Bicycle Mechanics - 700c wheel conversion on 27" wheel bike

A Schwinn I have originally came with 27" wheels and I only have 700c to put on it. I bought 2 'dropdown' bolts for the campy side pull brakes I have and find that the brakes are still not low enough. I seem to need another 1/8-3/16" reach??? I thought that drop down bolts were the fix for this problem??? That is why they made them in the first place.

You have any knowledge on this issue?

Oh, if you are going to tell me to measure my Campy brakes, I will need to know from where to where.
What knid are they? Campy side pulls from the 60s I guess.

http://sheldonbrown.com/home-drop.html

This may or may not be of some help.

http://sheldonbrown.com/home-drop.html
This may or may not be of some help.

I would sure hate to do that to a vintage Schwinn. Hope there is another idea / solution out there.

Turn it into a brakeless fixie?

To determine the necessary brake reach, you measure from the center of the brake mount hole (on the seatstay bridge for the rear, fork crown for the front) to the center of the brake surface on the rim. The difference in necessary reach between 27" rims (630mm bead seat diameter) and 700c rims (622mm bead seat diameter) is that you need 4mm more reach for 700c. I'd go a different route than drop bolts if at all possible, if it were mine. What model Schwinn is it?

To measure the advertised reach of a brake, measure from the bolt hole to the center of the slot that the pads go through. Depending on the length of this slot, brakes of a given reach can give you some wiggle room up and down from that center point.

jim

A Schwinn I have originally came with 27" wheels and I only have 700c to put on it. I bought 2 'dropdown' bolts for the campy side pull brakes I have and find that the brakes are still not low enough. I seem to need another 1/8-3/16" reach??? I thought that drop down bolts were the fix for this problem??? That is why they made them in the first place.

You have any knowledge on this issue?

Oh, if you are going to tell me to measure my Campy brakes, I will need to know from where to where.
What knid are they? Campy side pulls from the 60s I guess.

You can get tektro dual pivots with huge reach. Enough reach to do 99% of the 27" to 700c conversions. Sheldon brown has a selection on his site.

"To determine the necessary brake reach, you measure from the center of the brake mount hole (on the seatstay bridge for the rear, fork crown for the front) to the center of the brake surface on the rim. The difference in necessary reach between 27" rims (630mm bead seat diameter) and 700c rims (622mm bead seat diameter) is that you need 4mm more reach for 700c. I'd go a different route than drop bolts if at all possible, if it were mine. What model Schwinn is it? "



it is a Model C-19

"it is a Model C-19"


Do you by any chance have a link or a pic? I'm familiar with a lot of Schwinns, but not a Schwinn model C-19. Going by your brake question, I presume it's a road bike? Do you know how old it is?

I just saw your thread in C and V, since you say the bike originally had centerpulls I would strongly recommend sticking with those for the benefit of the long reach they provide. If the ones you have are no good, they're readily available on ebay for cheap. Some models have more reach than others, just make sure you get the correct brakes for your needs. I'm still curious about your Schwinn C-19, please provide more info on it-:)

The only thing the OP needs to do is a give us the break reach number and the problem will be solved.

The only thing the OP needs to do is a give us the break reach number and the problem will be solved.


:eek:

I had a Schwinn Le tour frame that fit 27's fine, yet throw a 700 wheel on it, and the brakes ran out of reach. These were Sante brakes on an 87 Le Tour. Never heard of a Schwin C19?? Is it older like 70's centerpull style, or older like mid to late eighties when the quality jumped up?,,,,BD


lol, just looked it up. C-19 is a wheelset from what I found?

Oh so it is centerpulls? missed that before. Tear the brakes down, polish and lube, and buy Koolstop pads. Problem solved. My 74 SS stops so well it still surprises me.,,,,BD

:eek:

Oh ****.

I'm going to go shoot myself now

Oh wait there's my antidepressants

:/

Oh so it is centerpulls? missed that before. Tear the brakes down, polish and lube, and buy Koolstop pads. Problem solved.

That's what I'm thinking, too. It's hard to beat centerpulls for long reach. I've got two bikes that I've converted from 27's to 700c's, the centerpull brakes reach the 700c rims no problem. And if the original centerpulls don't reach, it's not hard to find some with longer reach-

As for more info on the bike, it is a chrome frame I believe built in the 60's. I was told the model was 19, and 'C' for chrome.

I hear all the info that center pulls are the way to go. originally, I just had new 'older' Campy stuff and thiought it was nicer looking. Guess I will have to give that thought up and go back to the center pulls and the drilled Campy levers.

Perhaps I can find some NICE looking center pulls. The Weinmann I have don't impress me.

Maybe it's a 19" chrome frame?..........Here's a link to BF member Bob Hufford's excellent site. http://www.geocities.com/sldatabook/publications.html

Catalogs of "lightweight" Schwinns from '60 to '79, you might browse through and see if you can find your bike. Also, if you can post a pic in C and V, you can get it ID'd.

You're not alone in not liking the look of the Weinmann centerpulls, but FWIW, with Kool Stop pads installed they're functionally good brakes. I'm in the minority in that I even like the look of them. Some people say "clunky," I say "robust.":D

I have a touring frame with 27" wheels and cantilever brakes. I want to switch to 700 wheels. Do the cantilevers make the switch any easier?

I have a touring frame with 27" wheels and cantilever brakes. I want to switch to 700 wheels. Do the cantilevers make the switch any easier?

Look at the brakes. Is there adjustment range where the pads could be lowered?

I have a touring frame with 27" wheels and cantilever brakes. I want to switch to 700 wheels. Do the cantilevers make the switch any easier?

I've got one, too, equipped with Dia Compe canti's. Little or no vertical adjustability on those brakes. But what's really bad is that the distance between the brake bosses is quite a bit less than later canti's, so more modern cant's with vertical adjustability won't fit. Maybe someone else has an idea, but that's the way it is on my '80's touring bike with 27's and canti's. Eventually I'm going to cut the canti bosses off and use centerpulls and 700c's, but for now I'm sticking with 27's and the old canti's on that bike-

My experience with 27" wheels with cantilever brakes is that 700 rims have a smaller diameter, so if you don't have much adjustment for the pads as it is, you will likely have problems with the smaller rims.

As for cutting and welding etc, I bought my Univega Gran Turismo for $55, including Look pedals. I ain't cuttin' nuthin. <\C&V rant>

As for cutting and welding etc, I bought my Univega Gran Turismo for $55, including Look pedals. I ain't cuttin' nuthin. <\C&V rant>

Your bike, your choice. My bike, my choice. I really the bike, too; but the brakes suck. FWIW, I've been riding "vintage" bikes since they were new. In my opinion, some are worth fretting over in terms of originality, some aren't. This one isn't.

I'm wondering about putting disc brakes on my 1984 touring bike... It's only an idea...

Eighties Shogun with Shimano canti's. When I bought the bike it had a 27" in front and a 700 in the back. It now sports 700's front and rear, and fresh paint. The brakes adjusted with no problems. There's only 4mm difference from what I hear? Most canti's should be able to handle that easily.,,,,BD

http://i114.photobucket.com/albums/n267/Kustombyker/GUN1.jpg

Eighties Shogun with Shimano canti's. When I bought the bike it had a 27" in front and a 700 in the back. It now sports 700's front and rear, and fresh paint. The brakes adjusted with no problems. There's only 4mm difference from what I hear? Most canti's should be able to handle that easily.,,,,BD

http://i114.photobucket.com/albums/n267/Kustombyker/GUN1.jpg

Bikedued,
Is your Shogun repainted? If it is would you tell me how you did the pinstripes around the lugs?

Yep, rattle canned via Plastikote, and several coats of clear. The lug striping was done with Testors silver model paint and small brush.,,,,BD

I'm in the process of having an old UniVega powder coated black. Guys at work are going to do it for a second time next week. If they don't get it right this time, I'll paint it myself. Wonder if testors will stick to powder coating. Guess I'll have to try, because, I think the striping really accents the lugs well.