A big difference to being a fixed gear crit rider with my career as a UCI cyclist is that I have to take care of all my material myself. Back in the days, during training camps, stage races, or classics I just had to jump on the, clean and checked, bike to race it and I would give it to the mechanics straight after. This process was my everyday mode of operation. During my days at home, I had a very technical dad who always made sure my training bikes were in top condition. The contrast was huge when I entered the fixed gear crit scene. I basically knew little to nothing about the technical side of maintaining a bike. I could switch the inner tubes of my clinchers as solo training rides forced me to get handy in that, but not much more. As a fixed gear crit rider, suddenly I had to do everything myself, and although I struggle sometimes, I surprisingly like it. I don’t think I will ever get as handy as a pro mechanic, or my dad, but what I really appreciate is getting to know the material I am using and how changing those materials might benefit me as a racer. Although I see that, in general, the knowledge on material is much higher in the fixed gear peloton than in the pro road peloton, I often see mistakes being made regarding material that could easily be avoided.
Tekst & Photography: Brian Megens
Instagram Rob v/d Brand
I’ve seen too many people in the fixed gear crit scene with tubes rolling off, so this time we will dive into the craft of gluing tubes. As gluing tubes is a craft on its own, we asked a pro to explain us the art of gluing a tube properly on a rim. Dutchman Rob v/d Brand is a mechanic who currently works for the World-Tour Team Dimension Data and before had Giant-Alpecin, Rabobank Development, and Argos-Shimano as employers. Having glued the tubes of world class cyclists like Degenkolb, Kittel, Dumoulin, Cavendish and more, this man must understand his job. Rob will explain us the process of gluing tubes in detail (see below) but first we had some question for him.
What is the most common mistake made when people glue their own tubes?
Often they have too little pressure in the tube when they put it on. Another mistake often made is that people do not use enough glue. So, my tip is not to go cheap on glue, and too much glue will always come out anyways, you just have to clean a bit more but at least you go safe. If you are in doubt if you used enough glue when mounting the tube, lift the tube a bit and your will see if the glue is spread evenly. Also after drying the tube, try to push the tube to see if the glue is attached to the rim everywhere.
What do you think of taping tubes?
It is ok for training but I would never recommend it for racing. However, we sometimes do use tape as an extra, between the first and second layer of glue, with very deep narrow rims to make sure that the tube also in the middle attached to the rim. Nevertheless, with rims getting wider this probably will occur less and less
What do you recommend for fixed gear crits, tubes or clinchers?
Tubes, although clinchers are really good nowadays I still believe in the advantages of a tube. Regarding roll resistance and cornering tubes normally are better than clinchers. On cobble stones and rough terrain tubes are also much more flexible avoiding flats from the impact of uneven surfaces.
25mm or 28mm?
I believe 25mm are the ideal width for tires, with wide rims though. 28mm are ideal for cobblestones.
What is the ideal pressure for tubes?
The advantage of tubes is that they also function really well with low pressure. For crits with tight corners, uneven surfaces, or in rainy conditions I think this is ideal as you can easily lower the pressure to 6.5-7 bar (25mm) and the wheels still roll well but also provide a lot of grip.
Do riders in the teams ride with (more or less) the same pressure, taking weight into account of course?
There are riders that like to ride with lower pressure, but in general we look at the weight of the cyclist to determine the pressure we put into the tubes. Usually, we put 0.2 to 0.3 more bar in the rear wheel than in the front.
When gluing tubes on new rims:
Tools & equipment:
– a brush
– a stand for the wheel
Step 1: Preparing the rims
Roughen the surface of the rim with sandpaper, after that you clean it with white spirit
Step 2: Create a first layer of glue on the rim
Spread glue on the rim to create a first layer of kit and let it dry for 24 hours.
Step 3: Repeat step 2 and wait another 24hrs
Step 4: Create a first layer of glue on the tubes
Spread glue on the tube and let dry. The layers on both the rim and the tube are necessary to make the final glue layer attach properly to both. For example, the tube will ‘suck up’ most of the first layer of glue, to avoid this to happen with the final layer of glue, a first layer needs to be added.
Step 5: the final (third) layer of glue and getting the tube on the rim
Make sure to put some pressure in the tube, it needs to be flexible enough to put over the rim but also strong enough to keep its shape. Spread the kit evenly on the rim, as mentioned better to add a bit too much glue than ending with too little on the rim. Place the wheel on the floor or use an old bike front fork (assemble upside down) so that the wheel can be assembled in from one side. The hole for the valve must be pointed up. Put the tube on the rim. Try not to roll the tube on as this will remove glue but try to stretch the tube as much as possible so the tube will make contact with the rim from above. When the tube is on, pump it up to 7-8bar so that the tube forms itself. If needed, replace/straighten the tube, also put a bit extra pressure at the valve.
Step 6: Check if the tube is straight
Put the wheel in a wheel aligner and check if the tube is straight. Clean the sides of the tubes, rim and don’t forget the valve!
Step 7: Let the wheels dry
Put the wheels in a dry warm place and let them dry for at least 24 hours
When replacing a tube:
When the tube is removed in a correct manner, so do not roll and pull the tube from the rim, you will leave a nice even surface ready for the next tube to be glued on. In order to achieve this:
Step 1: use a screw driver to lift to tube on one place
Step 2: cut the tube straight through so that the tube is not connected as a circle
Step 3: hold one of the ends of the tubes and pull it straight off the rim
When you still have uneven glue on the rim:
Step 1: Get rid off the glue in the middle of the rim
use a hot air gun to heat the glue and remove it with a small spoon
Step 2: get rid of the glue on the sides of the rim
use a small knife to get rid off the kit that you couldn’t take out with the chisel
Step 3: clean the rim with white spirit to make it ready for a new glue layer