SF Cyclotouring

Ride reports and other ramblings from a San Francisco cyclist.



It is a good rule of thumb that for bicycle tubing that a wall thickness 0.2mm larger has similar stiffness to a tube which is 1/8" larger.

-- Alex W.


Grand Bois Lierres, First Impressions of

Grand Bois Lierres by jimgskoop
Grand Bois Lierres, a photo by jimgskoop on Flickr.

Last weekend I mounted Gran Bois Lierre tires on my Trek 400 650B conversion. The next day I did a ~30 mile ride on 'em over pavement and some hard-packed dirt roads. I inflated the tires to my usual ~4 bar. They mounted similarly to the Col de la Vies -- I had to manhandle the bead all around the rim to make the tire seat evenly. While the CdlV's measured almost exactly 35mm wide on my Velocity Synergy rims, the new tires measure close to 37mm wide.

These Lierres might feel a teensy bit more plush and smoother than the Col de la Vies I had previously, but it's certainly not a night-and-day difference. I should also note that the CdlV tires I had on before were bought used with a lot of wear on them already, so the squirmy block tread -- which most folks say is the worst thing about those tires on pavement -- was already quite worn down. Off road, the Lierres didn't feel like they had quite as much grip as the CdlVs. One thing I definitely don't like is that their grooved tread tends to pick up lots of micro-gravel and other bits which seem to happily wedge in there and later launch off, making a racket inside alloy fenders. If anything sharp sticks on the tire, no doubt it'll work its way through the casing with each wheel revolution, causing a puncture.

Right now, I'm not convinced that these tires are $100 better than a set of Col de la Vies.


Chainstay Dimpling

~37mm wideGrand Bois Lierres~37mm wideTire Clearance -- BeforeTire Clearance -- BeforeRear Wheel
Col de la Vies Measure ~35mm~35mm Col de la ViesTire TalcWood BlockDrilling 7/8" HoleYup, hole drilled.
Just a little off the top.Chainstay BlockTest FitFlaring one endCut.Hack
PartsSlotFileFit TogetherStuck TogetherThe Magic Goop

Via Flickr:
The Trek 650B gets Gran Bois Lierres and dimpled chain stays for improved tire clearance!