Author Topic: To oversize or not?  (Read 538 times)

To oversize or not?
« on: March 08, 2019, 05:45:50 pm »
Some time ago last year, after being measured-up by Grant, I ordered a Strada Speciale frameset from Mercian Cycles, in lightweight Reynolds 853 Pro Team tubing, which I'm still waiting to have built, hopefully before this summer.

The intended use is as a (relatively) lightweight summer road bike, mostly for training, fast club rides and the odd sportive, but no proper racing and definitely no loaded touring or commuting on it (I have other bikes for that). At the time I ordered it with non-oversized tubing and threaded for a 1" headset. The frame size is 53cm centre-to-top (c-t), and I'm about 172cm / 72Kg.

Recently some fellow cyclists have hinted that I should have gone for oversized tubing, to reduce flex - but taking into account the frame size and my weight, is that really necessary? My power output is also currently relatively modest (recently tested FTP is about 200 watts), though I hope to improve on that a bit with more training.

Provided a frame comprised of non-oversized tubing would be stiff enough for me, I think I would prefer to stick with that, partially for aesthetic reasons (unlike some, I prefer the look of skinny tubing, at least on this sort of bike), but also think it would be less susceptible to denting, bearing in mind how thin 853 Pro Team tubing is in places....
Old enough to know better, but young enough to do it anyway

Re: To oversize or not?
« Reply #1 on: March 08, 2019, 05:55:20 pm »
I *think* at the time I was being measured up for the frame, I seem to remember Grant implying that going for that frame/Reynolds tubing in non-oversize would be fine for that frame size/my weight, but less so if the frame size was much larger and/or I was much heavier.
Old enough to know better, but young enough to do it anyway

DaT

Re: To oversize or not?
« Reply #2 on: March 08, 2019, 06:02:07 pm »
My Bob Jackson Vigorelli (track) bike is 631 non-oversized with 725 stays. Even with grinding up hills I've not noticed any flex and I wouldn't want it stiffer due to comfort. I'm 68kg and 5' 10".

Re: To oversize or not?
« Reply #3 on: March 08, 2019, 06:11:59 pm »
My Bob Jackson Vigorelli (track) bike is 631 non-oversized with 725 stays. Even with grinding up hills I've not noticed any flex and I wouldn't want it stiffer due to comfort. I'm 68kg and 5' 10".

Thanks, though the 853 Pro Team tubing is thinner (at least in places) than 631 or 725, so would perhaps have more flex, though I think it's not so thin in the places where stiffness is really needed. BTW as I understand it, my frame (stays and forks included) will be entirely in 853 tubing, though I think originally you had to get the forks and/or stays in something else.
Old enough to know better, but young enough to do it anyway

mattc

  • n.b. have grown beard since photo taken
    • Didcot Audaxes
Re: To oversize or not?
« Reply #4 on: March 08, 2019, 07:23:25 pm »
I *think* at the time I was being measured up for the frame, I seem to remember Grant implying that going for that frame/Reynolds tubing in non-oversize would be fine for that frame size/my weight, but less so if the frame size was much larger and/or I was much heavier.
Are you now much heavier, and/or going for a much larger frame?

(EDIT: <does some googling> it's a StradA Speciale, not a StradE, isn't it?   /pedantry
I'm having a blitz on possible LW steel frames at the moment!)
Has never ridden RAAM
---------
No.11  Because of the great host of those who dislike the least appearance of "swank " when they travel the roads and lanes. - From Kuklos' 39 Articles

Re: To oversize or not?
« Reply #5 on: March 08, 2019, 07:25:33 pm »
I wouldn't go oversized at your weight and the small frame size. I'm more like 80kg and I commute on a 60cm frame.  That isn't oversized and doesn't seem to flex.
Never tell me the odds.

Re: To oversize or not?
« Reply #6 on: March 08, 2019, 08:19:05 pm »
Flex is dependent on the external diameter of the tube to a great extent, and pretty independent of the type of steel used. So your 853 won’t flex any more than the same size tubing in, say, 725 or 653.
We are making a New World (Paul Nash, 1918)

LittleWheelsandBig

  • Whimsy Rider
Re: To oversize or not?
« Reply #7 on: March 08, 2019, 09:05:39 pm »
I wouldn't go oversize at your height/ weight and no significant loads. Stiff vs. flexible doesn't vary actual speed in my experience but does make a difference to perceived speed.
Wheel meet again, don't know where, don't know when...

Re: To oversize or not?
« Reply #8 on: March 08, 2019, 09:38:08 pm »
I *think* at the time I was being measured up for the frame, I seem to remember Grant implying that going for that frame/Reynolds tubing in non-oversize would be fine for that frame size/my weight, but less so if the frame size was much larger and/or I was much heavier.
Are you now much heavier, and/or going for a much larger frame?

(EDIT: <does some googling> it's a StradA Speciale, not a StradE, isn't it?   /pedantry
I'm having a blitz on possible LW steel frames at the moment!)

Oops, fixed!
Old enough to know better, but young enough to do it anyway

Re: To oversize or not?
« Reply #9 on: March 08, 2019, 09:39:12 pm »
Thanks for the reassurance everyone, I will leave it as is! Skinny it will be (the bike that is, not the rider, well not yet...)
Old enough to know better, but young enough to do it anyway