On Jul 31, 9:11 am, daveornee daveornee.2ul...@no-
mx.forums.cyclingforums.com wrote:
Scott Gordo Wrote:
I just had a wheel with a cracked MA3 rim replaced with an Open Sport,
and I'm having more trouble than usual getting the tire mounted.
Usually I can get them on without levers or with very minor
persuasion, but the same exact "worn-in" Michelin Axial tires that fit
fine on the MA3s needed significant plastic leverage to pop them on.
We're not talking hernia-inducing industrial strength force here, but
a good deal more than normal. What's worse is that while riding I
noticed the tire has a bit of a flat spot.
After checking for any inconsistencies in the rim itself, I swapped
the Axial with another used tire, a Bontrager this time. This one came
smoothly off a Mavic Reflex rim, but I had the same issues when
installed on the new Open Sport. (I should include that I also
installed a brand new, unpatched tube as well, even though the
previous tube looked fine.) I checked the tire's alignment on the rim
while inflating and pushed/pulled where it looked uneven, but without
much luck.
I think that the ERD between the MA3 and Open Sport rims is identical
or within a mm.
Is the diameter of the Open Sports much wider than the MA3s? If so,
are there tires people find work well with them? I hate to buy a new
tire because this is my "trickle down" bike, but if it gets rid of the
maddening flat spot then so be it.
TIA.
Scott
The Effective Rim Diameter is a dimension for spokes, not tire Bead
Seat Diameter. 622 mm is the "standard" for Bead Seat Diameter (BSD).
All 700C rims & tires are to meeet the 622 mm BSD. However, due to
manufacturing tolerances and even spoke tension, exactly meeting the
622 mm standard rarely happens.
--
daveornee- Hide quoted text -
- Show quoted text -
I just flatted on the way in, so I'll get another opportunity to be
sure that the beads sit properly pre-inflation
Thanks for the info on BSD. I knew ERD wasn't the same thing, I was
just using it to suggest that the rim is the same dimensionally as far
as spoke length goes anyway. The fact that all 700s should have a
622mm BSD makes that moot, obviously.
With that said, I've definitely had tires that fit tighter or more
loosely on my MTB's rims. This is, as you said, likely due to
inconsistencies in the manufacturing process, but are there any
recommendation for road tires that have a tendency to run slightly
bigger?
/s