Zipp 404s and Poor Cross-Wind Handling or Just a Bad Glue Job?

[RyanH]

So...I really like the Zipp 404s (Firecrest) but so far they're terrifying to descend with once there's even a bit of wind and in a few other situations, so I'm trying to figure out if that's just how they are, or if maybe my somewhat sloppy glue job is contributing to the problem.

Basically, above 35 mph, the front end moves a lot. When descending in a straight line, the wheel wants to weave. We were descending down Kanan, a fairly straight road in the Santa Monica Mountains last week with a 10+mph cross wind and I got dropped by a 120lb junior since I was moving all over the place at 40mph. Yesterday, I sprinted to catch on to a semi truck, and was doing 35 or so, wind was a swirling mess, but the front end felt scary.

For reference, I've ridden 46mm wheels as my go to daily for the past few years. I've also done a handful of bad glue jobs, particularly with Conti Sprinters since they're such a PITA to get on and never had a problem. 46mm rims, to me, feel like a push in crosswinds, not a weaving instability issue.

Here's a video of the Zipps spinning on the floor:
https://goo.gl/photos/ELeASWZqyKW59rsH8
https://goo.gl/photos/jE21zKoYJ77xCp7K6

Here's the Reynolds RZRs which I've never had an issue with:
https://goo.gl/photos/KatuP4EfVkSdhD128

[mimason]

Without commenting on the glue job is your headset loose or was it speed wobble? You can eliminate wobble by resting you knee against the top tube.

With respect to the glue job you should be able to tell on a flat road too or a wheel stand.

Were you riding in the drops?

[KarlC]

Only time i have this issue when I was on Zipp 404s (Firecrest), it was not the wheels it was that my front end was not tight / right.

[RyanH]

These wheels have been on all 3 bikes and feel the same, while the other wheelsets provide an immediate improvement. Admittedly, every time I've descended lately or gone above 35 has been somewhat windy, but I didn't expect them to be this bad. At under 30 they feel fine.

@mimason, not speed wobble, more of a weaving. I've been up to 60mph on the R5ca, it's a very confident descender.

@KarlC, no issues in cross winds with the 404s down in SD?

[mr_tim]

looks to me like you've got the centre of the tread walking at on point, so it would feel off as it gets high up in speed & the walking off the centre tread line becomes more pronounced / frequent.

[jekyll man]

I've seen a few people say that wheel is susceptible in cross winds, so I'd be inclined to think it's that.

Don't think your tub is an issue, if it had a huge hop in it, then maybe.

[Kayrehn]

The tires will probably need to be very much misaligned to be a factor in this issue. Probably the wheels reaction imo.

[itguy]

Will 25mm tyres help in reducing the effect of xwind? I mean, in terms of handling. I am running 23mm on 404 clincher and it is really scary at times. Even when cornering.

[tb123]

Couple of things, I've got a set of 404 Firestrike Clinchers, most of the time the wind doesn't bother me much, but there have been a few times when cornering where there is a change of direction in wind that has caught my attention, feels like the wheel either gets stood up or falls over, but its not a lot of fun.

The other thing you mentioned when drafting the truck, I've had similar things happen when drafting cars etc, the front end is all over the place and very unnerving.

Descending at high speed with a cross wind can also be an issue at times, but then that's what you get with deep wheels.
I'm running 25mm Open Corsa's, think Zipp recommend 23mm tyres for most aero benefit on those wheels.

[RyanH]

I don't have a definitive update but since this thread popped back up, I'll add a few things. I reglued the front tire shortly after posting this thread. I think it helped some but I haven't done a 50+ mph descent in a cross-wind since so I'm not positive. Also, the rear hub had play and I tightened that down. I think that may have helped too. We did a 42mph sprint the other day and the wheels felt solid, which I'm fairly certain wasn't the case before. So maybe it was the play in the hub or maybe they are very sensitive to any tread wandering.