Crank Arm Length 172.5mm to 175mm

[campy man]

Been riding 172.5mm crankarms since Day 1 but thinking about giving 175mm a shot, mid-compact rings.

I'm more a spinner than masher, will climb if a hill is on the route but more a Rouleur type. Heard 175mm cranks are good for climbing but can cause some issues with knees.

Would be great to hear from riders that started with 172.5mm and tried 175mm crankarms.

[R3awak3n]

I dunno, I have 172.5 on all my bikes and put some 175 on one of them and did not notice any difference. Like at all. I did have to lower my saddle though :)

[Tickdoc]

Been riding 172.5mm crankarms since Day 1 but thinking about giving 175mm a shot, mid-compact rings.

I'm more a spinner than masher, will climb if a hill is on the route but more a Rouleur type. Heard 175mm cranks are good for climbing but can cause some issues with knees.

Would be great to hear from riders that started with 172.5mm and tried 175mm crankarms.

I've got a 170 crank 8sp and a 175crank 11 speed on the way, and I've been wondering the same as you.

Everything else I've ever ridden is 172.5.

[kramnnim]

I tried 175s and hated them. Hated.

[Louis]

There's some relevant stuff in this thread:

http://forums.thepaceline.net/showthread.php?t=182188

I switched to 175 and I like them. (see link for details)

[eBAUMANN]

I ride 172.5 and 175 interchangeably, don't really notice much of a difference.

That said, if you are a spinner, you will probably be better off sticking with 172.5's, as a shorter crank arm will allow you to spin faster (in theory). On the other hand, a 175 arm offers greater leverage and there are more than a few articles out there suggesting that a longer crank will get you up a hill faster, mainly because it will (in theory) allow you to push a slightly harder gear (due to your increased mechanical advantage) which in turn moves you along quicker...or something.

Other things to consider:
- pedal strike
- toe overlap
- saddle height (as mentioned previously)
- pedal/knee alignment

Bottom line...its only 2.5mm, just ride whichever feels more comfortable, if they feel the same, ride whatever you have ;)

[oldpotatoe]

I ride 172.5 and 175 interchangeably, don't really notice much of a difference.

That said, if you are a spinner, you will probably be better off sticking with 172.5's, as a shorter crank arm will allow you to spin faster (in theory). On the other hand, a 175 arm offers greater leverage and there are more than a few articles out there suggesting that a longer crank will get you up a hill faster, mainly because it will (in theory) allow you to push a slightly harder gear (due to your increased mechanical advantage) which in turn moves you along quicker...or something.

Other things to consider:
- pedal strike(2.5mm)
- toe overlap(2.5mm)
- saddle height (as mentioned previously), 2.5mm
- pedal/knee alignment

Bottom line...its only 2.5mm, just ride whichever feels more comfortable, if they feel the same, ride whatever you have ;)

If my HS math is right, the 'circle' described by 175mm cranks vs 172.5 is 16mm difference, 1/3 of an inch. I think in a blind test, most couldn't tell the difference. 170 to 175 maybe, but not 2.5mm, IMHO.

[saab2000]

I started cycling with 170s decades ago. 'Graduated' to 172.5. Tried 175s because I thought "If some extra length is better, well more must be better yet". Didn't work out that way and I'm back on 172.5s.

If I change anything again it's going to be to go back to 170s.

[witcombusa]

I ride bikes with cranks from 165, 170, 172.5 and 175. If you get of one and right on another, you feel the difference for a couple minutes. If it's been a few days, you don't even notice...

[Ralph]

A person who rides a shorter crank arm can make up that loss of leverage by using a lower gear or just spin a tad more. My fitter says no real difference in power output when riding different crank arm lengths.

So......why not use the crank arm length that fits your body?

[superbowlpats]

As others have stated, you'll most likely not notice a change from 172.5 to 175. I ride 56 cm bikes and have 175's on my CX bike (because that's what it came with), 170 on my road bike (switched from 172.5) and 165 on my TT bike. The 165's were to help with my hip angle. so other than the hip angle improvement I honestly don't see any impact of the crank length on my cadence (~90). in all cases be sure to make the appropriate changes to your seat position.

[commonguy001]

I've put lots of miles on 175s and quite a few on 172.5s and prefer a 175 if I have a choice. My cycling inseam is 88cm so I'm not trying to run an overly long crank for my height.

When I raced I tried some 177.5s on my TT bike and didn't feel I could get on top of the gear so I pulled them after a couple of weeks. It was pretty easy to tell they weren't going to work.

[saab2000]

As others have stated, you'll most likely not notice a change from 172.5 to 175. I ride 56 cm bikes and have 175's on my CX bike (because that's what it came with), 170 on my road bike (switched from 172.5) and 165 on my TT bike. The 165's were to help with my hip angle. so other than the hip angle improvement I honestly don't see any impact of the crank length on my cadence (~90). in all cases be sure to make the appropriate changes to your seat position.

Why would you change your seat position? The center of the arc remains the same.

[carpediemracing]

Been riding 172.5mm crankarms since Day 1 but thinking about giving 175mm a shot, mid-compact rings.

I'm more a spinner than masher, will climb if a hill is on the route but more a Rouleur type. Heard 175mm cranks are good for climbing but can cause some issues with knees.

Would be great to hear from riders that started with 172.5mm and tried 175mm crankarms.

Having moved from 175s to 170s to 175s etc...

First, how long are your legs? With a sub 29" inseam I have found 175s to be great. After watching me turn to 175s many years ago (2003) a couple friends (former teammates) with 34" inseams said, well, if he's using 175s I'm going to get something longer also. Both went to 180s and both have tried shorter cranks, returning immediately to the 180s as soon as possible, sacrificing crank quality to get the right size. One enjoys some longer rides (Belgian Waffle Ride, for example) as well as group rides, the other was just a plain hammerhead, doing 3 hours daily and duking it out with current and ex-pros on group rides, but he can't ride anymore due to a medical issue.

Knee issues - only if you have a problem bringing your knee up 5mm more. I lower my saddle to accommodate the longer cranks, so pedal axle to top of saddle distance remains constant. For me my knees hurt if I move away from a small range of pedal->saddle distance so I keep that constant. I have absolutely zero problems with knees going back and forth if I adjust everything. I also generally don't think "I have longer levers, I'm just going to monster this gear up the hill". My peak power doesn't change much so I'm putting similar stress on my knees.

(I have extremely sensitive knees, for what that's worth.)

With longer cranks your knee/leg comes up higher. I'm not skinny so that's an issue as soon as I hit about 170 lbs, and in the last 15 years I probably averaged 180-185 lbs. When I'm 160 lbs I'm generally clear of leg-torso impacts, but this is one of the primary reasons I'm back to exploring 170 cranks.

Keep in mind that you'll need to move your saddle forward a few mm with longer cranks (to keep knee->pedal relationship the same). The saddle adjustments will mean a slightly longer and lower stem for the longer cranks (because your saddle moved down and forward).

For cadence I'd give myself 4-6 months to adapt to longer cranks. Shorter cranks, maybe a few weeks tops. When I go to longer cranks it's a commitment. I'll try to change in Oct/Nov so that by March I'm acclimated. My cadence dropped significantly the first time I went to 175s, from maybe 105-110 rpm comfy spinning on 170s to under 90 rpms on the 175s. However, by the time I started racing, I was okay spinning at about 100 rpms. Nowadays 100-105 rpms is okay. I recently went back to 170s as an experiment but I haven't adjusted to them yet (it's been maybe 5 or 6 rides).

Remember that for aerobic stuff it's power to weight. My bike and I weigh about 190 lbs total, or 86 kg. My aerobic/mental ability let me hold 160w on longer climbs. It doesn't matter what crank I use, that w/kg (1.86 w/kg) is what determines how fast I can climb. Adjust for wind, mechanical efficiency (like if I have a flat tire, etc), but the basic formula remains in place. Leverage has zero to do with that bit because my w/kg doesn't change much.

For non-aerobic, unsustainable big gear rolls (53x15 on 170s, standing) longer cranks allow you to roll a bigger gear at lower rpm, and possibly do it seated, because you're already maxing out effort (800-1000w for me) and now leverage can help apply the power a bit differently. My favorite application of 175s, vs 170s, is on a 200 meter hill that maxes out at 6-8%. On 170s I'd sit and spin a 53x17 or 15, on 175s I'd roll a 53x14. In a sprint I could use an 11 or 12 on the 175s instead of a 12 or 13 on 170s. It's a hill in the Bethel Spring Series, and I've promoted and raced there 5-8 times a year from 1993 until last year. For about 10 years I'd do 80-odd racing laps on that course a day, and virtually every win I've ever had has been on that hill. 22 years of racing there, say 6 times a year is 133 race days, so, conservatively, 4000-5000 laps. Whenever I went back to 170s I faltered there, and in fact the reason I'm trying 170s now is because it's not really possible to hold a race there anymore due to traffic. Now I'm more concerned with flatter sprints.

Age also matters. When I was young I could spin much better, and I think I had more power. I know my top speeds were 20% higher than they are now, and I don't think I've gotten much less aero, and my bikes are pretty similar if not slightly more aero due to more aero wheels. I used 167.5s for my peak speeds, 170s I was close, but as I got older I slowed significantly on 170s. Going to 175s helped reverse the slowing trend but now I'm slower than before I went to 175s.

Back to climbing. Going up a long climb (for me it takes almost 2 hours to climb all of Palomar, the climb itself and the climb to the bottom of the climb), I noticed basically zero difference with different crank lengths. Only losing something like 30 lbs took some time off, and it wasn't earth shaking either, like 8 minutes over that close-to-2-hours, with similar average power for the entire climb (mid-upper 150 watt range).

For steep climbs, the ones where you're close to zig zagging just to stay upright, long cranks also doesn't help. There's a climb near me that takes about 6:30-8:00 for me to climb (the fast riders do it in less than half that time). It's hard to climb it slower because I'd topple over, there's a minimum speed I have to go, minimum power. I thought for sure the 175s would help because I could use a bigger gear or whatever but it didn't. With lower cadence (for a given pedal speed) there's a longer dead spot, bigger surge, so you end up being a bit more surge-y.

Remember that for actual climbing, meaning situations where you're using your aerobic capacity, not sprinting anaerobic stuff, it's all about power to weight. What cranks I have really doesn't help for aerobic stuff, once you're at the limit you're reduced to a certain power output and that nets you a particular speed based on grade, weight, wind, etc.

[carpediemracing]

Why would you change your seat position? The center of the arc remains the same.

You don't fit to the arc, you fit to leg extension. Specifically it's about the leg extension at the bottom and knee angle at "peak power", so when foot is forward (say 1 to 5 o'clock position on the right side). Raising my leg more doesn't bother me because I really don't apply much power seated, and when standing the position is much more fluid.

Screw with those seated knee angles and I'm in pain in less than an hour of easy pedaling, as I recently proved to myself.

To maintain knee angles for longer cranks it'll require moving the saddle down and forward the same amount as the difference in crank length. When going from 170s to 175s my saddle goes down 5 mm, forward 5 mm.

[carpediemracing]

If my HS math is right, the 'circle' described by 175mm cranks vs 172.5 is 16mm difference, 1/3 of an inch. I think in a blind test, most couldn't tell the difference. 170 to 175 maybe, but not 2.5mm, IMHO.

Honestly I'd probably find a 2.5 mm crank length difficult to tell, as long as saddle position relative to pedal remained identical.

Saddle position is critical though. Recently, I had a (Guru) fit done, and I'm definitely a self-fitter. I was doing it as a favor to the fitter who is a cycling advocate, old time friendly rival, and just a good guy all around. The fitter would ask if I wanted to go up or down, and by default he was using 5 mm increments. Believe me, you can tell when it's up or down 5 mm.

As we honed in on my "ideal" saddle height (or, really, saddle to pedal distance), we ended up a bit high. The fitter dropped the saddle 5mm (mechanically/remotely so I was pedaling the whole time). It felt wrong so I asked him to raise it less than 5mm, like 3mm. I felt like such the Princess and the Pea for a that tiny adjustment, but at least for him it was just typing 3 somewhere and touching something on his iPad. Saddle went up 3mm and it felt right.

After doing the Guru fit he then used a laser level/square to measure my bike. The measuring is done after the Guru fitting bit, apparently to avoid any preconceived notions on fit.

My saddle->bar distance was off but mainly due to the fact that the Guru system couldn't even match my current set up (and I was curious about extending more). My bike length is outside their range of motion, by 2 cm I think, so trying 2-3 cm longer wasn't possible.

However, when he measured the saddle, which is really key for no pain for me due to sensitive knees, I was a bit shocked when he came up to the exact millimeter (518 mm) for my bike as the fit bike. That "3mm up" was exactly what I needed, and he wasn't giving me any idea of where I was, plus he measured BB to saddle rail (same saddle on both, same crank length on both, same pedals on both), so it's a number that's foreign to me. I measure BB->top of saddle, adjusting for pedal or crank changes.

So ultimately you'll be able to feel some differences.

In a related thing I was racing track and road in 2009. Because I was already on 175s on the road I decided to use 170s on the track, not the standard 165s. I felt I could swing 5mm but not 10mm difference, and I was racing road one day and track the next, and I was doing this weekly.

I tried using 170s on the road in 2008 to prepare for the track but I was miserable, unable to do well in my favorite races, etc. When I went back to 175s over winter 2008-2009 things seemed much better, so I raced on the road on 175s (typically Sunday, sometimes Sat also), did a group road ride Mon, raced Tues on 175s, Wed at the track on 170s. My racing on the road wasn't bad, in fact it was pretty good, but on the track I lacked snap. I finally switched my road bike to 170s later in the season (late July or early August) to try and improve my track racing. I adjusted the saddle etc on my road bike to match the cranks.

I can't pinpoint exactly what it was but I felt much better on the track, doing much better, and against the same riders. Instead of getting dropped from behind the moto in a keirin I won the race, instead of getting dropped in a miss and out I was in the final 3 and only got caught at the line, etc. I got one week of track racing in after the road bike crank switch but crashed the following Tuesday so my season ended the second week of August. I decided not to return to the track so after I recovered from the crash (few weeks in wheelchair, couple more months not riding) I put 175s on and promptly upgraded to Cat 2 the following year.

So although I can't tell you exactly what was happening (no powermeter on track bike, not even speed for all but one week, and apparently on the track a cyclocomputer that I can see is illegal, but whatever), there was an improvement when I made my bikes' crank lengths consistent, even over a 5mm difference.

[fuzzalow]

I think if you have the souplesse in your pedal stroke it will get thrown off by a change in crank length if you A-B between bikes of different crank lengths. If the changeover in crank length is for only one bike you will adapt your stroke to the newer stroke movement in due time.

At a saddle height of 743mm I ride 175s. I had actively ridden 175 switching to 170s between my road bike and a Brompton, which comes stock with 170s. I didn't like, and couldn't spin, the 170s. I didn't like, or wish to entertain, adapting what I know is my good pedal stroke into a 170 crank. And I was always going to put 175s on the Brompton, it was just the time period before installing a Sugino 175 crankset into the bike that I had to ride both sizes.

If you have the skill, turning over a gear at 95+rpm should be very easy and effortless. Being able to do this is both a combination of a learned firing sequence in the stroke and a correct setup on the bike that provides stability which therefore allows the maintenance of fluidity in your stroke. But don't kid yourself that you can slop-dash crank arm sizes to a finely tuned and ingrained pedal stroke and just do it. Riding a bike is just riding a bike to a bicyclist. But to a skilled sport cyclist/athlete it has more skill and finesse than any bicyclist on a Citibike or a beach cruiser is cognizant of.

[fuzzalow]

The fitter would ask if I wanted to go up or down, and by default he was using 5 mm increments. Believe me, you can tell when it's up or down 5 mm.

I don't mean to sound critical of paid, so-called "professional" fitters, but good grief to anyone semi-conscious, what fitter thinks in terms of 5mm increments?

Caveat emptor.

Every time I hear somebody give pompous sage advice to solve somebody's cycling maladies in saying "get fit by a good fitter" I cringe. Yeah? Then I gotta ask what determines "good" and then how do I find this guy?

[ultraman6970]

It depends a lot of the rider, some riders get knee pain going from 170 to 172.5 right away even if they lower the saddle a little bit. Other ones wont notice anything will get 175 w/o any problems... all depends.

My personal experience, cant use 175 at all, even if i lower the saddle.

W.o trying is hard to tell.

[Bob Ross]

The fitter dropped the saddle 5mm ...[snip]... It felt wrong so I asked him to raise it less than 5mm, like 3mm. I felt like such the Princess and the Pea for a that tiny adjustment
I don't mean to sound critical of paid, so-called "professional" fitters, but good grief to anyone semi-conscious, what fitter thinks in terms of 5mm increments?

Point of reference: My wife has been using Paul Levine @ Signature Cycles as her fitter for years. In almost every instance any changes made have been on the order of 1mm or less. Sometimes 1.5mm, once in an extremely rare while 2mm, but mostly 1mm. Or less.

Paul calls her The Princess and The Pea!

[OtayBW]

I don't mean to sound critical of paid, so-called "professional" fitters, but good grief to anyone semi-conscious, what fitter thinks in terms of 5mm increments?

Caveat emptor.

A 5 mm difference in saddle height (with slight fore/aft adjustment) on leg extension and possibly drop/reach - especially if you're near the top of your range - is definitely something that matters to me.

[Ken Robb]

I have had 170, 172.5,175 and 180 cranks. I'm 6'1 and most were/are 175. I can detect a 5mm difference but not 2.5. When I first got the 180 cranks I really noticed a big improvement in my ability to muscle up hills but after doing this for a while I developed some discomfort in my knees so I swapped the 180s for my familiar 175s.

[tv_vt]

You won't know what works for you until you try them. You'll find your own sweetspot eventually. I'm 6-2 and have tried everything from 170 to 180. Early bikes only had 170 for choice. Then I got a 175 and no looking back. After trying longer ones and 172s for a little while, I'm good with 175.

There is no miracle length. All can work, but some give better sensations than others. And it can also depend on what terrain you ride in and your style of pedaling.

Just try em - they won't kill you, and see for yourself what you like. Don't need to overthink it.

Cheers.

PS. like others have said, you should raise or lower your seat so that full extension length stays the same. Which means for every 2.5mm change, your knee at top of stroke is 5mm higher or lower. Going from 170 to 175 means your knee is 1cm higher - not insignificant. And the circumference of one crank revolution changes about 8 mm for every 2.5mm change. No big deal until you throw in cadence - 100 rpm means your feet are traveling almost a meter more every minute (800mm). That starts to add up.

[drewellison]

Point of reference: My wife has been using Paul Levine @ Signature Cycles as her fitter for years. In almost every instance any changes made have been on the order of 1mm or less. Sometimes 1.5mm, once in an extremely rare while 2mm, but mostly 1mm. Or less.

Paul calls her The Princess and The Pea!

Wow! I have pizza and beer on a weekend, and that alone counts for 2mm of difference in fit between Friday and Monday.

I'm a self-fitter. I've never quite understood all the guidelines (rules?) in fitting, like knee over pedal axle for maximum power. So what do you do when you start going uphill and you're knee is no longer over the pedal axle? It seems to me that knee angle might be a better guide?

As I've gotten more and more into stretching and core strengthening over the years, I've moved my saddle back, lower, and dropped my bars (after going through a bar raising trend about 10 years ago. (Grant Peterson influence?) I do it all by feel. YMMV, of course.

Someone mentioned fitting crank length proportional to your body? Then if someone 5'2" rides 165mm cranks, my 6'1" body should have 195mm cranks, all else being proportional.

[kramnnim]

Someone mentioned fitting crank length proportional to your body? Then if someone 5'2" rides 165mm cranks, my 6'1" body should have 195mm cranks, all else being proportional.

I think about this every time I ride with a friend who is 6' 7". His top tube is almost as high as my saddle. He uses 177.5s. I'm convinced he needs a bike with 36" wheels and 200mm+ cranks.

[Ralph]

The length of the femur might in some way correlate to best crank arm length for a person. But generally....I don't think crank arm length much matters for most folks. Just another of many variables. (high school physics....levers and pulleys) The body/brain compensates.

[carpediemracing]

I don't mean to sound critical of paid, so-called "professional" fitters, but good grief to anyone semi-conscious, what fitter thinks in terms of 5mm increments?

Caveat emptor.

Every time I hear somebody give pompous sage advice to solve somebody's cycling maladies in saying "get fit by a good fitter" I cringe. Yeah? Then I gotta ask what determines "good" and then how do I find this guy?

This is part of the fitting process. The rider starts at an absurdly low position, so maybe 5-7 cm too low. You want to get too high also, as you start feeling stuff that doesn't seem right. Ditto bars, they were much too low and close to start.

Initially I was asking for 1-2 cm movements, like "just keep going... keep going...".

It's not the fine tuning part, but when I asked for a smaller increment, that 3 mm, it felt fine so after that I didn't ask for any movement either way.

We also checked 170 vs 175 cranks. I didn't want to test 172.5 since I don't own any, but I have a set of 175s (2 sets actually) for my 2 (Cannondale SI) SRMs. I have one set of 170s for my SRM, but those are easier to find.

Finally he asked me to try the whole "can I take my hands off the bars and not fall forward" position. I ended up in basically a BMX bike position. Seat tube angle was in the 65 degree range, saddle was pretty far back, and the bars had to be pretty close and high. We're talking maybe 20 cm of saddle movement here (while maintaining saddle->pedal distance), so obviously a coarse kind of thing. He wanted to gather data because this was one of the things that people think is "right" and he wanted to see where I was in terms of that way of checking position.

A race car driver (amateur, perhaps like a Cat 3 bike racer, he had an SCCA license and raced Formula V, Ford, and Atlantic) told me that when he gets new parts he tries extremes. For example he had an engine on a dyno (before wheel dynos were around/common) and he got new flutes (I think that's what they're called, they're intake cones that direct air into the carb) for his Weber carburetors. They came in different lengths so he tried a bunch of them, from shortest to longest. He looked at the HP curve for each, decided what curve looked best, and got a set of flutes that he guessed would work. They did (175 hp out of a 1.6 liter Fiat engine, at about 9000 rpm, this back in the early 80s). The flutes he tried were as short as about an inch and the long ones, which prompted me asking about the whole thing, were about 8 inches long. He got three or so sizes, tested them, then either bought a fourth or he installed one of the three, I forget what he did. He also played with suspension settings, height, etc (chassis was a 1967 Brabhams chassis, if I recall correctly, with coil overs and such, so tons and tons of adjustments).

Point being that you try a range of settings and narrow your fit down. Making 1 mm changes at the beginning of my fit would have been a waste of time. At the end I asked for the bars to come down because he couldn't extend them any more. There was a cusp of about 2mm where suddenly I'd have this very minor pain in my shoulder blades. If the bars came up 2 mm they were gone, down 2 mm it was there. The fit was worth it even just for that, to educate me on what to look for in a bar that's too low.

As it was the fit took about 4.5 hours for the first part, and we started (at my request because of work hours) at 8:30 PM. We did a second part a different evening, about 2.5 hours, but that was primarily trying a number of different saddles, double check cleats on a second set of shoes, and verify insole size. The Guru rig is nice because you can replicate your leg extension quickly with different saddles which have different rail->top heights.

[fuzzalow]

^ Thanks for the response. Not intended on my part as character or competence assassination. There is much to the fitting game. Very much to it and any capsule synopsis is an injustice to those that really know what they are doing.

[MesiJezi]

I've had both and was not able to tell the difference. I had a bike that I could've sworn had 175mm cranks on it because they felt longer, but when I took them off to replace the bb I realized they were 172.5. :rolleyes:

[Ti Designs]

Take a look at the three images below - this is really what happens when people pedal.

http://www.pezcyclingnews.com/wp-content/uploads/2014/01/pioneer-endurance.jpg

http://www.pezcyclingnews.com/wp-content/uploads/2014/01/pioneer-hammer.jpg

http://www.pezcyclingnews.com/wp-content/uploads/2014/01/pioneer-spin.jpg

Note that they are not pushing the pedal in the direction it's going, not even close. If most people can't push the pedal in the direction it's going, or even within 30 degrees of that, why would you assume that you can tell 2.5mm of radius difference?

If you can look at those images and not see that there's more to be gained by working on how the rider pedals than anything on the bike, you either don't understand vector math, or there's a motor in your down tube.

Crank length isn't really about torque. Yeh, a longer lever are will produce more torque, but then so will a lower gear ratio. Crank length is about staying within the rider's range of motion. Pedals do two things that test range of motion, they go over the top (end range of motion at the hip) and across the bottom (end range of motion of the leg). Go beyond either one and you're fighting the bike.

[RedRider]

Crank length makes no difference to maximal power output.
Longer or shorter cranks can help reduce injury risk or improve range of motion in a new and faster position but it's the new position that is making the difference not the crank length by itself.

[93legendti]

I can tell the difference-I have 175's on my Fat Bike and tandem, 172.5's on everything else. On the bikes with 175's I move the saddle down and slide it forward. My legs are much happier that way,


I can also tell if my stem is 2.5mm longer or shorter, my bar width is changed by 2.5mm, my stem height is changed by 2.5mm and my saddle fore-aft position is changed by 2.5mm... Ymmv