chain, how loose/tight...


21 replies to this topic
  • milk

Posted August 30, 2008 - 10:45 PM

#1

just wondering how loose or tight does everyone run their chains... stock chain in particular...

myself i run it pretty much to spec but i was thinking it seems a little tight. should i consider running it a little looser for off road where i'm really taxing the suspension? would that put more stress on the chain? just kinda thinking outloud here...

  • Older and Slower

Posted August 31, 2008 - 04:47 AM

#2

I run my chain pretty loose. While the thing is sitting on the side stand, both the top and bottom runs droop pretty good. The way i check mine is to sit on the bike with the side stand up, adjust my weight towards the back until the counter shaft, swing arm pivot and the rear axle line up, and reach down with my left hand and pull up the top run of chain. If i can flop the chain up and down about an inch to an inch and a half, why it's good enough for me. Since this is the non-scientific approach, it always makes for a looser chain than anticipated which is perfect for me as i'd rather replace the plastic chain guide than the countershaft bearing or worse yet, the countershaft itself.

Just the way i've done it for about the past 30 years and it has served me well. Remember YMMV.

Cheers - Paul

  • ronm12

Posted August 31, 2008 - 10:31 AM

#3

+1 with slow and old. looser is better. also, adjust chain at its tightest area(some spots in chain are tighter than others) that way, when chain is at its tightest spot,it still will be within acceptable range.

  • milk

Posted August 31, 2008 - 11:45 AM

#4

ok so is there any draw backs to running it loose? like premature tooth wear on the sprockets or chain skipping or anything like that or is that just if it's way too loose?

  • DR Da-da

Posted August 31, 2008 - 11:57 AM

#5

My step-dad threw a chain years ago because he admittedly didn't bother to properly maintain (i.e. clean/oil/tighten) his chain. The chain became so loose that it got wedged between the countershaft sprocket and engine case. This caused his rear wheel to lock up at about 45 mph, the bike to lay down, and him to skid down the road into a bridge's guard rail (fortunately, no serious injuries aside from road rash).

I'm a big fan of keeping the chain's slack within the manufacturer's recommended limits, and measuring that slack in the recommended location using the recommended method. This practice has never failed me.

Craig

  • gravelrash

Posted August 31, 2008 - 04:39 PM

#6

I was running mine on the loose side. To the point that it was starting to chew away at the front of the plastic chainguard. Tightened it up one notch, which was within spec but a bit too tight as far as I'm concerned, and noticed right away how better the transmission shifted. And I'm not imagining this.

  • mxrob

Posted August 31, 2008 - 06:00 PM

#7

The bottom line of chain tension is having enough slack so that the tightest position (a straight line drawn through the countershaft, swingarm pivot and rear axle) does not bind the chain. Certainly with the less than fine-tunable notched snail adjusters picking loose over tight, when you have to choose, makes the most sense. After that it's all up to the chain guide, lower roller and swingarm buffer to make sure the chain is feed onto the sprockets correctly because as suspension moves chain slack varies wildly. 1 notch looser is nothing compared to how lose the chain is when your suspension bottoms out. :thumbsup:

  • VB1959

Posted August 31, 2008 - 06:23 PM

#8

When I'm riding doun the street the chain is alway bobing up and down making clacking noises but when I tighten it up it one notch it is to tight. I was wondering if anyone out there has bought a chain tensioner for this problem? And did it cure it?

  • mxrob

Posted August 31, 2008 - 06:30 PM

#9

When I'm riding doun the street the chain is alway bobing up and down making clacking noises but when I tighten it up it one notch it is to tight. I was wondering if anyone out there has bought a chain tensioner for this problem? And did it cure it?


You can't tension out the thumper in the thumper... nor do you want to. Although a mechanical slide carb does smooth things out substantially down in thumpville. :thumbsup:

If you have the stock lower roller it will make clacking noises (hard plastic). Replace it with one of the urethane rollers with bearings. Of course you've romoved and flung the upper roller right? Frames tend to make a lot of noise when you rip pieces of metal out of them. :worthy:

  • wrw7255

Posted August 31, 2008 - 07:21 PM

#10

The FSM spec is 1.2 to 1.8 inches of slack in the middle of the chain between the counter sprocket and the rear sprocket with the chain adjusters in the same position on both sides. Follow the factory service manual spec and you should have no problems.:thumbsup:

  • Maniacdriver

Posted August 31, 2008 - 07:38 PM

#11

I just bought a 92 DR650,should I get rid of the upper roller or is just the newer bikes?

  • mxrob

Posted September 01, 2008 - 06:46 AM

#12

I just bought a 92 DR650,should I get rid of the upper roller or is just the newer bikes?


Can't answer that one from experience. If the roller is mounted high enough to stay out of the chain's line of fire between the two sprockets under suspension compression then it will not be ripped off like the 96-08 models. :thumbsup:

  • ThumptyDumpty

Posted September 02, 2008 - 07:25 AM

#13

When I put my 14T Cs on the other day ( which I'm very happy with ) I went to my factory manual for some chain tensioning guidance. If I read it right it says measure slack at bottom of the chain, midway between front and rear sprockets. [COLOR="Blue"]The thing is,they call for 1.2 to 1.8" of travel and my chain bumps into the black plastic slider on the bottom of the swing arm before I even have 1.2".[/COLOR] I talked to jesse at Kientech and sound like he uses the bottom/mid point as his reference point as well. I talked to the service guys at the local dealer and they said "Hmmm, thats strange ", well at least they didn't charge me. I decided to adjust it so the chain just touched the slider and then back the snails of 1 more notch. It does not feel tight and does not seem to be slapping around either.

  • DR Da-da

Posted September 02, 2008 - 07:46 AM

#14

The thing is,they call for 1.2 to 1.8" of travel and my chain bumps into the black plastic slider on the bottom of the swing arm before I even have 1.2".


Keep in mind that it's total travel you're measuring - not just travel from the chain's static position to full up. Pull the chain down until it's taught, then push it up until it taught. Measure the TOTAL deflection from it's full down position to it's full up position, and this will give you your chain's true slack.

Craig

  • ThumptyDumpty

Posted September 03, 2008 - 05:13 AM

#15

It looks like with my setup that if you [COLOR="Red"]pull the chain down[/COLOR] then measure travel up to where it bumps into the slider its about 1.6":, right in spec.

  • sarkmych

Posted September 12, 2008 - 10:03 AM

#16

I just read an article in dirtrider magazine where a race mechanic adjusted the tension to 1/4-1/2" slack with the rear shock compressed to the tightest point of chain tension. i.e where the sprockets and swingarm link line up. It seems to me that it is too tight. Is that for race bikes only?

  • mxrob

Posted September 12, 2008 - 10:10 AM

#17

I just read an article in dirtrider magazine where a race mechanic adjusted the tension to 1/4-1/2" slack with the rear shock compressed to the tightest point of chain tension. i.e where the sprockets and swingarm link line up. It seems to me that it is too tight. Is that for race bikes only?


No, all you really need is a small amount of slack at the point where the countershaft sprocket, swing arm pivot and rear axle are all lined up. That is the point that the rear wheel is farthest from the CS sprocket. :thumbsup:

  • kliffsbuggy

Posted September 12, 2008 - 11:47 AM

#18

It looks like with my setup that if you [COLOR="Red"]pull the chain down[/COLOR] then measure travel up to where it bumps into the slider its about 1.6":, right in spec.


That's the way I'm rolling, no problems here.:thumbsup:

  • milk

Posted September 12, 2008 - 12:32 PM

#19

ok, i loosened mine because it seemed really tight but i think i'm going to tighten it again from what mxrob says, well after i check it again :thumbsup:

  • kliffsbuggy

Posted September 12, 2008 - 12:44 PM

#20

ok, i loosened mine because it seemed really tight but i think i'm going to tighten it again from what mxrob says, well after i check it again :thumbsup:


Just remember, to do it MXrob's way..."No, all you really need is a small amount of slack at the point where the countershaft sprocket, swing arm pivot and rear axle are all lined up."

You will need to load the suspension so that the counter shaft, swing arm, and rear axle centerlines are all LINED UP. Not an easy task, but doable with some ratchet straps. That's whay suzuki gives you an "unloaded" setting. It's easier for most people to follow.
Translations on japanese manuals to English have gotten much better over the last 20 years, but sometimes you gotta read between the lines.

I pull the chain down, and measure the distance between it and the slider on the bottom of the swing arm.
1.5" is my optimum, 1.75" is max, anything greater, is time to adjust. When in doubt, loosen the chain, then use the snails to tighten to your desired spec, much easier that way.

Sorry, probably should have been more specific in my first answer. Sometimes I forget, not everyone has been doing this for 40 years....sorry.




 
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