2017 TT Bike Project

Having accidentally bought a new time trial bike for 2018 already I thought I’d take some time to write about how I rode two personal best time trials this year by completely overhauling the riding position on my old bike. Hopefully readers of this who are looking to time trial faster can take away a few nuggets of information and reach their goals faster without having to buy a new bike… yet!

Watch this video to see how I helped coach Oliver Bridgewood of Cycling Weekly to a sub50 performance!

Fuelled by discovering the fabled 3cm rule and receiving a few raised eyebrows at a December time trial in 2016 I decided to take action and completely restart with my TT position.

Not only this but being head coach of BPC I thought I should practice what I preach and update my 3 year old 25TT personal best.

I went through the same process I would take any athlete that approached me with a goal of improving their time trial performance. I won’t talk much about fitness and TT training in this blog but will focus on the bike fit, equipment selection and aero testing.

The old position

Over the last few years I had spent a lot of time tweaking my position further and further away from what most would consider a sensible way to ride and closer to convincing myself that a 150mm stem was perfectly normal.

I was finding it harder and harder to get anywhere near my best power outputs so something was definitely wrong. However I just couldn’t tear myself away from the aero at all costs attitude. I was hoping at some point I would magically adapt to this extreme riding position and the watts would come flooding out. Alas this was not the case.

The attitude stuck as I was still nudging my 10TT personal best along ever so slightly each year. In 2016 my PB on the F11/10 course was 19:15 (up from 19:48 in 2015) for 394w normalised power and 380w average power at around 91kg. Using Best bike split I estimated a CdA of 0.202.

This type of thinking led me to start questioning whether or not I’d got the right balance between aero and power output. You can read more about this in a feature I wrote for Cycling Weekly here:

http://www.cyclingweekly.com/news/latest-news/power-vs-aerodynamics-get-balance-right-324633

My previous best for 25 miles was 51:14 back in September 2013 down on the fast Welsh course so often visited by keen testers. I revisited several times in the following years and have a book full of excuses as to why I went no faster. If you have a few hours or are struggling to fall asleep I’d be happy to talk you through them all.

The final nail in the coffin was barely scraping the top ten in the Bentley Bypass winter 10TT where I rode 20:08 for 399w normalized power and 392w average power. This may have been a slight improvement in power on my previous time trial in July 2016 however my best 20 minute effort around that time on a road bike was 442w average power. This is a huge gap that needed addressing.

The fit

I begun the TT bike project by completely abandoning my old riding position. I’ve had great experience with bike fit thanks to Garth Kruger at Vankru Cycling down in Southampton as he is a sponsor of our race team, Spokes BPC racing.

Last year Vankru made some significant changes to my road bike position which I’ve had great success with. Saddle sores are now a thing of the past!

So knowing that I could get all my power out in my road bike position that’s where we started my TT bike fit. The back end set up from the road bike was tweaked slightly to accommodate a more aggressive back angle and pelvis angle. Only small amounts mind, we came forward 2cm and down a little.

This position was already significantly different from my old one as I used to be slammed as far forward of the bottom bracket as I could get. My saddle tip is now 6cm behind the bottom bracket where previously it was 5cm in front! A huge change, but I immediately felt able to pedal much more freely.

You can see from the above picture how much further back on the bike I’m sitting compared to the bottom (poor quality) picture.

This also meant the stem had to be significantly shortened, 150mm down to 110mm and the pads moved further back than that still. All in all the pads were moved 160mm back! Another huge change but when you look at my back angle and body position there are only quite subtle changes and it doesn’t appear to be the complete overhaul that it actually is.

Next stop was the front end. I’d spent a lot of time at home experimenting with different angled extensions, angles, widths and arm positions. My main goal was to be able to breathe deeply and keep my chest relaxed as I felt that was a big cause of my power loss on the TT bike.

I settled on the top hand position with the steepest angle I could get. In this position it felt easier to tuck my head down and roll my shoulders in which makes a noticeable difference to the frontal area. As can be seen below.

Having done all of this preliminary work before the bike fit, me and Garth could really make some fast progress and find the balance between what I thought would be fast and what would keep him happy in terms of comfort, injury prevention and bike fitter guidelines.

We settled on a pretty slick looking and powerful feeling position that we were both happy with.

It’s all well and good saying a position feels good or looks good but the truth comes when doing proper aero testing.

Aero Testing

I enlisted the help of Rob Barrett at Float Aero who took me through several outdoor and indoor testing sessions where we were looking to find the fastest position and fastest equipment choices for me.

Unfortunately there’s no one size fits all when it comes to aero so just because something is fast for one guy doesn’t mean it will be fastest for the next guy.

We started by continuing the theme of the bike fit and experimenting with different front end setups such as high hands, low hands, wide elbows, narrow elbows. Slowest was low hands and wide hands/elbows. Fastest was high hands and hands/elbows completely together, in fact just looking at the speed I was lapping the velodrome at there was nearly a 1.5mph difference at the same power.

Unfortunately the fastest position wasn’t rideable and I nearly fell off palmer park velodrome! We settled on a variation of high hands and narrows hands/elbows with a small gap inbetween.

We tested 4 or 5 skinsuits including; Smart/D2Z version1, Kalas, Velotec and Castelli Body Paint 2.0. The Castelli tested the fastest.

Next up was helmets. I tested a Lazer wasp, kask bambino, bell javelin and giro aerohead. The Aerohead was fastest when in my new front end set up and the castelli skinsuit. That was a relief having already spent £200 on one!

We did complete some tests using different front wheel depths but all that told us was a zipp 808 was faster than a non branded 50mm clincher… surprise surprise.

I was limited on options when it came to front wheel choice so as much as I would have loved to discover which wheel was fastest with my frameset I didn’t have that luxury.

I had already chosen a Flo cycling 62mm front wheel both for road racing and time trialling. I was able to set this up as tubeless with some super thin vittoria tyres which reportedly test very well in terms of rolling resistance. They measure up at 24mm on these rims which are 26mm at their widest so there is a beautifully smooth junction between the tyre and rim… lovely.

A few other equipment choices I made were the move to speedplay zero pedals, a single front chainring setup with no front mech and some trip calf guards which tested very well on me saving almost 13w of drag.

To give you some context around the good work that Float aero have done, my first test runs in the new bike fit position my CdA was testing at around 0.235 on the outdoor velodrome (up from a traffic assisted 0.202 in 2016). However with all the changes we made we were able to get this figure down to 0.21 which may not sound much but a reduction of 0.025 is huge.

So now I was pretty sure of my setup and equipment choices I had to get out there and race some races!

Racing

In 2016 my PB on the F11/10 course was 19:15 for 394np 380av. Estimated CdA from Best bike split 0.202

An 18 was in sight so long as I hadn’t made the wrong choices in position/equipment and could actually pedal hard.

I completed a test event on the Bentley bypass H10/8 course just to give me a comparison from that shocker back in December.

Annoyingly I only went 1 second faster!!!

At that point, I was panicking that all my hard work would come to nothing but when consulting my power meter I was up 18w on Decembers event so I chalked that one up to it just being a slow day!

Next up was my first crack at the F11/10 again. The conditions were far from perfect and the car park was full of complaints about a ‘stonking headwind to the 2nd roundabout’. ‘Great’, I thought.

However I’d been putting in some good sessions on the TT bike and was confident I could hold on to 450w for the longer sections of the course so I set off not worrying about the wind but worrying about the ~19mins of pain I was about to endure.

Results were in and I managed to win my first ever open event in a time of 18:45 taking a few big scalps along the way such as Peter Harrison and Chris Bartley of the Athlete Service test team. The 18 was mine for a power of 425np 417av. Estimated CdA from best bike split 0.200

So for all my hard work the CdA in real world conditions had only been improved by 0.02. The significant difference was the power output. Previously I could only complete a 10TT at 97% of my road FTP, but this time it was 104%.

 

When you examine the power file more closely you can see I was riding at 430-450w for the long straight sections. The average and normalized power for that course usually reads low due to the gift hill and lengthy first turnaround which takes almost a minute to roll around.

Using best bike split I tried to estimate what my ride would have been on the V718 course had I made the trip to hull on that same day. The results were 18:33 with the same normalised power on the same bike profile, so not really worth the 5-hour drive on that occasion.

Interestingly the CdA actually comes out as 0.193 on average for that course, i guess due to different yaw angles experienced and smaller amount of time spent sitting up and out of the aero tuck, or just loads more big lorries on the course!

25TT

At around the same time of year I decided once again to begrudgingly make my way to deepest darkest Wales for another crack on the super fast R25/3H course.

I was confident of updating my old PB of 51:14 but had only hoped to sneak under 50.

I had tapered for this event and was having some good results on the road at the time bagging a 2nd place in the Hatfield Puncheur a National B band 2 race.

But I wasn’t expecting to go under 50 by quite the margin I did.

I rode a 47:52 off 398NP, 385av power and sneaked into the top40 all time list. I’ve since been nudged out of that list now the Nat25 has happened so I might have to go back!

The biggest win of that ride for me was that I was holding 400-405w for the long uninterrupted sections of road so right up at my road bike FTP. That just shows how important it is to get a bike fitter to look at that back end set up and make sure you can ride at your full capacity. The fact my NP for that 25miles was equal to my best for 10miles the previous year is no coincidence!

Next Year

I’d love to pick up a ‘17’ next year but based on my current CdA that would mean I’d need about 475w and a perfect day up in Hull which is obviously out of reach being 50w up on my current best.

Sounds like a perfect excuse for having bought that new bike to me 😊

Leave a Reply

Your email address will not be published. Required fields are marked *