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The owners manual says the chain slack can be anywhere from 0.8 to 1.2 inches (ideally at 1 inch). I just adjusted my chain to 0.8 inches. Is that a bad idea or will I just not have to worry about it for longer?
 

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The owners manual says the chain slack can be anywhere from 0.8 to 1.2 inches (ideally at 1 inch). I just adjusted my chain to 0.8 inches. Is that a bad idea or will I just not have to worry about it for longer?
Better to err on the side of too much slack than not enough. A too tighter chain will put extra forces on the counter shaft (the one that holds the front sprocket) and create premature wear. A classic sign of this is when the counter shaft seal that's pressed into the engine casing starts leaking oil.

I set my chain slack to 30mm (1.2") and usually tighten it when it gets to about inch and a half of slack.

A quick anecdote: I snapped a chain once from having it set too tight. I was travelling a road unknown and hit a bridge way way too fast which got me a little airborne. When the bike landed the rear suspension compressed fully and the chain was at its tightest point of the swing arm travel.
Because I didn't have enough slack, the forces on the chain were too great and it snapped.
Scary stuff at 80mph! :eek:
 

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If your chain is like mine, it needed adjusting after a very short time...200 miles or so, but has been in specs ever since and I now have 3700 miles on it. I expect to get 50,000 miles from it.
 

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I just bought my 300r last Friday. I had 40 miles on it by Monday and I had 2 inches of play in it. Went up to service and he adjusted in a couple seconds. He said he's never seen that before.
You must have been doing the hard break in huh?! :laugh:
 

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I once owned a ZZR1100 - big, fast, torque monster. Bought it secondhand with about 30,000kms on the clock. Chain looked baggy but OK, planned to replace it very soon.

A week after buying it, I took it out for a high speed run. Got it pretty much up to top speed, which was around 280kph, then feeling happy with everything, I throttled back and slowly dropped back to sub-warp speed. At about 200kph, something went bang behind me and the bike lurched. I pulled over and it turned out the chain had snapped. I felt very lucky that it hadn't let go at 280kph, when it could have wrapped itself around the rear sprocket and jammed the rear wheel, which would have been briefly interesting :)

I also had a front tyre deflate at 140mph on a GSX1100F. Again, everything seemed to be OK while the throttle was pinned back and only got interesting when I slowed down, whereupon a bit of a death-weave set in. Careful juggling of rear brake and steering eventually got it stopped. Turned out there was no puncture and the valve was OK, so those in the know suggested either the tyre had grown off the rim due to centrifugal force or the valve had temporarily unseated due to same. It never happened again.
 

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Checked my chain at about 300 miles, and it has about a 1-1/2" of slack (37-38mm)

Is that too much slack?
 

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I would say yes a bit, mine is set for 25mm at its tightest point.
I check at least 4 different points usually more.
 

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I'll have to make an adjustment then tonight then it sounds like
 

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Better to err on the side of too much slack than not enough. A too tighter chain will put extra forces on the counter shaft (the one that holds the front sprocket) and create premature wear. A classic sign of this is when the counter shaft seal that's pressed into the engine casing starts leaking oil.

I set my chain slack to 30mm (1.2") and usually tighten it when it gets to about inch and a half of slack.

A quick anecdote: I snapped a chain once from having it set too tight. I was travelling a road unknown and hit a bridge way way too fast which got me a little airborne. When the bike landed the rear suspension compressed fully and the chain was at its tightest point of the swing arm travel.
Because I didn't have enough slack, the forces on the chain were too great and it snapped.
Scary stuff at 80mph! :eek:

80mph....... Shame on you sir for having illegal fun on your motorcycle.
 

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Most of us had to adjust our chains early, then infrequently. I needed to adjust mine after just a hundred miles or so, but it's been in spec ever since. Actually, that need for an early adjustment is normal. I always check my chain tension and straightness when I pick up a new bike too since that is something the set up guy usually does, often incorrectly.
 

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adjust for at least an inch, at tightest point as tested
at midpoint of lower run of chain.. when on a rear stand
its easy to turn rear wheel slowly while lifting chain
with one finger at multiple locations thru the turn..

otherwise use a piece of cardboard box under rear wheel
on sidestand, which makes it easier to turn wheel
as it slips over the cardboard, thus easier to take
more/closer tests of chain for tight spots..

alignment is important, regardless of tension..
even slight misalignment thus bowing of chain
along its top run [between sprockets] can result
in strong pressures on chain links and sprockets
their teeth.. thus premature wear etc..

as many observe, its better to be too loose than too tight..
if in doubt, err on the side of loose rather than tight..

especially at first its well worthwhile to look on adjusting
chain as a process, which becomes easier and better
the more you become familiar with it..
thus its good, and worthwhile to 'play around with it'
at first.. finding out for yourself what happens
and how things influence each other etc..

eg, tightening axle strongly can effect tightness,
which side is adjusted first, can also effect
position of axle [chain side first] etc..

but basically, its pretty fundamental
and designed for novice owners
to be able to do effectively..

without doubt tho, a well aligned rear wheel
sprockets and chain in good condition
[not too tight] and lubricated will make
a noticeable difference in smoothness
of all drivetrain functions, gear changes
etc, and just the ride feel itself...
 

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Most of us had to adjust our chains early, then infrequently. I needed to adjust mine after just a hundred miles or so, but it's been in spec ever since. Actually, that need for an early adjustment is normal. I always check my chain tension and straightness when I pick up a new bike too since that is something the set up guy usually does, often incorrectly.
It depends on the specific model, but for the majority of bikes (particularly smaller sport bikes) there is actually very little physical "set-up" involved when the bike is removed from the crate*. In the case of the CBR250R/300R, basically the only thing that requires assembly is filling the battery with electrolyte, charging it, and then installing it in the bike.

Although this is a CBR150R, you can see the bike is fully assembled inside the shipping crate...



From there, it's just a matter of the dealership technician checking everything over... fluid levels, tire pressures, throttle & clutch operation, fastener tightness, chain free play, etc. It's actually pretty rare that they need to make adjustments during the PDI, especially when it comes to Honda motorcycles... as one might expect, Honda does a very good job of getting things right at the factory.

After every line item on the PDI sheet is checked off, the technician takes the bike for a test ride. And yes, every new bike should have a few road test miles/km's on the odometer before the customer takes delivery (If your new bike literally has 0.0 miles/km's on it, you should be asking what else may have been skipped over on the PDI check list).




* Some bikes (typically off road bikes) will be shipped with the front wheel off of the forks, both to use the forks as an attachment point to secure the bike inside the crate, as well as keep the size of the crate as small as possible... same for handle bars. The front fender on an off road bike will often need to be installed as well. In some cases street bike clip ons may need to be rotated into position and the pinch bolts tightened. For a touring bike that comes stock with a tall windshield, that will also need to be installed.
 

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I'm going to attempt to tighten the chain tonight. In your guys' opinions, how many turns on the locknut should I start off with, to tighten the chain about a 1/2" (13mm)? I don't want to overtighten, but I'm quite novice to how many turns each swingarm nut will need to make the chain a 1/2" tighter.

Also, should I test the chain slack with me sitting on the bike? Or it it okay for the bike to be on it's side stand or have the rear lifted to check the slack? The slack was at about 38mm with the bike on its side stand.
 

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It looks like it may be time for me to join the cbr250 forum lol
 
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