Tag Archives: Dura Ace

More Clearance with Single Pivot Sidepull Brakes

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Shimano 105 dual pivot sidepulls

I’ve been wanting to mount some wider and more comfortable tires on my 1990’s Terry Symmetry, which was built during the sad era of zero brake clearance for wider tires.  Even after switching from the 650c rims which the bike was designed for, down to 26″ 559s, I had no room for fenders with the 32 cm (actually measuring at 28mm on my rims) Paselas I was using.  But, since I mounted the fenders without going underneath the fork crown and brake bridge, I wondered if I could use some wider tires which might provide more comfort than the competent but harsh riding Paselas I’ve been using.

So, I purchased a set of Schwalbe Kojak 26 x 1.35 tires.  Since, there are almost no tire options available for road bikes running 26 inch tires, and while I usually do not care for Schwalbe’s offerings, I was left with these Kojaks as the only choice as an alternative to the Panaracer Paselas.  The Elk Pass tires offered by Rene Herse Cycles that I had previously tried proved to be so flat prone that I could no longer tolerate them.  When I mounted the Kojaks, which were very difficult to install on my rims, the Shimano 105 dual pivot brakes contacted the tires, so I knew I was going to have to figure out a different brake option that would provide better clearance.

Dura Ace single pivot sidepulls

Fortunately, I am not the first cyclist to crave wider tires on a road bike, and to push the limits of tire clearance.  There are many forum posts and websites devoted to finding solutions to this problem.  A number of possible solutions to the tire clearance problem exist, but the clearest path involved choosing single pivot sidepulls, which can generally offer better tire clearance than their dual pivot counterparts.  While dual pivots are super easy to set up, I’ve never been put off by single pivot brakes, except for: see below!

Weinmann 600 sidepulls

First off, I tried these Weinmann 600 brake calipers, which were sitting in a NOS box in my parts bin.  Handling these calipers and using their hardware proved shocking:  these brakes come with very low quality bolts, and some of the nuts had been cross threaded.  So, this low quality brakeset has been set aside.

Dura Ace Centerpulls

But, then I thought:  what about switching to centerpull brakes?  That would mean installing front and rear hangers, but could be an option to consider.  I dry mounted these first generation Dura Ace centerpulls but they actually proved to have less clearance than the Shimano 105s.

So, I tried out a number of different options ranging from the very nice Dia Compe BRS 200s (which didn’t have quite enough brake reach on the rear brake), to these oddball Dia Compe AC 600s (pictured last), which feature a strange offset angle for cable routing, apparently to reduce wind resistance, which is nothing short of ridiculous.  And, they have no quick release mechanism, a must for any brake caliper.

Rear caliper installed backwards

Front caliper with much more clearance.

Finally, I settled on a set of Shimano 600 single pivot sidepulls which are actually the matched set to the Shimano crankset I’m using on this Terry.  But, there were several problems to deal with.  There as less clearance in the rear than in front, so I mounted the rear brake backwards, which provided a few more millimeters of clearance.  Since this bike is designed for recessed brakes, it was also necessary to deal with the too wide opening for the nutted bolt.

Bikes designed for recessed brakes should not use nutted brakes unless care is taken to find a way to center the bolt inside the too wide opening.  In this case I used a leather washer which snugs into the recessed area, and then a larger washer to cover the area.

At the rear, clearance is good (relatively speaking) and performance seems okay for now.  Cable routing was odd, and I’ll think about a different solution, as there is some friction on the rear cable.

Here’s the bike with the Kojaks installed and the Shimano 600 single pivot brakes, with the rear brake installed “wrong” on the front of the seat stays.  We will see what happens when I take this bike out to test both the tires and the brakes.  I’m hoping for a more comfortable ride on the Kojaks and no decline in braking performance.  A long test ride will prove illuminating.

The Many Faces of ALAN

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My mid-80’s ALAN bicycle is one of my favorite rides.  For awhile it left my stable to seek accommodation with a small-of-stature family member, as it is a tiny bike with 24 inch wheels.  The bike didn’t work for that rider, so I regretfully (NOT!) accepted the bike back last winter.

For the past months I have happily ridden this bike all over the place.  It’s so little that I can easily transport it inside my Highlander with an internal bike rack.  Weighing in at 19 lbs means it can be lifted and carried just about anywhere, so it’s also a perfect bike for exploring unusual terrain involving a portage or two.  But, as you can see from the above photos, I had set this bike up for my family member with a simple 1×7 indexed drivetrain and a very upright riding position.  I had also used a 152mm crankset to accommodate the bike’s lower 25cm BB height, and that meant a lot of spinning. As I contemplated changes to make the bike more sporty and with better ergonomics for my own enjoyment, I realized that I hadn’t given the bike a complete overhaul since acquiring it 5 years ago.

The bike went through a number of iterations during that time, including several setups with drop bars and city style bars, but even after all that fun experimentation, the hubs, bottom bracket and headset hadn’t been touched since 2013.

ALAN frames are built with aluminum tubes screwed and glued into steel lugs.  When I stripped the bike down for an overhaul, I wanted to also examine all the lugs to make sure the frame was holding together after over 3 decades of use.  The bottom bracket shell provided my first look at how ALAN bikes are constructed. The main tubes appear to have flutes, which I can only imagine were installed after the straight portion of the tubes were screwed and glued into the BB shell.  You can see from the 2nd photo above that the BB shell was also threaded to accept the chainstays, but those tubes do not have flutes, but are simply the straight tubes threading into the shell.

As part of the overhaul I used my torque wrench to check the bolts joining the stays and brake bridges to the frame and lugs.  I haven’t been able to locate the torque setting recommendations for these bolts, so I intended to adjust any bolt with a lower torque to its corresponding bolt with a higher torque.  However, all the bolts were adjusted evenly so no changes were necessary.  As I examined the frame I noted the SN on the bottom bracket:  D26173, and wondered if this was a date code.  Based on my research, the BB number is not a date code, and it appears that some ALAN frames had a date code on the seat tube or on the seat tube lug.  This bike had a frame dimension code on the seat tube lug:  46 x 48, but no other SN.  And, its ALAN “headbadge” is on the seat tube. Fortunately, it is also possible to date a bike by its components.  The Shimano Dura Ace brake calipers were marked with a “KK” code, which means the brakes were manufactured in November of 1986.  So, I would surmise that this ALAN is a 1986 or 1987 model.

Once I overhauled the BB, headset, hubs, and pedals, it was time to think about the changes I wanted to make.  I swapped out the tall dirt drop stem for a less tall Nitto Technomic stem paired to a Nitto flat bar that I cut down (5 cm off each end) to make the bar more suited to this little bike.  But the real Tour de Force was installing Simplex Retrofriction shifters on Velo-Orange thumbies.  I hadn’t used these much praised shifters before, and was kind of skeptical about how they would perform.  How could they really be better than SunTour’s ratcheting shifters?  Simplex Retrofriction shifters are not a ratcheting mechanism, but instead have an internal spring acting as a directional clutch.  Using them was eye opening.  These shifters are far more subtle and precise that any others I have used.  The only downside is the ridiculous amount of travel when used with an 8 speed drive train, as you can see from the 2nd photo above.  That’s a small price to pay for the silence and precision of this amazing component.

I wanted to use a crankset with longer arms to provide for a more comfortable cadence, but not too long given the bike’s low BB height.  I sourced these NOS TA 160mm cranks from eBay, with 48/38 rings.  I was worried that the T.A. cranks would sit too far inboard on the Dura Ace 115 mm spindle.  They worked out well in this case, but with only a tiny bit of clearance from the drive side chainstay.  The bike’s very short chain stays means that one must not cross-chain this drive-train, but that is also sometimes true of bikes with longer chainstays.  In practice, this crankset was just right for this bike, although I had to get used to having the extra larger chainring for shifting to bigger gears!

Hailing from the 80’s, this bike’s wheelset is Shimano 600 tricolor hubs laced to 24 inch Mavic Open 4 rims.  The seatpost is the ALAN spec’d 25.0 American Classic that most early ALAN bicycles were equipped with.  I’m using MK3 Vee Rubber micro knobby tires, which have performed perfectly and with never a flat in the last five years.  My no longer available Detours seatpost bag serves as a de facto rear fender, blocking mud and debris from my backside.

Here is the ALAN as reconfigured, with a double TA 160mm crank, lower and flatter Nitto bars, and Simplex Retrofriction shifters mounted to Velo Orange thumbies.  I’m happy with this configuration, and hope to keep riding this one of a kind bike for years to come.

Overhauling a Shimano Octalink Bottom Bracket

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I was definitely skipping class when Shimano introduced its splined Octalink cranksets and bottom brackets back in 1996.  Since I have always been a fan of square taper bottom brackets, I saw no need to trouble my mind with this “new” system, a system which Shimano has long since replaced with outboard bearings and a right side crank arm with an integrated spindle.

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The Octalink design was meant to supply a better attachment to the crank arms.  But, with this shallow V1 model, it is unlikely that Shimano achieved its objective.  The V2 model has much longer splines, and its ISIS competitor, even longer.

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Dura Ace Octalink crankset with self-extracting dust caps

So, I was planning on selling this BB along with its mate – a very nice Dura Ace crankset that I took off an abandoned titanium triathlon bike, a bike which had seen some use, and then neglect.  I wanted to take a look at the BB to make sure it was in good shape.  I was assuming that, due to its sealed cartridge mechanism, an overhaul, if needed, would be impossible.  I was wrong!

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When I removed the rings from the spindle I saw that they housed two sets of bearings on each side – a set of needle bearings to contact the spindle and a set of ball bearings to contact the spindle’s race.  Both rings are supplied with two outer seals.  The outmost seal is easy to remove – it just falls off the spindle, but the inner seal can be left in place while doing an overhaul, since your work will be done from the inside of the rings.

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View of ring from the outside, with first seal removed and 2nd seal in place.

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View of ring from the inside. You can see both sets of bearings.

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Lock ring removed from inside of ring.

Peering down into the inside of the rings, you can see a lockring which needs to be removed to access the bearings.  This is easily done with the tip of a small screwdriver.  Then, you have access to the bearings and can remove them.  Before doing so you should note that Shimano’s own technical specs for this BB do not provide instructions on how to do so, but just a schematic of the parts.

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When you remove the bearings, do not do what I just did!  I was unprepared for the bearings to simply fall out of their clips (causing a PTSD experience reminiscent of recent freewheel overhaul mishaps).  The needle bearings and ball bearings went for a little journey around my work bench.  I was most concerned about the needle bearings, as I didn’t have replacements for those, and was planning to replace the 1/8″ ball bearings anyway.  Fortunately, I recovered the bearings with my magnet, but while doing so I pondered why Shimano would think it would be acceptable to use such tiny bearings in a bottom bracket.  1/8″?  Really?  Apparently, the needle bearings take the load off, literally, from the tiny 1/8″  ball bearings, so things are not as bad as they may seem.  I don’t know about the general reliability of Shimano Octalink bottom brackets, but Shimano’s cartridge bearing square tape BB’s use much larger bearings, although the non drive side bearings are typically smaller that those on the drive side.

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Once I had the bearings back into their flimsy clips I added grease to the cup.  It was a bit of trial and error getting the bearings back in.  I found it best to grease the clips heavily, then install the bearings. The needle bearings go in easily. For the small 1/8″ bearings which come last, it was necessary to turn the cup over and gently place the ring over the bearing clip.  Otherwise, the bearings just wanted to fall out of the clip (as they are inserted from the outside of the clip).  Once in place, I re-installed the lock ring and tried the rings out on the spindle to test their smoothness.  All was good – they were once again smooth as glass.

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Park Tool’s service guidance for these bottom brackets states that “it is recommended to leave the needle bearing and ball bearings in the cup” and that the ring should simply be flushed with solvent and re-greased.  That might be okay if there isn’t a lot of debris inside the rings.  I’m glad I removed the bearings, as it gave me a chance to evaluate the rings, and to take a close look at how the mechanism is meant to work.  And, if you have been looking for a Dura Ace Octalink BB and Crankset, those items will be for sale on eBay soon.