Belt tension differences

[Wildrice]

Hello Spyder lovers,
My Gates Krikit belt tension gauge arrived today---thus on my 2015 F3's I do reading on the top & bottom of the drive belt--both at approx 240 lbs. Following a video by an english accent gentleman--he shows me the best way. This doesn't involve any changing of tension or alignment on my part. My concern is that after jacking up the rear end on the rear shock post--blocking the front wheels & running probably 10-15 mph stationary vehicle with lots of error code lights--I shut it down--take another reading & it's at 190lbs both sides of belt--I lowers the F3's to the ground without moving it & it still reads approx 195 lb. I do need to mention that I removed the Baker built upper roller in the process--but I estimate the additional roller to be approx 3-4 lbs load at most. haven had the opportunity to test ride. My belt alignment may get a fine tuning as the space is closer on the spyder rear wheel than the outside but still not touching the driven pulley.
Your thoughts ??
Darrell

 

[Lastchance]

First thing I did last fall when I bought mine was check tension and alignment, forgot what it was but lower it to 220 as there was no set spec that I could find at the time, alignment was credit card to 3/16 best i could find. After watching sense then I decided on 180, did it a couple weeks ago, saw that vid but did it on the ground, took a couple tries to get alignment back up go forward, belt 1/16 off inner lip now 180 middle upper and lower, took 100 mile ride belt 180 still 1/16, sounds like you got it if that's the tension you want and belt doesn't rub inner lip. I know I'm leaving mine right where it is !!!

 

[BajaRon]

Hello Spyder lovers,
My Gates Krikit belt tension gauge arrived today---thus on my 2015 F3's I do reading on the top & bottom of the drive belt--both at approx 240 lbs. Following a video by an english accent gentleman--he shows me the best way. This doesn't involve any changing of tension or alignment on my part. My concern is that after jacking up the rear end on the rear shock post--blocking the front wheels & running probably 10-15 mph stationary vehicle with lots of error code lights--I shut it down--take another reading & it's at 190lbs both sides of belt--I lowers the F3's to the ground without moving it & it still reads approx 195 lb. I do need to mention that I removed the Baker built upper roller in the process--but I estimate the additional roller to be approx 3-4 lbs load at most. haven had the opportunity to test ride. My belt alignment may get a fine tuning as the space is closer on the spyder rear wheel than the outside but still not touching the driven pulley.
Your thoughts ??
Darrell

You never want to use the rear shock mount as a jack point. You run a great risk of damaging something if you do.

 

[Wildrice]

You never want to use the rear shock mount as a jack point. You run a great risk of damaging something if you do.

The rear Shock mount is welded to the horizontal rear frame--all heavy duty gauge welded steel. Are you saying if I use a floor jack I should position it to the left or right side of lower shock mount. Balance may be effected. My original Q on this thread is why is the a 50 lb difference on the drive belt from rear wheel on the floor versus raises--but the bigger Q is why does it now show 195# with the rear wheel on the ground. Where did the initial 55# diference go from 240 lbs parked wheel on ground--jackedop rear ran tire to 10-15 mph --lowered the rear tire to the ground & now it reads 195lbs versus initial 240lbs.
Darrell

 

[billybovine]

When you jack up the rear wheel by the shock mount. You are not allowing full drop of the swing arm. Must be jacked up by the frame to allow the shock to fully extend.

From the 2013 Service manual.

 

[Wildrice]

Frame & shock mount bracket

You never want to use the rear shock mount as a jack point. You run a great risk of damaging something if you do.

Ron--I just took this photo--the horizontal frame has a strong weld to heavy gauge metal bracket which is used to attach lower rear shock. Are you say that placing the floor jacket under this center bracket mount which protects the shock is bad???--it looks like one & the same to me--heavy welding to the frame. Are you suggesting I should lift on either side of this bracket?
Darrell
PS: somehow this topic has changed from my orginal Q of a tension variance:banghead:

 

[Wildrice]

When you jack up the rear wheel by the shock mount. You are not allowing full drop of the swing arm. Must be jacked up by the frame to allow the shock to fully extend.

From the 2013 Service manual.

View attachment 134487

Billy---I just took this photo--the horizontal frame has a strong weld to heavy gauge metal bracket which is used to attach lower rear shock. Are you say that placing the floor jacket under this center bracket mount which protects the shock is bad???--it looks like one & the same to me--heavy welding to the frame. Are you suggesting I should lift on either side of this bracket?
Darrell
PS: somehow this topic has changed from my orginal Q of a tension variance:banghead:

 

[IdahoMtnSpyder]

You never want to use the rear shock mount as a jack point. You run a great risk of damaging something if you do.

Not the case. The only time you don't want to use the shock mount for jacking is when you are checking belt tension or changing the rear tire. To just raise the bike there is no restriction on using the shock mount other than cradle the mount with the jack plate. Both cases are discussed in the service manual. I asked BRPCare about the discrepancy in the manual. When Steve asked me to point out the places in the manual I discovered upon closer reading the difference and both jacking under the shock mount and jacking under the frame are specified.

 

[Wildrice]

Not the case. The only time you don't want to use the shock mount for jacking is when you are checking belt tension or changing the rear tire. To just raise the bike there is no restriction on using the shock mount other than cradle the mount with the jack plate. Both cases are discussed in the service manual. I asked BRPCare about the discrepancy in the manual. When Steve asked me to point out the places in the manual I discovered upon closer reading the difference and both jacking under the shock mount and jacking under the frame are specified.

My rear shock mount has a heavy duty mounting & protective bracket--thus placing th jack on the shock mount bracket does not touch the reach shock--the protective bracket & horizontal frame bar and welded big time on both sides.
Why would this method effect or be bad for checking belt tension??? Placing the jack next to the bracket are the same stress points.
Darrell

 

[IdahoMtnSpyder]

Hello Spyder lovers,
My Gates Krikit belt tension gauge arrived today---thus on my 2015 F3's I do reading on the top & bottom of the drive belt--both at approx 240 lbs. Following a video by an english accent gentleman--he shows me the best way. This doesn't involve any changing of tension or alignment on my part. My concern is that after jacking up the rear end on the rear shock post--blocking the front wheels & running probably 10-15 mph stationary vehicle with lots of error code lights--I shut it down--take another reading & it's at 190lbs both sides of belt--I lowers the F3's to the ground without moving it & it still reads approx 195 lb. I do need to mention that I removed the Baker built upper roller in the process--but I estimate the additional roller to be approx 3-4 lbs load at most. haven had the opportunity to test ride. My belt alignment may get a fine tuning as the space is closer on the spyder rear wheel than the outside but still not touching the driven pulley.
Your thoughts ??
Darrell

I think what's happening is this. The pivot point of the swing arm does not coincide with the front sprocket, so as the swing arm moves up and down the centerline distance between the sprockets changes slightly. When you first measured the tension the shock was probably compressed and reflected the length it had when you were riding it. The air bag may have even lost some or all of its air. Then when you jacked it up, and ran it, the compressor pumped up the air bag extending the shock thus changing the belt tension. When you lowered it it stayed the same which is why the reading was the same. Lifting the bike by the shock mount is no different than holding it up by the tire when it comes to shock movement.

The manual says to jack it up under the frame. That is not because it is not safe to jack it up under the shock, but so that the shock will extend fully. Full extension is the only way to have a consistent condition from one time to the next for checking the tension. According to the Technical Service Bulletin last year any tension from about 550 newtons to 1050 newtons is OK. That is with the shock fully extended. The criteria is to set the tension so that the resulting belt vibration occurs at a speed range acceptable to the owner.

 

[Wildrice]

Jack location for belt tension measuring

I just rewatch the video again and noticed the guy placed the jack at the "back of the center frame" which is about 2 ft closer to the front. I jacked it up from that location & my Krikit reading was 120#, versus the 190 # reading on the shock crossbar frame.
Thus It's me that was in error. I don't remember seeing any specs that low--ones ive seen with it jacked were in the 180# range. If anyone has what they believe is an accurate setting --pls advise.
Again my apologies,
Darrell

 

[IdahoMtnSpyder]

I just rewatch the video again and noticed the guy placed the jack at the "back of the center frame" which is about 2 ft closer to the front. I jacked it up from that location & my Krikit reading was 120#, versus the 190 # reading on the shock crossbar frame.
Thus It's me that was in error. I don't remember seeing any specs that low--ones ive seen with it jacked were in the 180# range. If anyone has what they believe is an accurate setting --pls advise.
Again my apologies,
Darrell

No need to apologize. This is an issue that has not been free of confusion!

I have my RTS belt set to about 190 to 200 lbs and a Smooth Spyder belt tensioner. I get vibration around 80+. You'll probably have to go higher since the F3 belt is longer. You might try 210 to 220 and see what happens. 235 is close to the max of the range BRP recommends, for the RT anyway.

The best way to find what works is trial and error, but that is not a great option considering what a pain in the rear it can be to get the tension and tracking just right.

 

[billybovine]

Hey this got sorted out while I was ryding. You did not pick up my point about measuring belt tension at full swingarm droop. IdahoMtnSpyder explained it better than I it appears. He also brought up the small change in belt tension due to airbag inflation. I had not considered that. Maybe because I have never owned a model with an airbag shock. It's been a long standing myth that jacking at the shock will damage something. I do believe that every bent shock bolt has been blamed on jacking on the shock. :roflblack:

 

[Wildrice]

Hey this got sorted out while I was ryding. You did not pick up my point about measuring belt tension at full swingarm droop. IdahoMtnSpyder explained it better than I it appears. He also brought up the small change in belt tension due to airbag inflation. I had not considered that. Maybe because I have never owned a model with an airbag shock. It's been a long standing myth that jacking at the shock will damage something. I do believe that every bent shock bolt has been blamed on jacking on the shock. :roflblack:

On the F3---that floor jack can't touch the shock bolt--the protective bracket housing welded to the frame prevents that from happening. But I do understand the swing arm movement is based on the jack position. It's always something--thanks for your feedback.
Darrell