I have new cycling shoes.

They fit fairly well -- I've worn them for an hour -- but I'd like them a bit wider at the toe (I have wide feet).

Can they be widened? They uppers are not made of leather. I think that when a shoe-shop widens leather shoes, they do that using some product which softens the leather, and which doesn't work with a synthetic upper.

I tried one shoe-shop, who told me they couldn't do it, because they only have the product for leather.

Can it be done at all? Does it need a special product (for synthetics), or perhaps some heat, or only patience? I realise that widening might not be as effective as it is with leather, but if it can be done at all then even a little might help.

  • 1
    What are they made of if not leather? Fabric? Some sort of leather-effect plastic? The former might stretch a little, especially wet
    – Chris H
    May 27, 2021 at 20:20
  • 1
    Microtex is Fizik terminology for synthetic leather.
    – Weiwen Ng
    May 27, 2021 at 20:49
  • 1
    Tricky, with a coated fabric. Anything I could suggest would have a significant chance of damage. If you really want to try, the first thing might simply be time and pressure, with a shoe stretcher alone.
    – Chris H
    May 27, 2021 at 21:08
  • 3
    Try Shimano's wide options. Fizik is definitely not the right choice for someone with wide feet.
    – MaplePanda
    May 27, 2021 at 21:35
  • 1
    @MaplePanda actually, some of Fizik’s more recent shoes may be moving to a different last than their previous, pretty narrow last. That said, the OP can try shoes whose normal last is relatively wide, e.g. Shimano and Specialized, or they can see if any wide lasts are available.
    – Weiwen Ng
    May 27, 2021 at 21:57

3 Answers 3



I took them to a shop whose website says they work with (help to fit) walking boots and ski boots (as well as with leather town shoes).

The man there said that he'd use heat when widening them, but wasn't specific about his equipment and technique.

It didn't make a big difference -- not big enough if the shoes were the wrong size to begin with -- but enough to be welcome/noticeable.

  • Does it need a new answer when one is already about heat molding? Jun 4, 2021 at 13:50
  • A comment under the previous answer said, "Whatever happens, do let us know how you get on."
    – ChrisW
    Jun 4, 2021 at 14:42
  • @VladimirF I think a new answer is justified as well. The previous answer relied on literature from Bont, which has a special design - their sole actually extends up to the sides of your foot like a bathtub, and they use heat moldable resins for that. No other shoe I am aware of has this design. Also, Bont gave no indication that this alters the shape of the upper. Some Shimanos were heat moldable in the past, but they’ve discontinued that style. Thus, I think we can’t rely on Bont’s word to confirm that any shoes can be reshaped with heat at all.
    – Weiwen Ng
    Jun 4, 2021 at 17:13
  • I emailed Customer Service at Fizik to ask whether a cobbler could do it and if so how (using what product). They replied to say that cobbler could but they wouldn't say how, said to ask the cobbler. I asked the cobbler if he used heat and he said yes; I asked, "a hair-dryer?" and he replied, "more powerful than that".
    – ChrisW
    Jun 4, 2021 at 18:26

According to this manufacturer's web site, some shoes can be "heat-molded":

Heat Molding

This cycling shoe is the most heat moldable shoe on the market today. Bont's resin is developed in house and has been perfected over 36 years to be an extremely stiff resin that becomes pliable at relatively low temperatures. The base of the shoe is moldable which means all stiff areas of the shoe can be molded in a standard oven. You do not need to mold your shoes if they fit you straight out of the box. To mold your shoes, remove any cleats, laces or cleat mounting screws and innersole before molding. Failure to remove the innersole can result in it becoming deformed by the heat. Pre heat the oven to 70°C/160°F. Place the shoe in the oven for 20 minutes. Higher temperatures will void your warranty and may damage your boot. Caution: Do not place your feet in the hot shoes or you may burn your feet. Let them cool a little and test the shoe temperature with your hand before placing your feet in the shoes. Tighten the straps and allow to cool. If you have any lumps or bunions on your feet or if there are any areas causing discomfort, while the shoe is hot you can use the round end of a screwdriver to press out any part of the boot. You can heat mold the shoes as many times as you like.

I read some people recommend a hair-dryer, but this suggestion of an oven seems to me more measured, a more accurate temperature.

  • 2
    The link is about Bont shoes, and the question is apparently about Fizik. Bont uses a foot-shaped last so it's less likely they'd have the problem in the first place.
    – ojs
    May 28, 2021 at 6:55
  • Yes the OP is about Fizik.
    – ChrisW
    May 28, 2021 at 7:18
  • 4
    Usually, only special parts of shoes can be heat molded and that part is visibly different. I know this only from cross-country skiing shoes but the heat moldable material on mines is transparent and softer on touch. And it is only located at the heel, no widening in the front possible. Higher quality ice skating shoes are often heat moldable in a larger area to exactly fit the shoe but again, only when the manufacturer marks it so, the cheaper models are not. BTW, the temperature for the skating boots is much higher, 180° for 3-5 mins shoprainbo.com/heat-molding May 28, 2021 at 7:28
  • Whatever happens, do let us know how you get on. I rode some 46 size Lake shoes that were way too small for me, for years. I splurged on new shoes and 49 was about the right size !
    – Criggie
    May 28, 2021 at 8:01
  • 1
    If the manufacturer intended their carbon shoes to be moldable, I think they would need to select resins that are compatible with heat molding, and I believe that only Bont currently do this. Also, the heat only affects their sole. On almost all shoes, this is flat, and molding wouldn’t do much. Bont’s sole is made in a bathtub shape, so the carbon sole itself does contact your foot. Molding can help with things like bone spurs, but if your feet are too wide entirely, I wouldn’t expect molding to do much on a Bont shoe. This is based on other customers’ feedback on forums.
    – Weiwen Ng
    May 28, 2021 at 11:29

Some googling returns sprays that can either condition Synthetic Leather (also known as Faux Leather) or "relax" the material to encourage stretching using an adjustable form (some pieces of wood roughly foot shaped)

Another option is to apply the conditioner in a nugget or wax, while you are wearing the shoes. You can also choose to wear an extra layer of socks to help enlarge the shoes where you need it.

As a kid I remember wearing new real leather school shoes in a paddling pool and then wearing them around outside for a couple hours as they dried. This helped a lot but being real leather, might not apply to your artificial shoes.

Regardless - it comes down to your risk tolerance. If the leather tears while stretching, you've ruined some expensive shoes. Though in that case a repair patch could cover a gap and be a perfect fit for your foot.

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