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What makes a bike slow?

I recently swapped my Defy Advanced (carbon) for an aluminium Domane (because winter). The bike fit is almost identical on the Domane, and I'm rather foolishly still running summer wheels/rubber (Fulcrum DB4s with exposed bearings, GP4000s tyres) - same combo as I had on the Defy. There's not a huge amount in it weight-wise and yet the Domane just feels so damn slow compared to the Defy. This is borne out by Strava times on my regular routes.

So what it is that makes a bike dull, slow, and lifeless? Or is it all in the mind and body of the fool pedalling it? Granted I've been off the bike for most of the month due to a virus but I wouldn't expect to be over 2mph average slower on routes I've ridden for years. It just feels like the Domane needs more coals piling on constantly and doesn't respond to increased effort in the way the Defy did.

If you're new please join in and if you have questions pop them below and the forum regulars will answer as best we can.

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Judge dreadful | 1 year ago
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A lot of the differences in winter and summer riding, come down to conditions ( road and weather ). No one in their right mind will ride on a wet road, with poor visibility, the way they ride on a dry road, with good visibility. Add in the increased propensity for stronger gustier winds, and lower average temperatures during the winter months, and it all adds up to slower riding. As you ride faster in the winter, you ( tend to ) find that you'll get colder quicker. Your muscles stiffen up, and ( without realising it ) you're just not getting the figures you do in the summer. Winter kit tends to be more restrictive too. All in all, if you want to get summer speeds in winter, you have to push harder, and be braver ( more stupid ). If you can, get decent power meters, and base your efforts on NP, not speed. There's a good reason for the saying "winter miles for summer smiles".

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belugabob replied to Judge dreadful | 1 year ago
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Judge dreadful wrote:

No one in their right mind will ride on a wet road, with poor visibility, the way they ride on a dry road, with good visibility. .

I was thinking along similar lines, for driving in the current icy conditions, but it would appear that lots of motorists are not in their right minds.

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kil0ran | 1 year ago
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Well, another ride for me today and further improvement.

Now I need to work on finding a suitable bar tape for the wide tops of the Venturemax. I'm wondering if I might just use grip tape, or maybe even go retro and use Tressorex.

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Simon_MacMichael | 1 year ago
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Thanks for kicking off this thread Kiloran, some very interesting replies, will be flagging it to our tech team, lots of interesting angles that they can get their teeth into for articles.

 

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IanEdward | 1 year ago
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Interesting, I don't get on with my winter bike either, almost exactly the same fit as my summer bike and my gravel bike, but always seem to end up with more low back issues. I've put it down to long slow steady rides in a fixed position instead of summer rides where I usually mix it up with hills etc.

However back to the OP - how are the drivetrains? I saw an interesting YouTube video that seemed reasonably credible and suggested that there could be 10W difference (ish) between two otherwise reasonably well maintained drivetrains. I doubt 10W would add 2mph but (I think) I notice the difference when I refit a freshly waxed chain...

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kil0ran replied to IanEdward | 1 year ago
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Good point about position for winter riding, I too am less dynamic on the bike in winter months.

As far as the drivetrain goes the Domane is probably slightly better specced now. New chain and cassette and it's an Ultegra R8000/105 5800 mashup compared to Tiagra 4600 on the old Defy. Same brakes, rotors and wheels/tyres. Oh and the cranks are the same because I run 165s so I swapped them over when I sold the Defy.

This thread has been an interesting read over the past few days, I think I'm ultimately going to put it down to a combination of factors - weather, health, a drop in fitness and frame differences.

I've had fast/comfortable ally bikes in the past - Triban 3 and a Merida CX bike spring to mind - but there's just something about this Domane frame that makes it dull and lifeless. It's a lovely bit of kit and probably the best engineered bike I've owned - utterly silent even with full mudguards installed - but it just doesn't put a smile on my face. Of course Trek market it as an entry-level road bike and so perhaps I should expect it to be like that, otherwise they wouldn't have the opportunity to upsell riders. I guess I've been a bit spoilt by riding "boutique" frames and very high quality carbon frames like the Defy.

What this all means is a return to a Defy in the spring I think. If I was just commuting on it I'd put up with it but cycling for me now is leisure, and leisure should be fun and enjoyable. If only Giant had better colour schemes.

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IanEdward replied to kil0ran | 1 year ago
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To be fair I lifted that point about moving around less on winter rides from somebody on Singletrackworld 😎

Curious about your 165mm cranks, what height are you, what prompted the change?

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kil0ran replied to IanEdward | 1 year ago
2 likes

178cm so by rights I should be riding 172.5mm cranks. But 165s were recommended by a fitter 5 years ago, and by a different fitter this year. I've got reduced hip flexion from an old injury (an OTB moment involving loose wheel nuts and a Raleigh Grifter c. 1982). I find them better for hills, I'm more able to get over the top of the stroke with them. Fitter noticed that at my preferred saddle height I was getting a lot of knee splaying on standard length cranks. Should note that I run my saddle lower than average for my height too - I've got a pretty narrow fit window as an unfit 52yo and I'm particularly sensitive to saddle height. 9 hours a day at a desk doesn't help with the back pain either.

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mark1a replied to kil0ran | 1 year ago
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That's interesting regarding the fitter's recommendation with cranks - I'm a similar age to you (53), similar height (180cm) and old knee injury from a c1982 BMX incident (tabletop, succesful launch, unsuccessful landing), and the fitter (Gary from GA Cycles, not far from you and highly recommended) said 172.5mm were perfect. I've had zero fit issues since visiting them.

Other measurements as follows:

 

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IanEdward replied to kil0ran | 1 year ago
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Ah OK, sounds very 'you' specific!

I'd asked as I've seen some interesting stuff on YouTube (Road Cycling Academy) recommending shorter for virtually all riders. I'm always on the lookout for things to reduce back pain although changing cranks on 4 bikes would be an expensive business 😖😖

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kil0ran replied to IanEdward | 1 year ago
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Yeah, there's a bit of thing about shorter cranks in general. I think potentially like most things (oval chainrings) it's quite rider-specific. As you said so much of bike fit wisdom is based on race rather than real-world fit. Guy who did my recent one is an ex-Pro Conti and national team rider and he was very adaptable - takes the view that speed comes with comfort, not slamming and stretching everything. First thing he did was shorten me up 20mm on saddle position. He also said that the current gravel vogue is leading to 10mm being shaved off the typical stem length which is great for control but will end up giving people back issues if they do long road rides. He's also expecting shoulder and neck issues if people use flared bars for longer rides if they've been used to road bars.

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kil0ran replied to IanEdward | 1 year ago
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It's complicated but as I understand it the fit starts with the feet and moves up the body. So cleat position comes first, then crank length (based on hip flexion and knee tracking), then saddle height. That sets your bottom half up and then it's just a question of finding a comfortable body angle. First fit I had done I was surprised that the solution to my back pain was to go longer on the stem, felt counter-intuitive but it completely solved it, to the point I did RideLondon the next weekend with zero issues.

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IanEdward replied to kil0ran | 1 year ago
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Ha! I've moved to 100mm on road bikes and 90mm on gravel, at least 10mm shorter than average for my height (6ft).

In fairness I've moved saddles back too which I find helps unweight hands and forearms, although recent back pain episodes have got me thinking about shuffling saddles forward 10mm again 🙄

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kil0ran replied to IanEdward | 1 year ago
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Bike fit for me is like cat herding. You get something right and that in turns puts something else out of whack. So off you go and chase that, and it then something else goes wrong.

On the plus side I've got a box of stems from 80-120mm, all pro-style gaffa taped so I don't end up with brand/colour clash. Same applies to seatposts. Currently experimenting with flared bars (Ritchey Venturemax)

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Judge dreadful replied to IanEdward | 1 year ago
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The 'short crank' trend in the pro pelotons is more about making it easier to maintain form / position on the bike, and therefore increasing aero gains, than anything else. Personally, I like shorter cranks, because injuries mean that my range of motion, particularly in my ankles, isn't what it once was, and therefore I find that the more comfortable I am, the more I can increase my power. Unfortunately ( for me ) my best bike runs a Carbon chain / crankset, and they really aren't cheap, so I'm making do with 172.5 mil, when my preference is for 170 mil. There are also big issues with supply chains at the moment, and 170 SR chain / cranksets are like hen's teeth right now.

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Awavey replied to IanEdward | 1 year ago
1 like

My winter bike is my summer bike, so it's the same setup but I always suffer lower back problems in winter with it, even riding the same routes. Someone told me its just because its colder and your body just doesnt like spending hours in the cold and damp, and your back gets the worst of it, plus your weight changes both through excessive eating and fat retention to stave off the cold and you are inevitably more tired fighting off colds/flu viruses, plus I find it harder in colder air to breathe due to asthma, so it's just harder efforts to ride in winter, generally takes more out of me and I'm largely slower most of the time.

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Gimpl | 1 year ago
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I've posted before that I have two Defy's, an aluminium one set up for winter now with cheaper wheels, mudguards etc and a Composite 1 set up for long, comfortable summer rides. I'm always a gear lower on the alu one, in part due to the wheels but also clothing, air density, temperature and so on. Long ago I gave up trying to compare the two, they have different purposes and I just roll with it. 

Originally I bought the alu one as a frame, seat post and fork (both carbon) and took everthing else off the CF one, wheels, groupset, handlebars. The only new thing was the cables. The ride was without doubt more 'buzzy' on the alu one even with all the same gear. Nowerdays I simply can't compare the two as I've changed too much on the CF one. 

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kil0ran | 1 year ago
1 like

Well, a bit faster on today's identical ride, but still 1mph average off the Defy times. I did make a minor fit adjustment (10mm shorter stem) which made a big difference to hand and lower back comfort. 

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IanMSpencer | 1 year ago
2 likes

Adding to the list, wheels and condition of wheels is a biggy. If a wheel isn't in good condition, loose spokes will sap energy. Heavy rims and tyres will sap energy. Knackered bearings allowing the wheel to flop about won't help either.

If you can, and with rim brakes and rotor differences it is not always straight forward, try comparing wheelsets between bikes, that might help pin down major differences.

Looking at the frame stiffness discussion, there are a couple of key places where rigidity is important, but elsewhere softness gives ride comfort gives pace over the long term. The Defy does seem to have a great combination of a complaint ride, yet there is a torsional rigidity between crank and rear wheel - so the seat is loosely coupled to the rear wheel, but the pedals are quite rigid. If you are feeling brutal, step on one pedal while off the bike and see how much you can flex the frame against the rear wheel - there will be quite a bit of movement even on a stiff bike.

The comfort of the ride should not be dismissed. If you are getting uncomfortable from your bike, you are going to have to work through that discomfort to apply effort. The Defy has a gentle cockpit, so no buzzing fingers and potential RSI type injuries, and the compliant seatpost combined with the right saddle allows you to sit without needing to fidget and stand to protect your backside.

So a well maintained, comfortable bike that is a pleasure to sit on will deliver performance over one that lacks those things. I'm not a great believer in professional bike fits for the happy amateur, in part because a lot of bike fit theory is built on performance rather than comfort and endurance - I have evolved a bike position that suits me and is transferable between bikes and allows me to regularly ride long distances - I doubt it is "optimal" for performance, but I can get off my bike after 80 miles, have a shower, and carry on doing stuff without moaning and groaning. That being said, evolving a good position is important - listen to your body.

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kil0ran replied to IanMSpencer | 1 year ago
1 like

Thanks Ian. Definitely not the wheels/tyres as I'm still using the summer wheels I used on the Defy. Bearings still surprisingly good considering they have minimal sealing (Fulcrum DB4s). I'm feeling more beaten up by the Domane compared to the Defy despite having transferred the position over almost exactly so I guess that just goes to show how all that D-Fuse stuff really does make a difference.

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CyclingInGawler | 1 year ago
6 likes

What will make a bike "dull, slow, and lifeless?". Well, from past experience, adding around 30 kg of camping gear to the racks on your 531c-framed "fast tourer" will have that effect. 
But.....

The change in feel and performance when you get to drop that 30 kg. at the campsite and just ride around the local hills without it is just awesome! Particularly if you happen to be riding just south of Dublin in August 1987, when you too can dream (however fancifully) of winning the TdF :).

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David9694 replied to CyclingInGawler | 1 year ago
2 likes

Did you not get some "whip" when loaded? It's why they developed 531ST.

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CyclingInGawler replied to David9694 | 1 year ago
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I didn't ride it quite that heavily loaded very often. The trick then was to avoid too much of a rocking motion; treating each day as a marathon rather than a sprint, and just spin up the hills. 

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BBB | 1 year ago
1 like

"...Granted I've been off the bike for most of the month due to a virus but I wouldn't expect to be over 2mph average slower on routes I've ridden for years..." 

Only that would make a difference of 2mph in this scenario. 

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Ride On replied to BBB | 1 year ago
3 likes

On day 23 of the virus now,feel mostly over it but my cycling and running VO2 max estimates on garmin have dropped dramatically and my resting heart rate is still sitting 7 points above the average for the year. So dont underestimate the impact of seasonal bugs you are fighting.

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kil0ran replied to Ride On | 1 year ago
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It's a good point - for a time during the bug I had a resting heart rate of 90bpm (usually low 60s) and a temp of 39.6C. But the bike "felt slow" before that.

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hawkinspeter | 1 year ago
2 likes

I'm sceptical about huge differences between frame materials. Ultimately, flexing is going to absorb energy which is good for road bumps, but bad for transmitting forces from the pedals to the back wheel. I can see maybe better comfort for the rider if the frame is more compliant, but unless your tyres are super hard, then they'll be providing the majority of the shock absorption.

What makes me really sceptical is the lack of numbers. How much frame compliance provides the maximum benefit? If the frame is really flexy, then it becomes unrideable, so somewhere between unrideable and super stiff is the supposed sweet spot of compliance, but I'm not aware of frame builders showing figures except for a vertical compliance.

Also, considering that the power gets transmitted from the foot to the pedal, through the cranks, chainwheel, chain and ultimately back wheel, then which part do you want the compliance and in which direction?

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jaysa replied to hawkinspeter | 1 year ago
3 likes

'How much frame compliance provides the maximum benefit?'

The French magazine Le Cycle tests bikes for lateral movement at the headtube, pedal box and rear dropouts, leading to advice on what type of rider the bike would suit. For example:

Headtube @ 196 Newtons:
BMC Roadmachine 01: 5mm
CMT GT2 (Titanium): 11mm
Kuota Kobalt (entry level carbon): 7.4mm

Pedal box @ 392 Newtons:
BMC Roadmachine 01: 1.3mm
CMT GT2: 1mm
Kuota Kobalt: 1mm

Rear dropouts @ 192 Newtons:
BMC Roadmachine 01: 5.4mm
CMT GT2: 5.7mm
Kuota Kobalt 3.4mm

Their observations:

Roadmachine is super-stiff, for strong men. Unforgiving - must drop gears when tired or on steep hills.

CMT GT2: For sportives: very supple for a heavy rider, just right if lightweight. If you sprint hard, you will rapidly reach its limits. Easy to live with when the going is hard.

Kuota Kobalt: all rounder: feels supple for heavier or more powerful riders.

Thanks and apologies to Le Cycle for quoting their copy, from 2016.

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hawkinspeter replied to jaysa | 1 year ago
1 like

Thanks for that.

Their choice of categories based on frame flex implies to me that it's just a case of more flex leads to more comfort and less flex leads to a faster ride.

There's some other considerations about flexy frames. Generally, stiffer frames use more material and are heavier (for the same frame material), so there's a trade-off there with carbon frames designed to have beefed up areas that you'd want to be as stiff as possible. There's also a correlation between lateral stiffness and vertical stiffness although there are tricks to getting vertical compliance (good) without horizontal complaince (bad) such as arranging carbon fibres in certain directions.

What I have trouble with is the idea that 'lively' frames are faster due to them acting like a spring and returning some energy back to the rider. Springs do absorb energy when flexing (they get warmer), so isn't it more efficient for there to be minimal flexing?

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marmotte27 replied to hawkinspeter | 1 year ago
2 likes

The last bit has been shown in experiments.
Some springs like those of suspension forks have a damper that works by converting energy into heat thus absorbing it. The bike frame however acts like an undampened spring, the energy stored is completely returned into the drivetrain (there are videos that show how this works: https://youtu.be/BH_AL4rxrp8 ). The metal/frame material doesn't absorb any energy that could heat it up.
This smoothes out the power output, helping the rider put out more energy, or get less tired with the same energy output.
What happens with stiffer frames is that the energy is transmitted into the riders body, where it is dampened in the body tissue, by being transformed into friction and ultimately fatigue.

Where the sweetspot for this lies and thus the ideal frame stiffness will depend on your power output. A professional rider putting out 300W on average will need a stiffer frame than a cyclotourist putting out 150.

The crazy thing was when in the 90s and 00s cycling magazines (especially German ones, but elsewhere as well) were trying to convince average leisure riders they needed professional level stiff frames to be "faster". Luckily this has been shown to be complete myth.

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