Wider Pedal Stance Needed For Gravel (Also Applies to Road)

By Rick Schultz

Background: As a bike fitter, I see a lot of cyclists that have knee pain and want relief. By the time they come in to see us, they are usually on the verge of giving up on cycling. Next, when going through their evaluation and assessment, I always ask if they also experience hip pain. Unsurprisingly, they hesitate and usually answer “Yes, how did you know?”

I also have many clients that bring in both a mountain bike and a road bike to get fitted. Many are more comfortable on their MTB than they are on their road bike. After discussion, they mention they feel too narrow on their road bike but feel exactly right on their MTB. These days, many are bringing in gravel bikes complaining of the same things.

Following is a recent conversation and general solution.

Hi Rick. I just read your 2018 article about pedal stance and knee pain. I ride a gravel bike with Shimano MTB pedals, but my bike has narrow road cranks. I need a walkable shoe so “road” pedals are out. I’ve tried moving my cleats all the way inboard on the shoe but that makes little difference. I still get lateral knee pain on longer rides. I want to see if a wider stance will help.

Pedal spacing adapters are one solution, but I was hoping for something better for the long term. Have you encountered anything else that might help?

Thanks!

J

Good morning J,

Assuming that your crank arm length is correct, following is some general information and several things that might help;

• Crank width / Q-factor
  • Dura Ace/Ultegra = 146mm
  • GRX = 151mm
  • XTR = 162mm, 168m, 171mm, 174mm
  • XT = 172, 178, 181mm

Replacing road cranks with gravel cranks adds 5mm

Replacing road cranks with MTB cranks adds 16mm, 22mm, 25mm, 26mm, 28mm, 32mm, or 35mm

• BB Shell width for gravel bikes = 135, 142, 148mm

BB shell widths vary by +7mm – +13mm

Probably not feasible since this would require a new frameset.

• Pedal width for MTB not advertised not advertised anymore from Shimano
  • Shimano SPD-SL 51mm, 53mm, 55mm (51+4mm), 57mm (53+4mm)
  • Shimano SPD 55mm
  • LOOK MTB 53mm, 56mm
  • ISSI Road 50mm, 55mm
  • ISSI pedals 52.5mm, 58.5mm, 64.5mm
  • Crank Brothers 52mm, 57mm

Replacing Shimano SPD with ISSI adds 3.5mm or 9.5mm

• Shoes/Cleats
  • SPD-SL = 5mm left to right
  • SPD = 5mm left to right

You said you already moved the cleats inboard all the way

• Pedal Washers
  • +1.5mm each, maximum of 2 per side

• Pedal extenders
  • +20mm, +25mm, +30mm

As you can see there are several solutions, cheapest ($) to most expensive ($$$$$)

1. $ Pedal Washers ($1-$2 each)
2. $$ Pedal Extenders ($15-$25 pair)
3. $$$ ISSI Pedals ($65-$105)
4. $$$$ Shimano XT Crankset ($235 -$620)

Of course, you can also combine the above to gain a total of 3mm / 0.12” (1 pedal washer each side) to a whopping 120mm or 4.72” (2 pedal washers each side + 2pedal extenders + 2 ISSI pedals + XT crankset).

As you can see there are lots of options allowing you to fine-tune your stance width.

Hope this helps,

Rick

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Coach Rick Schultz is an avid cyclist who trains, races and coaches in Southern California. Rick is an engineer by trade, and in addition to being a coach, he’s a bike fitter and prolific product reviewer. He’s the author of Stretching & Core Strengthening for the Cyclist in the RBR eBookstore. Check his product reviews website, www.biketestreviews.com, and his coaching site, www.bikefitnesscoaching.com. Click to read Rick’s full bio.