Cr tunnel/EZ Ryde help

[GroundPounder]

I purchased a 144 ez Ryde suspension along with a tunnel from cr racing. The tunnel wasn't drilled for the suspension mounts but Chad supplied me with the rear mounts. Ez Ryde supplied me the measurements for 3" pitch, 7t drivers. I'm running 2.52 pitch, 9t drivers.*Does anyone have my current set up that could supply me the measurements or know how about going about this? This is for 09 impulse nytro that I'm building for the SHCRA Hill climbs. *Thanks in advance

 

[SNAFU]

This is how I would approach this.
For a 3" pitch track, the driver circumference at the base of the teeth should be about 3x7=21". Thinking about this as a circle, the driver diameter at the base of the teeth should be about 21/3.14=6.7" (Circumference = pi x dia.). So the driver radius is half that or 3.35". Similarly, the driver radius of your 2.52" pitch drivers would be about 3.61". So, the front of the track will be about 0.26" forward using the 2.52" 9th drivers compared to the 3 pitch 7th drivers. I haven't looked real close at how the EZ Ryde mounts, but you should be able to use the suggested mounting locations. The difference between the driver diameters would be made up by adjusting track tension with the rear idlers. You would need to loosen your idlers and slide then forward about 1/4".

 

[GroundPounder]

Ez Ryde

Thanks alot. I've been looking at the diagram that Cody at ez Ryde sent me and was very confused. I would attach the drawing that was sent to me but for some reason it will not attach to this thread. Since my old tunnel was a 121, I thought about using the old mounting points as a reference, or even a xtx since that was a 144. I just want to make sure I have a handle on this, don't want to turn my new tunnel into Swiss cheese.

 

[LoudHandle]

While Snafu's math is accurate, he possibly overlooked that it is the circumference that EZ-Ryde's mounting location is based on (IMO). Assuming a half wrap of the track on the driver (it is slight less due the approach angle at full ride height) the difference is about 1" more track is used to get around your driver than the 7 Tooth 3" Pitch. If you know you have at least a 1/2" of extra slack in your tail roller slots then mount as directed.***NOTE***IF NOT then you likely need to adjust the front mount dimension shorter by a 1/2" and the same with the rear mount dimension.

 

[GroundPounder]

Ez Ryde

This may sound stupid, but is there any way to find out if I will have the slack that you mentioned before installing the skid and having to re - drill new mounting holes?

 

[LoudHandle]

This may sound stupid also but hear me out. Get two boards (plywood or whatever you got laying about) drill your driver holes and base your actual mounting dimensions off of that hole just like they tell you to in the drawing. It will be easier if you pick one side of the board to represent the top of the tunnel. Assemble it all with the track and verify before you drill your new tunnel. It will be much easier to re-drill a hole in the wood than buy a new tunnel. Hope that helps you thru your dilemma, if not EZ-Ryde will draw your exact setup and send you the dimensions for a fee.

 

[SNAFU]

Here is another thought. What paddle height is your track? The clearance between a Camo extreme with 2.5" paddles and the exchanger with 3" pitch 7th drivers is only about 3/8". Your larger drivers will move the track closer to the exchanger so you need to consider that.

 

[GroundPounder]

Ez Ryde

I'm going to be running a backcountry 1.75.

 

[LoudHandle]

As the 3" pitch track would be a 146", are you sure the install dimensions are for a 144"? If not you need to adjust for that difference as well (1" further forward typically).

 

[GroundPounder]

Ez Ryde

That's what threw me off when I was looking at the diagram that was emailed to me, but on top of the drawing was for a 144, 7t 3pitch.

 

[irondave86]

Didn't the Ez Ryde come with mounting plates for the front holes? (I attached a picture of the front plate) You need to use the original front suspension holes to locate the plates. Then you'll need to build a template to locate the rear mounting holes. Have you installed the tunnel yet?

 

[GroundPounder]

Ez Ryde

I'm almost done installing the CR tunnel, which is a breeze, but I didn't receive any type of mounting hardware from ez Ryde, just the suspension. I was told that I could either use my original front mounts from my old tunnel or a piece of. 60 steel. I'm going to call them again tomorrow and try to talk to someone different.

 

[irondave86]

Those plates make locating the front hole easy. I always dealt with Christian.

 

[GroundPounder]

Ez Ryde

Thanks, when I call tomorrow I'll ask for him.

 

[bwylde]

Also Nextech sells these front mount plates that work really well with EZrydes, as they can be abit of a pain to tune-but once done, they're a great skid.
http://carbonsled.com/rear_suspension.htm

 

[GroundPounder]

Cr tunnel

Well guys this is the deal. Been talking to Cody at ez Ryde and apparently I'm the first person to put a 144 in a cr racing tunnel, hence no brackets for the front mounts. In case anyone wants the measurements for a 144 track, 2.52 pitch with 9t drivers, and 1.75 lug let me know. Guess it's time to fab up some front mounts. Thanks for all the help guys, and as always any input would be greatly appreciated.