chain issue with R6 swingarm

[wolfgangh]

Hello all,
as VMA500 has correctly pointed out after watching the video of my first engine start, I have an issue with the chain hitting the upper side of the pivot. It has "an angle", under load it would cut into the swingarm pivot like a chain saw.
I am running 16/42 sprockets, swingarm is a 2006 R6, and currently have an swingarm angle of 11° without rider which is considered to be ideal. My headstock angle (is it called rake in english?) is 22 deg.

In would need to reduce the swingarm angle to 8° to 9° to clear the pivot (or actually the chain slider) from the chain. Even then it would touch but not cut into.

I wonder what swingarm angles you guys out there with R6 swingarms in standard RD/RZ frames operate at? Does anyone have the issue with chain clearance as well?
It would be great if someone would measure this for me, together with the rake since this also effects swingarm angle.



thanks.

[begbie]

I think the 50mm plus of added wheel base with the R6 arm, and shorter forks will have more of an effect on handling than a few degree's of swing arm angle.
There are many comprimises to be made when fitting modern running gear to 30 year old frame tech.
I have an RZV rolling chassis with R6 front and rear ends and the Geometry seems far from ideal, but I doubt if I'll ever ride it hard enough to explore
even these limited handling capabilitys.
Your RD looks great and will sound great, I think this is why most of us modify old bikes in this way... for the look.

[pstamper]

My chain rubs right on the wear guide. Was going to larger front sprocket but looks tight. Looks as if all all the measurements are with completely unloaded suspension? I have my bike on stands currently and would be interested to see how it is setting with the 2006 R6 suspension mods. Have done it once but not accurately. I might find a more better scale to check weight bias before next track day also. The setup works well at track days and had an ex Aprillia Cup racer ride it and he said it was great.

[rd84]

Hi Wolfgang,

I've got a 17T sprocket on mine - however I tried a 18T which I thought was too big - there didn't seem enough clearance inside the sprocket cover.

Does your chain rub on the swingarm pivot area when you are sat on the bike ? - what about partial rider weight to allow for negative G ? At what point does the chain stop rubbing on the swingarm ? - The original RD500's always seem to have chain grooves in the swingarm protector - so some contact must be normal

Cheers
Paul

[pstamper]

Mine rubs on the guide and I think it is barely on it when I sit on the bike. I have ride height adjuster built into shock and have it slightly raised. Here are some pictures. My chain is loose for the track and the last two pictures shows the play with a it being cold. 70 degrees. I have a 23.8 steering angle and not sure what the swingarm angle is. Doing some other test things on bike today.

[wolfgangh]

Hello Pstamper,
thanks for looking into this. Is that a 17T sprocket on your pictures - what is your rear sprocket size?

I have adjusted my swingarm now to a compromise, the chain would only touch the chain guide when bike is rested, but hopefully not cut too strong into it. My headstock angle is now ca. 24 deg, my swingarm angle at 9,5 deg, both with bike fully unloaded.
When I remove the engine next time, I will modify the engine mounts on the frame such that I can tilt the engine slightly forward - raising the rear by few mm. This will also help clear the swingarm.

[pstamper]

Running 16/44 520 chain. Chain has cut into the wear guide but I also run chain fairly loose for the track. Thought about 17 tooth but looks tight and could go larger on back to keep similar gearing.

[two-stroke-brit]

looking at the top picture , i wonder how much, if any difference it would make doing the chain adjusting with the bike on its wheels , as opposed to paddock and engine jack.
mark

[wolfgangh]

looking at the top picture , i wonder how much, if any difference it would make doing the chain adjusting with the bike on its wheels , as opposed to paddock and engine jack.
mark

Hello Mark,
on the top picture I had removed the dogbones and adjusted the swingarm angle with the engine jack so that the chain stretched in a straight line from the front sprocket to the rear sprocket, without an angle around the swingarm pivot. It would still rub against the chain slider, but probably not do any major harm. This was my reference point of the swingarm angle under driver load (sag). The resulting swingarm angle was somewhere between 8 and 9 degrees - I cant measure it more accurate.
Since my bike with the existing suspension has a sag of 25mm , the swingarm angle fully unloaded would be slightly above 9 degrees whereas it should ideally be around 11 deg.
I am just leaving it this way now, guess this is not the only compromise on an 30 year old chassis geometry.

Once engine is fully tuned and adjusted, I could still put it into my ANTENA3 bike with Micoproducts chassis

[two-stroke-brit]

Thanks wolfgangh for the reply, i guess its always going to be a compromise.
nice work any hoo.
mark

[Jeppe500]

Hi guys !
I been running 17/43 and 520 chain with no issues all last season.
Have a swingarm from a YZF750 on my bike.
//Jeppe

[pstamper]

I would think the 17 counter sprocket would help with my chain issue also. Plenty of room on everything? I think I used a Honda 900 RR front sprocket and milled it down. Would be nice to have the extra gearing for track days.

[Jeppe500]

My frontsprocket are a 900RR.
Needed it because of sprocketaligment.
The gearing is almost the same as 15/38.

[Matty]

Hi Wolfgang,
I've been running a 520 chain with 17/42 tooth sprockets with a '99 R6 swingarm with no slider wear issues. Rake angle around 24 degrees.

[wolfgangh]

Thanks guys for all your valuable replies.
I think I am safe for now, I may still upgrade from 16T to 17T frontsprocket if any extensive wear happens. My swingarm angle is a bit less than what I wanted it to be ideally though.

best regards

Wolfgang