David Laird

Hi Folks,

I recently posted a thread about upgrading my '72 Paramount P-15. My bike currently has Campy NR high flange hubs with 27" Weinmann rims.

I want to build up a set of wheels similar to this, but with 700C rims instead. I have the same model hubs w/skewers now, but no rims or spokes. Can any of you mechanics recommend a good set of polished rims and appropriately-sized spokes for a 24" vintage Paramount frame? Where can I buy, say, a wheelset's worth (e.g., 150 spokes) of spokes of varying sizes? Do most bike shops have these (DT or Wheelsmith stainless)?

Currently, the bike has Campy NR brakes, which are too small to fit 700C rims instead of the current 27" wheels. I have a set of Weinmann 610 centerpull brakes which I could use instead of the Campy brakes if they will fit. Do any of you mechanics know if Weinmann 610 centerpull brakes will fit, or should I try and find some Weinmann 750 centerpull brakes?

For you vintage purists out there, I would keep the vintage 27" wheelset and Campy brakes in case I wanted to return the bike to vintage stock https://www.bikeforums.net/images/smilies/smile.gif

mtnbke

It always amazes me that people want to convert bikes from 630 (27") to 622 (700c). The difference is only 8mm, and only 4mm functionally.

In my book there is no legitimate reason to ever convert. I know many are brainwashed that 27" "sounds old" while 700c normatively represents new or modern. However, just use the appropriate ISO sizing terminology (622 and 630) and you strip away the power of that nonsense.

You can get epically good tires in 630, even for obscure applications like wide tandem unsupported touring tires. You still have more choices in anything more mainstream than you would ever really need. What you don't get are tires at your local LBS, or Performance store. However, 630 tires are constantly going on sale at the online places (Nashbar etc.).

You can still source great rims NOS for 630 from whoever you really want, again even obscure stuff like Mavic Module 4 rims for purpose built touring bikes. If you'll willing to just plan ahead a bit you can always have an extra set of rims and tires on hand, and higher quality stuff and at a lower price point than 622.

In my book there is never a defensible reason to convert down from 630 to 622, other than "that is what everyone else is riding."

However, there are a ton of brakesets that would work. Check out Velo Orange, they have some proprietary brakesets that would more than accomodate this conversion. They have stuff that, believe it or not, is so adjustable it will work on both 622 and 584 (650B). They even have centerpull that will pull this off.

Regardless, though don't do it!

randyjawa 

In my book, I have found that 700c wheels are considerably lighter, offer a much wider and easier to access range of tires and rims, and, offer a better ride quality.

The Weinmann calipers will work just fine. Rims, be they 27" or 700c can be readily accessed on Ebay, and probably some retail outlets.

Hope that is a help.

mtnbke

Trying to figure out how the same rim and tire is considerably lighter and affords a better ride quality. Absurd.

Comparing apples to apples tire/rim and wheelbuild being identical except for 630 to 622 no cyclist could tell the difference.

It absolutely is true that you can get wider tires in 622. However, what is simply more true is you can get more of any kind of tire in 622 just as a function of availability. However, that is changing as tires being made in 630 are more commonly sold in ISO standard as say a 630-28 or 630-32 instead of the old 27 x 1 1/8 or 27 x 1 1/4. The iso standards is what allows the wider offering on 622, not something fundamental about the 622 rim itself. Almost all tire manufacturers use the ISO designations now and no longer limit themselves to the common fractional sizes, which imparted an upward bound on width. Heck nobody rides 635 but even in that you can still get a world class Conti touring tire in 635-48.

Pick a rim, pick a tire, pick your favorite wheelbuilder and all of those being equal, it is asinine to suggest there is a fundamental discernible difference between 622 and 630. Comparing identical or similar quality rims/tires is the key here. This is not like 622 (700c) to 584 (650B), which is a healthy 38mm. We're talking identical rim and tire widths for the most part, and only 4mm on each radius.

You can get world class stuff in 630, for any application (training, racing, touring, tandeming) end of story.

I think it is absurd that we still use the archaic 27" in common use. Half the silly love affair with 650B is just calling it 650B. If people called them 26 x 1 1/2" trust me, no one would be as interested. I also think it is silly that we spec 622 across the entire size line from 51cm through 63cm. I've always felt that anything 60cm and bigger should use 630, 635, or even the obsolete 642. In automobiles all cars don't try to use one "standard" rim size whether they are compacts, sub-compacts, minivans, or sports cars with just different widths.

The stubborn adherence to a limited range of wheel sizes and crank lengths make no defensible sense. Suggesting that there is any detectable difference between like rims/build/tires from 622 to 630 is just intellectually dishonest.

randyjawa 

Don't you just love it when people speak opinion, insisting it to be fact.

I did the test, weighed the wheels and ran both sets on the same bicycle, a 1975 CCM Tour du Canada. I will not go into detail here, but the difference in weight was 2.9 pounds and the ride feel was noticeably improved - in my book.

And stating in my book is like saying in my opinion. I respect the right for others to have a different opinion than I do, and can do so without calling their opinion "absurd".

AZORCH

+1

Michael Angelo 

Weinmann 750 should work but test for fit before you buy. Finding modern 700c rims that look identical to the 27" Wiemanns, there are none. The only one that looks similar is the H Plus son TB14, the profile is close but the rim is 23mm wide. The V.O rims are very tall and wide, great for building touring rims, but not very vintage looking, at least too me. I have yet to find a new polished rim that I like. I recently built a set of wheels using High Flange Campy hubs, Mavic Open Pro Rims and DT Swiss Competition spokes.



I took off the Mavic Open Pro Sticker ( very large non vintage looking) cut the "Mavic" out, and placed over the seam. I think they look the vintage part.

Road Fan

Even more than this, I'd suggest test fitting a 622 wheel with the original Campy brakes and make sure they won't work - there's a good chance that they will. I replaced my Trek 610's original 27" wheels with 700, and until I had a new high-rake fork made, have been able to use the original Shimano sidepulls. There's no "given" that says your original brakes cannot work.

You can also estimate the brake reach requirement by measuring. Measure the distances from the center of your rear wheel axle to the center of the brake bridge hole and from the center of the front wheel axle to the center of the fork crown hole. These should be in millimeters or 16ths of an inch, and done carefully. Then measure the distance from the center of the wheel axle to the center of the brake track (the rim radius). Subtract the rim radius from each of the first two measurements. The results are the estimated necessary brake reach for the front and rear wheels, on your bike. These numbers will be good for the 27 inch or 630 rims. Add 4 millimeters to the reach for each wheel to get the necessary brake reach for 700c wheels. Compare that to the reach of your brakes to see if they should be tried out before spending $$.

David Laird

Many thanks for your comments.

There are two major reasons for converting to 700C:
1. The other road bikes in my household are 700C, and I don't want to keep several different sizes of tires around.

2. I don't care for the straight-sided Weinmann rims. They only hold 70 lbs pressure with the Paselas I have installed. I would prefer hook-sided rims (vintage Mavic clinchers or Super Champion 58s -- both of which are difficult to locate) which would hold more pressure.

I could buy some double-walled rims (which look pretty decent) from Velo-Orange in either size. Anyone have any other recommendations?

I already have a decent set of Weinmann 610 centerpulls, and I was wondering if anyone out there has put 700C wheels on a vintage Paramount that was equipped with Weinmann centerpulls (IIRC, Weinmann centerpulls were standard on some models of the Paramount, so the vintage purists out there shouldn't have objections).

Also, I would like to build up the wheels myself. I have replaced many spokes (mainly rear wheel) in the old days when I used to do loaded cycle touring, but I haven't built up wheels from scratch. My old Wheelsmith wheels (from the shop in Palo Alto, CA) on my old Trek are still straight and true so I haven't had to replace spokes in awhile.

ColonelJLloyd 

Tires.

Tires.

I'm not sure what "epically good" tires are, but the suggestion that the 630mm tires selection is anywhere near as good as 622m is patently false.

It's nice that you're on a "save the 27"" crusade, but don't spout this as if it actually has any merit. It doesn't.

Tires.

Why would you compare apples to apples? The OP doesn't want to convert from 630 to 622 because he will need to lower the pads 4mm. If you read the original post well you would understand this.

jeirvine 

Could you give some suggestions as to where, other than eBay? I'd like to get some decent '70's rims for a restoration I'm working on, and don't want to break the bank.
Thanks,
-J

ColonelJLloyd 

The odds are good that 610 centerpulls will reach the 700c rims. Try that first.

After you've chosen your rims and have calculated your spoke lengths ask your LBS if they have them. If they don't and you don't want to have them order them I suggest eBay seller "childhood_dreams". I have several hundred spokes from Lee over the last year. He can be contacted directly outside of eBay. Send me an email and I will share his contact info. He typically uses Sapim spokes and cuts them with a Phil Wood spoke cutter. I haven't had the first issue. His service and turnaround time are tops.

There are very few polished rims made today in any size. For a sport-touring bike like your Paramount, I would choose the Sun CR-18 or the VO Raid. While the VO rims do have a taller sidewall than vintage rims (a functional benefit) it seems slightly less pronounced on the Raid rim as opposed to the PBP. The Raid's rounder profile would look a bit more at home on a 70s Paramount than the "boxier" CR-18, but the CR-18 is an excellent rim for the price. I've used both on recent builds.

Polished CR-18s (622x18)







Velo Orange Raid (622x16). This is a 27" to 700c conversion using 610 centerpulls. The original calipers were Dia Compe 500 sidepulls.

ironwood

Weinmann 610s should work. Since you have other 700c rims and a set of 610s you should be able to try and put a set on the Paramount and see for yourself if they fit.

Maybe you should also recalculate the number of spokes you will need. I suggest counting the spokes in your present wheels.

busdriver1959

Another option: drop bolts. There are some on eBay now that are pretty pricey but patience might help. They are out there at reasonable prices. Seems like a shame to remove Campy brakes if you don't have to.

jimmuller 

You are one of the last people I would ever question about bikes (most of the rest being other people here in C&V) but I have to wonder about that 2.9lbs figure. A radius difference of 4mm means a longer rim and tire circumference of only 12.6mm. Also each spoke will be only 4mm longer, even if there are 72 of them. All other things being equal that wouldn't seem to add up to that much mass. Almost 3lbs??? Nah.

Oh wait, I forgot about the air. Maybe that's it. And your full vs. empty water bottle.

I would suspect that other things weren't equal. Perhaps the nominally equivalent rim was wider or of thicker material for 27". And perhaps the tire was different too.

Sure a weight difference of 2.9lbs would be noticeable. I just don't see how the radius difference alone would account for it all. Now I'm going to have to look up the density of steel and compute it all out. Dang.

Edit:
Wikipedia (that font of all perfectly accurate information at all times ) gives a range of density for steel as between 7.75 and 8.05 g/cm3. So assume a high value of 8, or .008g/mm3. A 2.2/2.0/2.2 spoke has a radius of only 1mm, so the cross-sectional area of the inner length of spoke (the part likely to be longer for the bigger wheel) is PI * 1 * 1 mm2, so the volume of 4mm of spoke length is PI * 4 mm3. Multiply this by .008 then by 72 spokes and you get a total mass differnece in the spokes of only 7.87g. That's less than .02lbs. Surely the extra mass from the longer circumference of the tires and aluminum rims doesn't weight much more.

If I was at home now I'd just go weigh one of my wheels with tire mounted. Betcha' a whole front wheel doesn't weigh enough to account for a pound loss, unless the smaller rim is made of an alloy of lighterthanairium and negatimassium. (They are kinda' scarce around here.)

Grand Bois

Opinionated peaple can be so annoying!

The best way to determine which brakes will work is to measure.

randyjawa 

Please make no mistake about it - I am not an expert in vintage road bicycles. What I know, if anything, is a product of trial, error and experience, not unqualified information from non-proven sources. That comment does not target jimmuller, who has impressed me with his, or her, ability to share information that is of a factual, and oft times, proven nature. Please don't be offended. That said...

Few things about my experiment were equal. I went from 27" concave Weinmann rims with eyelets, clad with Michelain World Tour tires, to 700c tubulars. Both hub sets were Campagnolo high flange NR units, with stainless steel spokes.

I weighed both sets and that was the difference in weight that I got. I did not want to go into detail in this thread, since the topic had little to do with the OP's concern, so I did not include all of the particulars of the comparison.

As I said, few things were equal in that test, and, in my real world, I have never seen a set of 27" wheels that could be compared to 700c ones, when weight and/or performance are the issues.

When I compared the ride quality of the CCM, fitted with the two wheel sets, the difference was quite noticeable.

The point I was trying to make is that it bugs me when people spout opinion, as if it were fact. Doing so can be miserably misleading, to people seeking factual information. Plus...

I was a bit angered by being told my opinion was "absurd" and that I was being "intellectually dishonest". I have no problem with opinions that clash. But if someone takes the time to insult me, I feel obliged to respond.

Sorry to drag this thread off topic.

jeirvine 

"People with opinions just go around bothering each other"
-Budda

Puget Pounder

Why is everyone brainwashed to you?

+Tires.

jimmuller 

I could tolerate that if only they wouldn't bother everyone else too!

First, thank you for the compliment. Second, trial, error and experience count for a lot. That's how one gets to be an expert! You have far more of it than I do. Book-larnin' goes only so far when it comes to making something work.

About those Weinmann Concave rims, we could look up the specs in Velobase or someplace, but my recollection is that they were very heavy. (Decades ago I had one on the rear of my UO8 for commuting through Cambridge. I never weighed it but I believe it made the bike feel sluggish. It lasted about a month before it pretzeled itself quite unexpectedly. So much for its supposed strength.) I don't know the World Tour tire, but from the name alone I would guess it to be heavier than a typical road tire. Finally, from the description of those 27" wheels I might even guess that it had thicker spokes, perhaps 2.2/2.0/2.2mm as compared to 2.0/1.8/2.0mm. Given those factors the 2.9lbs difference becomes more believable.

The OP's question was about brakes, but that's just part of the broader question of the 27" to 700c conversion issue. I have two bikes with 27" and I haven't converted them simply because I couldn't see any benefit. The biggest benefit would seem to be tire choices but I'm very happy with 27" Pasela TGs. Having the rim and tire at a slightly larger radius would increase its moment of inertia and thus may make it accelerate a tiny bit less. Some people may be able to feel that. Since I'm not competing with anyone it doesn't matter to me. I'm about to start a new from-scratch build (details much later), but it will use 700c. Our '82 Peugeot tandem has 700c. So I'm not prejudiced either way.

As for the brakes fitting, do as GB says, just measure the extra reach available on the calipers.

A scientist, an engineer, and a mathematician were discussing bike wheels.
The scientist: Multiply the density of steel times the cross-sectional area of the spokes times the additional spoke length, times the number of spokes.
The engineer: Measure the weight of the two wheels.
The mathematician: Assume a spherical wheel...

randyjawa 

Though still off topic, this thread got me to thinking. I just went and weighed three front wheels, very nearly identical except for the rims/tires mentioned...

Wheel #1: 27" Fiamme alloy rim, 27" x 1 1/8" clincher tires, Campy high flange hub = 3lb 11oz

Wheel #2: 700c tubular with Fiamme rims, Giro Continental tires, Campy high flange hub = 2lb 8oz

Wheel #3: 700c clincher rim with 700 x 23 tire = 3lb 3oz

Difference, for the Tour du Canada, = 1 lb 3oz per wheel which would add up to 2 lb 6oz, but keep in mind, as JM said, those Weinmann rims were heavy units, perhaps adding the additional 3 oz.

jimmuller 

This is the most interesting comparison, clincher to clincher. The 27" tire is 5mm wider, roughly 1/4". That combination is 8oz heavier, half a pound.

rj doesn't say here but we can assume the hubs and QR skewers are similar. The rims would be different, though if the 27" rim was the Yellow Label I recall that as reasonably light. It might be wider than the the 700c rim though, and thus heavier. The tire probably accounts for most of the extra weight, I'd guess.

The tubular wins on weight hands down.

It also occurred to me that in the original comparison the freewheels could have made a big difference if the World Tour-equiped wheel was meant for carrying a load and thus had bigger cogs.

Thanks for the weight measurements!

randyjawa 

Nope, freewheels were not fitted for the tests, as I recall.

Road Fan

Yes, measure it, and look at the second paragraph of my post (#8) for detailed instructions. It works like a charm.

Keep in mind, Campy NR brakes were made in two lengths: what we now call short or regular, and what we now call medium or long. The first category had reach up to about 48 mm, and the second had reach up to 59 or 61 mm. That means the middle-length ones are a match for the Weinmann 610s. If you need longer and you might, go to the Weinmann 750s, the Diacompe 750s, or Mafac racers. The 750s will reach about 75 mm and the Mafacs will reach about 71 mm. You can measure the reach of your Campy brakes by measuring with a ruler from the bottom of the brake shoe slot to the middle of the brake, on a line that's perpendicular to the brake shoe bolt. You'll have to eyeball the position of the brake bolt center, but that will be the reach. You might need to subtract a few millimeters to account for the fact that the bottom of the slot is not where the brake shoe center is.

And regarding the joke, none of your three wise men measured the geometry of the frame/rim/brake as a system. Strange!

Paramount1973 

Just as a data point, I chose VO PBP rims for my 1973 Paramount build. I found a pair of NOS Shimano Dura-ace center pulls from the same era and these have more than enough reach. There is a selection of 27" tires available but compared to the variety of 700c - not even close. Thus my decision to convert.