Archive for February 2015

A Time for Tubes

I’m very fond of tubeless fat bike wheels and moved to a set of SUNringlé Mulefüt rims (on Hope hubs) in mid-2014. These have worked great until the last two weeks when they went wrong with the On One Floater tires I’ve been using in snow. I was experiencing slow leaks on the rear that seemed to get more rapid as the day progressed, yet when aired up at home and in room they’d hold air reliably for days on end.

After a real rough time at the FunPromotions FatBike Series race yesterday at Addison Oaks (rear went flat slowly making for a hard ride / need to stop / etc) I gave a more serious look at the problem. Here’s what I found… The side knobs on one half of the rear tire (drive side) have become torn. I had noticed some slight tearing along the edge knobs before, but as the tire held air fine as tubeless for numerous rides before this, I didn’t think it was a problem. Apparently now it is. (This high res photo shows a bunch of the typical diagonal wrinkles, and the end of each one has a torn side knob.)

I suspect that a combination of new tears developing while riding and the freezing cold keeping the sealant from working normally resulted in the flats I was experiencing. I could dump more sealant in, get these holes to seal, and hope for the best, but I’m not sure that’s the best idea…  Instead of hoping for reliability out of something visibly failing I’ll switch to a tube on the rear.

The Surly Nate has seemed like a good winter tire and I could grab a pair of them to replace the Floaters, but I’m not too keen on rushing to buy new tires now just for the remainder of winter… Maybe I’ll just stick with a tube on the rear for the time being, and then decide what to do snow tire-wise some time before the next winter.

Kurt Kinetic Road Machine + Pro Flywheel

Earlier today I purchased a used (but nearly new) Kurt Kinetic Road Machine and Pro Flywheel from someone local for cash plus a set of nearly-new tires that I didn’t need. I’d been interested in trying out a trainer with a heavier flywheel than the Cycleops Fluid 2 that I’ve used for the last few years as I suspected it’d smooth out my pedal stroke and make for a more outdoors-y feel. I’ve had problems getting my heart rate to the same levels on the trainer as when riding outdoors, and I suspected it was from the higher drag, constant hill climbing feeling that I was getting with the Fluid 2.

For my first ride tonight I did TrainerRoad’s 8 Minute Test (without the Pro Flywheel) and thus far I’m very happy. There is a much longer coast/spin down time with this trainer vs. the Fluid 2 resulting in less of a climbing-stairs feeling and something more like riding into a strong headwind. This I’m fine with. The result of the power test put me at a 304W FTP, and during the test I was able to reliably get my HR to roughly my maximum, somewhere in the mid 170 BPM range. The last time I did a test (back in October) I was barely able to hit the 160s.

On my first try with the large flywheel — after removing it to wipe everything down — I noticed that there’s a bit of vibration when I’d get it to higher RPMs. I imagine it just needs a little aligning, but if I continue to have issues hopefully Kurt will help sort things out. The larger flywheel provided an even more intertia, and it almost felt like riding down a gentle grade with a steady headwind when using it. Serious effort was required to get it started, but once it was going it seemed to smooth things out even more.

I’ll try it out on some longer sustained-effort rides in the near future and perhaps even do another power test with it, just to see what happens. I really hate power tests, though…

† TrainerRoad claims that it’s Virtual Power is roughly 3% off from a power meter when used with a Kurt Kinetic Road Machine. It’d be nifty if this is the case, as I wouldn’t mind having a 300W FTP… That’d put me at roughly 3.79 watts per kilogram.

Low-Cost 29+ Stand

Building on the Low-Cost Fat Bike Stand idea and needing a way to support the forthcoming Jones Plus build I’ve built a 29+ bike stand from PVC pipe. By taking the previous plans, narrowing the main section, and adding length and height I got something which securely holds a 29+ (700c x 3.0″) wheel.

Modifications to the original plan involve narrowing the center pieces by 1″, adding 0.5″ to each support leg, adding 1″ to the pieces between the upright and the back side, lengthening the horizontal pieces for an 11.75″ opening, and increasing the height of the upright for a 25.5″ opening. This results in a stand which allows the wheel to set in, touch the ground, and slightly lean sideways against one of the uprights. The stand can also be placed directly against a wall and approximately 1″ will be left between the tire and the wall.