Lower ratio option - to save ageing knees - !

[Eurostar]

Think about Q rings, they lower the ratio when your knees need it the most. And you can get them on a free trial at the moment. http://www.rotoruk.co.uk/qrings/

 

[Smokin Joe]

Seeing as the idea is to reduce pressure, don't shorter cranks result in more torque required due to the shorter distance form the centrepoint of rotation and, therefore, increase pressure on the knees? If this is desired over the amount of actual movement, then that's understandable, but I'm just thinking about the theoretical basics of it all.

Logically that would seem to be the case, but apparently it isn't so -

http://cyclefit.co.uk/short-cranks-better-pedalling

There is a recently conducted piece of research which suggest that no rider needs a longer crank than 140 or 145mm, I can't remember which as I've lost the link article. I've always used 172.5mm cranks (6'1" tall) but I've recently switched to 170 and even that little drop seems better. I wish now I'd bit the bullet and gone to 165.

 

[Sharky]

With shorter cranks, you raise the saddle to keep the leg extension the same. So say you go from 170 to 145, you would raise the saddle by 2.5 cm. This then gives an extra 5cm from the pedal at the top of the rotation to the saddle and this means that the hip angle is more open and the angle at the knee is less, which in turns means less stress on the knees.

 

[Smokin Joe]

With shorter cranks, you raise the saddle to keep the leg extension the same. So say you go from 170 to 145, you would raise the saddle by 2.5 cm. This then gives an extra 5cm from the pedal at the top of the rotation to the saddle and this means that the hip angle is more open and the angle at the knee is less, which in turns means less stress on the knees.

Funny enough, I've given a bit of thought to saddle height lately. The traditional method of determining it is to sit on the bike wearing your normal cycling shoes and position so the leg is straight when the heel of your shoe is on the pedal. I've now used that method but then dropped the seat post by 1cm, and combined with the shorter cranks that feels so much better. I can stay seated on sections of a climb where I would normally be standing on the pedals and get more power down while feeling more comfortable. I'm sure from looking at videos and still pictures that most pros use a lower saddle height than the average amateur.

I'd like to hear Old Roadman's thoughts on this as he rode in the professional peloton.

 

[oldroadman]

It depends on what riding you ant to do. Looking back, as an odd shape (short legs for overall height - don't even start guessing!!), 167.5 were fine. For just pottering about a compact (34/50) with a 12 - 26 cassette gets you anywhere. Ageing knees - got those - like to spin not push. It's awful to see the so-called "coaches" in TT oriented clubs still advising youngsters to push massive gears at a young age. This will come back to bite one day. As for saddle height, err on the side of low and spin the gear. But remember to do some stretches post ride, as this definitely shortens fibres which need to be re-stretched for best flexibility.
SJ at 180cm or a bit more might be Ok on 172.5, or 170 now (good move if you are inclined to spin), the real factor is not height but inside leg length.
So far as the Rotor/Oval ring thing is concerned, found no difference really, but then on another string someone called me wrong on that, and what do I know? Just one thing, 53x15 is the same whether it's round or oval, and any benefit would only possibly be gained when pushing a big gear. So would not apply to most riding when a nice 90-110 rpm evens everything out! Watch a pro race, the only time you see big gears used properly is at maximum effort, or in a sprint, or in a TT. Even then the gear is usually going over fast. Most of the time, even when lined out, the gear still goes over quickly, which helps recovery when the pressure eases.
Summary - gear lowish, spin, work out your inside leg relative to seat height (bike fits may help, or the Bernard Hinault basic method, mentioned many times before), start at the "ideal" point and err on the side of slightly lower. And enjoy!! Any help?

 

[oldroadman]

Funny enough, I've given a bit of thought to saddle height lately. The traditional method of determining it is to sit on the bike wearing your normal cycling shoes and position so the leg is straight when the heel of your shoe is on the pedal. I've now used that method but then dropped the seat post by 1cm, and combined with the shorter cranks that feels so much better. I can stay seated on sections of a climb where I would normally be standing on the pedals and get more power down while feeling more comfortable. I'm sure from looking at videos and still pictures that most pros use a lower saddle height than the average amateur.

I'd like to hear Old Roadman's thoughts on this as he rode in the professional peloton.

The trad method you use does not work for everyone, but clearly does for you, and lowering a single cm was an interesting idea. If it's worked, why not, and well done. It does help with spinning a gear evenly and quickly to be a bit lower. Just reading reiver's post above tells us all we need to know about cadence, keep it brisk and less stress is the result. Now, naughty old feller that I am, I'm quite happy to take Ibuprofen 400mg after a feed (better for the stomach) or use the gel around the kness, ankles, hips, to keep the possibility of inflammation low. No-one wants my samples nowadays - of any sort!

 

[simongt]

@simongt How 'bout this one? Just shy of £30. 170mm crankarm, too.

42/34/24t

Interesting setup, but the rings are spot welded onto the spider. Trouble is if, like most of us ( ? ) we tend to favour one or possibly two particular rings, when it / they wear down, the whole chainset has to be replaced, rather than just the offending ring /s.
I think one or two folk have missed my point that it's at the high end I'd like to lower the ratios a bit, as I very rarely use the low end of the cassette and can't recall the last time I used the granny at the front - !

 

[CharlesF]

It depends on what riding you ant to do. Looking back, as an odd shape (short legs for overall height - don't even start guessing!!), 167.5 were fine. For just pottering about a compact (34/50) with a 12 - 26 cassette gets you anywhere. Ageing knees - got those - like to spin not push. It's awful to see the so-called "coaches" in TT oriented clubs still advising youngsters to push massive gears at a young age. This will come back to bite one day. As for saddle height, err on the side of low and spin the gear. But remember to do some stretches post ride, as this definitely shortens fibres which need to be re-stretched for best flexibility.
SJ at 180cm or a bit more might be Ok on 172.5, or 170 now (good move if you are inclined to spin), the real factor is not height but inside leg length.
So far as the Rotor/Oval ring thing is concerned, found no difference really, but then on another string someone called me wrong on that, and what do I know? Just one thing, 53x15 is the same whether it's round or oval, and any benefit would only possibly be gained when pushing a big gear. So would not apply to most riding when a nice 90-110 rpm evens everything out! Watch a pro race, the only time you see big gears used properly is at maximum effort, or in a sprint, or in a TT. Even then the gear is usually going over fast. Most of the time, even when lined out, the gear still goes over quickly, which helps recovery when the pressure eases.
Summary - gear lowish, spin, work out your inside leg relative to seat height (bike fits may help, or the Bernard Hinault basic method, mentioned many times before), start at the "ideal" point and err on the side of slightly lower. And enjoy!! Any help?

Oldroadman, please help an ignorant fellow and explain what "going over fast" and "goes over quickly" means.TThanks

 

[oldroadman]

Oldroadman, please help an ignorant fellow and explain what "going over fast" and "goes over quickly" means.TThanks

Keeps spinning quickly, over 90-110 rpm. In the pro race situation, when riders are moving very fast (55-70 kph), usually big gears are in use but leg speed is still high simply because of the speed. In a settled peloton, perhaps moving at 40-48 kph, the gear will be a smaller one, legs still turn quickly. This all helps save energy, is efficient, and aids recovery from big efforts. Hope this helps?

 

[migrantwing]

Interesting setup, but the rings are spot welded onto the spider. Trouble is if, like most of us ( ? ) we tend to favour one or possibly two particular rings, when it / they wear down, the whole chainset has to be replaced, rather than just the offending ring /s.
I think one or two folk have missed my point that it's at the high end I'd like to lower the ratios a bit, as I very rarely use the low end of the cassette and can't recall the last time I used the granny at the front - !

For that price, I'd be tempted tp get it. After all, it's what you want. How about trying a different cassette, or just spending a bit more on a crank that you want, but with the option of removing/replacing chainrings? It's a win-win situation.

I realise money is tight these days. I'd like to swap out my cassette and swap out my 34t for a 36t or 38t. Guess I'm just gonna have to either save up, or work harder

 

[CharlesF]

Keeps spinning quickly, over 90-110 rpm. In the pro race situation, when riders are moving very fast (55-70 kph), usually big gears are in use but leg speed is still high simply because of the speed. In a settled peloton, perhaps moving at 40-48 kph, the gear will be a smaller one, legs still turn quickly. This all helps save energy, is efficient, and aids recovery from big efforts. Hope this helps?

Thanks, it now makes sense to me and reminded me that those speeds are way beyond me!

 

[oldroadman]

Thanks, it now makes sense to me and reminded me that those speeds are way beyond me!

Beyond me too nowadays - except I can still descend just like the old days (but no cadence required..!) 90 rpm is easily done though, just on a much smaller gear. Nothing like 50/34 chainset and plenty of cogs 16 and bigger on the cassette

 

[CharlesF]

Beyond me too nowadays - except I can still descend just like the old days (but no cadence required..!) 90 rpm is easily done though, just on a much smaller gear. Nothing like 50/34 chainset and plenty of cogs 16 and bigger on the cassette

Yeah, I am giving up and fitting a trple

 

[oldroadman]

That's not giving up, it's a sensible way to keep going. You could do big boy's gears too, 34/44/53 with an 11-20 cassette, or have a nice easy 32/42/50 with 12 - 28 and just enjoy yourself. 50x12 spins out nicely on the descents, to remind us of youth!

 

[simongt]

A pal at work has recently started cycling, using a straight bar hybrid. As he's been to spinning classes @ the gym, he has fixated himself on 90 -95 rpm. As the bike he bought has a 'stock' chainset, he's stuck in the middle chainring most of the time in order to achieve his desired cadence. He admits it is B####Y hard work thought - ! Perceived wisdom on cadence appears to be listen to your body and try and maintain between 70 - 90 rpm average. Apparently Lance Armstrong was a 100 rpm rider, wheras Jan Ulrich is a 70 rpm man. I had another go today and I just can't get my 62 year old legs to spin any faster that about 80 rpm, even downhill at full tilt - !