Editor’s Note: Lennard Zinn’s regular column is devoted to addressing readers’ technical questions about bikes, their care and how we as riders can use them as comfortably and efficiently as possible. Readers can send brief technical questions directly to Zinn.
Sewing pockets into skinsuits
I’ve been wanting to do what you mentioned in the chip timing article for a very long time, namely sew pockets into my skinsuits. Castelli’s 3/4 length CX skinsuits don’t come with any pockets, which make them virtually useless for anything but racing. Our team has a very good relationship with Castelli and I wouldn’t have a problem getting a yard of the skinsuit fabric, but I’m hesitant at letting somebody else try for the very first time to sew a pocket onto a skinsuit. Any suggestions on where to take it?
I’m predominantly a XC mountain biker and would like two small pockets, one for a multi-tool, C02 etc., and one for a gel or chews.
Well, it’s not too tough to do, and I would not hesitate to have anybody who has any experience sewing stretch fabrics to do it.
I assume from your question that you don’t feel qualified to do this yourself. But I think anybody who has done some sewing of stretch fabrics could do it just fine, and I’m sure you have plenty of friends who would fall into that category. You simply have to cut the piece the way you want it and fold the edges under. Then you pin the piece on carefully with the pins running perpendicular to the direction of the seam you’re making so that the pins don’t pull out as you stretch the fabric while sewing it on.
I think you are actually the best person to pin the pockets on, so that you can put them exactly where you want them, as well as check their size. Pin them on, put the stuff in the pockets you plan to carry in them, and put the skinsuit on. Then you can see if you have them in the places you want them. I wanted to avoid having my pocket sitting on my rib cage or on the crest of my pelvic bone, for instance, and unlike a jersey, it’s hard to tell with a skinsuit exactly where those points are unless you are wearing it.
As you sew, you have to stretch the fabric; otherwise, when it does stretch in use, it will break the sewing threads and eventually your work will all come apart.
If you don’t want to do it yourself or have a friend do it, I’m sure you can find people who do outdoor equipment sewing repair or custom sewing. Just remember that if you don’t tell them the right spot to put it, it won’t turn out the way you want.
Removing tubular glue
I am seeking a better/faster method of removing the tubular glue from my alloy or carbon tubular wheels. I have tried all sorts of methods but they all require a ton of time and sore hands.
I used to use my bare hands and nails and that was horrible. I then started using a butter knife with acetone rubbing alcohol and that was a little better. Recently, I tried holding rolled up cloth to the rim with zip ties (the cloth was rolled up almost like a road tire in size), dousing that cloth heavily with mineral spirits and then wrapping the rim around with Saran wrap many times to seal it around. I let it sit for exactly three hours and the glue came right off. The problem with this method is that it smells horrible and the process can be messy, but it was quite effective.
I was wondering what your thoughts might be about using a Dremel to attack this glue on my rims. Could I do this to my alloy rims or carbon rims? Also is there a Dremel head safe enough for such a task that would still be effective?
Carbon is so soft that I wouldn’t risk letting a spinning Dremel tool go astray on it. If you slip off of your glob of glue, you could bore right through many carbon layers, at least if you are using a carbide bit. It wouldn’t be a great idea with an aluminum rim, either.
And if you are using a sandpaper roll or disc or an abrasive stone bit, it will be of less danger to your rims, but it will clog up immediately with glue and be next to useless. I suppose you could use a rotary wire brush bit, but then a Dremel is pretty small and weak to drive it.
I assume “with acetone rubbing alcohol” means with acetone followed by rubbing alcohol? Usually acetone does a pretty good job on tubular glue. Rubbing alcohol does nothing; don’t even bother with it. VM & P Naptha is less smelly to work with than acetone and is very effective at removing tubular glue.
Corrective lenses for mountain biking
I’ve been reading your page for years now and really respect your opinions so I’m looking for some advice.
I’m getting close to 50, and my eyes get worse and worse each year. My close-up sight is really bad — I can’t see the numbers on my cell phone without my glasses — but I also have a pretty significant correction on my long distance vision, too (though I can get by without my glasses so long as I don’t have to read street signs too far off in the distance). I now wear progressive bifocals all day long.
But what about mountain biking? I have been living with just plain ’ol protective lenses. I had a pair of magnifying glasses in my Camelback if I had to stop to fix a chain or something like that. But now my sight is so bad I struggle to see what gear I’m in when I look down at my drivetrain. And I do tend to wander off the trail when I don’t have anyone in front of me, so I am wondering if maybe having better distance vision while on the bike might help there too. But I don’t know anyone riding with bifocals or progressive bifocals.
The other more, ahem, senior guys in my group have distance issues and wear the appropriate corrective glasses. With all the steep ups and downs and turning in mountain biking, not sure bifocals are doable. What do you know about this? Are any brands better than others for progressive bifocal corrective lenses?
Being well over 50 myself and seeing (or not seeing) my close-up vision slip away, I feel some of your pain. Just you wait, you youngsters; you won’t be laughing at us squinting at the fine print when you get to be this age!
The long lenses are uncorrected, but Dual Eyewear has what you need for riding while still being able to read your computer and fix your chain. I don’t know about bifocal offerings in prescription riding glasses, but would be interested to hear your feedback if you do come by any.
Pricey handlebar tape follow-up
Maybe the simplest answer as to why good bar tape is “expensive” is because it’s worth it. Don’t agree? Try riding without any for a few hundred miles.
I can’t speak for others, but if you saw the production steps we take for our Fat Wrap bar tape, you would be amazed that it is so INexpensive!
First, our standard material is cast in mattress-sized blocks. The material must be carefully controlled or you end up with little air pockets, which can ruin the batch. If you are making the style with cork particulate, it goes in up front, and gets mixed in. Sampson still offers with and without cork. As well, we have other styles, such as the grip-tex material, like the product we produced for USA Pro Challenge this year, which is already in sheets. This is a more expensive material from the start. There are only a few companies who manufacture the materials, so this can increase cost as you might expect.
Once the material is cured, it is removed from the casting form and the big foam block is put into a machine like a bread slicer — except this one slices the material off in 3.5mm slices length-wise.
The big sheet is now about four-by-seven-feet by 3.5 millimeters — think a big floppy sheet of plywood. This is then fed into another cutter, which cuts the bar tape into strands that are roughly 30mm wide.
For our Fat Wrap, the strips of bar wrap are now fed into a grinder that puts a bevel on the edges, so that when you wrap the bars, the tape feels seamless and smooth. This is where the process slows considerably, as you have to feed the wrap in fairly slowly so that the bevel is smooth and even.
Sampson supplies adhesive brake strips for the back of the levers, so a double sided tape is applied now, and then strands are cut into brake strip sizes for inclusion. Sampson removed the adhesive from the handlebar tape years ago, as our material is pretty durable, and the team mechanics did not see any difference in gapping with or without it. Now that carbon bars are common, Fat Wrap is a great choice, as there is not any residue left on the bars when it is time to re-wrap, which can save huge amounts of time and swearing by not having to try to carefully strip the residue off carbon bars!
After the tape is beveled, it is rolled and a protective wrap is placed around it for packaging.
Lastly, you have the end caps; the cost of the injection molds for the end caps, the brake strips, and finishing tape all going into a package! We have used a recyclable header card and poly bag for many years on our standard package to minimize our materials used. For the special products such as the tape that Sampson made for the USA Pro Challenge, the box is made with all recycled materials.
The average retail price for Fat Wrap is still under $20. When we introduced Fat Wrap in 1992 it sold for about $12-14 — so still pretty good!
I have to agree that if you see all the times the material is touched by hands in order to produce what you assume is a simple, low-tech product, it is one of the real values in bike parts!
— Eric Sampson