Why We Like Custom Gearing

Our Rene Herse cranks are available with chainrings from 24 to 52 teeth, in single, double and triple configurations, including 11-speed compatible versions. We even offer tandem cranks. That way, riders can benefit from customized gearing, but it also means that we stock a lot of chainrings. We try to keep all ring sizes in stock, but sometimes, demand outpaces supply. We’ve just received a new shipment, and all chainrings are back in stock.

It’s easy to see why the big makers limit their chainrings to a few combinations, but the downside is that most riders find themselves with gearing that doesn’t work well for their riding styles. It’s not just that the gears are usually to large, but also that you need to make far too many front shifts.

Why are front shifts so disruptive? With a 50 x 34, the small ring is 32% smaller than the big one. That is a huge step. You probably need a gear that is 5-10% smaller, not 32%, so you shift 3-4 cogs on the rear to compensate until you finally arrive in the gear you need. Multiple shifts take time: Your speed drops, and your rhythm is gone.

To solve this problem, you could make the step between the chainrings smaller, like the 46 x 36 found on some cyclocross cranks in the past. Front shifts now are 22%, and you only need a single shift on the rear to get back to your optimum cadence. The drawback is the limited gear range: A 36-tooth small ring is fine for ‘cross, but most riders need smaller gears when climbing mountain passes.

However, the smaller ‘big’ ring of the cyclocross setup provides the answer to the original problem. If we select our big chainring so that we ride in the middle of the rear cassette during normal riding, we can respond to small changes with just a few shifts on the rear. Pick up a tailwind? Click and we have a bigger gear. A small rise in the road? Click-click-click – a few seamless downshifts as our speed drops, and we are over the crest. No front shift required!

With a 46-tooth big ring, I can surge across gentle hills with just a few shifts on the rear. That means I can select my ‘small’ ring so that I can climb even the steepest mountain passes. For me, that is a 30-tooth. Now the large step between chainrings is OK, because I don’t shift on the front unless I get to a really steep hill. A hill that steep breaks my rhythm no matter what.

Your ideal gearing depends on a number of factors: your cadence, your strength and speed, and the terrain where you ride. From your current setup, you know which gears you use when riding on flat roads. Select your big chainring so that these gears are in the middle of the cassette, and your riding will be much smoother. That is the secret behind custom gearing. The small chainring can be up to 16 teeth smaller, because that is the maximum that modern derailleurs can handle reliably.

We offer our Rene Herse cranks with so many chainrings because we recognize the need for custom gearing. Click here for more information about Rene Herse cranks.

Photo credit: Nicolas Joly (Photo 4).

About Jan Heine, Editor, Bicycle Quarterly

Spirited rides that zig-zag across mountain ranges. Bicycle Quarterly magazine and its sister company, Compass Cycles, that turns our research into the high-performance components we need for our adventures.
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34 Responses to Why We Like Custom Gearing

  1. Steve Palincsar says:

    36 x 46 is even better when you make it a triple and add a 24 or 26 tooth inner ring. Don’t the Herse crank arms make that an easy adaptation?

    Also, when you make that shift from the 46 to the 36, if you’re not in a hurry you can skip the rear upshift and simply wait a heartbeat and you’ll be in the right gear. Much beyond a 12 tooth difference, that’s no longer a practical option because the difference in gears is so large.

    • Yes, René Herse cranks are available with triples, and the chainring choices are easy to configure. I’d probably opt for a 38 middle ring and do most of my riding on that one. Then a big ring for downhills and tailwinds, and the small ring for steep climbs.

    • Greg Parker says:

      26-36-46 is not advisable. The middle ring will “hide” when shifting.

      A 24-36-46 will shift better.Or 26-38-46.

      The old triple-chainring Touring Paramounts had a 36-46-54 for that reason.

      You don’t want the middle ring to be mathematically in-between the other two. It should be a bit larger than that.

      • Good point – it’s important to remember that the middle ring shouldn’t ‘hide’ between the other two, otherwise, the chain just goes straight to the big ring during upshifts. However, it’s not the arithmetic mean that matters, but the line that connects the tooth tops of the inner and outer chainrings. The middle rings teeth should protrude beyond that line. The result is a bit more generous than the ‘arithmetic mean’ calculation, and a 46x36x26 usually will work fine.

        It’s easy to check if you suspect this could be an issue on your cranks. Put a ruler across the chainrings. If it touches the inner and outer, but not the middle, then your middle ring is too small in the way Greg mentioned.

      • Pol says:

        Currently running a 50-38-26 with Campagnolo Athena 3×11. Very happy with it. Up-shifting from the small to the middle ring works fine.

      • Greg Parker says:

        I think the flexibility and performance of modern chains makes the difference, vs vintage drive trains.

      • Mike says:

        By coincidence, the chainrings on my daily driver are 46-36-26 or 24. I say by coincidence because they were chosen by the guys at my bike shop when I brought it in for a full drivetrain overhaul some 5 years ago when the original rings were completely worn out. I didn’t pick the ring sizes; however, I’ve had no complaints, nor any reason to change them, nor any problems shifting between all three rings, in the years since (and I think one or two of them have been changed in the intervening years, though with ones of the same size). I do use all of them: 46 for general riding, 36 for starting/stopping, and the little one for hauling heavy loads, such as concrete and sand, home, uphill, from the local hardware store.

        I think that problems with shifting between the rings is due more to maladjustment of the derailer than to “hiding” of the middle ring.

      • Steve Palincsar says:

        Not necessarily. 26/36/46 was a standard combination on the XTR M900 triple, and I have two bikes that have it. The middle ring is perfectly accessible on both.

  2. Larry T says:

    Great ideas all! Compact doubles reach only what I call the “vanity” market – those who think there’s something weak or lame about having a small chainring for big climbs. So they suffer with the awful front shifts and having to shift multiple cogs in the rear with a 50-34 and the like up front. I’m fortunate in doing just fine with a standard (from awhile back of course!) 52-42-30 setup and something like 12-26/28 or 30 out back, but if I needed new parts right now, your offerings would be might tempting!

    • The 50×34 was developed when tires were much narrower. With a 20 mm tire, your gearing is much lower than with a 35 mm. If you don’t carry anything on your (racing) bike and you are a very fit rider, a 50×34 is a great choice.

      I used to race on 52-42, which was used the opposite way: 42 for general riding and climbing, and 52 for when the pace heated up. The 52-42 would be totally useless for me right now, but when racing, I attacked on the climbs and hung on during the fast flat portions of the course, so this gearing was ideal.

      On the other hand, my Urban Bike has a 42×26, because I don’t do fast paceline sprints on that bike. I ride in the 42 most of the time, and when climbing with a full load (and often a trailer), the 26 comes in handy.

      It all goes to show that gearing depends on many factors – even for the same rider – and there isn’t ‘one size that fits all.’ For me, the common thread is that I need a chainring somewhere in the 42-46 range, and most current offerings have large rings that are too large and small rings that are too small for my riding.

  3. marmotte27 says:

    I noticed on older bikes (in ‘The Golden Age..’ and elsewhere; also on recent bikes modelled on older bikes), that at the time a number of bikes used more than the 16 tooth difference between chainrings. Encouraged by this I set up my bike with 44-26. Shifts fine, even if the derailleur (an FD-CX-70) needs a careful adjustment.

    • Older systems can shift over larger tooth differences, because the chainrings are further apart. With the narrow spacing of modern drivetrains, the angle at which the chain climbs from the small to the big ring (and vice versa) is much steeper. It makes sense that this angle, and not the absolute tooth difference, determines the quality of your shifts.

      Our 1946 René Herse tandem has a 48×28 chainring combination, and it shifts great even with the ultra-long chain of a front-drive setup.

    • Rick Thompson says:

      Similar setup: RH 44-26 with CX-70. With 9 speed chain the CX-70 has a narrower gap and needs to be set right, but then shifting is fine. Most rides are in the 44, could almost do 1X, but if a steep hill comes up the 26 is the lifesaver. (11-28 cassette, 700c x 44 tires)
      I may not ride as hard as some, but feel no need for any more gears than this.

      • Conrad says:

        I have had trouble with the CX-70 derailleur. It is possibly the only derailleur currently in production with a smooth inner cage that will work with the common sense but definitely not industry standard gearing. I use a 46-30 double and prefer 8 or less cogs in the back so the wider chain makes trimming the derailleur fussy. Hence I am using old Suntour front derailleurs right now that work quite a bit better than anything currently in production.

  4. SteveP says:

    Does this mean my 44/22 front rings shouldn’t actually work with my IRD FD?

    • If it works, then it works. Rider skill and also tolerances of the parts play a big role, too. Up to 16 teeth difference works reliably for most riders. A greater spread, and you start to push your luck. Often it works, but component makers need more certainty than that.

  5. Stuart Fogg says:

    I’m using 48-42 at the front and a wide 15-34 (8 speeds) at the rear. I love the single shifts and the range is wide enough for where I ride. The relatively large gears may add a few grams but reduce stress in the chain.

  6. Tbone408 says:

    Any plans to make a narrow wide chainring?

  7. The Shimano 14-28 11 sp cassette is my friend. Five to seven per cent difference across most of the range. Good with 50-34 (c.32–96″)—in practice the big change from 15t to 21t cogs when going from 34 to 50 isn’t that big a deal. Excellent with 50-39-24 (c.23–96″) using a 9 or 10 speed triple FD operated with a bar-end shifter. You can also make a 14-32 with Miche or out of two Shimano cassettes which works brilliantly with 50–39–24 (c.20–96″). Currently using 42–34 and 11–28/32 for daily rides and 11–40/42 for touring.

  8. John Allen says:

    My day-touring bike has an old Cannodale frame, unchangeable 126mm dropout spacing so max 7 sprockets. 50-34 on the front and 13-15-17-19-22-26-32 SunTour ultra-spaced freewheel at the rear, originally a 6-speed but I dished the inner sprocket. Large chainring lines up with the middle sprocket in back. I use the large chainring with all rear sprockets. Shift the front down to the 34 and I have two more lower gears. Range is 28 to 104 gear inches, easily remembered sequence, no “surprise” changes.in step size.

  9. George Van Zee says:

    For all the reasons you stated in your blog is there an 11 spd 48 t outer ring ?
    Thanks ,
    George VZ

  10. Phillip Cowan says:

    Concerning disruptive front shifts you wrote “your speed drops, and your rhythm is gone”. That sentence made me think of something that I’ve noticed over the years and that is that the recorded times of single speed riders is usually not that far off from the geared riders. Even though the single speed gearing inevitably must be a compromise the mental game is easier because you’re always in the “right” gear. I often thought that training on single speed then racing on gears is a viable strategy. There is a nugget of truth in the old saw that “gears make you weak” (not that I’m giving up my 46/30 any time soon,lol).

    • When I first started racing as a college student, I was surprised how little speed changed across hilly terrain. Everybody coasted down the hills, because anything more was just wasting energy. Everybody rode a good pace on the flats, and on the hills, the attacks kept the pace high. Of course, that is also the most efficient way to ride a hilly ride, as it minimizes the losses due to air resistance.

  11. Joseph Penner says:

    Where’s the breaking point when it makes more sense to coast in an aero-tuck vs up-shifting? I was surprised when I timed myself on a 12-mile course with different bikes and found that I gained time on a 5-mile downhill section with a bike that had a high gear of 44-14 (by focusing on the aero-tuck), compared to a bike with a 48-12 (focusing more on pedaling). My takeaway: low-gear options are much more valuable than high.

    • If you do the full aero tuck with your hands next to the stem and your elbows and knees well tucked-in, you are about 30% more aero than you are in the drops. At speeds above 27 mph, it’s hard to make up for that by pedaling. If you’re very strong, that threshold will move upward, but you’ll also wonder whether it’s worth putting out 500 Watts to ride at 30 mph, when coasting in the aero tuck would have you go 29.5. And at higher speeds, it’s no contest.

  12. John French says:

    With downtube or bar-end shifters, the “double shift” required to shift smoothly across the large gap between chainrings is no problem: I just move both shift levers by roughly the same amount in the same direction. This shifts to the other chainring, while shifting 2-3 cogs in the opposite direction on the rear, for an overall change in gearing roughly equal to a single rear shift.

    Of course, I agree that it is better to set up the gearing so that most riding can be done in a single chainring. I discovered the ease of double-shifting with barends after switching my chainrings from 40/32 (where the front shift was small enough to not require double-shifting) to 46/30, as I’m becoming a stronger rider and was spinning out the 40t chainring regularly.

    • marmotte27 says:

      Interesting to me to see that you put bar ends and downtube shifters on the same level concerning the ease of double-shifting. I have no experience with bar-end shifters but I would have thought they’d be the worst option in that respect. I’m probably wrong in imagining that you have to almost let go of the handlebar to shift, and on both sides for double-shifting…

  13. John Duval says:

    The popular 11-32 cassette gives 8-13% jumps, but almost a 300% range. That alone is more range and smaller steps than I rode 30 years ago with two chainrings. Having chainrings in two tooth increments is very valuable for 1x to get the most out of the available range.

    I think many modern bikes have very wide range gearing so that they can serve the vanity of very big gears, and still satisfy how people actually ride. Get rid of the seldom used gears, and things look very different.

  14. Rod A Bruckdorfer says:

    In 1982 when I bicycle toured across the Canadian Rockies, I used a 46/42 chainring combination with a 5 speed 14-34 freewheel. Since then I never used a 52/42 combination.

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