Renthal Twinring wear?

[grayracer513]

Companies that don't spend millions on advertising ...

...often have products that market themselves.

[alstar250]

So..what you're saying is to forget that TwinRing and go ahead and order that SuperSprox ? I was like the all silver look of the Renthal, but hmmm... maybe I will just go with a silver Primary Drive Steel sprocket. So I have 2 questions...

1) Does anyone think the weight of that steel sprocket will be noticeable? Is the stock sprocket steel?

2) I bought a ORN6 (per Gray's rec), how do I determine if I need a new one? It's about 1 yr old

[geshields]

Received an e-mail that stated that he thought my chain was too worn because it no longer has the sharp edges on the top and bottom of the link, instead they are sort of rounded over. Although he did send me a link to the Regina website that shows how to measure chain wear.

In case anyone else needs it - http://www.reginachain.it/eng/use_and_maintenance/how_to04.shtml

I ill be taking this sprocket off when I get back home tomorrow and shipping it off to them so they can test it. I am curious to see what the results say.

[grayracer513]

I bought a ORN6 (per Gray's rec), how do I determine if I need a new one? It's about 1 yr old

Look at the link Regina put up. Check the chain for pins that have rotated in the plates. Check for damaged O-rings, and for links that seem unusually stiffened.

Then check fro wear by measuring the length, as I recommended earlier in the thread:

https://www.thumpertalk.com/forum/showthread.php?p=8857721#post8857721

[MuDPoUNdeR]

I have had the twin ring and love it. I have countless hours on it and little wear. Although for me I replaced it all at the same time. New chain and sprockets, kind of a rule of thumb.

What's your chain tension set at right now? You are using chain lube right? Your chain looks on the dry side with that rust building up on the chain.

[geshields]

Chain tension is set at 2" of play from the rear bolt on the chain slider. I use lube before every ride and I lube the chain after each wash also. That rust is from one time when I got back from the track, hosed the bike off, but then could not wash the bike because of a house emergency. In Houston, that was really bad. I saw it the next day and washed and lubed it but the aesthetic damage was done. After I wash the bike, I towel dry the chain and then apply WD-40 to it to make sure there is no leftover water. After that I then apply either Motul Chain lube, the green stuff you see on the chain there or synthetic Motorex 622 chain lube.

[Wes Woodin]

I must say that I have had incredible luck with mine when I had it on my old bike. I wroth the review when I bought it long ago. I ran mine with a did 520 VT chain. I rode it very hard on my 08 bike. 40hrs. no wear. I did run a did 520 ert2 with an Iron man spocket and believe it was a better sprocket, but it was much heavier. 2 hours on that sprocket, with that wear.............. something is wrong. I would have changed both sprocket and chain at the same time.

[FinchFan194]

2 inches of chain slack from the rear bolt seems a little high too. I tighten mine until I can pull up hard on the chain at the rear chain guide bol and can only get my index and middle finger in there.

[grayracer513]

2 inches of chain slack from the rear bolt seems a little high too. I tighten mine until I can pull up hard on the chain at the rear chain guide bol and can only get my index and middle finger in there.

Then what you should do is to pull the relay arm bolt out of the swing arm and try to swing the rear wheel past the point where the centers of the axle, output shaft, and swing arm pivot align. I bet it doesn't.

The service manual for your bike gives you the specs for your particular year model.  Your '08 requires a minimum of 1.9" of clearance measured at the rear slider bolt with the bike on a stand. Does this chain look too loose?



It's not. Here's the same bike with a 1.95" block under the chain:



If you run it any tighter than that, you run the real risk of blowing the hub apart, something like this:

[alstar250]

^^^^^

Thats sweet! I'm going to do that tomorrow (make a block) so I can just slide it under and tighten the tensioners accordingly without having to constantly check and recheck tension after every 2 turns of the bolt...hahaa Great JOB

[grayracer513]

The larger step on the block is 2.25", BTW. If the short side fits and the tall side won't, it's all good.

[geshields]

I use that same method but I use a piece of acrylic. Works great and makes it real easy to setup.

[nickeenoo]

So..what you're saying is to forget that TwinRing and go ahead and order that SuperSprox ? I was like the all silver look of the Renthal, but hmmm... maybe I will just go with a silver Primary Drive Steel sprocket. So I have 2 questions...

1) Does anyone think the weight of that steel sprocket will be noticeable? Is the stock sprocket steel?

2) I bought a ORN6 (per Gray's rec), how do I determine if I need a new one? It's about 1 yr old

I just put a Primary Drive steel rear on my bike, before that I had a TAG aluminum. The steel sprocket is substantially heavier on the bench. I did not weigh them but other threads have stated steel chainwheels are roughly three times as heavy as aluminum and this feels about right. I was not pleased about buying the steel rear but after a lengthy "discussion" regarding finance with my bride I had no choice.

I was particularly concerned with the weight in breaking bumps and "chatter" as the rear wheel has to change directions very rapidly. To my great surprize I could feel almost no difference if any at all.

On a side note I went with a 50 tooth rear and really liked how it tightened up the gears and "got me to third sooner" (that was for you Gray).

Time will tell how the PD steel chainwheel holds up but as for the feel of the weight, I am pleasantly surprised.

Nate

[FinchFan194]

Then what you should do is to pull the relay arm bolt out of the swing arm and try to swing the rear wheel past the point where the centers of the axle, output shaft, and swing arm pivot align. I bet it doesn't.

Your '08 requires a minimum of 1.9" of clearance measured at the rear slider bolt with the bike on a stand. Does this chain look too loose?

It's not. Here's the same bike with a 1.95" block under the chain:

If you run it any tighter than that, you run the real risk of blowing the hub apart, something like this:

Well I did say 2" was a "little" too high! I meant it literally by .05". Kidding of course, I do like your idea with the block of wood for chain adjustment. I am going to make one tomorrow and readjust.

Anytime I get beyond my two fingers I get lots of chain noise while riding so that is why I run it tight. If you are saying the noise won't hurt anything then I will gladly loosen it up.

BTW wasn't that sprocket an Ironman in the last pic? They are notorious for the bolts coming loose. I always thought a chain that was too tight was more likely to cause internal damage the the drivetrain? Maybe I am wrong feel free to correct me:worthy:

[grayracer513]

BTW wasn't that sprocket an Ironman in the last pic? They are notorious for the bolts coming loose. I always thought a chain that was too tight was more likely to cause internal damage the the drivetrain? Maybe I am wrong feel free to correct me:worthy:

Well, you are mostly wrong, yes. The rear chain is an external component, and bears mostly on external components. The trans output shaft is the exception, and in the case of some older KTM's, the first thing that fails when you run the chain too tight is that the output shaft is pulled out the back side of the crankcase.

The centers of the output shaft, swing arm pivot and rear axle form the 3 points of a triangle when the suspension is fully extended. The distance between the axle and output shaft form the "bottom side" of the triangle, and naturally, since the other two distances cannot change, it must get longer as the swing arm rises and the "triangle" flattens out. If the chain isn't long enough to pass the center point with at least 1/4" of true slack, it forces a tremendous amount of pressure on the chain, sprockets, hub, trans, engine case, frame, and swing arm, and any way you slice it, something has to give, spring, bend or break to let it happen.

Ironman sprockets don't deserve the reputation you allude to. The failure in that picture is due to the sprocket being pulled over to the side, which occured because the chain was too tight. Not one of the bolts was loose. The Ironman IS more prone to being pulled over like this because it lacks a full circle base ring, but it still won't happen unless the chain is set wrong.

Read:

https://www.thumpertalk.com/forum/showthread.php?p=4584448#post4584448

https://www.thumpertalk.com/forum/showthread.php?p=48654#post48654

The chain slap sounds awful, but doesn't really hurt anything. Avoid it by not applying too much load at too low an RPM.

[FinchFan194]

Good info in those threads I have read them before on here. I will be re adjusting my chain before my next ride! As far as Ironman sprockets go, check out my rear wheel. . .

[geshields]

Got my new Ironman sprocket delivered just now. Here is a pic showing it and how they have now reinforced the middle with an inner ring....

I will be sending in my TwinRing to Renthal and let them run their tests on it. It will be interesting to hear their take on the accelerated wear. Especially since my chain is well within spec of even their suggested measuring!!!

[barns19]

mine is the same after just one ride. did renthal get back to you? what did you do about it? i am not happy.

[grayracer513]

This thread is two years old.

[Jeekinz]

This thread is two years old.

Even still, there's alot of bashing going on and the OP used an old chain with a new sprocket. FWIW, my twinring that came on a used bike, I rode for 4 motos, some trips in the woods, and 2 solid MX practice sessions and it doesn't look as worn as the first pic.