on smaller cc bikes (400's), always used 520 chain, all the race teams use 520 chains, I have always used 520 chains on my road bikes ( all Ducati's) since then and Never ever had an issue, the only issues i have seen with chains coming adrift is from the use of split links and or poor fitting, maintenance etc. I have actually purchased ex race chains (and tyres) from a WSS team not to far from myself. Just imagine the power and snatch a WSS/WSBK bike will put onto it's chain over 1 race let alone a race weekend, I doubt most road user's would be able to do that to there chains over 1 to 2 years, so I have no issues with using a 520 chain on any of my bikes, but i never use a split link.

[350TSS]

Just to start a debate (???) I would have thought that a 520 chain should actually be stronger than a wider chain. The catastrophic failure modes for a chain would be 1. fracturing either of the side plates or 2. pin separation from the side plate
The side plate thickness would not change as between a 520 and a wider chain but a wider chain, if there was any misalignment in the chain run, would suffer a higher force at the pin attachment point because the longer pin would be a longer lever.
The wider chain should of course last longer because the loading on the rollers would bve spread over a wider contact area.
Discuss (???)

[makemdan]

FWIW I've put the sprocket on the shelf for future use (maybe).

Just to add to the debate, what's the difference between a heavyweight and super heavyweight chain?would a super heavyweight 520 be stronger than a standard 525?