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Author Topic: Belt slack different for a C spec?  (Read 1157 times)

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Offline Sdaniels

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Belt slack different for a C spec?
« on: December 29, 2020, 02:02:05 pm »
Need guidance on this because the service manual makes no sense.  It says to have the bike on the side-stand or a stand to get the rear wheel elevated....the wheel cannot be elevated if it's on it's side-stand.  So which is it?  The other question I have is does the C-spec have different slack measurements?  Rear shocks on a C spec are slightly longer than Bolt/R spec...does that have any effect on it?  I don't know & all I have is the Bolt/R spec service manual to go by.  Manual states 7-9mm deflection with 10lbs applied with the special tool.  I've read elsewhere 6-8mm.


2015 C-spec

Offline lunkhead

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Re: Belt slack different for a C spec?
« Reply #1 on: December 30, 2020, 05:36:47 am »
I have about 10mm or so of free sag that goes away when on the sidestand. Lifting the frame doesn't drop the swingarm any further. How much free sag do you have?
C-SPƎC

Offline Sdaniels

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Re: Belt slack different for a C spec?
« Reply #2 on: December 30, 2020, 07:19:05 am »
By free sag, do you mean how much slack there is when the 10lb is applied with the tool? 

EDIT:

Okay, put the bike on a stand, rear wheel elevated, got 12mm slack using the tool.  Got exactly the same measurement with bike on the side stand so that question is answered.  Adjusted to 10mm of slack.  Also noticed the right side tick mark was off a bit.  Way to go Yamaha  ::)  This was the first adjustment in 4K miles.
« Last Edit: December 30, 2020, 08:49:41 am by Sdaniels »
2015 C-spec

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Offline lunkhead

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Re: Belt slack different for a C spec?
« Reply #3 on: December 30, 2020, 11:30:21 am »
Free sag is how much the rear end sags without rider on board. Pull up on the bike while vertical to top out the suspension and see how much it sags when you let go. Too much and it'll sag when resting on the sidestand. The shocks should be fully topped out on the sidestand if the preload is set correctly so it won't be any different than lifting the rear. Watch some Dave Moss videos if you haven't already. He recommends 5 to 10mm free sag.
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Offline Sdaniels

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Re: Belt slack different for a C spec?
« Reply #4 on: December 30, 2020, 12:21:31 pm »
Not sure why you're asking about suspension sag.  I'm asking what the belt tension is for a C spec if it is, in fact, different from the Bolt or R spec.  But, since you asked, I got 6mm sag with shocks on the second setting from soft. 
« Last Edit: December 30, 2020, 03:21:29 pm by Sdaniels »
2015 C-spec

Offline lunkhead

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Re: Belt slack different for a C spec?
« Reply #5 on: December 30, 2020, 06:21:07 pm »
You basically set the belt tension with zero suspension sag. If you had way too much free sag for some reason, you might not be able to adjust the belt on the sidestand and would have to use a lift to get the swingarm to go all the way down.
C-SPƎC

Offline Sdaniels

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Re: Belt slack different for a C spec?
« Reply #6 on: December 31, 2020, 07:29:41 am »
Ahhh, got it.  So what about the belt?  How much slack should I have?
2015 C-spec

Offline lunkhead

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Re: Belt slack different for a C spec?
« Reply #7 on: December 31, 2020, 05:06:29 pm »
I would use the recommended setting because it has to be set so it'll never go too loose. I've heard of teeth being stripped off a Zero FX belt from being too loose but never a problem with the factory (overtightened) settings. One FX owner insisted the dealership made the belt too tight so he loosened it. The belt lost teeth and the shop put another on. Again, he thought it too tight and again, he loosened it. Dealership installed another belt and the owner finally left it alone.
C-SPƎC

Offline Sdaniels

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Re: Belt slack different for a C spec?
« Reply #8 on: December 31, 2020, 05:48:28 pm »
So 7-9mm?
2015 C-spec

Offline lunkhead

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Re: Belt slack different for a C spec?
« Reply #9 on: January 01, 2021, 06:18:13 pm »
Yes, or for us Americans, about the thickness of a cigarette. You're only likely to have problems under certain conditions if looser. Low gear, high HP, good traction, irregular road surface, supension topped out all contribute. For high speed and mileage with only soft take offs, you can run a little loose but the Bolt isn't meant to be ridden that way ;D. Some bikes can run up to 2" but probably use a different swingarm angle and a thick, old style belt.

I have the Progressive shocks that make the bike lean a lot more on the sidestand than the stock C-Spec so I know the swingarm arc is causing the belt to get tighter than Yamaha orginally intended. I set it to stock specs and now it's almost at 1/2". I won't make it any less if it doesn't increase much more soon or cause a problem.

My MP tension gauge seems to be assembled wrong with the o-ring installed inside so the spring can't do it's job. I lubed it with silicone to make it move freely but I'd like to rebuild it. Thought I'd mention that in case others got one that felt like it sticks.

I couldn't find a video of how slack a belt gets under load but here's a chain:

https://m.youtube.com/watch?v=-t3QLWMse00
« Last Edit: January 02, 2021, 01:42:44 pm by lunkhead »
C-SPƎC

Online legion95928

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Re: Belt slack different for a C spec?
« Reply #10 on: January 03, 2021, 08:13:38 am »
Not sure why you're asking about suspension sag.  I'm asking what the belt tension is for a C spec if it is, in fact, different from the Bolt or R spec.  But, since you asked, I got 6mm sag with shocks on the second setting from soft.

To actually answer your question: The C Spec "specs" are the same as all the other Bolts...
2014 R spec
OEM Fender Eliminator
Mirrors
Koso Speedo
Ceramacoated Exhaust Heat Shields
Kuryakyn Hypercharger
Cobra fi2000R
Blasted out Stock mufflah!

Offline lunkhead

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Re: Belt slack different for a C spec?
« Reply #11 on: January 03, 2021, 01:18:51 pm »
Sorry, I overlooked that question. The C-Spec SM isn't freely distributed but the OM is if you didn't get one. Belt tension specs can be found in both.
C-SPƎC

Offline Sdaniels

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Re: Belt slack different for a C spec?
« Reply #12 on: January 03, 2021, 01:23:34 pm »
I wouldn't mind paying for a service manual but it's ridiculous what they're asking for a C spec-specific. 
2015 C-spec

Offline lunkhead

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Re: Belt slack different for a C spec?
« Reply #13 on: January 03, 2021, 02:52:13 pm »
Every year, I would organize our shop manuals and when a previous year got superceded by the next, I would throw it out. That's how I got my 2014 Bolt manual and all the manuals for my older bikes. Unfortunately, paper manuals were replaced with digital around the time the C-Spec came out so I had to buy mine. I haven't had to organized them in years since we haven't needed the space for more but I'll take a look in case someone ordered one since then. On the bright side, we've never had to do any repairs on a Bolt other than general maintenance and accessorizing.
C-SPƎC

Offline Sdaniels

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Re: Belt slack different for a C spec?
« Reply #14 on: January 03, 2021, 05:03:36 pm »
Yeah, most of the stuff applies to both bikes & the stuff that doesn't isn't rocket science.
2015 C-spec