'03 24-Speed Specialized Allez' w/ AVENIR Bike Trainer

No offense, but probably. There's nothing unusual about the Tiagra derailleur that would cause the problem. Here are a couple thoughts, explained as best I can without actually seeing your predicament (care to post a pic?):

1) make sure the resistance wheel is loosened all the way down before putting the bike in. If the resistance unit is up too high, then the wheel won't drop in far enough for the 'holders' to clamp to the rear skewer.
2) make sure *both* holders are adjusted towards the center so that the tire is centered on the resistance unit. Only moving one holder toward the center could cause your wheel/derailleur to be too close to the frame of the trainer on the opposite side.

Quoted message said:

No offense, but probably. There's nothing unusual about the Tiagra derailleur >that would cause the problem. Here are a couple thoughts, explained as best >I can without actually seeing your predicament (care to post a pic?):

I don't think there is anything wrong with the derailleur. I know my brain slipped somehow.😄 I still haven't figured out, how to attach photos to e-mail because there is something whacko about the software n' hardware technology with my digital camera🙁.

Quoted message said:

1) make sure the resistance wheel is loosened all the way down before >putting the bike in. If the resistance unit is up too high, then the wheel >won't drop in far enough for the 'holders' to clamp to the rear skewer.
2) make sure *both* holders are adjusted towards the center so that the >tire is centered on the resistance unit. Only moving one holder toward the >center could cause your wheel/derailleur to be too close to the frame of >the trainer on the opposite side.

In terms of your explanation, while I am still 😕, I like the way you explained it, thankyou.🙂 I just need to keep re-reading it a couple of times, from the website.🙂 It makes far more sense, than, the instructions included with the trainer.🙂

Chris516 said:

In terms of your explanation, while I am still 😕, I like the way you explained it, thankyou.🙂 I just need to keep re-reading it a couple of times, from the website.🙂 It makes far more sense, than, the instructions included with the trainer.🙂

Where is the derailleur interfering with the trainer? Is it hitting one of the black steel uprights on the side, or is the silver holder hitting the derailleur instead of grabbing the skewer?

If it's hitting the uprights, then your problem has to do with my option #2 above. If the silver holder is hitting the derailleur, then you problem has to do with my option #1 above.

What Avenir trainer model is it?

Also, make sure the silver holders are fully retracted before you try to stick the wheel in. Maybe that's obvious, but worth a mention.