Weight Weenies
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Small bikes, long stems?
http://weightweenies.starbike.com/forum/viewtopic.php?f=3&t=116504
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Author:  phourgenres [ Tue Jun 11, 2013 3:51 pm ]
Post subject:  Small bikes, long stems?

I see a lot of the pros doing this. The 5'9 guys riding a 52cm with a 130mm stem or a 6'2 guy doing the same on a 56cm.

I ask, why?

I understand there is weight savings and the head tube is shorter for a slightly more aggressive geometry, but isn't that at the cost of less control? I've always heard the longer the stem the less control you have when you turn. So, for those pros taking the crazy descends and sharp 90 degree turns at a km out, it would seem advantageous to ride a frame that fits them and go with the shorter stem.

Author:  Weenie [ Tue Jun 11, 2013 3:51 pm ]
Post subject:  Small bikes, long stems?


Author:  MarkGiardini [ Tue Jun 11, 2013 4:11 pm ]
Post subject:  Re: Small bikes, long stems?

5'9" isn't that tall!

Author:  Shinobi [ Tue Jun 11, 2013 4:37 pm ]
Post subject:  Re: Small bikes, long stems?

I guess that depends on what your definition of "less control" is. I would say too short a stem would give you less control, since any minor handlebar movement translates into large angular movement of the wheel, hence a twitchier ride. With a longer stem, you will need to move your arms further in order to get the same angle of rotation of the wheel. This just means you have "finer" control.

Think of it like trying to adjust the hands of a clock. By adjusting near the center of the hands (shorter stem), you're moving the hands faster with less effort but lower accuracy, but by adjusting near the end of the hands, you're able to be more precise, at the cost of more movement/more effort.

That said, I think you pretty much nailed all the points of riding small bikes with long stems -- lower weight, more aero position, etc. At the end of the day, cornering isn't so much turning of the wheels as it is leaning into the turn -- if you're turning your wheels 90 degrees on a descent, you're going to the hospital no matter what size stem you're using :).

By the way, 52cm for 5'9" doesn't seem too awkward. I think that's the cusp of the suggested height range for most geometries?

Author:  phourgenres [ Tue Jun 11, 2013 5:30 pm ]
Post subject:  Re: Small bikes, long stems?

Thanks for feedback, Shinobi.

Not sure what you're talking about, MarkGiardini. Never said it was...

Author:  eric [ Tue Jun 11, 2013 6:40 pm ]
Post subject:  Re: Small bikes, long stems?

Could be that they need to use smaller size frames to get a short enough head tube. Most frame makers have lengthened head tubes over the last few years.
I'd need to run a -17 degree stem with no spacers on a new Cervelo to get the same bar drop that I have on my 2009 Cervelo with a +8 stem and no spacers.

Also more pros are using bars with a shorter reach. I switched to a shorter reach bar last year and went from a 110mm to 120mm stem on my 56cm frame.

Author:  MarkGiardini [ Wed Jun 12, 2013 2:42 am ]
Post subject:  Re: Small bikes, long stems?

phourgenres wrote:
Thanks for feedback, Shinobi.

Not sure what you're talking about, MarkGiardini. Never said it was...


No, but you're implying that a 5'9" person riding a 52 CM bike is strange.
FWIW I have 54 size Venge and S size TCR, both suit me fine.

Sorry if I mis read what you said, it was midnite when I read it :)

Author:  climberevan [ Wed Jun 12, 2013 3:05 am ]
Post subject:  Re: Small bikes, long stems?

I'm just a little over 5' 9" and ride a 52cm CAAD10. It fits great with a 110mm stem, but I previously had a 120mm/ -17 on it and was happy with that as well. On my Seven (54), which has a ridiculously long head tube, I have to run a 120/-17 to get my bars to roughly the same position.

I think that for pros the main motivation is lower bars. As eric says, most manufacturers have lengthened head tubes in recent years, and since pros are riding the same frames as we can buy, they fight those longer head tubes. It really is more efficient and (obviously) more aero to be a bit lower if your body can handle it.

Author:  Wingnut [ Wed Jun 12, 2013 3:09 am ]
Post subject:  Re: Small bikes, long stems?

I'm 5'10" and I ride a Merlin Ti with a 56cm top tube and 54cm seat tube centre to centre...oh and I ride a 13cm stem too... :noidea:

Author:  MarkGiardini [ Wed Jun 12, 2013 6:38 am ]
Post subject:  Re: Small bikes, long stems?

FWIW, if anything.

My TCR SL is 135 mm head tube and 535 top tube, using 100 mm Giant Contact stem.
My Venge is 140 mm head tube and 548 top tube using 90 mm Specialized 16 deg stem.

Being a compact frame, the TCR in size S is very similar to the Venge in M and the the geo, or should I say the positioning on the bike, taking all the above in to consideration feel very similar to me.

If I had gone the M in a TCR, it's actually 555 mm top tube and 150 mm head tube, significantly larger than the M in a Venge.

Long story story, both bikes fit me perfect, both stems are slammed, and there's no killer back pains after I get off!

Author:  deermatt [ Wed Jun 12, 2013 7:42 am ]
Post subject:  Re: Small bikes, long stems?

Im 5'9 and I ride a 52 supersix, with a 90 stem, fits very well. A lot of track racers use small frames too and long stems because the frames are stiffer. They're also easier to adjust , where on a bigger frame is you either just fit, or dont.

Author:  mattr [ Wed Jun 12, 2013 7:53 am ]
Post subject:  Re: Big bikes, short stems?

Why do so many nodders buy huge bikes, have the bars up round their ears, a tiny stubby stem and the saddle as far forward as it will go, and they STILL can't reach the pedals properly.

Then weave around, pretty much out of control, in the middle of the club run.

Author:  MarkGiardini [ Wed Jun 12, 2013 8:43 am ]
Post subject:  Re: Small bikes, long stems?

The only time I've seen the above is when a frames on sale so the guy does everything he can do in order to make it some how fit!

Author:  mattr [ Wed Jun 12, 2013 8:58 am ]
Post subject:  Re: Small bikes, long stems?

I see it regularly on "show us yer bike" threads........ :wink:

Author:  Devon [ Wed Jun 12, 2013 1:29 pm ]
Post subject:  Re: Small bikes, long stems?

I'm 6'6 and I ride a 58. Remember that frame size means bugger all. I have one bike in 58 and another in 62, they are near enough the same size (15mm difference in the TT). The only measurement that really matters (massively simplified here) is the top tube length.

I'd personally always go for a smaller frame and have longer stem/setback post etc.: Much less weight, more agile, prettier bike and more versatility for movement on the bike/changing kit.

Also what mattr said, completely agree!

Author:  Geoff [ Wed Jun 12, 2013 1:57 pm ]
Post subject:  Re: Small bikes, long stems?

+1 on the headtube length (for the purpose of getting the bars low enough). The toptube length (within reason) is irrelevant. Assuming the headtube angle, seattube angle and bottom bracket height are the same, you can attain the same effective toptube length with a longer stem and saddle setback.

One of the positive effects (for me) of a longer stem is that it slows-down the steering a bit. A little stability is a good thing, in my book.

Author:  Weenie [ Wed Jun 12, 2013 1:57 pm ]
Post subject:  Re: Small bikes, long stems?


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