Sunday, November 29, 2020

Post 218 - Bike fit/positioning tweaks

With it being the off-season, and with no need to necessarily be training for hours and hours and hours on end, 6 days a week, I decided I would spend some time and effort on tweaking my fit and positioning on both my road bike and my triathlon bike. I had already spent some time thinking how I could improve (see posts 211 and 214), and one thing to do would be to try to optimise my bike positioning. It has been about 6 years since I had my road bike fitted, and 3 years since the tri bike was fitted. Also, I had bought a new aero stem for my triathlon bike, and it made sense to combine installing the new stem with tweaking the positions. 

Two popular online triathlon forums are SlowTwitch (USA-based) and TriTalk (UK-based), and I am a fairly frequent reader of both - some of the topics are interesting. In particular, on SlowTwitch, people will sometimes ask for critiques of their bike fit. There seem to be quite a few good bike fitters on SlowTwitch, who will often give good advice. So I thought, nothing to lose, nothing ventured nothing gained, and set about taking a few videos and photos. 

Easier said than done... I had to take pictures off my walls to have a blank background, move everything out of the way, put the turbo trainer up against the wall, take all the cushions off the sofa so that my phone could be far enough away, use cups and books to prop the phone up, and record normal speed and slo-motion videos of me riding on both bikes, in a variety of positions. Then I had to move everything so that I could take videos from the front, rather than side-on. Then I had to put everything back. Then I had to edit the videos so that they were short enough to upload to the internet quickly, but long enough to give a good idea of my pedal stroke motion and positioning. I also had to take screenshots/photos of the videos, so that my positioning could be seen at a range of points on the pedal strokes.

The idea was that I'd put the videos and photos to the forum and hope that I would get some good advice from bike fitters who knew what they were talking about. I figured that because I'd already had both bikes professionally fitted in person, all I'd be doing would be minor tweaks. Ideally I'd have unlimited money and access to the best equipment and bike fitters in the world, and I'd start again from scratch on the new generation of modern superbikes (some of which are claiming to be 9 watts faster than previous models - and lets face it, my bikes, from 2013 and 2011/2012, are now a good few models behind the cutting edge, so I wonder how many watts I am giving away if the difference between the current and the most recent previous model is 9 watts?!)

Anyway, I am trying to make the best of what I have bike-wise, and I have to draw lines somewhere. I can buy a new stem, because that is (relatively) inexpensive - the stem I got was a £250 stem - crazy money, but I got it for £80 in a sale. I can't really spend £12,000 on a new superbike with optimised crank length and a personalised saddle.

So, with the photos and videos taken and everything uploaded, I composed what I thought was a fairly polite message for the SlowTwitch forum. The forum topic can be found here:

https://forum.slowtwitch.com/forum/Slowtwitch_Forums_C1/Triathlon_Forum_F1/Fit_critique_-_any_thoughts_greatly_appreciated_P7343116-3/

The first few replies were "interesting" - 

"Dude you're skinny"
"jesus your lean, id say gain weight, watts and health"
"I dont know your background, health life info etc just a judgement from what I see"
"I'd suggest you invest in a razor for those hairy legs!"
"Eat a cheeseburger dude"

Maybe cheeseburgers are the answer to going faster...

Some replies were quite complimentary, as I had posted some of the data from my better performances (100 mile time trial, 263 watts, 158bpm, 4.1 watts per kilo (decent), and yet "only" 3:58 - clearly not as aero as I could be, and not using the best aero equipment, clothing, latex tubes etc):

"4.1 watts per kilo for 4 hours. Damn! Wow!"
"Fantastic riders can ride fast in all sorts of positions. This dude is clearly a fantastic rider."

With regards to my Kona bike (a fairly slow 5:24, 3.1 watts per kilo), I feel I should have been faster and would have been faster had I used latex tubes and a better aero position and better aerodynamic clothing. It was said: "Riding 3.1 watts to go 5:24 at Kona means there is a lot of room for improvement, especially if it was within the past few years." I certainly agree with this.

Quite a few comments seemed to say that my positions looked good and that I should avoid radical changes, which made sense - they shouldn't look bad and I wasn't after radical changes. 

Many other replies were useful, but difficult to implement. I was trying to make the best of what I had. It's clear that I should probably be using shorter cranks, and a lot of people had this opinion. I have 175mm cranks on my road bike and 172.5mm on my tri bike. I'm tall, but a lot of my height is in my neck and head, which is "useless" height when it comes to bikes. "Oh you're 6ft1, you need an XL bike" but the reality is I only need medium, or medium-large. And so because my legs are shorter than a more "average" 6ft1 person, I need shorter cranks. 

Conventional wisdom seems to be that in Ironman racing, when you are bent over in the aero position, shorter cranks are better anyway, as your thigh then doesn't come up as high at the top of the pedal stroke, which keeps your breathing a bit easier and keeps your hip angle more open, meaning your legs are in better shape for the run. I also think blood flows to your legs a bit easier when the hip angle is more open. 

But, for me, getting new cranks for even one bike would cost around £1000. My power meter is crank-based, so the shorter cranks themselves (160-165mm) would cost around £500 and then the power meter would be another £500. Particularly in the USA, it seems you go to visit a bike fitter before you buy a bike, and he puts you on a rig on a jig, and everything can be adjusted - crank length, stem length, different types of saddle, saddle height, saddle fore and aft, arm pad height and fore and aft positioning, so your position is optimised. From this then, the fitter will recommend the best bike for your positions - different bikes suit different body positions and body types. The fitter will also tell you what crank length you need, and everything is optimised before you buy anything. Trying to retrospectively optimise is more difficult and costly. So, I have to draw lines somewhere...

It's the same for saddles. A good bike fitter will let you try many different saddle types to find the best one. Apparently I don't sit on my saddle correctly. I just sit on it, I don't think too much about how I am sitting on it. Apparently I don't roll forward enough and I bend too much from my lower back. I asked how to sit better on it, and the answer seemed to be, when you try all the different saddles, you'll just know which one works, it'll just feel right. A saddle can cost £200. Trying 5 different saddles means spending £1000 and a lot of time changing out saddles. So I am making the best of the saddle I've got.

The comments that I could work with all seemed to suggest that my saddle was too high and that I was too cramped at the front. I naturally ride with pointy toes. One comment was: "I'd be curious as to how your run feels having such dramatic plantar flexion with the pedaling action. Not to say it's incorrect but I feel certain that repetitive use and fatigue of the foot and ankle in such a manner would be detrimental to the run." This is a fair point, and maybe another reason as to why my Ironman runs are relatively weak, but there's not much I can do about it - I'm just a naturally pointy rider (a "ballerina"), and it's the same for running - I land on the outside of my forefoot, which causes problems - fatigue, callouses and rapid wearing out of running shoes. But it is what it is.

So the pointy toes can lead people to think my saddle is too high. I dropped it right down by 3cm (obviously too low) and the pointy toes remained. It's not like I was stretching to reach the bottom of the pedal stroke. So that was useful to know what I was working with. The pointy toes weren't going away. But it was said that at the bottom of the pedal stroke, my knee was extended a bit too far (i.e. my leg was a bit too straight), so on the tri bike, the saddle did come down a bit to allow a bit more knee flexion at the bottom of the pedal stroke, the front end did get lowered a bit and lengthened out a bit, and the arm pads came closer together. I also twisted the aero bar ends closer together and installed a new aero computer mount. To install the new stem, the entire cockpit had to be dismantled - an absolute pain - oh to have a new superbike where the entire front end is integrated and simple to adjust with one allen key.

There was quite a lot of back-and-forth between myself and one fitter in particular. The guy that runs the forum said of him that he was an excellent fitter, which I was glad to hear. He was also happy to work with what I had, rather than saying "go and buy new cranks and a new saddle." So I'd make a change, and then try to find time to set up the "video studio" - taking down the pictures, moving the turbo trainer and bike, stripping back the sofa, propping up the phone, then take the videos, edit them, upload them, and refer the fitter to them. He'd have a look, and make further suggestions, and the process would repeat itself until we were happy. In the end, the saddle came down by about 1.5cm (and therefore also moved forwards a fraction), the front end got lowered by almost 2cm, the front got lengthened by almost 1.5cm, and the aero bars and pads got brought closer together to reduce the frontal area. 

Most of the comments I received were more to do with the tri bike - fair enough as it's a triathlon forum. The importance of training in the aero position was stated and I maybe need to pay more heed to this as often I will sit up when training - it's more comfortable, you can put out more power, and the heart rate doesn't go as high. Dropping down into the aero position is a bit less comfortable (but way faster), and my heart rate generally goes up 5-10bpm. But its a balance. You can then drop your power a little as the aero position means that less power is needed to cut through the air. 

Watts per kilogram is an often-quoted measure of outright cycling performance - increase your power and decrease your weight and you'll go faster - but decrease your weight too far and you just become weak and feeble. Watts per kilo is a great metric if you're climbing a hill, but if you are time-trialling on the flat, it's all about your watts per CdA. Watts per what?! CdA is the coefficient of aerodynamic drag - how small your frontal area is and how well you slice through the air. The lower the CdA, the better you will slice through the air and the faster you can go. Expensive tri-suits can cost £500+ nowadays - they feature aerodynamic material, ribs and boundary layer trips and all sorts of technology to make you go faster. Aerodynamic socks are said to be worth 5 watts or more. 

A lot of athletes will spend time (and money!) in a wind tunnel, scientifically optimising their CdA, perfecting their position, testing various pieces of equipment (aero helmet, clothing etc) to find out which works best for them, so they know they are really well dialled in, as best they can be. It must be a good feeling to have things absolutely perfected. I need to train more in the aero position and be comfortable in the aero position for a long time, particularly for a race like Kona or an out-and-out 100 mile time trial.

It was a fairly similar story with the road bike positioning and tweaking. I installed a new carbon fibre seat-post (which I picked up in a sale for about 70% off its normal price), and the saddle came down a bit, it got pushed forwards a bit, and a longer stem got put on the front to lengthen it out. The front also got lowered a bit. As a result, my knee is a bit more bent at the bottom of the pedal stroke, and it's also a bit more over the pedal, while my upper body is a bit longer and lower over the bike.

The end results are shown in a series of photos and videos below, with some more descriptive text. The "old" positions are on the left and the new positions are on the right.


Below is the road bike, with drive-side pedal at 12 o'clock. The most obvious difference here is that I am more stretched out - the handlebars are lower and further forward, so my arms are reaching further and my back is less upright. Overall, the lower you are, the faster you'll be, and the new position is slightly lower and hopefully slightly faster!



Below is the "drive" phase of the pedal stroke. The photos don't really show it, but my knee is further forward in the new position (I made my own plumb-line with a shoelace and an Ironman cowbell to verify this!)
  


At the bottom of the old pedal stroke, my knee was too far back. Between the drive phase and the bottom, the pedal was in front of my knee so I was pushing more forwards than down. In the new position, the knee is a bit more bent and it's a bit further forward, more in front of the pedal spindle. These are two of the best photos for illustrating the changes. They are minor changes and the photos don't look that much different, but they are significantly different!
 


Chainring side recovery phase - the new position looks a bit more aggressive.
 


Again below the new position looks a bit more "forward" and a bit more aggressive.
 


It's a bit easier to get lower in the new position as it's more stretched out. I look a bit hunched up in the old position.


The full-on aero position is below. My head is held much lower in the old position, but my back is hunched. The new position just looks a bit "smoother" and more natural.


A short video of the old position on my road bike


A short video of the new position on the road bike



And now the triathlon bike photographs and videos. Another comment was that I need to decide what I want to use the bike for - out and out 10 mile time trials, sprint triathlons, or Ironmans, or anything else in between? The answer is that I want to use it for everything. You can optimise the position depending on the race - for shorter time trials with no running afterwards the position can be very aggressive, but for Ironman racing with a marathon to run afterwards, the position should maybe be less aggressive. I am quite flexible and able to hold an aggressive position quite well, and so was happy enough to go for quite an aggressive position.


Below are two photos of the old position, at Kona in October 2019. You can see that my stem is quite high. It's a decent position, but I wouldn't say this is a particularly aggressive position and I probably could have gone lower. My back here is pretty flat, and my helmet is above my back. Compare these with the photos of the new position which follow.



When I came back from Kona, I lowered my stem. You can see from the photo on the left below (what I am calling the old position) that the stem is lower than it was Kona, and my back is a bit more rounded, and my helmet is no longer above my back. In the new position on the right, the stem is lower again (mainly because of its angle), and it's also a longer stem - my upper arms are fairly vertical in the old position but less vertical in the new position. I think the less vertical you can make your arms, the more aero they'll be - like having a windscreen which is vertical (e.g. a bus, not aero) versus a sloped windscreen as on a normal car - more aero). I reckon having your upper arms more forwards and out of the way might open up the chest and lungs a bit more. If I had the money, I'd have shortened the cranks, and this would mean my knee would be lower, my thigh would be further away from my chest, with more of an angle between my thigh and my torso (i.e. an open hip angle). This would be much more optimal. Anyone got a spare £1000?!


Visually looking more relaxed and stretched out in the new position, with my knee a bit further forward and my leg a bit more bent at this point in the pedal stroke. It was said that I appear to be working for the bike, rather than the bike working for me, and that my my bike was too short (front to back) - I have a 130mm stem on it, which is quite long. Having a more conventional stem length of, say 80mm, would mean I'd need a longer bike to get into the same position. So I need a longer, lower bike, with shorter crank lengths. But the best I can do is optimise what I've got...


Still the same pointy toe at the bottom of the pedal stroke. No matter how low the saddle goes, the toe will still be pointy and the foot will never be flat, I'll never have a 90-degree angle between my foot and my leg at the bottom of the pedal stroke. In the new position, the knee is further forward and slightly more bent, which is good. I am holding my head in quite a low position, especially compared with the Kona photographs above. People were querying was this sustainable. I think it is - you wouldn't be holding this position all of the time. When going fast, you'd get as aero as possible, you'd shrug the shoulders in tight and get the head turtled down low, but when going slower, uphill, feeding etc, you'd come out of the aggressive aero position, sit up, stretch out a bit and allow the muscles and back to loosen out a bit.


Drive side recovery phase - now a much flatter back, more horizontal forearms and less vertical forearms.


In the old position, to get really aggressively aero, I had to hold my head in a crazily low position. In the new position, I don't have to do this.


Front views now. The side views are good for seeing the pedalling action, while the front views are good for seeing the frontal area. You can see my elbows are now closer together, my hands are now closer together, I am lower, and have visibly less frontal area.



I wonder if a wide-body aero helmet would almost "hide" my shoulders and upper arms, enhancing aerodynamics? No matter what you do, change, tweak or upgrade, there will always be something else to think about...



Playing around with different levels of shoulder shrug, different hand positions, and different head positions. Take me to a wind tunnel or velodrome to establish which works best...! I certainly think the new position visually looks much better and more aerodynamic than the old position from the front. One other thing I will do for racing is reduce the amount of bar tape on the base bars - as it is, the tape comes right down and around to the cross-part, rather than staying behind the brake lever. It's more comfortable to train with the excess, but less aero for a race. So when racing, I'll cut it back.



A short video of the old triathlon bike position


A slow-motion video of the original position


A short video of the test I did with the lowest saddle position. I could probably have got away with this position, but it felt like too big a change. I will ride my new position and get used to it, and in time, I may consider dropping the saddle a fraction further, so it is more like in this video. You could ask different bike fitters for their opinion and they might not agree - it's something of a science, something of a black art, and often something of a compromise between the fitter and the rider.


A short video of the position I finally went with.


A slow motion video of the new position


The original position, from the front


Slow motion video of the original position, from the front


The new position, from the front


The new position, from the front, in slow motion


Finally a couple more photos. Below is a comparison between myself and a pro. The positions aren't that different really, and I was told "your position is 99% of the way there and better than 99% of everyone else's. Time to focus on training and racing." I suppose this is good advice! I was also advised: "Don't let perfect be the enemy of good." This is very good advice, whether for bike positioning, or for racing. Don't be disappointed with a good result simply because it wasn't perfect. Good is still very good. 10:05 at Kona was OK. I can tend to overthink and be too critical. I have a good bike position. I have the ability to train and ride reasonably well. I have some good results behind me. Accept all this, be happy with it, and just get on with it! (easier said than done for me).
 


The photos below illustrate some final aero tweaks I made to my equipment, rather than to me and my position. You can see the red computer between my arms in both photos. You can see it was previously mounted on a cylinder between the aero bars. Now it is mounted on a much more aerodynamic side mount that you can barely see. So there's a bit less frontal area. I got a new aero stem. The stem faceplate on the left with the silver shield on it was a flat faceplate, perpendicular to the air. Not very aerodynamic. The new aero stem on the right (with "3T" written on it) is much pointier and aerodynamic. I already had a nice aero brake mounted. The gear levers are visible at the top of my hands. I debated upgrading these - you can get aero shifters which don't stick up and out. But (so far anyway) I have drawn a line here as this is quite a marginal and expensive gain, and often I grip around the shifters anyway.


Below are close-ups of the set-up, with the front bottle mounted.


Below on the left you can see the aero shape of the new stem. There was no getting away from a few cable ties to mount the front bottle cage holder. A few bits of tape can also make a (very cost effective) difference. I have taped over every hole and bolt and whatever else isn't totally flush, to try to improve the aerodynamics further. In the photo on the right, on the underside of the armpad holder, you can see unused bolt holes. I subsequently taped over these. You can see on the underside of the base bar, where the aero bar clamp feeds through the base bar, that I have taped over the bolt holes. There were other things I taped up too - the aero bottle cage bolts, the stem bolt recess, the computer mount cable ties. Anything and everything I could think of and see, I taped up. Why not?


So the end result of this process is that hopefully my bikes are now optimised, albeit with the self-imposed constraints. Both bikes are now certainly faster than they were when I went to Kona. I'd love to know by how much, and I'd love to get out there and do some outdoor riding to see and feel the difference on the road. But it's winter now and so it'll only be the hybrid that I take out on the road on the odd day when it's dry and not freezing. Most of the rest of my cycling until March/April 2021 will be on the turbo trainer.

I had all my bikes serviced too. The road bike hadn't been serviced since August 2019 and the tri bike hadn't been serviced since October 2019. My hybrid hadn't been serviced since early 2019. So it was high time. New chains, new brake pads, cleaning them up, lubricating everything, new tyres, new latex tubes, getting everything back to tip-top condition. I have a friend who is probably one of the best bike mechanics in the world, he travels the world with a mountain bike team as their mechanic. So he did the work. I have no idea how how got the super fast (and super fragile) and super super tight Vittoria Corsa Speed tyres onto my racing wheels. He said he lost skin off his thumbs... I couldn't even get them onto my looser training wheels. After he got them on, he said the only way to get them off would be to cut them off (meaning the latex tubes would also be ruined). So I had better hope I don't get a puncture... they are intended for short-course racing only, and I am looking forward to seeing how fast they are with latex tubes, but I'll not be taking them for long spins, I will have to stay very local, in case I get a puncture...

It's amazing how the cost of what you think are just a few bits and pieces mounts up, and by the time he had charged for his time and labour and lost skin, it was a fairly hefty bill, but it needed to be done and I was happy to pay it, knowing the work was all as good as it could be. You don't notice how bad the bikes get (and mine weren't bad, I do take care of them - but the chains were stretched and everything just needed revitalised) until you have them serviced and then put them on the turbo trainer, and there's almost silence when you pedal. New, clean, non-stretched chains, meshing perfectly with clean cog teeth, everything new and lubricated and perfect. It's superb. Again, I look forward to getting out onto the roads to enjoy the feeling and speed of a "new bike", but it's so cold and the roads are so wet and dirty that it might be a while...

I also learned quite a it about bike fitting, what to look for, where to start, and how to improve things. So although it was a long and often tedious process, that probably took nearly 2 months from start to finish, I have to be happy with the outcomes. I'm also happy that I've been able to get back to the swimming pool once a week. The pools are generally very quiet and the lanes are now much wider, so it feels pretty safe and it's nice to be able to swim again.

One thing I am less happy about is the fact that my right foot has been sore pretty much for 7 months now, when I run and after I run. The faster I try to run, the worse it is. It clearly doesn't look like it is going to resolve itself any time soon. I saw one specialist who was said to be excellent, but he couldn't really diagnose it and it didn't really help. I'm currently waiting for a scan. Not ideal.

Now, what to target in 2020? Or indeed what will I be able to target in 2020, for various reasons...?

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