I have been braking for a bit too long with worn off brake pads on not so new rims so I basically killed them.

I currently have the stock wheels of an FX Trek 7.2 bike.

I will most probably change them. The thing is, that I would like to use the opportunity to install thinner tires. The current rims would support a range of 28-37mm wide tires.

The wheels I am looking at support 19-28mm wide tire range.

Will any of those new wheels fit on my bike without any further replacing? for instance because of the width of the fork?

How about brakes? I will obviously need to tweak them, but will it require more than just a set-up?

2 Answers 2


If you are buying high end wheels, some of them cannot be fitted with brakes at all or can only be fitted with disk brakes. If it's a fairly good quality wheel, make sure it has has been "machined" for brake pads (or just look at the photos, if it's a coloured wheel with a shiny silver strip where the brake pads go then it has probably been machined).

Also, some wheels are for bikes with only one gear and you won't be able to fit your gears onto them, or perhaps it will not accept as many gears as your bike has. Count the number of sprockets/wheels on your rear wheel and see how many gears can be fitted to the new rear wheel. Definitely avoid "track" or "fixie" or "single speed" wheels.

Different frames do have different widths for the rear wheel, but you can usually get spacers to make it fit if the wheel is designed for a narrower frame than your bike.

Aside from that, be careful what you buy! Good quality wheels are very expensive (you can pay more for one wheel than you paid for the whole bike) and some wheels are not very strong, or have terrible bearings, or are ridiculously heavy.

You should consider just buying a new rim, and having a bike shop fit the new rim to your existing hub/spokes. My local bike shop will only charge 50 bucks to do that. If your wheel is in good condition, you might struggle to find one that is the same quality without spending too much money. Trek is able to place huge orders so they get their parts much cheaper than you can.

Adjusting your brakes is no problem. You just loosen the bolt that holds the cable on the calliper, pull it until they are in the right position for the new size rims, then tighten the bolt. Then you have to adjust the angle and position of the pads, since they will also be wrong - again just loosen the bolt holding the pads on, move them into the correct position, then tighten the bolt.

Your brake pads will work better if they are adjusted exactly right, but I think exactly how to brake pads should be positioned is better asked as a separate question (no doubt it has already been answered many times). You don't have to get them perfectly right, but it's worth reading up on.

  • Most Linear pull brake pads are sold with a set of spacers and washers that can be rearranged to protrude further towards the rim if necesary. Iv'e seen similar setups for cantilevers or caliper brakes. You may need to read the user/owner/maintenance manual for your brakes to be sure.
    – Jahaziel
    Commented Nov 21, 2012 at 18:23

When buying new wheels, make sure the spacing matches up. Road wheels typicall use 130mm rear and 100mm front spacing where as most mountain bikes use 135mm rear and 100mm front. Hybrids vary, but it looks like this one has Shimano RM30 hubs which are 135mm spacing like a mountain bike. However, if you find a 130mm spaced wheel you like, you can add spacers to make it fit the 135mm spacing of your bike if need be.

I think it's worth a shot trying out a 700x28c tire on this bike without changing the wheels, which would be much cheaper than switching the wheelset.

FYI, I got my spec information for the wheels from here: http://www.firefoxbikes.com/hybrid_Trek_73FX.html

  • 1
    A little update on what I did: I did not want to change the wheel right away so I followed your advice and bought a pair of Ultremo ZX 28mm. I dropped from 1180g to 680g. I got them delivered to my office, installed them right away. I only had my mini-pump so could not get the right pressure yet, only 3bar instead of 8. Only rode the way home, in wet conditions while being extra careful. And WOW! so much faster! I don't know if it is them being slick, or lighter, or lower air resistance, but I rode 1 kmh over my usual average. Wonder what it'll be in the dry when properly inflated.
    – ptpdlc
    Commented Nov 23, 2012 at 21:15
  • Placebo effect - something new and shiny, money spent, self justification - subconsciously you just pushed harder. Happens to me all the time :)
    – mattnz
    Commented Nov 28, 2012 at 0:58

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