Re: [CR] Old Age vrs Crank Lengths


Example: Framebuilding

In-Reply-To: <342CC5BF-26C0-4E61-961C-0B7E2A957791@att.net>
References: <342CC5BF-26C0-4E61-961C-0B7E2A957791@att.net>
Date: Sun, 25 Jul 2010 19:59:51 -0500
From: Harry Travis <travis.harry@gmail.com>
To: Jon Spangler <jonswriter@att.net>
Cc: RICHARD HOWARD <rehoward1@verizon.net>, Dale Brown <classicrendezvous@bikelist.org>
Subject: Re: [CR] Old Age vrs Crank Lengths


Speedplay founder/engineer makes much of the company's expertise in custom fitting. They even distribute, to qualified folk, an extensive kit of wedges and extensions etc. for that customization.

There's a lot to be said for not falling though, whether while becoming familiar with a new cleat system, or when a temporary pedestrian walking on polished floor. Be aware to accessory covers for walking, and even rubber bumpers for better walking grip, now available for some Look -style cleats.

Yes, 165mm cranks from classic brands are harder to find; but the BMX crowd has established a firm demand for cranks down to 155mm length. They are available, inexpensive, and may even use on-topic bottom brackets. Bullseye was the name, but the same crank is now sold with a different label. BMX, yes, but you won't have to buy the purple anodized models.

Harry Travis Pine Barrens of NJ USA

On Sun, Jul 25, 2010 at 12:30 AM, Jon Spangler <jonswriter@att.net> wrote:
> Ted and Charles,
>
> Your posts about rehab and the many details of bike fitting offer a wealth
> of information.
>
> Charles, your comments on the many factors affecting one's rehab and
> recovery are excellent.
> There are SO many details to consider, all of them related....
>
> Ted's detailed descriptions of modifying cleats and bike parts to obtain a
> good fit remind me of my own
> less-sophisticated mechanical customization efforts.
>
> 1) I used long 5mm x 0.8 screws and nylon spacers between the pedal and the
> toeclip to functionally lengthen my
> (off-topic plastic) toe clips to accommodate work boots and running shoes
> and place the ball of my mismatched feet
> over the pedal axle.
>
> I used rubberized midsole material from my local shoe repair shop to add
> stack height to the (off-topic Look)
> cleats on one shoe to deal with a leg length issue, plus a whole package of
> the cleat wedges to position my surgically-
> reconstructed right foot.
>
> I may need to make a pilgrimage to visit Ted in southern California and
> learn more about the techniques I'll need to
> achieve the results I still seek...
>
> Jon Spangler
> who is encouraged in Alameda, CA USA
>
> Message: 12
> Date: Sat, 24 Jul 2010 21:09:57 -0700
> From: "Ted Ernst" <ternst1@cox.net>
> Subject: Re: [CR] Old Age vrs Crank Lengths
> To: <Classicrendezvous@bikelist.org>
> Message-ID: <C6FC9B0AC1724565B6B6913F43ED1140@D8XCLL51>
> Content-Type: text/plain; format=flowed; charset="iso-8859-1";
> reply-type=response
>
> All the individual experiences have put the hammer right on the nail!
> Everyone's problem and solution(s) is different and yet many are similar in
> origen.
> First when I do fitting with a rider who has had an accident, operation,
> has
> a congenital problem, any other a/o part or all of the above, I ask what
> they perceive a their limits are and where does it hurt or restrict
> activity.
> First I start with the foot position on the pedal and any ankle movement
> difficulty and work to resolve that.
> Too little foot on pedal and toes could get numb and not get best leg
> muscle leverage and efficiency.
> Too much foot into pedal gets into arch so that the "inner" center foot
> tends to "bend" on pedal and power loss results in more knee pressure and
> loss of efficiency.
> I would set foot position first and if you ride with clips and straps, if
> you have to, cut the toe clip in half and get it welded up to proper
> length.
> Then I go to leg length and set saddle height to good position for the
> longer leg.
> I've had good luck taking pedals and widening the plates to make up for the
> leg length discrepancy. Good welding can work miracles!
> Widest I've done is 3/4".
> By making the plates wider ala TA interchangeble plates, way ahead of it's
> time, you keep the leverage the same while allowing the short leg the same
> rotation and power without twisting back/spine too much on pedal
> revolution.
> Rotation and ankle float is an individual thing and do what's comfortable
> and works for you.
> I broke my femur head in a spill in '82 and has 4 pins in it to make it
> happy again. The foot slants out a few degrees after the set so that it
> took
> about a year to get my foot angle on my cleat to eliminate my knee pain.
> Because my fooy is angled out a little it made my hips a little off when I
> sat on saddle. I moved my saddle a few degrees over to straightn out my
> hips
> and I found that i could pedal straighter and easier on both knees and hips
> so that my inner thigh presure was eqal on saddle and I didn't get thigh
> soreness on one side of my inner leg by my groin. Paradise regained!
> Seems you can go about half the difference easily and body is able to
> adapt,
> but I like to go no more than 5mm diff.
> Then you can raise heel somewhat on stroke to compensate and not have too
> much difference in muscle stretch and efficiency.
> If you set saddle for short leg, then longer leg gets jammed and knee
> overloads losing much strength, and then hip get pushed up instead of
> pulled
> down by short leg giving back the same unbalanced stress.
> For years I rode 165 cranks on track bike, we started racing on fixed gears
> for all races from 1/4 mi to 50 mi.and then we got road bikes with 170's
> and
> we could go back and forth w/o any noticeable stride.
> I tried 172.5 but after over 20 years on 165/70 the 2.5's seemed to make me
> ride "squares" but then that was my "feel". Went back to 170.
> Remenber if you go down in crank length your leverage diminishes so that
> you
> may have to gear down a cog or you push too hard with higher ratios on
> shorter cranks overloading your knees.
> Your circle on longer cranks is much greater diameter and the resulting
> knee
> crunch is not always tolerable, so use crank and gear ratios accordingly to
> balance equation.
> I often use the tapered wedges Big Meat or the LeMond fit kit stuff to
> balance foot out so that your natural angle of downward push feels equal
> pressure on pedal.
> I also have taken nylon, plastic, delrin type material, cut to cleat
> outline, drilled holes/slots in plate and gotten longer screws , and
> attached the spacer in between the cleat and shoe to make up leg length
> diff
> when too many of the 1mm wedges were not practical.. One guy with over an
> 1"
> diff on leg length went to orthpedic guy and had a 3/4 inch piece of wood
> made for his cleat spacer and had this fat cleat on one foot, but voila
> foot/leg/back problemos - GONE!.
> Once the foot and leg reach differences are worked with then at similar
> time
> the seat for and aft plus height are brought into place and then the
> clockwise rotation moves to the bar and stem set up.
> It's a logical sequence, and the computers aren't bad to get close enuf for
> regular riding.
> If you have difficulties in setting up a special need, then all those
> Robert
> Hall suit averages are out the window and it takes a little "extra"
> knowledge and experience to fulfill a rider's need so that they can
> maximize
> their pleasure and get the exercise and fun they deserve.
> Positions are tricky at best and riders that aren't quite symmetric present
> a real chalenge for the fitting person.
> We all vary so much and we are so unique that the only rule that's constant
> is there's not a general rule thats constant in bike fitting.
> Down in the drops, it's the lowdown from
> Ted Ernst
> Palos Verdes Estates
> CA USA
>
> <snip>
>
>
> ----- Original Message -----
> From: "verktyg" <verktyg@aol.com>
> To: <Classicrendezvous@bikelist.org>
> Sent: Friday, July 23, 2010 10:57 AM
> Subject: Re: [CR] Old Age vrs Crank Lengths
>
>
> Dick,
>
> I had a total hip replacement back in 2003. I went through 2 months of
> physical therapy plus several more months of range of motion exercises
> to get back to "normal". Knees are far more complicated and recovery can
> take longer.
>
> I used to ride 170mm cranks on my road bikes and 180mm on my off road
> bike. My road cadence was 90, off road it was mostly mashing.
>
> Some folks claim to have the "Princess and the Pea" gift and can tell
> the difference between 170mm and 172.5mm cranks. Right now most of my
> bikes have 170mm cranks but a few have 175mm - I can't tell the difference.
>
> After the hip surgery, my right leg is 3/4" shorter than my left plus my
> right foot is canted out about 10? more than before. I've also had
> chronic tendinitis in my knees and bone spurs under my knee caps which
> have worn grooves in the cartilage.
>
> I use a pedal extender on my right pedal plus I ride with toe clips and
> straps but no cleats. This allows me to move my feet around at will much
> more than I could do with clipless pedals.
>
>
> The angle of my feet in the pedals has a major effect on knee comfort.
> My feet are wide, 10 1/2 EEE so I use wide MTB pedals. The toeclips are
> mounted all the way to the outside of the pedals. I ride with my toes
> pointed outward and that's had a positive effect on the tendinitis.
>
> You mentioned range of motion issues. I don't know that a 5mm (less than
> a 1/4") change is going to make that much difference for you.
>
> You might want to try riding with just a toe clip on the affected side
> and let your foot "float". You may even need a pedal extender for that
> side.
>
> It can take months of exercising to get your range of motion back.
>
> Good luck,
>
> Chas. Colerich
> Oakland, CA USA
>
>
> Jon Spangler
> Writer/editor
> Linda Hudson Writing
> TEL 510-864-2144
> CEL 510-846-5356
> JonSwriter@att.net
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