Friday, December 7, 2012

Headset Index Steering


Headset index steering is a very common phenomena that presents itself as a notched movement of the handlebar in the headset; it's as if there are index detents controlling the the steering with a preferred home position. If one looks inside the headset, usually at the lower cone, you will be equally spaced dents in the race. While this has been blamed on too loose a preload, the real cause is false brinneling; picture from http://sheldonbrown.com/headsets.html
The most common cause of headset indexing is fretting or "false brinneling". This is a well documented phenomenon. Unlike all the other bearings on your bike, the headset is basically a stationary bearing. You spend 99% of the time riding straight ahead or moving the headset only a few degrees in either direction. The constant road vibration works all the lubricant out from under the balls and there's not enough movement to bring fresh lube to the point of contact.The "dry" contact allows an etching sort of wear, eventually forming pockets, which cause the indexing. FBinNY


I have a Nuovo Record headset that is indexing and tried a number of fixes that might be helpful to others with the same problem. First, this is on a 30 year old Italian bike that had the headset when I bought it a couple of years ago. Also, if you don't know, part of riding vintage bicycle is to keep the vintage components working as long as possible. I noticed the indexing about 6 months ago and overhauled the headset which seemed to make it better, but it returned a short time later. The indexing isn't dangerous and is unnoticeable while riding so it is an OCD matter if anything; so of course I must fix it!

The two fixes (after an overhaul) normally mentioned are to remove the ball bearing retainer and install loose bearings or to remove the crown race and turn it 90 deg (to change the position of the divots with bearings in the retainer. I first turned the crown race, but all that seemed to accomplish was to move the location where the headset indexed. This may work depending how badly the race is fretted and when I took the time to inspect better inspect the crown race I saw the fretting covered almost the entire race. I then removed the ball bearing retainer and installed what turned out to be 22 3/16" loose ball bearings (2 more than what was used with the retainer). But this really didn't work either. The fretting made it difficult to properly preset the bearings and while the bearings didn't index , they still felt rough none the same.



 

The last thing I tried was using the crown race off of a Tange NJS Levin, which is advertised as a Nuovo Record copy. However it turned out it wasn't a good fit; as you can see above, the Levin is more of a Nuovo Gran Sport copy (with the addition of the banded engraving of a Nuovo Record). The Levin uses 5/32 balls (the same as a Nuovo Gran Sport) and the Record uses 3/16". The result is the crown race is smaller in diameter, leaving a larger gap between the lip of the crown race and lower cup, which will allow more crud to get into the bearings. If I had to go this way I would probably use the lower cup of the Levin as well.

My fix finally came from Boulder Bicycle/ Rene Herse http://www.renehersestore.com/servlet/StoreFront who was selling the crown race for what is most likely a Vicotry/Triomphe headset. The Triomphe and Victory headset parts are pretty much imterchangeable with Nuovo Record including 3/16' bearings and the crown race; Victory and Triomphe headsets also share the same crown race . A little history here; Triomphe and Victory were designed not only as a mid-level component but also as a legacy design to those that preferred the old Nuovo Record (Triomphe) and Super Record (Victory) over the new C-Record. In the the case of headsets Campagnolo chose not to make an alloy like the Super Record, so the Victory was made to resembled a Nuovo Record instead. To differentiate the Triomphe headset it was made without the banded engraving similar to a Nuovo Gran Sport; the Triomphe headset used the same locknut and upper cone, all other parts differed in model number. The Victory is such a close copy of the Nuovo Record that the only obvious way to tell them apart is the tool flats on the threaded top cap; Nuovo Record has 6 flats, Victory and Triomphe has 2 flats.

Installed the s the Victory /Triomphe crown race but after a few rides it was obvious that the problem had not gone away. The problem was there was also fretting in the lower cup. Fortunately the NR lower cups are still available on ebay. After it arrived I installed it with the new crown race and the indexing was finally gone.




Sunday, November 18, 2012

Pulleys That Work With a Nuovo Record Derailleur?

No pictures right now but I wanted to throw this out as I am dealing with this issue again.First I found a thread that talks about this issue
Split-NR-SR-RD-pulleys

07.07.2012
I have two pairs of the Soma pulleys on two different bikes and am finding they seem to have a weak point. I have one set on a bike with a NR derailleur and another with a GS derailleur; the GS I ride most the time. Recently I noticed the shifting of the GS had gotten sloppy and there was a lot of friction in the drivetrain. I removed the pulleys and found both had bushings so worn that the steel sleeve was rattling around; I probably had 4000 miles on them. I checked the bike with the NR derailleur and found the jockey pulley was worn but the tension pulley was not. I'm not sure what the problem is and it may be my fault for not servicing them enough (I've never had this problem with Campy pulleys). I do have one theory however. When I first installed the Soma pulleys on the GS derailleur I was surprised to see some green corrosion inside the bushing and outside the sleeve. I'm thinking the manufacturer may has used a grade of brass with too much copper or too soft (or something like that).
I do have a fix however that is still in the experimental stage . I have a number of worn Campy pulleys where I pounded out the bushing (these bushing seem to never wear out of spec) and did the same for the worn Soma pulleys. The GS/NR/SR bushings are 12mm outside diameter, where the Soma pulleys are 10.1mm (the difference is the thickness of the brass; I first tried to drill out a Soma pulley which crack it). So I ground down the OD of tht Campy bushing to fit the Soma body using a simple tool; I slid the bushing onto a 1/4"x 6" drive extension some black tape underneath  so it would say put. I then attached the extension to a drill motor and clamped the drill motor in a vice.   I then took a file and ground the Campy bushing to about 10.1+; slightly narrowing on one side so it could be easily inserted into Soma bodies; the bushings were then pounded  into the Soma bodies with no problem. In regards to which sleeve to use, the Campy sleeve OD is 9.3 mm while the Soma are 9mm. The Campy sleeve is also about .2-.3 longer, so you either need to grind down the Campy bushing or use the Campy sleeve (I used the Campy sleeve). I have installed the Campy bushings in two Soma pulleys and road tested them for about 6 month and they show no sign of wear.

 As of April 28, the combination pulleys have worked flawlessly with no sign of excessive bushing wear. 

Thursday, June 7, 2012

1970's Olmo Gran Sport


 This is the latest and probably the last revision of this bike.



Originally it was constructed as a Cross Bike for fire roads; and a chance to show off some Campagnolo Nuovo Gran Sport (GS) components. For the longest while I did not identify the maker until I could be sure. I am now sure it is an Italian Olmo Mexico like this one Vintage Olmo Frame . This frame appears to have the same combination of lugs and lug cut outs, seat clamp seat stay ends and fork, so there is enough similarity to ID my bike; the only difference is the dropouts. My bike has Campagnolo short dropouts will the Mexico has Gipiemme dropouts. Either that it could be a Competition sans any identifying marks identifying it as an Olmo.

When I first put this bike together I was going for a Gran Sport grouppo but I was foiled by not being able to find Grand Sport brake calipers with standard length arms, so I ended up with Triomphe  levers and calipers with some generic gum looking hoods, until I could find the appropriate Gran Sport brakes.I first bid on a set of GS levers, which I got for a very good price. I then bought some "OEM" gum brake hoods. The hoods are likely replicas, but they look so good, no one has found a way to tell the difference. Then bought a set of Campy standard NOS GS arms from Boulder Bicycle/aka Rene Herse and used them to replace the arms from the Triomphe calipers I already had.(Boulder Bicycle is a great resource BTW). But the OCD in me would not allow this to continue, so I found some of under the cap slotted washers and flat nuts that came on the GS and Nuovo Record brake calipers (also from Bouolder Bicycle). This process has been very frustrating process. Originally I bought a set of GS calipers but the arms were too short. I sold these calipers and bought the set of Triomphe I had been using. Had I just waited a little longer, I could have simply switched the arms on the original GS calipers, or bought a NOS set of GS standard brakes and levers (with hoods) that Boulder Bicycle recently added to their store for $200; either way I would have spent less and done a lot less piecing together, but as they say hindsight is always 20:20. I finally found some OEM dome nuts and they do look good.

So here it is;
  
Front GS Bake caliper with the OEM shiny dome cap
  
The GS levers with Globe World logo gum hoods.

A GS rear derailleur with a Regina Corsa 14-27 freewheel and stainless rear housing.

A GS crankset; the large chainring is an Ofmega 51t and the arms have been filed down to meet with the crank arms.

GS rod actuated front derailleur.

The GS downtube brase- on levers were the same as Nuovo Record, however the clamp on were sometimes different. I modified these with a short threaded stud so I could use the GS clamp-on tensioners. 

I put together this wheelset with Nuovo Tipo hubs (used with most Gran Sport equipped bikes) and some Velo Orange PBP 700c box section rims.
and of course no bike of this kind would be complete without a Selle Italia Turbo saddle.


I still have a Mavic Shimano 105 wheelset with some Kenda 32mm cross tires, and this is the only 700c off road bike I have; so simple wheel change (and a little rear derailleur tweaking) allows me to jump back and forth between road and off-road.

Saturday, April 14, 2012

Interesting Bottom Bracket


Recently I saw this auction on ebay. I'm slowly putting together a Victory gruppo so I bit on the description


Campagnolo Victory - Bottom Bracket + Spindle


This is what the seller had put up for auction; if nothing else those are not Victory cups. I did a little research and and eventually won the auction'

I like to think of myself as knowing Campy components and your's stuck out. First as I said, the BB was  not a Victory BB; the spindle was Victory but the the Campy bottom brackets were aluminum with steel races, marked  the old "Brev. Inter." (International Patent) markings rather than "Made In Italy". Below are some Super Record cups that look similar, compliments of   VeloBase.com



According to Bicycle Classics.com * Victory 109 mm 68-SS spindle, fits 1958-1987 Record Pista cranks too, FRENCH or BSC, same as Record 68-P-120 Pista except it is marked 68-SS . While it's possible the previous user used the C-Record cups with the Victory spindle and crankset, but it's more likely the user needed to replace the C-record Pista spindle and did so with the Victory spindle.

 * Bicycle Classics.com also said Only the double NR and SR cranksets used the rifled (thick-wall) cups. All singles and triples used Record (thin-wall) cups. Which shows even the experts are sometimes wrong.

Sunday, February 12, 2012

Casting out Shimano

Okay, I have nothing against Shimano. They have been the driving force in bicycle components for the last 30 years and much of the time Campagnolo has been playing catch-up. But even as Campagnolo is trying to catch up, they make the most functionally beautiful components ever seen. Back in October of 2011, I replaced the shifters (combined with brake levers) on my 1999 Schwinn Peleton. I replaced the Shimano 9 speed shifters with Campagnolo 10 speed shifters, and while the two do not usually play well together, but there was a way make the Campy shifters work with a Shimano 9 speed drivetrain. Later I tried to up the ante and use a mixed drivetrain and make a 10 speed system work using a Campagnolo rear derailleur and a conversion cassette and a ShiftMate adapter. While all these measured worked, eventually I decided that the most elegant solution was to simply convert the bicycle from Shimano components to Campagnolo.

I had already switched the shifters and crankset with Campy Daytona gruppo parts (this group was later renamed Centaur). I decided to stay with the Daytona/Centaur group, however when a set of Athena differential skeletal calipers became available I jumped on them. Campy came up with the idea of differental brakes, where the front is dual; pivot and the rear a less powerful single pivot, as the rear brake does less to stop the bike than the front. To be honest, it probably doesn't amount to a whole lot one way or the other, but I just liked the idea and they are one pretty brake. I then added the front and rear Centaur derailleurs.


In order to make this all work, I would need a Campagnolo wheelset and 10 speed cassette. The cassette (Centaur 13-26 was a birthday present and I found a Daytona/ Mavic wheelset on ebay. If the truth be known I hadn't really planned to lay out the cash for the wheelset quite yet, but it was exactly what I was looking for and less than I had intended on paying. Since Campagnolo has stopped including hubs in their gruppos, it was either find a wheelset like this or buy a Campy brand wheelset; fortunately I was able to do the former.

Once this was done all that was necessary were 2 small parts to completely eradicate Shimano components from the bike (sans the peddles); if your curious the stem and seatpost are Nitto. The first were the cable adjusters and the last was the cable guide. Once this was done, the bike was a finally a campy bike. I plan however on keeping the ShiftMate and 10 speed Miche/ Shimano cassette in case I need a rear wheel on the road. Even as Campy seems to be having a resurgence since their 11 speed systems hit the market, actually finding parts is his and miss; mainly miss. So here is the bike complete with a butchered Brooks saddle (the term "butchered" is not a judgement of the quality of the modification, it simply pertains to a Brooks saddle where some of the leather has been cut off to make a more sleek saddle).

Thursday, January 5, 2012

The Miche Conversion Cassette

A conversion cassette is a way to make Shimano and Campagnolo play together. One common conversion is to use Campagnolo shifters with an otherwise Shimano drivetrain; these are referred to as a Shimergo. The primary reason is Campagnolo has a more positive shifting mechanism, which tends to last longer and is rebuildable. Shimano on the other hand makes cheaper and mored varied cassettes and very well made freehubs. The conversion uses a Campagnolo 10 speed shifter and a Shimano 9 speed drivetrain. The conversion is made possible by re-routing the rear derailleur cable called “hubbub” routing. I put a conversion together using the hubbub routing and it works very well (see the above Shimergo link).

Next I decided try a conversion cassette as another way to combine different components, maintain 10 speeds and to test the quality of the shifting. Unlike the hubub routing, a conversion cassette uses both Campagnolo shifter and rear derailleur. Campy and Shimano have different splines, so you can’t put a Campagnolo cassette on a Shimano freehub; further Shimano and Campagnolo use different spacing so a conversion cassette would use a Shimano spline with Campagnolo spacing (or visa versa). One way to do this to buy one ready made; Wheels Manufacturing, IRD, and American Classic all make a form of a conversion cassette; the one thing they have in common are they are very expensive; $200+. The one exception is Miche. Miche makes cassettes with individual cassette cogs and spacers. While they don't advertise building a conversion cassette many have suggested that it would be an easy conversion to simply use the Shimano cogs with the Campagnolo spacers.So, I mounted a Campy 10 speed rear derailleur and I needed to make the front derailleur 10 speed friendly again. Campy 9 speed compatible 10 speed front derailleur have a spacer that
clicks into place and I removed it as I was running a 9 speed chain drivetrain; it was a simple procedure to install it again.








Next I bought a Miche Shimano spline and spaced 10 speed cassette; it’s cheaper to buy a complete cassette than 10 individual cogs. At the same time I bought 7 Campagnolo spacers (the Shimano
spacers are red and the Campy’s are blue). I then switched out 7 the 7 Shimano spacers for Campagnolo spacers. The reason there are not 9 is the first and last cogs have integral cogs; the fact that they are on the ends of the cassette mitigate any issues with the different spacer width.

I installed the Miche conversion cassette on the Shimano freehub and one thing was immediately evident, the cassette had grown by 1.19mm. (The Campy spacers are .17mm wider than Shimano’s). The result was the end 12t cog did not connect with the splines. I tightened the lockring while holding the cog in place and after a few turns I could feel the cog connecting with the splines and I was able to continue to tighten the lockring without out the cog turning. Now I had mounted the Miche cassette with the Shimano spacers and even with a 1mm spacer behind the cassette, the cog connected with the splines, so I know it was very close. Further this is not unusual with some 10 speed freewheel combinations, so unless you are the type that uses the last cog regularly and exert a lot of pressure on it such as sprinting, it should not be a concern. I also noticed that the derailleur cage was very close to the spokes when the chain was in the last big gear. This is also not unusual for 10 speed drivetrains, especially Miche who has the last gear offset toward the spokes. The general rule is, if the derailleur is not hitting the spokes it will work; in my case the cage had about 3-4mm clearance, which I find acceptable.

After adjusting the rear derailleur, I took the bike for a test ride and the conversion cassette worked pretty well; it should be noted that one should not expect the near flawless shifting that comes from a Shimano or Campy cassette. There was however, a rough shift in the area of the 6 and 7 cog (smallest to largest). While on the 6 cog, he 7 cog was trying pick up the chain for a few revolution and then would settle down and stop. I was able to adjust this out with the barrel adjuster by turning it down as far as possible while the derailleur was still shifting from the first to second cog, but the shifting felt flat. Somewhere in the back pf my memory, I remember reading that Campy used different spacing between some cogs. I looked it up and sure as heck Campy places a .14mm wider cog between 6 and 7 (the other 8 spacers are 2.41; the spacer between 6 and 7 is 2.55). Since the Miche spacer is actually 2.26, I needed a 2.40 spacer to account for the wider spacer. This of course is in all practicality the same as a standard Campy spacer; and having a few in my parts box I used it to replace the Miche 2.26 spacer between cogs 6 and 7; it is an optical illusion that it looks thinner, the OD of the spacer is simply smaller.

The difference was remarkable for such a minor tweak. First the shifting felt more positive on all the gears not just cogs 6 and 7. Second to keep the rear derailleur cage away from the spokes, I set the stop as close as possible, which resulted in an increased effort to click the shift into the end gear (this may also have been due to the spacing). Well, .14mm apparently moved the indexing outward and the shift now feels the same as the rest.

There is another method of making Campagnolo and Shimano play together using a shifter adapter called a Shiftmate.This little gadget uses two tiny pulley wheels to change the shifter cable pull. Not only does it work for Campagnolo and Shimano cross platforms, it allows one to mix and match shifters and cassettes of different speeds and manufacturer. I currently have one that allows the use of my Campy 10 speed shifters with a Shimano 10 speed cassette. After riding with the campy spaced cassette long enough to determine it was working very well, I replaced the Shimano spacers and installed the the shift mate on your left. I was a little tricky getting it right, but if you read and follow the instructions exactly, it appears to be working very well. I will update after several road rides. FTF

Two weeks later and about 300 miles later the shiftmate has yet to miss a shift; thi sis the way to go.

But back to the Miche Conversion Cassette; if you want to know if you can make a conversion cassette with a Miche cassette the answer is a resounding yes; as long as you are willing to put up with slightly inferior shifting and pay attention to the details. And it is certainly cheaper than a new wheelset and the other conversion cassettes..