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Author Topic: Belt Tension Slack  (Read 810 times)

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Offline NY Andrew

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Belt Tension Slack
« on: June 24, 2021, 10:49:16 pm »
Finally getting around to checking belt tension. Attached is what it looks like static and then me pushing up 10lb force. Bike is on kickstand. Not sure if Iím checking right or if itís this get out of spec. Not even sure how to use those little indentation lines on the little window of the bike belt hole. Thanks.


2018 Yamaha Bolt-R

Offline ShakerNorm

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Re: Belt Tension Slack
« Reply #1 on: June 24, 2021, 11:06:22 pm »
Looks like you're doing it right - The Manual says that when you push up on the belt with 10 lbs of force (with the little meter thing you have) - the belt should move between 6 to 8 mm.
If I remember correctly, the lines are 2 mm, so you're probably at the limit, and might be smart to tighten it a little.

If you're doing it on a LIFT, with the rear wheel hanging free - the measurement should be 7-9 mm
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Offline NY Andrew

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Belt Tension Slack
« Reply #2 on: June 25, 2021, 08:11:59 am »
10-4. Only 3,000+ miles on it but it is 2018.
And based off the service manual it seems the only way to properly adjust this is by removing the muffler and seemingly having it on a lift or rear jack? Hate removing my aftermarket muffler but if it can be done without a jack or lift I guess I may just have to do that then.
2018 Yamaha Bolt-R

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Online joko

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Re: Belt Tension Slack
« Reply #3 on: June 25, 2021, 04:37:30 pm »
Like Norm indicated, the measurements are slightly different if the bike is on the kickstand or on a lift but you can take it either way.  The muffler doesn't get in the way since it's on the other side so I see no reason why it would need to be off.

Offline ShakerNorm

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Re: Belt Tension Slack
« Reply #4 on: June 25, 2021, 05:16:48 pm »
You shouldn't have to remove your exhaust....  you'll have to loosen the rear axle bolt (Don't take it off, just loosen it a little), then use the adjusters to tighten it a little. Make sure you tighten it EVENLY on both sides, then LOCK IT DOWN with the jam nuts. 

It's a good idea to check the marks on both sides of the swingarm, and that they move the same amount on each side. If they are uneven - make sure that your wheel is aligned properly, or your bike will ride a little awkwardly, and your drive belt will wear unevenly and excessively. (Yes - motorcycles DO need alignments - but it's the BACK wheel, not the front!) Since they are cast in - they are not precision, but they are a good reference.

One great thing about these is that after an initial stretch and break-in, the belt seems REALLY stable, and will need almost no more adjustments, except, of course, when you change tires and have to remove it completely, anyways.

There is also no limit on how long it will last. I'm still riding with my original belt after buying my bike in 2013, and it still looks great, and will go on for thousands more miles.  Just check it for wear and damage.

If you want - there ARE Service Manuals in the Tech Library (in PDF) for anybody to download.  2 different versions, I believe. They are VITAL for anyone who works on their own bike. Also LOTS of other great resources there, too.
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Online DrM

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Re: Belt Tension Slack
« Reply #5 on: June 26, 2021, 10:10:45 am »
I would think it might be more difficult to get the rear wheel in alignment with the front wheel with the bike on its sidestand.  If I had the stock exhaust, I think I would remove it first and put the bike up on rods going through the hollow axles.  That would eliminate the possibility of the rear wheel being off vertical. as well as aligned left or right.

My aftermarket exhaust (Cobra) is shorter than stock, so I can slip rods into the hollow axels both front and rear without removing the exhaust (side benefit of a Cobra exhaust.)  What I am missing is some wheel attachments and laser lights to exactly measure alignment. Might have to make my own.

While the marks on the tension adjustments help, it only takes a miniscule difference (less than the eye to detect) to be off enough to affect steering and possibly cause wobble.  I believe imprecise wheel alignment is one of the major major causes of wobble, and I haven't seen a precision tool for us to measure it.

Offline lunkhead

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Re: Belt Tension Slack
« Reply #6 on: June 26, 2021, 03:45:24 pm »
I go by line of sight to align the rear wheel with the front. I align the front wheel first by eyeballing along the left and right edges of the tread and rim to get it centered with the rear (steered straight). Most trade-ins that we get are off far enough to use this crude method and if you have a good sense of what you're doing, the difference with an actual measurement is almost non-existent. It takes practice and a straight frame/wheels but it's a quick and easy method for almost any bike. IMO, wheel alignment is more important than perfect pulley alignment and they don't always jive so if you align the pulleys perfectly, it's a good idea to check your wheel alignment anyway. Neither has to be perfect but I like to know my wheels are aligned and trust that Yamaha fitted the final drive accordingly.
« Last Edit: June 26, 2021, 03:47:26 pm by lunkhead »
C-SPƎC

Offline NY Andrew

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Belt Tension Slack
« Reply #7 on: June 26, 2021, 07:16:09 pm »
Appreciate all the responses guys!!!

Sounds like itís best I donít even mess with it then and Iíll just wait until next year when I get inspection done to have them possibly adjust it.

My dumbass forgot to bring it up when they were replacing the steering & handlebar bearings along with the two new tires they put on and gaiters/tubes etc.

Only did 3k miles last year and this years been busy as hell so Iíd be surprised if I do more than that before next inspection time and it doesnít seem THAT far out of wack, more than Iíd like it to be off, but not bad enough Iíll cause catastrophic problems in 3k miles.

Less than 12 months Iíll just have them do it because I donít want to defeat the entire purpose of the new tires and all those bearings and cause any potential problems with all the above if something needs such precision.
« Last Edit: June 26, 2021, 07:18:07 pm by NY Andrew »
2018 Yamaha Bolt-R

Offline ShakerNorm

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Re: Belt Tension Slack
« Reply #8 on: June 28, 2021, 09:27:54 pm »
Dr M:

There's several ways to check the exact alignment of your rear wheel - but yeah, you're definitely right about not being able to do it on the sidestand.....

I'm thinking of getting a Centerstand for my bike, and this is just ONE of the MANY reasons for it!
(Here's the link for that little toy...... https://www.t-rex-racing.com/2013-2020-Yamaha-Bolt-Center-Stand-p/n79-13cs.htm)

There's 2 Basic ways to do it:

From the FRONT wheel - that you can do with a string....
https://www.motorcyclistonline.com/how-to/how-to-check-front-and-rear-motorcycle-wheel-alignment-mc-garage-tech-tips/

And from the REAR wheel - with 2 straightedges (they use 8' fluorescent tubes, but those are hard to find and FRAGILE)
https://www.motorcyclecruiser.com/checking-motorcycles-wheel-alignment/

Here's a couple more ideas:
<a href="http://www.youtube.com/watch?v=uDmn-zngFRY" target="_blank">http://www.youtube.com/watch?v=uDmn-zngFRY</a>
<a href="http://www.youtube.com/watch?v=4Dw2RZlUoUY" target="_blank">http://www.youtube.com/watch?v=4Dw2RZlUoUY</a>

I quite like the motorweek tool idea! A piece of coat hangar would make the perfect tool! And WHAT self-respecting mechanic DOESN'T have a few old wire coat-hangers around?
NOBODY hates winter more than a Canadian Biker!

Offline olfrt

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Re: Belt Tension Slack
« Reply #9 on: June 29, 2021, 04:30:18 pm »
I replaced my drive belt at about 87,000 k's. It was very noisy and 'chirpy'. I have drag raced my bike, ridden on hundreds of dirt roads, towed a small trailer over 10,000 k's, and now have a sidecar on it. The belt tension never varied from new, and I never adjusted it. (When I have removed the wheel to replace tyres, I just pull the axle bolt out without altering or loosening the adjusters). I do all the maintenance on my bike, and have done so since new. The belt is hanging in my shed, it has very little (if any) noticeable wear, but is very 'glazed' in appearance. I might refit it one day in the reverse direction to see if it is noisy that way. it was only noisy on acceleration, but very noticeable.
To be old and wise, first you must be young and stupid.

Offline ShakerNorm

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Re: Belt Tension Slack
« Reply #10 on: July 01, 2021, 04:41:53 am »
olfrt - You got a Sidecar rig on it, now?

OK - I wanna see pics!  ;D
NOBODY hates winter more than a Canadian Biker!

Offline olfrt

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Re: Belt Tension Slack
« Reply #11 on: July 17, 2021, 06:18:02 pm »
On a recent trip. 
Now that I have Tapatalk installed, I'll throw up some build and setup pics in the What have you done to your Bolt today (Mods and Accesories) section.
Sent from my SM-G981B using Tapatalk

« Last Edit: July 17, 2021, 06:41:48 pm by olfrt »
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Offline ShakerNorm

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Re: Belt Tension Slack
« Reply #12 on: July 24, 2021, 04:42:02 am »
SWEET, Olfrt!
I'm guessing it's hard on the mileage, but great for taking your S.O., friends or groceries!
NOBODY hates winter more than a Canadian Biker!