Thule TB60 roof track placement

oclv · 03-29-2008, 03:25 PM

I just ordered a set of Thule TB 60 roof tracks. These are the 5' track strips that fasten to the top into which the feet attach that hold the cross bars. They were designed for fiberglass tops, caps, etc. I will be installing myself. Can someone that has these installed by Sportsmobile post where they are placed on the Penthouse Top? Thanks. Basically I want to find out how far in from each edge they are, and how far from the rear or front they start. Any tips from those who have installed them would be appreciated. Any photos would be appreciated also. Thanks in advance. oclv

alta825 · 03-29-2008, 05:43 PM

my tracks are mounted so that the holes/nuts/bolts are just barely outside of the penthouse 'tent' walls - maybe 1/4" outside.

hope this helps...

-d

stiggs · 03-29-2008, 08:23 PM

i have the yakima tracks and racks i can take some picts and give you measurements when it is light out

John Kalmbach · 03-30-2008, 01:24 AM

When installing the Thule tracks, make sure they are parallel to the penthouse ceiling panels behind the canvas, and not to the fiberglass top. The fiberglass top is wider in the middle than at the rear and you would constantly have to adjust the towers on the crossbars if you want to adjust the crossbars fore and aft. These instructions might seem like it is a big job, but it is really quite simple.

1. Raise penthouse top.
2. Measure 18" forward from rear corner of p.h. canvas and mark. This dimension should keep the rear edge of the Thule track from "hanging" over the edge of the fiberglass top.
3. Using a piece of 4" x 4" (approx.) X 1/4" thick plywood, place the plywood along the p.h. canvas, perpendicular to the underneath side of the fiberglass top, and centered for and aft on your mark. This piece of plywood acts as a spacer between the canvas and your drill bit to locate the hole properly, it also helps protect the drill chuck from damaging the canvas. Using a 7/32" drill bit, drill "up" from underneath the top. Make sure you have safety glasses on, and close the doors and windows as the fiberglass dust will go everywhere (aka "itching" powder)
4. Confirm that the center-to-center dimension on the Thule track end mounting holes is 60".
5. Place a 2" x 10/32 stainless pan head screw through the hole from the top down. Hook your tape measure to the screw protruding through the top and measure forward 60" to the aft edge of the forward track hole you will need to drill. Follow step #3.
6. Remove screw from aft hole, place Thule track on top of fiberglass top and insert screws through track and fiberglass top in both the aft and forward holes.
7. You can now drill from the top down for the remainder of the mounting screws. SMB would usually drill a hole at every other Thule track hole. Confirm that the canvas is tight and will not be damaged by the drill bit.
8. Remove Thule track and screws and clean excess fiberglass "dust" from fiberglass top.
9. Align Thule track over holes. Apply clear silicone sealant to each hole so that screws/holes are sealed (this is critical as water will penetrate the canvas seams when the top is "down" if these screws/holes are not sealed). Insert 2" x 10/32 stainless pan head screw and install flat washer and nylon lock nut. After all the screws are secure, "break" off the excess threaded screw section and make sure there are no sharp edges that can cut the canvas. The thickness of the tops vary, so the longer screws actually make installation easier.
10. Repeat for other side.

Good Luck!

John K.

oclv · 03-30-2008, 08:39 AM

Thanks to all have replied. Stiggs, thanks for the offer but no need now as John has posted some very detailed instructions. I have printed these instructions and will use use them when the Sportsmobile arrives, hopefully in about two weeks. oclv

bluedog225 · 05-10-2009, 06:53 AM

Great instructions. I have a couple of questions before I install my Thule TB60 tracks.

1. Wouldn't the track be able to support more weight if located nearer the outside edge of the penthouse roof? That placement would seem to allow the downward force to be transferred to the rooftop better (allowing for less deflection of the roof surface).

2. Would butyl tape be a better sealant than silicone? I've had people in other RV forums steer me away from silicone for sealing roof openings and we don't use it in marine applications.

Thanks

Tom

oclv · 05-10-2009, 10:09 PM

I was going to direct you to the answer that John wrote for me a year ago but I see he has written it out again. I did as he described and have not had an issue. oclv

scatter · 05-11-2009, 10:23 AM

Twas me Tom, I'd stick with the butyl. Silicone is great stuff, but not the best for your application.

oclv · 05-11-2009, 09:18 PM

I didn't look to see who strarted thi thread and I just realized it was me and John's response was from last year. Cheers. oclv.

bluedog225 · 05-12-2009, 05:32 AM

I agree butyl is the way to go but I find it strange that these high-end manufacturers (Thule and Yakima) would both provide silicone with their kits. May butyl isn't "neat" enough?

I may email customer service for an answer. Will let you know.