My first trainer, something not right

[novetan]

After pouring thru the many trainers available in the market, based on good review, I finally settled on Elite Super Crono Power Fluid. I liked its gravity loaded design which gives a more natural riding feel based on rider’s weight and it is superbly quiet. They are also the sponsor for Sky, HTC, Liquigas, Cervelo, Shimano and Euskaltel using gravity loaded trainer, though may not be the same model. Hence I take it that this gravity loaded design must be good.

Today I did my first ride using my actual road bike with no particular training wheel. My rear tire was entirely new (Conti grand prix 4000s) and it didn’t take long to feel something not right. When I pedal out of saddle, or assuming a sprinting position with body leaning forward also out of saddle, both position spinning at cadence of ard 85 rpm (considering not very fast), the back wheel kept on slipping producing a whizzing sound.

Then I mounted my daughter’s 20” wheel bike with a not so new tire and the riding was smooth. No slippage.

Since so many pro has endorsed this gravity loaded trainer, it can’t be wrong. So the problem I encountered was it due to the tire or what?

 

[daveryanwyoming]

Hard to say, but it sounds like a combination of how far forward you're jumping when out of the saddle and the gravity based tension design on that trainer. IOW, it sounds like you're taking a lot of weight off the rear wheel when jumping forward and the design of the trainer relies on rear wheel weight to tension the rear wheel against the roller which is not the case for most roller designs. I'm sure the relatively slick GP4000s tread adds to the tendency to slip but isn't really the cause.

I don't have that trainer, but just eyeballing the photo it doesn't surprise me that a bike with 20" tires behaves differently as that would change the angle of the support arm as it swings back to handle the smaller rear wheel and on the smaller bike a jump out of the saddle likely doesn't remove as much weight from your rear wheel due to the smaller frame and shorter wheelbase. IOW, I'm not sure testing on the small bike is valid.

Realistically trainers aren't used out of the saddle that much, especially by pro's warming up for races. You usually sit and spin and grind out a warmup pace with some seated hard efforts. Hard to say if this trainer design is prone to wheel slip and of course we know nothing about your sprint technique and whether your weight is too far forward (a lot of riders skip their rear wheels when learning to sprint when they jump too far forward out of the saddle). Most conventional trainer designs allow you to adjust the clamp on force of the resistance unit to reduce or eliminate slipping doesn't sound like that's an option on your trainer.

Personally it doesn't sound like a big deal as full out of the saddle sprints aren't really something you'll do a lot of on a trainer but you might work on rising just slightly out of the saddle and work on keeping some weight on the rear wheel. It might help your sprint technique out on the road as well.

-Dave

 

[vspa]

i agree with Dave and i would like to add that i do own two Elite fluid trainers, but earlier models, though one of them is quite similiar to yours, so its quite clear that if you get out of the saddle and move your weight forward, the rear wheel loses traction, if you feel the need for going hard on the trainer you could train intervals sitting in the saddle like you would sit normally riding on the road, anyway sprinting on a trainer won't improve your technique, same for spinning bikes, because when you sprint on the road you actually move your bike side to side while indoor the trainer and/or spinning bike is in a fix position, i had one of the first trainers that came out 20 years ago as an option to rollers, believe me the difference with these new machines we have nowadays is quite something,