Author Topic: gearing  (Read 5156 times)

bludger

  • Randonneur and bargain hunter
Re: gearing
« Reply #50 on: April 11, 2020, 08:50:58 pm »
I've resolved that the next audax I do, I'll do fixed. I've really enjoyed getting to grips with fixed for regular length rides including up some hills. Nothing truly alpine so far but I should think something like the dun run will be well within my ability.

I don't know why it is but going up hills is a lot easier than I'd expected. I can't imagine doing SS since it wouldn't have the same momentum effect as the cranks and wheels are so integrated.
YACF touring/audax bargain basement:
https://bit.ly/2Xg8pRD



Ban cars.

Re: gearing
« Reply #51 on: April 11, 2020, 09:17:01 pm »
Agreed. The weird thing with fixed is that you can be out of the saddle honking, because you think you have to, then sit down and find that it is easier than it should be

Re: gearing
« Reply #52 on: April 12, 2020, 04:54:59 am »
another element of risk is that it is difficult to tell when a fixie rider is slowing down as the legs keep turning regardless.

Now you are just making stuff up :).
Once the UK opens up again, go to one of the open sessions here.
https://www.hernehillvelodrome.com/

Last time I was there, (granted over 10 years ago), there was 30+ riders in the main group, riding as tight as you want and people slowing down/speeding up.
You can easily see on it peoples hip when they're not actively pedaling, same way as you can see it on a roadie when he's still softly pedaling around versus actually putting in effort.

There was also the junior riders doing pursuit training and with their limited gearing (84"? I forget), they were pedalling a silly RPMs, as smooth as you like).

Ok, so you don't like fixed on the road. Fine. Don't do it then, but why do you insist coming into the fixed section of the forum telling us that we're doing it wrong?.

yorkie

  • On top of the Galibier
Re: gearing
« Reply #53 on: April 12, 2020, 04:41:51 pm »

There was also the junior riders doing pursuit training and with their limited gearing (84"? I forget), they were pedalling a silly RPMs, as smooth as you like).


Junior or Youth riders? Youth A (effectively under-16) are allowed a maximum gear development of 6.93m on the track, Junior riders (effectively under-18) have no gear restrictions nowadays. (6.93m comes out at approximately 86.6" gear)


Source: British Cycling 2020 Technical Regulations
Born to ride my bike, forced to work! ;)

British Cycling Regional Track Commissaire
British Cycling Regional Circuit Commissaire

zigzag

  • unfuckwithable
Re: gearing
« Reply #54 on: April 12, 2020, 04:54:14 pm »
Ok, so you don't like fixed on the road. Fine. Don't do it then, but why do you insist coming into the fixed section of the forum telling us that we're doing it wrong?.

i had a session at herne hill a while ago, it was alright - track/fixed bikes are designed for velodromes and everyone rides in sync, more or less. i don't mind fixies ridden on the road at all (as well as tall bikes, recumbents, velomobiles), i've ridden one myself until i found out it doesn't work for me (commuting 4-5months). i was asked for reasons why they are sub-optimal on the road and listed a few (and there are more!).

i haven't said you are doing it wrong, only that there are better (ime) tools for the job.

"velo fixe" is a slave of "freewheeling" board, so i can talk about freewheels no problem, especially as they turn a toy bike into a proper one. ( <-- don't read this too seriously ;) )

DaT

Re: gearing
« Reply #55 on: April 12, 2020, 05:07:35 pm »
Zigzag

I did my SR last season on fixed. Middle of a fixed RRtY before the suspension of audaxing. I ride at a reasonable pace. Did a 200k in 6hrs 47mins early in the year, that’s with 2,700m climbing. I can spin at 180rpm when needed, 160 is what I do every ride. I understand if riding fixed isn’t your thing but it’s ignorant saying you can ride with geared riders (I do), ride fast (I can) or that I’m somehow I liability.

At the moment I’m riding 650b*50mm with 48/18 that puts me at 72”.


Re: gearing
« Reply #56 on: April 12, 2020, 05:20:16 pm »
That is one weird-ass bike.  Fat tyres, fixed, cowhorns, discs, mudguards...this could only be YACF  ;D
And Darkness and Decay and the Coronavirus held illimitable dominion over all.

zigzag

  • unfuckwithable
Re: gearing
« Reply #57 on: April 12, 2020, 05:43:56 pm »
Zigzag

I did my SR last season on fixed. Middle of a fixed RRtY before the suspension of audaxing. I ride at a reasonable pace. Did a 200k in 6hrs 47mins early in the year, that’s with 2,700m climbing. I can spin at 180rpm when needed, 160 is what I do every ride. I understand if riding fixed isn’t your thing but it’s ignorant saying you can ride with geared riders (I do), ride fast (I can) or that I’m somehow I liability.

At the moment I’m riding 650b*50mm with 48/18 that puts me at 72”.

maybe you are special and could ride even better with a freewheel! ;)

i've ridden with some fixed riders which i consider special and saw them occasionally struggle to ride in a group/-etto (either on the steeper uphills or longer/technical downhills), hence my reasoned opinion in the posts above.

DaT

Re: gearing
« Reply #58 on: April 12, 2020, 06:19:53 pm »
That is one weird-ass bike.  Fat tyres, fixed, cowhorns, discs, mudguards...this could only be YACF  ;D
drop bars and aero bars. It wouldn’t be YACF without the dynamo!

bludger

  • Randonneur and bargain hunter
Re: gearing
« Reply #59 on: April 12, 2020, 07:28:05 pm »
(Snip)

prettiest bike I've seen in yacf so far. Is that an eccentric BB? Always wanted to try a fixed with a hydro on the front.
YACF touring/audax bargain basement:
https://bit.ly/2Xg8pRD



Ban cars.

DaT

Re: gearing
« Reply #60 on: April 12, 2020, 07:42:15 pm »
(Snip)

prettiest bike I've seen in yacf so far. Is that an eccentric BB? Always wanted to try a fixed with a hydro on the front.
Thanks, the hydros where cheap, £120 all in (no rotors). I love discs and hydros make it even better. The dropouts are regular horizontal with movable disc tab, pain to adjust really.

Re: gearing
« Reply #61 on: April 12, 2020, 08:44:32 pm »
I had a massive Hope Mono 4 on the front of my Inbred for a few weeks.  It had to be centred using annoying little shim washers.  In the end the dragging and "woo woo" sound drove me nuts and I fitted a V-brake instead.
And Darkness and Decay and the Coronavirus held illimitable dominion over all.

Mr Larrington

  • A bit ov a lyv wyr by slof standirds
  • Custard Wallah
    • Mr Larrington's Automatic Diary
Re: gearing
« Reply #62 on: April 13, 2020, 11:08:05 am »
That is one weird-ass bike.  Fat tyres, fixed, cowhorns, discs, mudguards...this could only be YACF  ;D

Depravo the Roadrat doesn't have the fat tyres, but he does have aero bars, a Schmidt, a B17 and a rack ;D
External Transparent Wall Inspection Operative & Mayor of Mortagne-au-Perche
Satisfying the Bloodlust of the Masses in Peacetime

guidon

  • formerly known as cyclone
Re: gearing
« Reply #63 on: April 14, 2020, 09:03:09 am »
what genesis frame is that? Don't really follow "new" brands  ;) any chance on a review of your machine DaT??

DaT

Re: gearing
« Reply #64 on: April 14, 2020, 09:51:18 am »
what genesis frame is that? Don't really follow "new" brands  ;) any chance on a review of your machine DaT??
The frame is a Genesis day one. Nothing else is stock so it may be a little pointless. It rides nice though, a bit quicker handling with the whisky fork but the trail numbers are still quite high. 650b*50mm is plush at 30psi. weighs about 10.5kg with aero bars, dynamo setup, pedals, cages etc. I’ve changed the bars to some Easton ec70ax carbon gravel bars and have an infinity saddle on the way.

Nelson Longflap

  • Riding a bike is meant to be easy ...
Re: gearing
« Reply #65 on: April 14, 2020, 12:08:13 pm »
Just getting back to the OP, my riding at present is a short (27 km) route with about 400 m of climbing. To maximise the benefit I usually use my Orbit Track bike (which rides really nicely on the road) geared at 48 x 20 (approx 64.4"); I've also used my Surly Cross Check single speed geared at 42 x 18 (approx 62.6"), the difference in gearing is enough for me to feel the difference.

Like zz I expected ss to be faster than fixed because of the better downhill speed with added recuperation, but it ain't the case. On this short, hilly route the fixed wheel is about 1 km/h faster under similar effort, and climbs *much* more easily; my route includes Swains Lane which feels fine on the fixed with a bit left in reserve, but the single speed is a case of max effort to get up the hill. It's not entirely a fair comparison as the Cross Check is a heavier bike, still wearing its winter/off-road tyres.

I like the lowish fixed gear because I can get up hills (I'm not very strong) and 28 km/h = 90 rpm is a comfortable all day sort of pace. Anything above 30 km/h for me is an increasing battle against wind resistance with diminishing returns for the extra effort required so I tend not to bother, especially riding solo. Actually you are never riding solo on fixed because your friend Mo Mentum is a constant companion, helping you up the hills, and Mo lets you know immediately about the most minute changes in riding conditions (gradient, wind, rider effort, ...); on a freewheel bike you have to pay a lot more attention to detect subtle changes.

I do agree that fixed wheel is a bit anti-social in the sense that it's faster up the hills than geared/ss bikes and slower down them, so doesn't work so well if you are aiming for some group coherence.
The worst thing you can do for your health is NOT ride a bike

Re: gearing
« Reply #66 on: April 14, 2020, 06:23:43 pm »
In my experience you spend more time going uphill than downhill so fixed bikes are very efficient machines   :)
the slower you go the more you see

Re: gearing
« Reply #67 on: April 15, 2020, 10:11:30 am »
Two of us were riding fixies on last year's Dun Run and the different up/downhill rhythm was very noticeable, even though the Dun Run isn't massively hilly.  We gained more on the uphills than we lost on the downhills.  I think we averaged 17mph for the last 100 miles, once we'd got off that accursed Lea Valley psyclepath.
And Darkness and Decay and the Coronavirus held illimitable dominion over all.

zigzag

  • unfuckwithable
Re: gearing
« Reply #68 on: April 15, 2020, 12:27:09 pm »
Two of us were riding fixies on last year's Dun Run and the different up/downhill rhythm was very noticeable, even though the Dun Run isn't massively hilly.  We gained more on the uphills than we lost on the downhills.  I think we averaged 17mph for the last 100 miles, once we'd got off that accursed Lea Valley psyclepath.

some stats from my relaxed round trip affair which i rode on a (geared) gravel bike:

distance: 392.7 km
elevation: + 3409 / - 3418 m
moving time: 14:40:14
calories: 7826
avg. watts: 155
avg. speed: 26.8 kph
avg. cadence: 75.2
avg. heartrate: 111.5

Nelson Longflap

  • Riding a bike is meant to be easy ...
Re: gearing
« Reply #69 on: April 16, 2020, 09:47:25 am »
In my experience you spend more time going uphill than downhill so fixed bikes are very efficient machines   :)

That's physics innit ... but the speed differential between fixed and free is greater downhill than uphill is also a factor.

Let's assume that geared bikes descend 8 x faster than they climb, while fixed descend only 5 x their uphill speed, and let's suppose the fixed rider is 20% faster up the hills. Assume too that on the flat both ride at the same speed. For a ride with 400m of climbing over 20 km (ie pretty damned hilly) where the fixed rider averages 12 km/h, and 400m of descending also over 20 km the numbers pan out as follows:

Before reading on ... do these assumptions seem realistic to you?

Fixed uphill: 20 km at 12 km/h = 1h40m
Fixed downhill: 20 km at 60 km/h = 0h20m
Total climbing+descending time = 2 hrs
Geared uphill: 20 km at 10 km/h = 2h0m
(you can see which way this is going!)
Geared downhill: 20 km at 80 km/h (wow!!!) = 0h15m
Total climbing+descending time = 2h15m

It turns out that the fixed bike really is more efficient on this scenario! Small gains on the climbs outweigh big gains on the descents. While the geared bike descends 80/60 faster than the fixie (+33%) it climbs at 10/12 of the fixie speed (-17%) and all the extra time spent climbing means the fixie wins.

OK I picked the numbers partly to make the arithmetic easy, but are they really that far from reality? It suggests to me that the downhill disadvantage of fixed wheel, while real, also has a significant psychological element that amplifies the feeling of being slower. The old cycling folklore that "fixed or gears ... there's not really that much difference" has more than a grain of truth.

Personally, I really enjoy the even, steady pace when riding fixed which seems to me a very efficient way to cover long distances. Just don't try too hard to keep up on the descents!
The worst thing you can do for your health is NOT ride a bike

Re: gearing
« Reply #70 on: April 16, 2020, 10:02:10 am »
IME gears are faster and/or easier than fixed.  How much depends on how hilly it is and how fast you're trying to go.

Bernster

  • ACME (Herts Branch)
Re: gearing
« Reply #71 on: April 16, 2020, 10:09:52 am »
Out of interest, do we know how much more efficient a fixed bike is climbing compared to a singlespeed (or geared) bike of the same weight and same gear ratio? I get that the lack of deadspots / flywheel effect improves pedaling efficiency, but ultimately isn't it still the same power vs weight equation that we have on all bikes when climbing (i.e. very little difference, and unlikely to be 12km/h vs. 10km/h)?

LMT

Re: gearing
« Reply #72 on: April 16, 2020, 11:26:29 am »
Out of interest, do we know how much more efficient a fixed bike is climbing compared to a singlespeed (or geared) bike of the same weight and same gear ratio? I get that the lack of deadspots / flywheel effect improves pedaling efficiency, but ultimately isn't it still the same power vs weight equation that we have on all bikes when climbing (i.e. very little difference, and unlikely to be 12km/h vs. 10km/h)?

In answer to your first point, I don't know.

I take your point though that it is still down to the rider at the end of the day. Riding fixed means you cannot be lazy when turning a gear especially when going up hills -is this a good thing? Probably not when more than likely your cadence falls and your knees and legs start to fatigue which is poor form whatever way you look at it.

bludger

  • Randonneur and bargain hunter
Re: gearing
« Reply #73 on: April 16, 2020, 11:28:21 am »
It's a funny one with me and fixed. LMT you're right in that silly low cadences probably aren't very good for you but I find that when I do ride fixed, I really give hills a good run up and attack them so that I very rarely actually end up grinding in a silly cadence.
YACF touring/audax bargain basement:
https://bit.ly/2Xg8pRD



Ban cars.

Re: gearing
« Reply #74 on: April 16, 2020, 11:36:34 am »
Ultimately fixed is harder. But it does force you to ride efficiently I suspect