Stems - How short is too short? TT set-up.

niceonetom

I got some clip-on aerobars last week and I've been experimenting with them a bit, trying, in vain, to find a comfortable and powerful position.

I've spent this evening plumbing new depths of geekiness by photographing myself in profile on the bike to see if I look anything like I'm supposed to. The camera does not lie - Fabian Cancellara, I am not. I've been consulting bike-fit charts and how-tos, measuring hip angles and knee extension and generally behaving like a triathlete with asperger's syndrome. It's shameful really.

But I think I've got a handle on it now, and a viable TT position is in sight... But in order to get the pads under my elbow, and my elbow under my shoulders (more or less) I'm giong to have to bring the bars in a bit, well, about 3cm or more actually... but that would mean an 80mm stem or shorter. Hmmm. So, finally, we get to it:

How short is it reasonable to go with a stem that will be used with aerobars? Given that I already find it a bit disconcerting to be steering with my elbows, is twitchyness something I need to really beware of? Anyone running a very short stem on a TT bike? thoughts?

Planet X

I would have thought that "stretched out" would lead to a more aero position?
All to do with frame size etc.?
Specific TT bike?

niceonetom

Superman style might be slightly more aero, but it gets uncomfortable quickly and I find it makes breathing deeply a lot harder. Breathing matters apparently.

From the little bit of research I've done a lot of fitters seem to recommend having the the elbow below the shoulder to allow the torso to be nice and relaxed between the saddle and the armpit, and if the torso needs to be more horizontal the elbows should go down not forward.

It's normal road-bike btw, but I'm using a different, zero-layback seat-post and the saddle all the way forward on the rails to get the hip angle open. It's ugly but effective.

Planet X

But there's no relaxed position in a TT. It's all "eyeballs out" gear.

niceonetom

Ok, not relaxed. Efficient.

Planet X

True.

niceonetom

If I get a feel for this TT thing, and see some improvement, I'd be seriously considering a Planet-X rig some time next year. Your TT bike looks bad ass - especially with the disc and everything. How do you find it?

I'd be considering the pink version, just to piss TinyExplosions off.

Nietzschean

you've only done the boards TT right?, and your thinking of getting a TT bike? nuts

Planet X

Didn't use it much last year really.

Not trained enough. Concentrated alot more on my road racing with the IVCA.

Looking forward to next year with the Vets. Rake of TT's available.

Actually, looking forward to doing my second 50 TT. Reckon I'll skim a few minutes off it.

Yeah, it's good fun doing a TT. Do one and you'll be back to beat you're PB every time.

Keeps me ticking over. Got a few club mates doing Vets. Keeps the edge going. When I heard a mate was doing 80 miles training on a TT bike................Jasus!
Addictive sh.ite to be honest.
Pure.

Lumen

Tom, can you provide references to "elbow under the shoulder, pads under the elbow"?

You're welcome to borrow my bike fit DVD, here are some screenshots comparing hoods, drops and aerobars.

I'd say if you need an 80mm stem to be comfortable, get one.

mloc123

Sounds like you need to shift your saddle forward to mimick the steeper seat tube angle of a proper TT bike. You can by a seat post the angles forward if you need.

As for comfort in TT position... since getting a proper fit on my Tri bike I could easily spend a few hours 'tucked' with no more discomfort. Before the fit (including the boards TT) it was uncomfortable and more importantly very inefficient, fit is everything on a TT bike imo.

Lumen

mloc123 wrote: »

Sounds like you need to shift your saddle forward to mimick the steeper seat tube angle of a proper TT bike. You can by a seat post the angles forward if you need.

Changing the saddle position is a good idea if you train in that position regularly. Otherwise, not.

Tom, thinking about this a bit more it seems a odd to have to change your stem in order to get the aerobar fit correct. You shouldn't have to do that, unless you are building a TT-specific bike. The whole point of clipons is that you just clip them on and go.

tunney

Planet X wrote: »

I would have thought that "stretched out" would lead to a more aero position?
All to do with frame size etc.?
Specific TT bike?

Nah, 90 degree angles are best in the torso area.

www.slowtwitch.com for all your TT bike fitting needs.

tunney

Planet X wrote: »

But there's no relaxed position in a TT. It's all "eyeballs out" gear.

Eh, not true.

6km TTs yes, go over 40km and its comfortable, then aero then powerful in that order.

flickerx

niceonetom wrote: »

I've spent this evening plumbing new depths of geekiness by photographing myself in profile on the bike

Post them up!

tunney

If its your road bike and you are changing the road position to accomodate aero bars that not the brightest really. I think you need to get someone to look at your position, what bars did you buy? If you want to keep your road position must of the aero bars are out - best you can hope for and maintain your road position is an ITU style position.

HAHA - now there are two triathlon boards.

TinyExplosions

niceonetom wrote: »

If I get a feel for this TT thing, and see some improvement, I'd be seriously considering a Planet-X rig some time next year. Your TT bike looks bad ass - especially with the disc and everything. How do you find it?

I'd be considering the pink version, just to piss TinyExplosions off.

Go for it -am very much considering getting a PX TT bike on the C2W scheme, but haven't decided if I should go for pink again, or possibly black with pink accents

TinyExplosions

tunney wrote: »

HAHA - now there are two triathlon boards.

This is for Time Trial, not Tri!

Lumen

Another thing...

I found when doing my TT setup that the best position (following the "don't change your upper body or saddle position" advice) meant adjusting the aerobar reach to be really short, basically the "uppy" bits are just forward of the shifters.

mloc123

Or get stubbies..

blorg

I'm comfortable on my aero bars with them much further forward than that (they are not adjustable.) Have done long long distances with them, most recently Cork-Dublin yesterday where I would have been on the aero bars any time I was not climbing over a 4% gradient. So probably 200km+ on them yesterday out of a 260km ride.

Only other thing I have changed on my road bike is to drop the bars down 10mm but I am still comfortable in the drops (have shallow drop bars now.) Saddle is in the same position. I do feel I could have them lower; on the fixie I dropped the bars down literally as far as possible... Maybe consider that? Do you have the bars as low as possible?

niceonetom

mloc123 wrote: »

Sounds like you need to shift your saddle forward to mimick the steeper seat tube angle of a proper TT bike. You can by a seat post the angles forward if you need.

With the seatpost/saddle combo I have on it now the tip of the saddle is ~5cm aft of the BB - that's the UCI minimum IIRC. I know this doesn't apply to you trisexuals but I fear running afoul of the commissars at the next boards TT.

Lumen wrote: »

Changing the saddle position is a good idea if you train in that position regularly. Otherwise, not.

Tom, thinking about this a bit more it seems a odd to have to change your stem in order to get the aerobar fit correct. You shouldn't have to do that, unless you are building a TT-specific bike. The whole point of clipons is that you just clip them on and go.

Well, I'm will fully ignoring the "leave your saddle alone" advice and going for an actual TT position. I accept that this will mean more than just clipping on the bars - I already have a different saddle and seatpost I'll use, plus attaching the aerobars, plus moving the stem under the spacers... so I'm not that fussed about adding a stem swap to the process.

From the photos I did last night I'm confident that my hip and knee angles are close to what they would be when deep in the drops on the road set-up, but with the whole position pivoted forward around the axis of the BB spindle.

flickerx wrote: »

Post them up!

Not bloody likely.

blorg wrote: »

<bragging masked as advice>

With respect blorg, you're now so far from what could generally be considered "normal" that I sometimes wonder whether your advice could really apply to the common man for whom 800km is a bad month not a good weekend. Thanks though. I think the bars cold stand to go a touch lower, but only if they could come a touch closer too.

After an hour out on the bike this morning I've come to the
conclusion that a lot of the problem is that the drop bars I have don't allow the aerobars to be positioned far enough apart - they're attached immediately beside the stem. Touch your elbows together and bring them up to about nose height in front of you... see how hard it is to breath deeply? I can get around this by choking up on the clip-ons and resting my forearms on the pads (closer to my wrists than my elbows) and letting my elbows come further apart, but this is a bit uncomfortable and makes steering much more sensitive - hence the stem question.

Thanks for your patience peeps.

blorg

I think aerobars generally do clamp on right beside the stem, you want as narrow as possible to get the aero, it is after all the narrowness that is the main advantage over drops. Haven't had breathing problems but I do tend to have my forearms and not elbows on the pads.

The steering you get used to in my experience.

Lumen

Tom, if you're going to deprive us of the semi-naked pictures of you on your bike, could we at least have a decent pic of the aerobars showing the clamp and pad position?

Diarmuid

blorg wrote: »

I think aerobars generally do clamp on right beside the stem, you want as narrow as possible to get the aero, it is after all the narrowness that is the main advantage over drops. Haven't had breathing problems but I do tend to have my forearms and not elbows on the pads.

Not everyone goes for really narrow pads

In terms of fit, the same wide range of preference is found. Ryder Hesjedal takes the term “wide” quite literally, with aero extensions mounted almost 12 inches apart. The exceptionally wide placement is very uncommon in a discipline where narrow forearm and elbow position is usually determined to be fastest.

“It’s something he tested in the wind tunnel over the winter, and it turned out to be a pretty fast position,” said Hopper. “Getting those elbows in front of the knees helped aerodynamics, plus the power output he could do in that position is better than what he did before,” he explained.

Lumen

What I've read says that your elbows only need to be inside the line of your hips.

tunney

blorg wrote: »

I think aerobars generally do clamp on right beside the stem, you want as narrow as possible to get the aero, it is after all the narrowness that is the main advantage over drops. Haven't had breathing problems but I do tend to have my forearms and not elbows on the pads.

The steering you get used to in my experience.

Not true, there is a point for all riders that once you go past it, narrower is slower. For some its wider than you may think.