DonRafa

Hi everyone,
I'm a Fuji user (Transonic 2.5) with a technical query.
Some days ago while doing a rather energetic interval session on my Tacx Antares rollers, my bike came out of the rollers at a high speed (25mph-ish) to a sudden and complete stop as it hit the ground (kitchen tile) with a forceful impact (chain derailed).
Even though I did not fall to the ground (I managed to stay fairly upright squatted on my bike) and there was no direct hit to the carbon fork structure, is there anything I should worry about the fork itself due to the abrupt change in speed and floor impact? Do I need to get my fork inspected for any issue? Maybe the carbon steerer tube took the energy blow and needs to be checked? Wheels remain true after the impact and everything seems to be "OK".
I know that forks are one of the strongest bike components due to the amount of abuse they take on a daily basis, but as a cautious rider I wanted to check since this was not an outdoor fall with a direct hit to the carbon fork itself but a violent change in force (from kinetic to static) at high speed taken directly (and violently) by the carbon fork.
Thanks a lot,
Rafa

leob1

If you were on the rollers, how could you be going at high speed? It would seem your speed would be 0 MPH.

ksryder

It's probably fine. It's less force than hopping a curb, which every bike can do.

DonRafa

On my balance rollers (not fixed trainer) I was doing 25, when my front wheel came out of said rollers and onto the ground I came to a sudden (and rather catastrophic) stop, hence the abrupt speed change. Thanks.

fietsbob

Video online?


you ride off the end of the roller to the side, or off the front?








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phughes

Yes, but your actual speed relative to the room, and floor was zero while you were on the rollers. I would speculate the speed you experienced when actually falling off the rollers was much less than 25mph. Had your speed been 25mph you would have traveled a bit of distance in your house before coming to a stop.

You said you made a sudden and complete stop when you came off the rollers, which means your bike came off the rollers, and stopped when the bike hit the floor. The "speed" you were going on the rollers is irrelevant, the only force your bike experienced, was the force of the bike dropping off the rollers, along with your weight, so no more force than that of dropping off a curb of the same height as your rollers.

jimincalif

I came off rollers once. The perception of speed makes it a strange experience. Your bike and body aren't moving, just the wheels and drive train, so there is very little inertia. You just stop. Far different than if you fell while rolling down the road @ 25 mph. As @ksryder said, it's akin to hopping a curb, or less. Never hurts to look your bike over, but if you find any damage I'd suspect it was there prior to this.

DonRafa

No embarassing evidence. Sorry

ksryder

PS you're not alone, everyone has a roller incident. Just like everyone has a "failed to unclip" incident. It's a rite of passage.

fietsbob

seen added fittings to keep you from coming off, *
and rollers with drums that flare to the ends and have a concave shape to help keep you in the centre.


* inline skate wheels on roller frame at the ends of the front or + other rollers for example...







...

TimothyH

Yep, everyone who rides rollers rides off them at least once. After a while you learn to do it on purpose.

If there is concern about the bike, the fork could be removed and inspected for cracks. If the carbon didn't impact anything then I wouldn't worry about it.

It isn't my bike however, and I can't tell anyone what to do or not to do.

And the whole argument about speed on rollers is just a distraction. Ignore it.


-Tim-

Kapusta

It The only stresses here are hitting the ground from the hight of the rollers, and whatever force a spinning wheel puts on the dropouts as it is instantly stopped.

The former is minor, the latter is utterly inconsequential.

JanMM

In agreement with Kapusta, the wheels were both spinning as if the bike were going 25 mph but the bike and bicyclist were both traveling 0 mph. There were some forces involved in the fall but not like there would have been in a fall at speed.

I owned/used a set of rollers in 1977 - 1978 and never fell off. No longer have to knock on wood about that but do have to knock on wood for never yet having fallen over related to use of pedal retention devices - since about 1975. (Knocking on head.)

DonRafa

Well, thanks everyone for your input and apologies for sounding a bit paranoid but it I had never experienced that and was quite shocking.

seeker333

Bike/fork is most likely fine. If you're worried about steerer, it's not too hard to drop the fork out to inspect for damage (crack).

Maybe you should wear a helmet if you continue to ride rollers on a tiled floor. Probably some hard cabinet edges nearby too, another hazard.

fietsbob

Elite Parabolic drum bike rollers .. https://www.elite-it.com/en/products.../rollers/arion