Synergy 650B -- first thing to suspect is deep well mounting issues.
Eyeball the junction of rim and tire while spinning the wheel: there's a
molded-in line on the sidewall. Watch the line as the wheel goes
around. Odds are (this is a /very/ common condition) you'll see the
line dip down below the edge of the rim and then rise up again.
There are 3 things you can do:
- reduce pressure down to around 20 or so and hand-manipulate the tire,
basically gripping it and pulling upwards
- run the pressure up to 120 psi or so
- do as Jan suggests in this blog post:
https://janheine.wordpress.com/2012/05/24/mounting-tires-on-rims-with-deep-wells/
There is, of course, an outside chance it's something else. But those
mounting issues with the Velocity Synergy are so very common.
On 06/18/2015 03:54 PM, Bill Lindsay wrote:
2-3mm out of round is enough to detect as a thump when you ride,
especially if it is in a sudden single spot. In my experience, it's
usually a 2-3mm low spot, not a 2-3mm bulge. I'll assume that's what
you have.
If that's the case, then what you want to do is:
1. Mark the sidewall of the tire and the spot on the rim with a sharpie
2. Remove the tire
3. Remount the tire as best as you can but with the tire rotated 90
degrees from where it was
4. Check again for a low spot. Did you find one?
5. If yes,
a. is it at the same mark on the tire? Maybe it's a bad tire
b. is it at the same mark on the rim? Maybe there's a rim flaw
c. is it at neither mark? Then it's probably the well known
'too-deep synergy rim well' documented all over the place. Build up
the well with more rim tape. I use gaffer tape for this purpose.
On Thursday, June 18, 2015 at 11:45:25 AM UTC-7, Michael Hechmer wrote:
I am getting a thumping vibration from a front wheel at speeds
above 25mph. The wheel is nearly new with a White hub and Synergy
rim. The tire is a brand new Pari-Moto. It was on my converted
Trek 620. I can't see any obvious cause and here's what I've done
so far.
A visual inspection of the tire and wheel didn't show any obvious
anomalies, so I checked the head set and decided to tighten it
just a bit. That didn't have any noticeable affect on the thump.
Then I swapped wheels with my Saluki, which also has pari-moto
tires. Rode both bikes over the same short, hilly course. The
thump definitely went with the wheel. Next I took the tire off.
Pari-motos go on very easily but are hard to get straight.. I
put the wheel in my little Minoura wheel stand. It is perfectly
round and nearly perfectly true. I carefully remounted the tire,
working to get it as perfectly straight as I can. Then I put the
wheel and tire up on the stand. The tire moves in and out about
2-3 mm away from the side wall and about 2-3 mm away from round.
I retested it and still got the high speed vibration.
--
You received this message because you are subscribed to the Google Groups "RBW
Owners Bunch" group.
To unsubscribe from this group and stop receiving emails from it, send an email
to [email protected].
To post to this group, send email to [email protected].
Visit this group at http://groups.google.com/group/rbw-owners-bunch.
For more options, visit https://groups.google.com/d/optout.
