Steel Track Frame stiffness

just noticed that the whole bb area kind of slightly flexes / bents (?) when pushing hard like starting from a traffic light with low rpm´s and quite heavy forces on pedals .

theres no damage to the lugs, no dents, cracks or whatever

apart from that, the frame feels stiff and good and rides very well.

has anyone had similar experiences?

i thought that maybe these frames are not really made for pedaling hard at low turns as on track you likely accelerate hard from higher speeds as from standstill ..

gear ratio is 42/16 which is quite short but lots of hills around my town.

..."these frames".... ?

What frame, exactly, are you referring to?

in with the new, out with the old

90´s (most likely) lugged steel track frame, tubing must be slx or something as its damn light and hast 27.2 seatpost, cinelli bb housing
from a small belgian frambuilder

Plum?

?

Plum Vainquer.

Not actually an insult.

just noticed that the whole bb area kind of slightly flexes / bents (?) when pushing hard like starting from a traffic light with low rpm´s and quite heavy forces on pedals .

theres no damage to the lugs, no dents, cracks or whatever

apart from that, the frame feels stiff and good and rides very well.

has anyone had similar experiences?

i thought that maybe these frames are not really made for pedaling hard at low turns as on track you likely accelerate hard from higher speeds as from standstill ..

gear ratio is 42/16 which is quite short but lots of hills around my town.

All bike frames flex. You've just noticed it for the first time.

yeah but isnt.

decals said himpe, google / seller said its a small framebuilder from belgium ...

All bike frames flex. You've just noticed it for the first time.

yeah maybe thats the point.

but im not sure if e.g. my 80s colnago super frame ( which is quite heavy compared to the himpe and surely made from thicker steel ) did also flex that much when riding.. would be surprised if i´d never noticed that ..

Can't say I've noticed my 60s/70s steel Johnny Berry frame flexing either, but it* is *stiff and has newly built and very stiff wheels too. What are your wheels like? Have you got legs like tree trunks?

stand next to your bike, hold the brake if there is one, put one pedal at the lowest position and push down on the pedal as hard as you can.

^ this.

I came second in the local track league a couple of years back on a 1959 Carlton with airlite/fiamme wheels. The only problem I had with flex was with an old Cinelli 1A stem and Criterium bars, swopped for Nitto Pearl and B123AA bars and that sorted it.

Mebbe your bottom bracket is worn or needs tightening up ?

wheels are ok, my legs are far away from being tree trunk like and bb is brandnew and tightened , cranks turn softly and theres not a sign of a rattle or something on it.

it is more like the frame is flexing, like the whole bb area turns from side to side .. but again, theres no damage or anything ..

kinda weird

all frames flex, some more than others. If you were to bolt down the frame by the dropouts to a solid chunk of steel, and the flex that you can visibly see will almost disappear.

My road frame - well I wouldn't call it flex - more like the bb can swing hahahaha. Lean it over and push the pedal down. It will move, even my alu/carbon road bike does!!

yeah i think then mine swings too . even when stepping on pedal in standstill the whole thing swings.
i think its at least more noticeable on the track frame because it has thinner tubing than most steel road frames ..

looks freaky anyway, always waiting for it to fall into pieces everytime i ride :)

This is normal.

Stop freaking out.

Go ride your bike.

riding it every day, sir - freaking out while riding - must be a pretty sick view for people around, me pedaling hard and looking at my swinging bb hehe

Don't call him "Sir" - it'll go to his 'Ed.

just a sec .. alright, jotted this down .

My Samson track frame flexes like a bitch. Go worried the first time it happened, used to it now.

It's completely normal - Carbon frames don't flex as much though. Don't panic.