Keeping your bike cool is important, especially if you’re racing in 100+ degree weather. If your dirt bike is overheating, a relatively inexpensive way to help prevent it is with a vented front fender. I’ve heard many people say they like the extra air-flow that their bike’s radiators get.
For a real test, you’d need to record the temperature differences with some temp strips. I don’t live down south in the raging heat, so I’ve never really needed the additional cooling. However, for the sake of YOU, I tested something that doesn’t require buying an aftermarket vented fender. I like free things, and if they work, that’s an even bigger bonus. I’m going to show you how to make a vented fender with some basic home tools.
First thing to do is lay out the design that you want (clean the dirt off the plastic). I just used a sharpie because that’s what we had laying around, and it works. Below is a picture of my layout. I took a peek at some motocross vented fendersto get an idea. I didn’t need anything fancy, so I just quickly sketched it on the bottom of my fender.
After I sketched out the design I wanted, I pulled out a cordless drill and a couple of drill bits. The first one is small for drilling out pilot holes. I just made 4 holes on the corners of each vent. See the picture below for an example.
I then use a larger drill bit to make bigger holes, making it easier to cut out the vents.
The next step can be done using a variety of techniques. For me, this was a fairly quick demonstration, so I wasn’t going for a ‘professional’ look. I just used the same drill to cut/mill out the pockets. It is a little messy, and not very…. perfect. Another way you could do this is by taking an exacto-knife and heat it up with a torch so it cuts through the plastic more easily. Below is the fender after cutting the vents.
Yeah, that looks a little rough. So, I took a small exacto knife to clean it up a little bit. I’m no artist, so I just shaved the lines as straight and clean as possible without spending hours on it. Besides, it’s not like people are looking at it up close anyway. It looks pretty good on the bike, and I’d bet it would help with overheating problems…. If it had any.
And there you have it. I just took an old fender I had lying around and turned it into an amazingly cool and high-tech bike modification. Ok, well it may be a chunk of worn out plastic, but it beats paying almost double for an aftermarket vented front fender when you have the tools at home to do it.
Going from an 85cc motocross bike to a full-size dirt bike is a big jump in weight, size, and height. It can be intimidating when you’re racing against adults and you can’t touch the ground with your feet. Even if it’s a 125 2-stroke, it still feels night and day different than a little 80. If you’re like me (5’6″) and you can barely touch the ground with one foot, an extra inch or two can be the difference between crashing and staying on the bike in a corner or tight single-track trails.
Chopping The Saddle
The most common (and cheapest) way of lowering the seat height is by trimming the seat foam. This is a good time to put on a new seat cover as well! Just take the cover off, trim the seat foam down to the desired size (you can usually take off 1-1.5″ from the middle of the seat and still have enough left). Then you simply stretch the seat cover back over and staple it. This mod is popular because it’s cheap, and pretty much anyone can do it with a little patience. The downside is that there is less foam to sit on, leaving you with a stiffer ride, as well as a curved seat.
Linking Closer To The Dirt
A lowering link is another common mod to lowering the ride height on your dirt bike. It’s an easy solution for short riders stepping up to a full-size bike. It’s a direct bolt-on, and lowers the rear end 1/2″ – 1 1/2″ on most bikes. Cost is probably the biggest factor when considering a lowering link, but it also changes the handling and suspension of your bike. Many riders complain that the pre-load is quite a bit softer, and that the front-end sits higher, changing the rake angle. Handling isn’t affected so much at slower speeds or trail riding, but experienced riders may notice it on the motocross track or at higher speeds.
Taking A Slice Out Of The Subframe
If you really want to go crazy, some guys (and gals) get a chunk of their subframe cut and welded back together to lower the seat height. There are more downsides to this modification, so I wouldn’t suggest it to be first on your list. The more pieces that have to be welded together, the more likely it is to crack or break (so make sure you get a professional to weld it, especially aluminum). Since the subframe is holding mostly the back half of the seat, that’s where most of the lowering is going to happen. Also, if you chop too big of a portion out of the subframe, it may end up causing the rear tire to hit and rub against the fender when the suspension is compressed.
Not only can you get a smaller diameter rear rim, but you can choose the amount of rubber around it. Motocross bikes come with a 19″ rear wheel, but some off-road/enduro trail bikes have an 18″ rear wheel. Swapping for the smaller wheel will lower the rear-end of the bike. Depending on what you have already, going from a 110/100-19″ to a 100/90-19″ rear tire can help lower the bike as well.
Adjust Shock Pre-Load/Sag with Locking Nuts
If suspension set-up is critical, I would not suggest this to be the first way of lowering your bike, even though it’s simple and can lower the bike close to 2 inches. If you look on the rear shock assembly, there will be two locking ring nuts holding the spring compressed. If you haven’t already set your sag/ride height (more on this in a future article), I suggest you do that first. Your race sag should be about 100mm (4″), but if you keep loosening the nuts and spring, it will eventually stop, and that’s where you will have the most sag (lowest seat height). Like I said before, if you are racing or riding hard, I would not suggest going past the proper ride sag because the suspension will be too low and soft. Trail riders can often get away with this (I have tried this personally and it works great in tight single-track).
Moving The Forks Up
In addition to the other mods, you can (or need to), move the forks up in the triple clamps. This will lower the front-end of the bike, and may be required for some of the previous mods because the rear-end will sit lower. Be careful though, and do one small adjustment at a time, because changing things around like this can mess up the geometry and handling of your bike. Take note of all the specs you’re going to modify as a starting point in case you want to go back to it.
Think Before You Act
All of these can change things that require more modifications:
Kick-stand too tall, little seat foam, lower ground clearance, less suspension travel, different handling, ergonomics, different gearing (smaller wheel), etc… And remember, you don’t always need to lower your bike. Being able to touch the ground with two feet isn’t a must, even when trail riding (although it does help in most cases). Just look at some of the top pro racers that are around five and a half feet tall (Carmichael, McGrath, Stewart). With all this in mind, do a little research to find out which one will cause the least trouble if you are unsure. Good luck, and ride safe!
Have you gotten your dirt bike stuck in a mud pit out on a long trail ride? Did it take long to get it out? Did you lose all of your energy from pulling it out? If you answered yes to at least one of those questions, then I can help make life (well, riding…. but isn’t riding your life anyway) a whole lot easier. If you don’t know what a tug strap is, it’s a piece of material that goes on the rear end of your seat that you can use to lift your dirt bike up.
First step is to get some material from a fabric or craft store. Should be pretty cheap because you only need a couple feet of it. You’ll be looking for fabric that’s similar to what tie-downs are made out of so it’s strong enough. Two to three feet should be enough.
Next is to measure it up to the bike. Take the bolts off that hold the rear of the seat and side panels. Pull the rear of the seat up and take the material and put one end up to one of the seat bolt holes. Now, there are two ways you can do this, one will require a little more length in material, but will probably be more sturdy. First one is by putting the seat back down so the holes line up (ready for bolts to be screwed back in), then wrapping the material over the seat and lining it up with the other seat bolt hole. You should leave just enough slack in the strap over the seat so that you can fit a hand through it, but too loose will leave it hanging out, causing it to catch on your or another object not on the bike. Next is to mark the spots on the strap material where it lines up with the holes (a sharpie or marker will work). Now we’ll look at the other option before we finish it…
The second way is to line up the start with the first hole, like we did for the first one. Instead of going over the seat now, first go under the seat with the strap, then wrap it around the top, and once again under the seat. So, it should be a complete loop around the bike (kinda’ like what the Hot Wheels tracks did where you roll the car down the track and it does a loop, and then…….. Oh, never mind). Just remember to leave enough room for you hand. I guess the down-side to this route is that you have to wrap the strap around seat one more time when you take it off (big whoop!). The strap should now be lined up with the second hole; where we left off for the first strap…
After you have properly adjusted the strap and marked-up the holes, take it off. Now you will get the holes out to the correct size. You can do this by drilling them, or using a propane torch to heat a bolt/nail and burning a hole through the material. Also, take the torch and fray the loose ends of the material that you cut/burned so it stays together (just don’t burn your lovely strap!). Now you can put some washers in between and strap it around your seat and go!!