Using road bike frame on Hybrid



leamcorp

New Member
Jul 7, 2007
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Hi, I have a 2004 Trek 7.3FX, which is a hybrid. I was told when I bought the bike that it used a standard road bike frame, but with MTB parts. The bike is quite heavy (compared to my Fuji road bike) and would like to taper some of those weight. The best that I could think of is to upgrade the frame.

The question is - can I just change out the frame (saw some frame on ebay) and re-used the parts? What should I look for when looking for a frame (to replace the hybrid). I'm not trying to make it a road bike, rather, just trying to pare down the weight and used it for local riding (road riding).

Here's the spec,

Frameset Sizes 15, 17.5, 20, 22.5, 25" Frame FX Alpha Hydroformed Aluminum Fork FX alloy taper gauge, straight blades Wheels Wheels Shimano RM65 hubs; Bontrager Ranger rims Tires Bontrager Race Lite Hardcase, 700x32c Drivetrain Shifters Shimano EF50, 8 speed Front Derailleur Shimano C102 Rear Derailleur Shimano Deore Crank Shimano M341 48/38/28 w/chainguard Cassette Shimano HG40 11-30, 8 speed Pedals Nylon body w/alloy cage Components Saddle Bontrager Race Basic Lux Seat Post Bontrager Sport Handlebars Bontrager Crowbar Sport, 25mm rise Stem Bontrager Sport, 10 degree Headset Aheadset Slimstak w/semi-cartridge bearings, sealed Brakeset Shimano M465, mechanical disc w/Shimano EF50 levers

Thanks.

Edit: forgot to add, the Trek has a disk brake.
 

alfeng

Well-Known Member
Jul 23, 2005
6,723
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leamcorp said:
Hi, I have a 2004 Trek 7.3FX, which is a hybrid. I was told when I bought the bike that it used a standard road bike frame, but with MTB parts. The bike is quite heavy (compared to my Fuji road bike) and would like to taper some of those weight. The best that I could think of is to upgrade the frame.

The question is - can I just change out the frame (saw some frame on ebay) and re-used the parts? What should I look for when looking for a frame (to replace the hybrid). I'm not trying to make it a road bike, rather, just trying to pare down the weight and used it for local riding (road riding).

Here's the spec,

Frameset Sizes 15, 17.5, 20, 22.5, 25" Frame FX Alpha Hydroformed Aluminum Fork FX alloy taper gauge, straight blades Wheels Wheels Shimano RM65 hubs; Bontrager Ranger rims Tires Bontrager Race Lite Hardcase, 700x32c Drivetrain Shifters Shimano EF50, 8 speed Front Derailleur Shimano C102 Rear Derailleur Shimano Deore Crank Shimano M341 48/38/28 w/chainguard Cassette Shimano HG40 11-30, 8 speed Pedals Nylon body w/alloy cage Components Saddle Bontrager Race Basic Lux Seat Post Bontrager Sport Handlebars Bontrager Crowbar Sport, 25mm rise Stem Bontrager Sport, 10 degree Headset Aheadset Slimstak w/semi-cartridge bearings, sealed Brakeset Shimano M465, mechanical disc w/Shimano EF50 levers

Thanks.

Edit: forgot to add, the Trek has a disk brake.
The frame isn't the problem ...

And, unless the "new" frame you are looking at was made in the 70s-or-before and/or was designed for 27" wheels, then the odds are that few, if any, of the parts (particularly, the wheels/tires) can be used on a contemporary road frame.

Your hybrid is probably closer to a 29er than to a road bike ... and, a 29er is closer to a MTB than to your hybrid ...

With a varying amounts of effort, and "spare" change, you can bring your bike's weight down to 24 lbs. (or, maybe less!) without any problem ... still, on the beefy side, but not heavier than a mid-range bike from a couple of decades ago.

Regardless, the main thing you want to consider is changing the tires -- make THIS change, first ... it could be all you need to make the ride more pleasant.

You may be able to fit 700x28 tires on your current rims, but if you want to use anything "smaller" (700x23 or 700x25), then you will probably need a narrower rim. You will need new tubes.
 

leamcorp

New Member
Jul 7, 2007
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alfeng said:
The frame isn't the problem ...

And, unless the "new" frame you are looking at was made in the 70s-or-before and/or was designed for 27" wheels, then the odds are that few, if any, of the parts (particularly, the wheels/tires) can be used on a contemporary road frame.

Your hybrid is probably closer to a 29er than to a road bike ... and, a 29er is closer to a MTB than to your hybrid ...

With a varying amounts of effort, and "spare" change, you can bring your bike's weight down to 24 lbs. (or, maybe less!) without any problem ... still, on the beefy side, but not heavier than a mid-range bike from a couple of decades ago.

Regardless, the main thing you want to consider is changing the tires -- make THIS change, first ... it could be all you need to make the ride more pleasant.

You may be able to fit 700x28 tires on your current rims, but if you want to use anything "smaller" (700x23 or 700x25), then you will probably need a narrower rim. You will need new tubes.
Already have 700x25 tires and that made it better. The weight is still a problem, expecially on steep hills. Not sure what the frame size/geomety is as Trek doesn't list those. It would be nice to have a lighter bike, without getting dressed up to go riding (meaning bike specific clothing/shoe) for anything less than 20 miles.

Seperate question - instead of hybrid to road bike frame... how about a road bike and just changing the handle bar to a flat kind. What would I need to change for this setup since shifters are different for flat bar. Thanks
 

alfeng

Well-Known Member
Jul 23, 2005
6,723
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leamcorp said:
Already have 700x25 tires and that made it better. The weight is still a problem, expecially on steep hills. Not sure what the frame size/geomety is as Trek doesn't list those. It would be nice to have a lighter bike, without getting dressed up to go riding (meaning bike specific clothing/shoe) for anything less than 20 miles.

Seperate question - instead of hybrid to road bike frame... how about a road bike and just changing the handle bar to a flat kind. What would I need to change for this setup since shifters are different for flat bar. Thanks
FWIW. I "rebuilt" an extra aluminum hardtail (no disc mounts) with some "spare" road parts, and I reckon the bare frame doesn't weigh significantly more-or-less than your hybrid frame. Without putting it on a scale, I reckon the "built" bike weighs less than 21 lbs. (with pedals) ... the fork is a carbon fiber ROAD fork (it's a light fork).

So, in theory, if you were to strip everything off your hybrid and replace as many parts as your budget allows, the resulting bike could weigh about 22 lbs. (disc brakes weigh more, AFAIK) ...

Now, to convert your bike to a "flat bar" bike, you JUST need an appropriate handlebar + brake levers + shifters & cables/housing + some handlebar grips. You may-or-may-not want a longer/shorter stem. If they are long enough, you can use your existing cables & housing.

A couple of years ago, a friend wanted to convert his old (90s vintage) Raleigh from an 8-speed which had drop bars & 105 STI shifters. The LBS wanted about $150 ... I told him I had some extra parts that I could give him, so his out of pocket cost was just the handlebars.

Ultimately, how much you choose to spend depends on the shifters you opt for ... for a ROAD bike brake calipers you will need brake levers that are either BMX-type or old-school, levers for "cantilever" brakes.

If you have Shimano STI shifters (which I presume is the case), you should be able to use a "Moustache" handlebar (a road bar with only about a 1" drop ... typically, people use bar end shifters) -- cost is between $30 & about $60, plus tax/shipping/whatever -- I've never seen anyone do THAT (mount STI brakes/shifters) on a set of Moustache handelbars; but, why not?

BTW. My friend reads the wrong how-to articles. He asked me about using hair spray to install the grips ... I had to tell him that the practice is probably a good thing if you are a race mechanic working for a sponsored rider, but for real people who have to pay for their own equipment, just use WATER to install & remove the grips.

ALSO, I asked him if he had two Nickels. Without understanding why, he gave me two. I then explained to him that BEFORE you install the grips, you want to put a Nickel on each handlebar end -- the coin on the end of the handlebar prevents the end of the grip from tearing and/or the handlebar from become a hole punch if something (like your body!) pushes against the handlebar's end.
 

sogood

New Member
Aug 24, 2006
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leamcorp said:
Hi, I have a 2004 Trek 7.3FX, which is a hybrid. I was told when I bought the bike that it used a standard road bike frame, but with MTB parts.
Not sure about 2004 models, but it's not true for their 2006 range and if you define "road bike frame" as one that's comparable with a typical road/race frame geometry. FX series frames have a long wheel base and the geometry is a mix of road and MTB. A touring frame may be closer.
 

leamcorp

New Member
Jul 7, 2007
11
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alfeng said:
FWIW. I "rebuilt" an extra aluminum hardtail (no disc mounts) with some "spare" road parts, and I reckon the bare frame doesn't weigh significantly more-or-less than your hybrid frame. Without putting it on a scale, I reckon the "built" bike weighs less than 21 lbs. (with pedals) ... the fork is a carbon fiber ROAD fork (it's a light fork).

So, in theory, if you were to strip everything off your hybrid and replace as many parts as your budget allows, the resulting bike could weigh about 22 lbs. (disc brakes weigh more, AFAIK) ...

Now, to convert your bike to a "flat bar" bike, you JUST need an appropriate handlebar + brake levers + shifters & cables/housing + some handlebar grips. You may-or-may-not want a longer/shorter stem. If they are long enough, you can use your existing cables & housing.

A couple of years ago, a friend wanted to convert his old (90s vintage) Raleigh from an 8-speed which had drop bars & 105 STI shifters. The LBS wanted about $150 ... I told him I had some extra parts that I could give him, so his out of pocket cost was just the handlebars.

Ultimately, how much you choose to spend depends on the shifters you opt for ... for a ROAD bike brake calipers you will need brake levers that are either BMX-type or old-school, levers for "cantilever" brakes.

If you have Shimano STI shifters (which I presume is the case), you should be able to use a "Moustache" handlebar (a road bar with only about a 1" drop ... typically, people use bar end shifters) -- cost is between $30 & about $60, plus tax/shipping/whatever -- I've never seen anyone do THAT (mount STI brakes/shifters) on a set of Moustache handelbars; but, why not?

BTW. My friend reads the wrong how-to articles. He asked me about using hair spray to install the grips ... I had to tell him that the practice is probably a good thing if you are a race mechanic working for a sponsored rider, but for real people who have to pay for their own equipment, just use WATER to install & remove the grips.

ALSO, I asked him if he had two Nickels. Without understanding why, he gave me two. I then explained to him that BEFORE you install the grips, you want to put a Nickel on each handlebar end -- the coin on the end of the handlebar prevents the end of the grip from tearing and/or the handlebar from become a hole punch if something (like your body!) pushes against the handlebar's end.
Oh, I wasn't thinking about converting my road bike. Rather, I was going to buy one of those $500 Ebay job (Motobecane, Dawes, etc), then changing out the handlebar/brake/shifter. Not sure if this will give me the weight saving or riding position that I'm looking for.

By the way, Trek does make more upscale version on their fitness model - 7.9FX. This model does use 105/Ultegra with R770 shifters, but its expensive for what I want to use it for.
 

dabac

Well-Known Member
Sep 16, 2003
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leamcorp said:
Hi, I have a 2004 Trek 7.3FX, ..The bike is quite heavy ..and would like to taper some of those weight. The best that I could think of is to upgrade the frame.

The question is - can I just change out the frame (saw some frame on ebay) and re-used the parts?

The only way to get a seriously light bike is to use light components all the way through .
Start by looking up the weights of the components you're considering to reuse.
If the bits you have turn out to be average or heavy when compared to similar products available then there's not much to be had by a frame replacement unless your current frame is ridiculously chunky.

(unless the "new" frame fits you much better than the old, but that's an entirely different question)

And you'd still expose yourself to a string of hurdles to be overcome if components refuse to play nice during the transplant.
Disc brake wheels - does the new frame/fork have disc brake tabs? If not, will your current rims work with rim brakes?
FD - top pull or bottom pull?, seat tube diameter?
ASO...