Caliper movement /tunnel flexing?

[Motorhead]

Is it normal for the caliper and rotor to move 1/8-1/4” as the track is spinning. I checked mine for a reason and expected the tunnel to be perfectly still where the caliper bolts thru it, but it is not!

While idling and rear is lifted off the ground to permit track to spin, I see in and out movement on my caliper, rotor and the guard that is bolted to the caliper!

Should it be perfectly still as the cog shaft rotates or is some tunnel flex normal?

 

[Byam]

I am pretty positive it’s the reason why it is not locked from factory. Maybe 1 out of 10 has no chassis flex.

 

[Motorhead]

I am pretty positive it’s the reason why it is not locked from factory. Maybe 1 out of 10 has no chassis flex.

I have never checked for this and there is a reason why I was checking it out yesterday. I took a couple of videos with my iPhone, but not sure how to make a video file small enough for posting!

 

[Kuzzy]

I am pretty positive it’s the reason why it is not locked from factory. Maybe 1 out of 10 has no chassis flex.

I agree that this is likely why they did that as well, and adding a BOP saver will help stiffen up the brake side, but that leaves the chaincase side to take the rest of the flex...........I will be adding a BOP saver myself, but only because so many have ran one without issues...However that still does not really leave a good feeling in my stomach lol as a new shaft and bearing are cheaper than a chaincase. Taking into account the many satesfied BOP saver customers out there, evidence points to there being enough room on the bottom gear side of the shaft to take up the additional flexing the chassis may be doing. That is where i currently stand lol.

 

[Fords4life]

Seen the same thing with my 2013 f1100 turbo, was the drive axle bearing on that side, axle was toast where bearing rides.

 

[Motorhead]

Seen the same thing with my 2013 f1100 turbo, was the drive axle bearing on that side, axle was toast where bearing rides.

Yeah not my case, but I didn’t think that much movement was normal!
Shall make a call concerning! Thanks all for the quick responses!

 

[hellflyer]

If your bearing isn't square on the shaft when you install the bop bearing lock this will happen. It will cause alot of problems in not a long time. If your using the wedgy thing loosen it and try it then.

 

[Motorhead]

If your bearing isn't square on the shaft when you install the bop bearing lock this will happen. It will cause alot of problems in not a long time. If your using the wedgy thing loosen it and try it then.

I have heard about pulsing brake lever if rotor is also locked in place by the BOP bearing lock, but that bearing not being square with shaft may be one of the possibilities, but with loctite instead of the BOP invention!

 

[hellflyer]

Same result I imagine! If bearing is Locked on off square that's how it acts. It'll push caliper pistons in on rotation then when you go to use the brake they won't be there it'll be soft .

 

[Sevey]

I have heard about pulsing brake lever if rotor is also locked in place by the BOP bearing lock, but that bearing not being square with shaft may be one of the possibilities, but with loctite instead of the BOP invention!

The bearing and the shaft are not running true. I got viscous one year and used green loctite on the bearing and created a crazy wobble.

If you use loctite, be sure to roll the drive shaft as soon as its together so the two 'mate' together. If you use the BOP wedge, slowly bring on the torque and keep rolling the shaft or track so it finds it own.

Its my opinion some tunnels and shafts are not 'true' and dont line up. The sloppy way it is manufactured with bearing and shaft tolerances allow them to find their spot. Keep in mind this tunnel is super thin and flexes alot while riding - god knows what it does when you jump the sled.
MS

 

[NYTurbo]

The bearing and the shaft are not running true. I got viscous one year and used green loctite on the bearing and created a crazy wobble.

If you use loctite, be sure to roll the drive shaft as soon as its together so the two 'mate' together. If you use the BOP wedge, slowly bring on the torque and keep rolling the shaft or track so it finds it own.

Very true, BOP saver can create issues.

 

[Sevey]

We were all used to the cast aluminum bulkeads that held the motor and shafts in place - jack shaft and drive shaft always ran true - if there was a problem it was likely the drive shaft was warped.

The procross sleds are built very light with thin tunnels and light bulkeads.
MS

 

[Motorhead]

The bearing and the shaft are not running true. I got viscous one year and used green loctite on the bearing and created a crazy wobble.

If you use loctite, be sure to roll the drive shaft as soon as its together so the two 'mate' together. If you use the BOP wedge, slowly bring on the torque and keep rolling the shaft or track so it finds it own.

Its my opinion some tunnels and shafts are not 'true' and dont line up. The sloppy way it is manufactured with bearing and shaft tolerances allow them to find their spot. Keep in mind this tunnel is super thin and flexes alot while riding - god knows what it does when you jump the sled.

Yes With loctite/glue, you also need to have everything ready for quick assembly prior to it drying during this process, I have found. And make sure that none gets on the rotor to keep it floating.
You had a crazy wobble and now I have a crazy wobble.

Thanks for reassuring that this can and does happen.
Do you think this is why some have luck with the loctite trick, and others don’t.
I mean with a crazy 1/4” or so wobble, how long can that loctite hold before it wears itself centered and spinning again?

 

[Sevey]

Based on my own sled, a friends sled and what others have written - loctite will hold but eventually the shaft breaks loose and will spin. I think -and- am willing to bet there is quite a bit of difference from sled to sled with respect to tolerances and 'trueness'. The cast bulkheads from the delta box and fx chassis were pretty square/true. The way these sleds are put together, i bet things could easily be 1/8" out.

Just my ten cents - but if your rotor is wobbling - fix it now. Mine was bad enough i had concerns that it may 1) oval the 3 bolt holes where the caliper assembly fits to the tunnel or 2) flex the aluminum tunnel to the point cracks may develop. When the caliper assembly is off - and you see how flimsy and flexible the tunnel is - i am gobsmacked to think that kind of design holds the power that is transferred to the shaft.....

Penny for your thoughts - i would love the engineers to go on record and just admit they built the drive system on this sled to float and not be fixed solid. I am convinced the drive shaft has been designed to be a perishable item that needs to be changed every 8-12,000 km.
MS

 

[Motorhead]

Based on my own sled, a friends sled and what others have written - loctite will hold but eventually the shaft breaks loose and will spin. I think -and- am willing to bet there is quite a bit of difference from sled to sled with respect to tolerances and 'trueness'. The cast bulkheads from the delta box and fx chassis were pretty square/true. The way these sleds are put together, i bet things could easily be 1/8" out.

Just my ten cents - but if your rotor is wobbling - fix it now. Mine was bad enough i had concerns that it may 1) oval the 3 bolt holes where the caliper assembly fits to the tunnel or 2) flex the aluminum tunnel to the point cracks may develop. When the caliper assembly is off - and you see how flimsy and flexible the tunnel is - i am gobsmacked to think that kind of design holds the power that is transferred to the shaft.....

Penny for your thoughts - i would love the engineers to go on record and just admit they built the drive system on this sled to float and not be fixed solid. I am convinced the drive shaft has been designed to be a perishable item that needs to be changed every 8-12,000 km.
MS

Oh I agree, it should be repaired whereas this kind of movement (Caliper wobble)can also create unwanted force on the other end of this shaft also, which is inner Chaincase and it’s interior,