This is an automated archive made by the Lemmit Bot.

The original was posted on /r/velo by /u/spingus on 2023-09-26 00:13:54.

I promised an update on my speed wobble situation so here it is!

For those who don’t care to click the original thread, we’re working with a brand new Cervelo S5 equipped with the latest Dura-Ace (relevant) including C50 deep section wheels.

I’ll give the answer first and then address all the other advice I checked out 😊

  • Multiple bolts were under-torqued in the cockpit
  • The free-hub was facocked. My mechanic called Shimano to ask for advice, they asked “is this the new stuff? “ yes. They sent us a brand new complete wheel.

Now the bike is mechanically sorted, I can better process its feedback –how it behaves in the wind, over bumps etc.

The bike has different kind of movement downhill now that seems mostly about the wind. I can work with that.

As I learn this bike I found that /u/mendip_wallfish who has the same model, gave excellent advice:

Take a bit of time to get used to it and relax more would be my advice

I now have the lightest of touches on the bars and control mainly through the saddle. If you will, it’s all about pussy control Still have work to do but it’s a lot better than it was!

Advice offered in the original thread and results:

  • Headset/Stem bolts: multiple bolts were indeed under torqued
  • Thigh squeeze top tube: mixed results. Before the mechanicals were addressed, no effect. After? I can make the bike wiggle on command with stability.
  • Listen to the Marginal gains podcast: interesting tech info but unhelpful in their suggestion to have a new bike day since this IS a new bike
  • Wheel balance: Brand new wheels, brand new fork/rear dropouts –alignment is not the issue
  • Deep section wheels more prone to it: yes, along with the aerodynamic frame this is a contributing factor in the wind.
  • More weight on front of wheel: OMG no. abort abort abort! –this introduced a lot more instability and the feeling I would dump it at any moment.
  • Speed wobbles happen, such is life/Get a new bike: I do not accept that. I have ridden at very high speed on my older bike with no wobble. I doubt this bike would win all three grand tours if it was so bad on descents. This is a solvable problem.
  • Short stem: Already had a through professional bike fit.
  • Tire pressure too low: I varied through the recommended pressures, no change.

Overall this was a fun exercise to solve the problem. Now I can focus on becoming a better rider with my steeply upgraded equipment! <3