goatalope

What geometry measurement will indicate toe/shoe clearance?

Road bike tire clearance is going up. Not uncommon to be able to fit 32s, even 35s. I had 32s on my Trek Emonda; however, my foot would hit the front tire if I didn't pay attention when slow city riding or doing sharp turns.

Maybe big tires and road geometry isn't the best combo. Anyways, how do I tell if a bike will have more shoe/toe clearance from a geometry chart?

Thanks.

Rolla

Some of it depends on shoe and pedal choice, cleat position, foot size, and crankarm length, so I'm not sure a geo chart can always predict toe overlap. Moreover, I think toe overlap can be easily accommodated for with practice.

This article may help: How to Tell If a Bike Will Have Toe Overlap?

Riveting

I'm no frame builder, but in general, a frame with a higher numbered head tube angle will donate to the cause of toe overlap, as well as less trail and fork rake, or a bottom bracket that's more forward. All of those things bring your foot and wheel closer together.

I've gone down one too many times doing a very small diameter low speed u-turn and had overlap occur which caused me to lose balance and fall. I'll no longer buy a bike if I personally experience ANY toe overlap on the test ride, but as was said, there's a lot of variables that can stack-up and cause it, or can be changed to alleviate it. Or you can learn to avoid it...until you don't.

Iride01 

Without making a drawing to scale and adding your own measurements for crank and toe I don't know that there is a good reliable way to judge that. But maybe consider fork rake, any difference in seat tube and head tube angle, as well as wheel base when you are comparing the geometry of multiple bikes .

I don't worry about toe interference, but I don't ride in traffic at less than 3 mph. At speeds higher than 3, I can't imagine it ever being an issue, except for carelessness when starting from a stop. But apparently it is and issue for you. Do you ride with cleats or toe clips? If so, I'd consider flat pedals if I was riding where traffic will slow me that much.

Nachoman

Toe reduction surgery.

Camilo

I've never owned a road bike, cross or gravel bike that I didn't hit the tire with my toe if I didn't pay attention. I've had road bikes since the 70s. 5-8… 54/medium bike size, normal tires in case anyone thinks it's an odd situation. I've always thought it's is normal and is no problem at all.

cxwrench

'Front center' is the term you're looking for. Center of bb to the center of the front axle.

cyclezen

There's no Geo measurement which would 'indicate' toe clearance - too many factors.
Besides Front-center, there is crank length, tire/wheel diameter, shoe size (and not surprisingly, shoe profile in the nose/toe area), cleat placement.
Toe-overlap has usually been a condition of 'road' type bikes, rare for what had been called 'touring' bikes.
There's a lot of history to this, and I won;t into that now.
But these days the problem is exasperated by bigger riders on smaller frames, general use of large tire sizes, and bike designers not adapting design for the overwhelming trend for use of large tires by a broad spectrum of riders.
Surprisingly, getting Front-center spec in manfacturer's specs is not a given. Specialized gives front-center, Trek does not... One can calculate front-center from the common geo specs given.
You need wheelbase, chainstay length, BB drop.
So, it becomes a personal investigation. For me, I generally ride 'Lg' commonly 56-57cm size in road frames, Have a 11/45 shoe size and the cleat is mounted well forward on the shoe sole , but Ball O Foot is positioned over the center of pedal spindle (I have a size 13 foot arch length with corresponding size 8 toe length... LOL! ) I still ride 700x23 or 25 on my road bikes. And use Sidi and Shimano shoes which don;t have a very pointy toe shoe profile. So, I can avoid toe-overlap if the front-center is at least 590mm or a bit greater. If I were to go to a 28mm tire, it would be very, very close...
My own observations for a few years is that a front-center of over 600mm would accommodate tire sizes up to at least 42, possibly larger - for large feet (size 12 or under...)
I've owned a few bikes, over the decades, which had toe-ovelap, and none have ever been 'keepers' or considered a FAV... besides toe-overlap, there have always been other things which have made the frame less desirable...
Toe-overlap isn't even a 'discussion' when it comes to riding with flat pedals, because foot/shoe placement is usually all over the map...
For some, toe-overlap is not a consideration. I find it totally annoying and know it could easily be eliminated in frame design, so it's a none-starter for me.
Ride On
Yuri

Kapusta

This^^^

I see this given for some MTBs these days, though I have not seen it for road bikes (though TBH I have not really looked.

In reality, I do not find toe overlap a problem. I ride pretty small road/gravel frames and toe overlap is the norm for me. It is only an issue when going very slow and turning very sharp, and I just move my foot out of the way. It is muscle memory and I seldom even realize I am doing it.

Viich

There really isn't a way around it if you want a good-handling bike in a small size other than a smaller wheel. I know they just don't sell, but XS adult road bikes should usually come with a 650C wheel, IMO.

Fredo76

Having raced, and having built my own frame, I've always thought that toe overlap was total BS, easily avoided, and an inferior design choice, caused by favoring something less important in a compromise, or by not caring, since bikes with overlap are common. IMO, toe overlap is always a minus, never a plus, and, with the possible exception of an hour-record bike for a four foot tall rider, totally unnecessary. If I ordered a custom bike and specified no toe overlap, and got toe overlap anyway, the builder would simply need to find another buyer, because I wouldn't accept the frame, period.

YMMV

Kapusta

What I find total BS is messing with the handling / geo of the bike (increasing offset / slackening HA) or riding too long of a frame just to avoid something that is a total non-issue.
YMMV

tkamd73 

I’ve got long feet, I can hit the front tire on all of my bikes, with either side of the crank full forward and the back of the tire about 6 in off center. Yet no issues riding, you could never turn the wheel that much at speed anyway.
Occasionally notice it when starting out, hardly moving, or trying to balance the bike when stationary. Not a big deal on a road bike, mountain bike, off road maybe an issue.
Tim

prj71

I don't have any toe overlap on my Trek Domane with 32s when doing sharp turns or riding slow. My clips are placed towards the front of the shoe and maybe the bike size is right for me. My GF doesn't have the problem either and she rides the same bike but with flats. I would literally have to try to make this happen.

Fredo76

Yeah, toe overlap is pretty much unnecessary, unsafe BS, since you can get what you want without it. I never fell over from it, but another 2 mph mix-up found me waking up in a stranger's car with a concussion; it doesn't matter, until it does. People who accept toe-overlap are mis-guided, imo.

Kapusta

I look at toe overlap sort of like pedal strikes on the ground: You need to adjust your riding technique to deal with it (not pedaling through heavily leaned turns), but I have never heard of someone on a road bike running shorter cranks or raising the bb enough to completely eliminate the possibility.

The difference is that I need to accommodate for toe overlap far less than pedal strikes in turns.

Things are a little different with MTBs, but even there we tolerate needing to adjust our technique to avoid them, rather than do what is need to completely eliminate the possibility (super high BBs or super short cranks).

cxwrench

Your lack of a clue is showing big time. I ride a 52cm frame, have size 40-41 shoes and have had toe overlap on every road bike I've ever had, my track bikes were really bad. It happens. It's not a big deal. To say that anyone should be able to not have it at all on a normal geometry bike is ignorant.

prj71

I found that buying a bike with a higher BB solves the pedal strike issue on MTB. My bike has 349 BB height. One of the reasons I purchased it. Care free pedaling. Don't need to worry about technique.

These manufactures making bikes with a low BB claiming more stability is just bunk. A persons center of gravity for stability while riding is around the waist area not the feet that are couple of inches off the ground. And with dropper posts that center of gravity can be adjusted for riding conditions.

Fredo76

Dumb can be normal, and often is, these days.

Kapusta

Sure, higher BB and shorter cranks HELP, but you still have to be mindful of where you pedal in some situations. You are mostly likely doing it without realizing it. If not.... I don't know what you must be riding that a 13.7" BB is allowing you to pedal through literally everything with no regard. I've had bb's higher than that in the past and still managed to smash my pedals.

79pmooney

+1 Front center roughly equals Wheel base - chainstay length. (I say roughly because there is an about 2" difference in height between the hub axles and the bottom bracket so this isn't quite exact but it is close. If you ignore published front centers and just use this calculation, you can quickly see what bikes work for you and which don't. To do this:

Measure the axle to axle wheelbase of a bike that works for you. Measure the BB center to rear axle. The difference is now the calculated front center. Now it's easy. Most bike specs publish both wheelbase and chainstay length.

Yes, you can also get there (and more exactly in theory) using the frame geometry but - the seat tube angle determines where the top tube starts. So where the top of the head tube is depends on both seat tube and top tube. Now you draw that line of the head tube angle and offset that by the fork rake. You are looking for a number where a few mms matters a lot. This method trusts 5 of the specs to be right on over about 1 1/2 meters of tubing.

And for all this, even with my simple calc, we have to trust the specs or bring our tape measure or shoes. Specs are published months before the first bike of that year rolls of the line. Changes happen. Carbon fiber means once the mold is made, no more changes for the frames off that mold, but - molds get replaced, there are varying levels of oversight between design offices, often on different continents, and manufacturing plants, different languages, etc.

Riveting

I disagree. The fact that overlap happens "makes it a big deal" to me also, because I don't want it to happen, at all. The fact that we don't want it doesn't make us ignorant (that's just an absurd thing for you to say), it just makes YOU more accepting of a bike's inherent faults, than we are willing to accept. I had overlap on a Trek Madone 2.3, went down several times because of it while doing 1-2 mph very tight U-turns where rotation of the cranks is needed to maintain forward motion and balance, toe overlap occurred, I went down. Some of us now want bikes that don't have it. Why is that a problem for you to understand. This thread is about how to avoid overlap. Go start your own thread on how to live with it.

70sSanO

Toe overlap is merely just a result of building a frame, typically smaller but not always, with a desired handling performance. On smaller frames it is especially tough, maybe impossible, to dial in those characteristics without toe overlap.

Whether good or bad is up to the individual and the value placed on certain handling characteristics.

If eliminating toe overlap is the primary design criteria, it is easy to design a bike without toe overlap. Changes to seat angle, top tube, head angle, fork rake can be made to increase the front center.

I highly doubt mfgs intentionally design toe overlap just for the sake of it.

John

Kapusta

No thread needed. Just don't pedal through a super tight, slow turn. Ratchet one pedal stroke if you need to. The only reason you would need to keep pedaling is if you are on a fixie. I've been riding road/gravel bikes for the past 25 years with toe overlap and never once fell over due to it.

Or alter the bikes handling. It's up to you.

A bike that changes its handling characteristics to avoid something that I already avoid without issue is my definition of "faulty design" for my needs. Perhaps in your case your needs are different since you can't manage the slow sharp curves that others can.

79pmooney

And does front center matter? If you ride with fenders it can. I've ripped a few stay brackets off the fender with my shoe coming down on the fender bolt riding fix gear. If my shoe doesn't slip off something has to give. The fender, my shoe or my foot. (Shoe is locked in place on the pedal with the old fashioned slotted aluminum cleat - zero float until that cleat is worn). Fortunately for my foot, it's always been the fender but I've also fallen over a couple of times.

All my overlapping fenders have plenty of black scuff marks from my shoes. I like bikes with more FC; both for this and because they tend to have (for me anyway) better weight balance for downhill corners. But this comes with a risk. Long FCs and corresponding long TTs can run into speed wobbles. (Aging doesn't help. The bikes I rode fearlessly in my 20s I cannot trust now on high speed descents. One of the best wobble-stoppers is youth, strength and confidence. Knowing what a high speed crash would do to my near 70 yo body has robbed me of that confidence.)