Gearing

I was on 50x16 which is 85" for town riding, but it just got unpleasant. I got a kick out of the effort it took to get up to speed and its ability to sustain it once there, but all things considered I'm glad I reduced it. There's just no need to make things tough for commuting, in my view. Depends how you get your kicks. I dropped to mid-70s for the Dynamo with the intention of going back up again afterwards, but the pleasure of easier riding threw that idea right out the window.

84" SS was just about sustainable for me when I first started commuting but conventional wisdom made me change to 66" fixed via 72" fixed. My legs got bloody big though.

I've got into the habit of trying to convince people to shun the fashion for deep V rims because I'm convinced that that extra rim weight is putting extra pressure on the knees at each set of traffic lights.

Anyway...my original question is thus...

Am I doing any damage to myself on flat fast rides (I'm training to start TTing this year) on 84" fixed? I really can't see how. My cadence is getting better...I'm starting to be able to sustain 90ish for a while but not quite for a full 10mi. I do tail off at the end.

I mean, my road bike is geared to 109" and I use that gearing in sprints and downhills. Apart from that, I'm happy spinning away at 80"ish on my road bike for hours on end and nobody tells me I'm killing my knees.

It's probably fine. How fast? How flat? Are your knees covered? Do you avoid excessive force on the pedals until you've warmed up? Do you 'rev up' out of the saddle if having to start from a stop/near-stop? Do you get any lingering pain in your knees? Do you have any history of knee injury? Do you think improved performance is most likely to come from legspeed or muscular endurance (within the limits of what your aerobic system can support)? Blah blah blah.

29:30ish for 10 when I'm balls out and I'm whittling this down as I get more and more used to being at threshold. I've just started trying to TT after nearly a year of exclusive endurance training. First time out my HR plateaued at 160! Cadence is averaging at about 80 over 10mi which I appreciate is a little on the mashy side of things.

I don't drive to where I am starting from which means that I normally have at least a few miles of city riding to do but I am very careful when pulling away from lights to use my body weight on the lead pedal and try not to strain my knees.

I had two minor ACL injuries (6 week recovery both times), one in each knee when I played basketball about 13 years ago and nothing since then. I have however had a fairly bad achilles strain within the last 6 months...I am fully recovered from this now.

I know that I struggle to spin above 90rpm in real life (170ish on the rollas) and as a 6'3" 13st rider I'm on the sprinter side of rider builds. I personally feel that once I've improved my aerobic fitness, most of my gains will be from muscular endurance rather than foot speed. That said, I have learned to spin a lot better in the last year or so...this year will be about finding out what I'm made of.

Thanks for the questions...they've helped me think this through a fair bit.

Thought it would at least be amusing to point out that my achilles strain was caused by riding 400mi with +20k ft of hills in three days while stuck on my big chain ring. The route took me across the Peaks, Pennines and over the Lakes...I'm happy when I'm mashing even if I know it will ultimately cause me problems :D

If you're not getting any pain (other than mild tenderness now and again) I'd just continue with that gear, but try to work on pedalling efficiency/pacing until race #1 arrives. Then experiment (a series of TTs on the same course is good for this, as even with fluctuations in weather from week to week, you can get an idea of how you respond to different approaches), e.g.

• race #1,2,3 in your 84"
  
• race #5,6 in ~90"; any faster? if not…
  
• race #7, 8 in ~79"; any faster?
  
• etc.
  

Gentleman. Thank you.

I haven't actually made any plans to race fixed or geared. I suppose I need to make a decision quickly and ultimately, geared is probably the sensible way to go.

Is there any merit at all in training fixed and geared? I remember how much my pedalling improved when I started riding fixed...

I see no problem in riding on 84" for racing and some training. My observation was that I don't think it is a sensible gear in the long term, especially if you are riding on undulating terrain or in urban areas, especially if you've had knee trouble previously.

As a general observation, there is a tendency amongst cyclists to ride bigger gears than is necessary which isn't helped by the cycling industry tending to fit 53/39 chainrings as standard to their products. That gearing is sensible if you're racing but for the majority of riders lower gears would be beneficial.

I switched the stock 12t for a 13t on my SS Brompton. 69" is plenty for urban stuff, especially with the rolling resistance of 16" Marathons. Everyone needs to spend more time doing 69.

My tank bike has 47/39 (big ring outside with 13-23, small ring with 11-21 on turbo with heavy resistance curve), and my more mercurial bike has 50/38 with 12-23. #notveryinterestingeventome #allaboutthechainline

I've got into the habit of trying to convince people to shun the fashion for deep V rims because I'm convinced that that extra rim weight is putting extra pressure on the knees at each set of traffic lights.

rotational mass, heavier wheel make it slightly harder to accelerate in traffic light (in theory).

I'm in the same boat, hell I switch my 52/42 crankset for a 46/30 and actually notice my journery time improved in London, wack a 13-24 freewheel on it and it's a great countryside gearing.

I see no problem in riding on 84" for racing and some training. My observation was that I don't think it is a sensible gear in the long term, especially if you are riding on undulating terrain or in urban areas, especially if you've had knee trouble previously.

This is all I meant really Dan. If the people who know about racing reckon you're doing it right and you've thought the implications through I'm happy, mainly because I don't know about these things. I just don't want you to hurt yourself!

Cheers Pete.

I have no idea how Tom regularly rides 84" in the city without causing himself grief.

Either there is something to the theory that if you get away with it for long enough or build up to it gradually you become stronger and less likely to injure or he has just been lucky so far.

I meant to say, I think he is the exception that proves the rule. Or he has titanium knees.

But you do need an exception, or the rule is clearly wrong ;)

To be honest, even if Tom can managed to ride with that gearing, he'll cripple his knees sooner than later.

my dad rode 80" (give or take) in the past since his 20's, and end up crippling his knees to the point that he can no longer 'grind' it without having some kind of pain, took me a while to force him to spin at 66".

Hmmm. I personally believe that if you very gradually build up to it over time you'll probably be ok. This is my very humble opinion. There are too many experienced riders out there turning big gears on a daily basis who don't have any problems for me to think that you are certain to cause yourself damage. I think its a bit much to suggest that Tom is going to knacker his knees because your Dad did.

The bigger issue is people ramping up their inches too quickly or just jumping in too big.

I'm not going against the conventional and very valid wisdom that spinning is better for your knees but if you're strong enough, you can spin 100" let alone 84".

My Dad hasn't riden a bike since his early teens and he is touching 70yo now. He has knackered knees...perhaps his ratio was wrong ;)

he probably wasn't spinning to the shop properly, just lifting and smashing his feet as he walk by.

I know fuck all about riding fixed, have only been doing so for a year and a bit. Probably shouldn't be voicing my opinions tbh.

Actually I liked to point out that I'm referring to riding on a daily basis rather than race/tt/etc.

I think I will try 84" for time trialling. As 90rpm at this gear works out about 22mph.

Everyone needs to spend more time doing 69.

Most important.

I speak with only a really basic knowledge so please correct me if I'm wrong. My experience is only of a couple of years of road cycling (club level) and 5 years of riding fixed. I've only done of couple of TTs.

Hmmm. I personally believe that if you very gradually build up to it over time you'll probably be ok. This is my very humble opinion. There are too many experienced riders out there turning big gears on a daily basis who don't have any problems for me to think that you are certain to cause yourself damage. I think its a bit much to suggest that Tom is going to knacker his knees because your Dad did.

So long as you get cause and effect sorted here:
Experience riders are riding on big gears because they are strong/fast riders.
Experience riders are not strong/fast riders because they have been riding big gears.

AFAIK the conventional wisdom is that your better off training for cadence and endurance first, then increase speed and power and reduce the length of the rides.
It's in the later stages of the training that your going to be riding shorter, faster and on bigger gears.
You may (perhaps) actually be better off going back to a lower GI and working on your cadence before working on speed. You still have time to do this before the season starts.

Everyone needs more 69 time though. This is a certainty.

There's a reason the juniors here and in Australia have gearing restrictions, limiting their highest gear. Spin to win.

72 "is the best gear.
thats why they used to have winter races on it-
and @hippy- yes

Unrelated to the discussion up there, I've now got a 19t on the back. My flat is cold and all my joints are suffering at the moment (my wrists and shoulders are as bad as my knees, so I don't think gearing is reponsible)

Also, on 84", cadence is approx 4 x speed (in mph) which I always enjoyed.