Details of French Track
Submitted by - Stephen Grammont
Revised Date 7/1/01

 

As discussed in the Weasel Track History Article, a heavier post-war track was introduced at some point. Speculation is that such tracks were used by the French in Indochina, but as of yet there is no definitive answer to this question. Until then, at least here on this website, the term "French Track" will be used to represent the heavier track discussed in this Article.

 

 

The two pictures above give a very good compare/contrast shot between the French Tracks (above) and Original 20" 2nd Pattern Tracks (below). Each is 20" wide, has a single hard edge for traction, and heavy rubber road pads for better traction and shock absorption. There the similarities end. Instead of recovering ground already documented, check out the Weasel Track History Article, to find out more about the other tracks.

 

 

The diagram above shows the composition of a section of French Track as seen from the road side. The components are discussed below in detail, but generally this track exhibits some very interesting features as a whole.

The construction is far more robust than the Original tracks in many ways. The heavy rubber Blocks that join the tracks are very thick rubber (aprox 1/2") and when damaged can be replaced individually by removing four nuts. Same with the Pad Blocks. If a pad were to become damaged, two nuts off, new pad on. Repairs could even be carried out without removing the entire track. If the whole track needs to be removed, unbolting a single row of bolts is all that must be done. Then the track can be removed/installed just like a pin linked tank track.

 

 

The pictures displayed above show the inner side of the French Track's assembly. Note how the Blocks provide a smooth running surface for the suspension system and obvious flexibility when bending around the drive/idler wheels. The guide is smaller than the Original's, but still looks every bit as able to take abuse. Perhaps even more able.

Now to discuss the component pieces in detail (are we having fun yet? :-)

 

 

 

The Lag (or Grouser if you like) for the French track is far simpler than the Original's Grouser. It consists of a single piece of cast steel, or perhaps iron (I don't know how to tell the difference!), compared to the Original's three pieces of stamped steel. There are 16 holes probably created as part of the casting process. Four of the holes are occupied by the rivets holding on the brass? Track Guide, which keeps the track on straight and prevents it from slipping off. There are no signs that the Lags were ever covered by a rubber coating.

Although certainly crude, it would be quite easy and inexpensive to create such parts compared to the Original's. This design is also far more robust when being used on rough terrain. The most damage I have seen on one of these lags is a slight bend from the outer edge to the middle. Even this doesn't appear to create any problems for the track's ability to function correctly. Other than a minor bend here or there, Lags generally show only minor surface nicks and rust.

 

 

The strength of the track assembly comes primarily from the two solid Blocks that are on the outer edges of the tracks. Each of these blocks is about 6" in length and 4" in width. Embedded in each are two "links" made from double roller chain #40 which are attatched to a brass (or some other non-ferrous metal) metal fitting. The bolts go through the fitting on either end, which in turn are bolted onto the Lags. The links are what actually keeps the tracks together, not the rubber.

The pictures below show a complete link with new roller chain (thanks to Paul for the pictures).

 

 

Like the bands on the Originals, the Blocks are the weak link for the French Track. This is not surprising since they take a lot of abuse and are expected to be constantly flexed as the track moves along the suspension. If you scroll to the very top of this article and look at the first picture you will see that the braces and rubber are starting to separate. This does not appear to affect the ability of the Blocks to hold the track together, but it does allow moisture to start eating away at the roller chain links. Rust forms and siezes up the chain, which makes it more likely to break. Eventually, just like the cables in the original tracks, the links do break and the Blocks are literally torn apart.

 

 

Conclusion

The French track is in some ways an improvement over the Original, but not without its drawbacks. The tracks are easier to maintain and can hold up better on rough terrain. Although the Blocks are subject to the same sort of rusting problems as the original bands, they can be replaced with spares very easily. If spares are not available, then new ones can be manufactured fairly inexpensively.

Unfortunately, these advantages come at the expense of extra weight (probably 50% more?). This brings down the top speed (not sure how much) and is likely to cause more strain on the drivetrain and drive/idler wheel arms. Whether these drawbacks actually have a tangible effect for current owners is unknown. I'll let you know in a couple of years :-) My guess is that for summer driving around on rough and wooded ground, the benefits outweigh the drawbacks.

Another potential problem area for the French tracks is deep snow conditions. The Original tracks provide incredible flotation and generally trouble free driving. It is not clear to me if the extra weight, lack of space between the Lags, and the absence of a rubber coating on the deep traction edge will cause significant problems in the snow compared to the Originals. If I had to bet, it would be that the French Tracks are noticeably inferior to the Originals in deep snow. I'll let you know next winter if this is the case or not!

Overall, it looks like the French tracks are a good choice for someone who needs tracks which can survive constantly slapping down on rocks, tree limbs, and tree stumps. This is most likely what they were designed to handle, especially if it is true they were used by the French in Indochina. But for snow conditions, the Originals are most likely superior.