going from 700c to 650c wheels



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Lee

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I'm rebuilding a 43cm Cannondale R700 for my son, who's just under 5' tall. The bike currently has
700c wheels, and I'm thinking about going to 650c wheels.

What else will I need to do. Will I be able to adjust the brakes for the smaller wheels, or will I
need to get drop bolts?

Should I replace the fork with a 650c specific fork?

What else do I need to know?

TIA,

Lee
 
>I'm rebuilding a 43cm Cannondale R700 for my son, who's just under 5' tall. The bike currently has
>700c wheels, and I'm thinking about going to 650c wheels.

This is a real bad idea. First, while I haven't worked out the numbers, it's very likely that the
cranks won't even turn, ie: they'll hit the ground.. The brakes won't reach, in short, don't do it.
Find a properly sized bike. Phil Brown
 
"Phil Brown" <[email protected]> wrote in message
news:[email protected]...
> >I'm rebuilding a 43cm Cannondale R700 for my son, who's just under 5'
tall.
> >The bike currently has 700c wheels, and I'm thinking about going to 650c wheels.
>
> This is a real bad idea. First, while I haven't worked out the numbers,
it's
> very likely that the cranks won't even turn, ie: they'll hit the ground..
The
> brakes won't reach, in short, don't do it. Find a properly sized bike. Phil Brown

Phil,

I hadn't considered the crank issue. Could be a show stopper.

With regard to finding a properly sized bike...there isn't one. He's 12 and only 4'10" tall, and
there just aren't any properly sized road bikes for him.

Thanks!

Lee
 
"Lee" wrote:

> With regard to finding a properly sized bike...there isn't one. He's 12 and only 4'10" tall, and
> there just aren't any properly sized road bikes for him.

I see a few women that height, riding 650c bikes.
 
Sure there are. You just have to look around a little bit. I bought a new Fuji road bike for my 4'5"
daughter a couple of months ago after some very intensive research into small road bikes. It's got
650 wheels stock, properly sized bars and 165 cranks; I couldn't ask for more bike for the money.
They make 43 cm frames in three different "women's specific" modles, ranging from $450 to $1300
street price. We had to substitute a shorter stem, but that was real easy with the threadless setup.
Works great. She loves it; we ride two-three times a week.

Good luck--let me know if there's anything else I can help with. "Lee" <[email protected]> wrote:
>
>"Phil Brown" <[email protected]> wrote in message
>news:[email protected]...
>> >I'm rebuilding a 43cm Cannondale R700 for my son, who's just under 5'
>tall.
>> >The bike currently has 700c wheels, and I'm thinking about going to 650c wheels.
>>
>> This is a real bad idea. First, while I haven't worked out the numbers,
>it's
>> very likely that the cranks won't even turn, ie: they'll hit the ground..
>The
>> brakes won't reach, in short, don't do it. Find a properly sized bike. Phil Brown
>
>Phil,
>
>I hadn't considered the crank issue. Could be a show stopper.
>
>With regard to finding a properly sized bike...there isn't one. He's 12 and only 4'10" tall, and
>there just aren't any properly sized road bikes for him.
>
>Thanks!
>
>Lee
>
 
"Jon Isaacs" <[email protected]> wrote in message
news:[email protected]...
> >Phil,
> >
> >I hadn't considered the crank issue. Could be a show stopper.
> >
>
> Its the big one. 650C wheels are over 2 inches smaller in diameter. Put
them
> on and you will loose over an inch of pedal clearance. This means you
must use
> shorter cranks. Otherwise the cranks will hit in even a shallow turn.
If you
> use a 650C Fork, then the ground clearance will be even worse.
>
> Another problem with this scheme is brake clearance, putting 650C wheels
on a
> 700C bike means your brakes will also need to be an inch longer, this
means
> using some 70's Long reach brakes, some people like some of em but I
don't.
>
> But your son will soon be growing, so it is somewhat expensive to buy him
a
> bike that will last him a year or so at most.
>
> My thinking, having had 3 step sons on bicycles, would be to find
something
> that works, either a MTB or a road bike and set it up as best you can. Enthusiastic kids can ride
> about anything...

Thanks Jon,

He already has a mountain bike, wants to ride a road bike like his dad... :)

We'll see how the bike with the 700c wheels fits.

Lee
 
> Something else to consider: The only thing the 650C wheels buys you is standover clearance when
> stopped. When your son is actually riding the
bike,
> the rest of the geometry, including seat height and top tube clearance
will be
> exactly the same with either size wheels.
>
> And since most kids are pretty good at hopping on bikes that are too big
for
> them, I think sticking with the 700C wheels is your best bet.

Or you could get him to learn to dismount while rolling and mounting the bike without having to
straddle it and stuff. I think Sheldon's site has a lot of info on this.

I rode a 19" MTB that I couldn't stand over not flat-footed when I was 15 or
16. I got a 17" after that...

FYI, I have a bad enough problem scraping my pedals with 700c. Who woulda thunk that long sweepers
at 30mph need that much clearance? ;)

--
Phil, Squid-in-Training
 
Trek makes some smaller bikes. Also, you could do like I did for my daughter who's about that tall.
I found an Old mid 80's Terry with the smaller front wheel, fits her fine. I also have 2 kids that
will follow her on it. :) I think I'll get my $100 out of it. I just ordered a front tire from
Sheldon, landed some brifters off of ebay, and am upgrading it to 9 speed. The reach to the downtube
shifters is an issue for her. Anyway, good luck on your quest, I found the Terry on craigslist in
the bay area and had my cousin pick it up for me. They pop up on ebay all the time too.

Lee wrote:

>
> "Phil Brown" <[email protected]> wrote in message
> news:[email protected]...
>> >I'm rebuilding a 43cm Cannondale R700 for my son, who's just under 5'
> tall.
>> >The bike currently has 700c wheels, and I'm thinking about going to 650c wheels.
>>
>> This is a real bad idea. First, while I haven't worked out the numbers,
> it's
>> very likely that the cranks won't even turn, ie: they'll hit the ground..
> The
>> brakes won't reach, in short, don't do it. Find a properly sized bike. Phil Brown
>
> Phil,
>
> I hadn't considered the crank issue. Could be a show stopper.
>
> With regard to finding a properly sized bike...there isn't one. He's 12 and only 4'10" tall, and
> there just aren't any properly sized road bikes for him.
>
> Thanks!
>
> Lee

--
Mark Wolfe http://www.wolfenet.org gpg fingerprint = 42B6 EFEB 5414 AA18 01B7 64AC EF46 F7E6 82F6
8C71 "Contrariwise," continued Tweedledee, "if it was so, it might be, and if it were so, it would
be; but as it isn't, it ain't. That's logic!" -- Lewis Carroll, "Through the Looking Glass"
 
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