Wednesday, September 18, 2024

When It Gets Old

Shimano FC-RS510 crank (Image courtesy of the internet)
 I think some of you who are regular readers here might recall that I had been having troubles with a wheel set which I had been using on my Tamland Two gravel bike. It is a carbon Irwin Cycles wheel set and I was having, what I thought was, issues with the free hub. As it seems to be turning out now, that is not the case.

Apologies to Irwin Cycles.

You might also recall how I had recently installed a DT Swiss hubbed Roval carbon wheel set on the Tamland Two, thinking that I had eliminated the issue with the free hub on the Irwin wheels, which, as it seems to be now, was not what was going on. 

I had been toying with the idea of blowing apart that Irwin rear wheel, getting a new rear hub, and relacing the new hub to the old carbon hoop. However; every time I picked up that wheel and spun the free hub it felt perfect. I happen to have two other Irwin wheels with similar rear hubs with a LOT less miles on them and they felt exactly the same. I also did not see any evidence of wear or damage inside the hub I suspected of causing my issues. So, I was reticent to blow up the wheel if it was still in good operable condition. 

And now I am happy I did not blow that wheel apart. 

Late into last week's ride I started to get similar "skipping" issues, but as I was feeling before with the Irwin wheels, it was now getting worse. I immediately knew I misdiagnosed the issue and I knew what was going on. 

My drive train was shot.

Specifically the crank chain rings. I thought about this as I shifted to the big ring for the remainder of the ride, and remembered that these chain rings were installed in late 2014! 

Doh! No wonder that small chain ring was allowing the chain to jump teeth! So, a complete swap of chain rings, chain, and cassette (although the cassette isn't all that old, I probably should swap it out), is in order. Time to research!

I found many times when a customer at the bike shops I used to haunt as a mechanic would need chain rings it was actually cheaper  to buy a crank set than it was to buy separate chain rings. Crazy, but true, and in my case, that still is true. I was able to source my preference in gearing, which is 46T/36T in a Shimano FC-RS510 crank for under 100 bucks. Two chain rings in those sizes would cost well over 100 bucks! Especially the Shimano ones which I would necessarily have to buy to fit the original Ultegra crank set on the Tamland. 

I also opted to try an experiment. The new fad is to go shorter on cranks. Now, I do not have any extenuating circumstances that would point me to using shorter cranks. No knee pains, nothing like that. So, maybe this won't matter, but I ordered 170mm cranks to try them out. Some folks rave about the shorter cranks and they have gone waaaay shorter with 165's or less. I'm not into radical changes because my belief is that minor changes can make huge differences. Let's take a "baby step" and see.... 

The RS-510's are a heavy crank set, since they are not made in the HollowTech manner, but are hot-forged aluminum and solid in nature. If the shorter cranks are 'meh!' or if I see no reasons to keep them on the bike, I will swap the chain rings to the older Ultegra crank set and donate the RS-510's to the Collective. I figure I am getting the arms for free anyway. 

So, are you a 'short crank' devotee?  N.Y. Roll already is singing the praises of shorter cranks, so I've heard a bit of The Hype. Let me know in the comments.

11 comments:

Tyler Loewens said...

I was chasing similar issues on my Hei Hei build earlier this year. I replaced all sorts of stuff until I finally remembered that the crank I used on this build had been transferred between bikes since late 2018 with the same chain ring. lol

Guitar Ted said...

@Tyler Loewens - Maybe we should maintain logbooks for each bike we own. Wait..... I bet some folks probably do that! :>)

Prairie Voyageur said...

I switched my three bikes to 165mm cranks and am not going back. I do have a bad knee though from years of soccer. I consider the additional cost in the price of a new bike and install a power meter at the same time.

shiggy person said...

One of the reasons I use the cranks I do. Most of mine use 110/74 5-bolt rings. I generally prefer non-ramped rings, which also reduces cost. Have not paid more than $40 for a single ring in years.
One exception is a White Industries VBC crank. The outer ring is also the spider. My first one lasted nearly 14,000 miles. Not a cheap replacement, but also not horrible. The inner ring can be any 74BCD (or larger) 5-bolt.
New Albion (Soma Fab) has some really good cranks at fabulous prices, especially the square taper versions (my preference)

wp said...

switched my Fargo from 175 to 170 3 years ago. Immediately felt the difference on my cranky right knee. Since moved my hardtail down to 165 with similar happy results. So far I'm a fan...

MG said...

I’ve tried going with 170mm cranks but always go back to 175s… That said, I also have 10 bikes with 175mm cranks, so switching one over will always feel strange.

Marc Pfister said...

As a long time 175 and 180mm crank rider I tried 170s several times and always hated them. It took some time on 160s for it to "click", plus going against the usual advice of raising your seat and spinning higher RPMs. I came from what I know now was a dysfunctional position with the seat too high which made me rely on increasing cadence to get power. With the short cranks I can apply more force with less dead spot waste, and can pedal at a lower foot speed which also helps your neuromuscular system apply power at the right place in the stroke.

Jeff said...

Pretty sure my next crank will be a 165. My road bikes have always been 172.5 and I have an old square taper shimano mountain crank that’s a 175, still going strong but doesn’t get much use any more. I found a shimano in a 46/30 that I will try, if I like it I’ll probably change the small ring to a 34 or 36. That seems to work for me.

tntmoriv said...

I have always ridden 175’s on my bikes, and it always worked for me. Or at least caused no problems. I swapped in a 170 for the same general reason GT did (cheaper available chainrings - but mine was in the parts bin from my wife’s old bike) and it seemed fine as well. I don’t use a power meter or anything so can’t attest to efficiency or power delivery. I will note that I have over 1,000 miles of hilly urban riding on my Brompton folding bike and it uses 170 cranks and I don’t have issues there. I did have a beautiful set of 180mm square taper Shimano XT Cranks in the late 1980’s that never worked for me. Felt too big, but that was during the BioPace craze era of 1988 so maybe the egg shaped loping was the problem!

Guitar Ted said...

Hey everyone! Thanks for chiming in with your crank length experiences. Every time I mention crank length this happens, by the way!

I think it is quite apparent, even from this small sample size of comments here, that crank length is highly individualistic and prone to human adaptability which probably makes judging what is "right" for anyone in a given situation a bit of a tough nut to crack.

Like many, I have no power data to lean on with which I might be able to make some conclusions for myself. I just go by feel, and I've used cranks from 170mm - 180mm with no issues physically. So, yeah.... A tough thing to pinpoint for myself. We will see how it goes with the Tamland.

Greg said...

I'd agree on the individualistic comment based on the other commenters, but I switched to a 170mm crank on a geared bike a couple years ago, and then on a single speed MTB this year. I think they are a significant improvement for me, but more so on the single speed. I don't notice the lack of leverage on steep sections, but do notice how much more comfortable I can spin at higher cadences. I have another single speed MTB that I inherited with 180mm cranks, and now it's super annoying when I ride that one. Spinning on the longer arms seem like such huge, slow, wasteful circles! Now I need another crankset! So the main problem with switching to shorter crankarms can put a dent in the wallet if you like them.