Technical FAQ: More on Giant seat masts, Campy down tube shifters, and cleat positioning
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Feedback on Giant seat mast
I’ve seen this product advertised and have considered trying one on my gravel bike. I wonder if these are safe and a possible solution for George’s seat height issue on his Giant TCR Advanced.
Well, sure, that would raise his saddle without having to do any alterations to the frame or seat mast. I have no idea how much springiness that thing would have and whether that would be disconcerting or not, although it appears that if you were to bring the seatpost clamp and the saddle clamp both very close to the bend, you could minimize the amount it moved up and down.
As for safety, I, of course, have no idea if it is reliable or not. If the rail is as strong as a cromoly saddle rail, and especially if the clamps are close to the bend, it certainly has the potential to be safe. And it shouldn’t void his Giant warranty.
I am writing to share that I experienced the same challenges as George has with his Giant TCR ISP. I successfully altered the seat mast to extend it by using a carbon fiber repair kit and a remnant section of the seat mast from when it was first cut to size. Using the seat-mast section to extend the seat mast, I applied a buildup of carbon fiber on the inside of the seat mast to hold the section in place.
A key to success is doing enough layers of carbon fiber in the buildup to give it sufficient strength. It is a fairly easy and permanent fix.
Wow, that’s an impressive do-it-yourself carbon fix. I think somebody should have a high degree of experience and knowledge with carbon before embarking on something like this, and the Giant warranty would, of course, be void.
Feedback on crank-spider tab thickness
I was very interested in your recent post regarding crank-spider tab thickness.
I’ve found that if the tab is too thick, then when changing to the inner ring the chain can balance on the teeth of the inner ring instead of seating properly. This is more likely if one changes to the inner ring while using one of the smaller sprockets. And if the tab is too thin, then one finds that one can’t use the inner chainring with the smallest one or two sprockets.
And I usually assume that I’ll encounter one of those problems with any double chainset. But not both problems, of course.
However, when I fitted a Stronglight 34-50 chainset to one of my bikes some years ago, I encountered both problems. The tab was so thick that the chain balanced on the teeth of the inner ring, while simultaneously being so narrow that the chain rubbed on the outer ring while using the 34 and smallest two sprockets. The solution that I’ve used in the past to solve the chain-rubbing-on-the-outer-ring problem is to make spacers that fit between the crank tab and the outer ring. Not just washers, but spacers that run a short distance up the inside of the outer ring. That cured the chain-rub, but of course, the chain-balancing-on-the-inner-ring-teeth problem still persisted. So, I made the top of the spacers bulge slightly towards the inner ring, and it’s been working perfectly for years.
So, I was most surprised to find that the FSA 34-50 chainset on a Specialized that I bought four years ago exhibited neither problem. Always changes perfectly onto the inner ring, yet never rubs on the outer ring.
Of course, the problem of the chain rubbing on the outer ring could be avoided by careful design of the outer chainring, but the FSA chainring doesn’t appear to be in any way special.
So, I’m somewhat bemused by those two chainsets; one of them has crank tabs that are simultaneously too thick and too thin, while the other has crank tabs that avoid both problems.
There clearly is more to it than spider-tab thickness — must have to do with the shape and size of the FSA shift ramps and the protrusion of the ring itself toward the medial side.
Feedback on Campagnolo 10-speed down-tube shifting
In regards to indexed Campagnolo 10-speed down-tube shifting, I have used the regular Campagnolo 10-speed TT bar-end shifters as bar-cons on a mustache bar, and as regular down-tube shifters on regular down-tube bosses. It is also possible to change the indexing mechanism to 7-, 8-, and 9-speed indexing on the right lever. I can’t remember which spare parts or part I cannibalized for that conversion myself.
However, as a fan of Campagnolo and down-tube shifting. I recommend finding a pair of Simplex Retrofriction down-tube levers instead, as I don’t think indexed shifting brings anything to the table when the lever is mounted on a down tube. Simplex’s clutched retro spring mechanism offers very fast, very precise and secure non-indexed shifting when paired with modern chainrings, cassettes, and chains.
Simplex retrofriction will most likely work with both modern and vintage Campagnolo rear mechs [derailleurs], and it will work with 9-, 10-, 11-, and 12-speed cassettes (same body and same total width of cassette). The Simplex barrel is quite small, but it actually matches a neat 180-degree travel when used with a vintage 1988 Campagnolo Athena rear mech OR and a modern Campagnolo Chorus 11-speed rear mech from 2008-2015. (The shiny Athena 11-speed mech would, of course, be the aesthetically correct choice for a rando-style rear mech, as I assume no carbon is allowed).
Oh, did I mention that the Simplex down-tube shifters are just drop-dead gorgeous?
Thanks for that nice suggestion. I used to race with those Simplex levers in the early 1980s on Campagnolo Super Record (non-indexed) groups. I loved their nice feel when shifting.
Feedback on cleat positioning
I just read this article, and it’s the one that most involves my situation.
I’m an (almost) 72-year-old very avid cyclist. In 1974, I had some very serious leg injuries when a Datsun 210 turned left in front of my Honda 750, closing speed at impact was near 100kph. I was very fortunate to have been wearing full leathers (it was March 30 and pretty cool weather) and a full coverage Bell Star helmet (state of the art at the time). Still, I spent 131 days in the hospital. (And met a student nurse who’s been my wife now for 44 years, but that’s another story!) I had no head injuries, no joints damaged. My injuries included a cracked bone in my right hand, which has healed with no after effects — it’s strong and fully functional. The big things were a badly shattered left femur and broken right fibula and tibia. (The car was turned 45 degrees, hence the upper and lower injuries. And a cracked pelvis. And a severed S1 branch of the sciatic nerve in the left thigh — I can’t lift the left foot; I can press down and with my Specialized S-Works 6 shoes, bicycling is no problem, now that I got the kinks of my situation worked out.
You might be interested in my story of fixing everything. My case is unique; I’ve had three broken bones in my legs: left femur, right tibia and fibula, all at the same time! As a result, my left femur is almost 3cm shorter and wasn’t put back together straight. I’ve still got a plate on the tibia, so my right leg isn’t quite factory stock anymore either! I’ve made numerous adjustments over the years and have come to settings that are as ideal for me as they can be. I have 7mm of shims under the left cleat and 4mm inside the left S-Works 6 shoe to correct the pressure to the ball of my foot (normally the outside edge comes down first). Did I mention that only the press-down muscles work in my left foot? My toe drops when walking, so I have built-up walking shoes tailored to compensate for that too. Also, the right shoe is as far forward as it will go and the left is all the way back so as to pull my hips as close to perpendicular to the top tube as possible. Then I started with the seat “straight” and rode with my Topeak mini-torque wrench in my pocket to adjust the saddle on the road. And “straight” never felt quite right. A little more tip, then back, then 2mm down, then turned. I’ve ended up with about a one-degree turn to the left. And it all feels great! I’m better balanced and more comfortable on my Cervelo R3d than I am walking! Scorch (it’s a burnt matte black color) has taken me nearly 20,000 km in two years on the road and 2617 km on the Tacx Neo Smart on Zwift (Level 18).
I’ve been fortunate with my health too. The only thing I’m on is vitamin D on my doctor’s orders! I said, “I drink lots of milk.” She said, “You need it because of your age and your activity. I’ve got active 30-year-olds that don’t exercise as much as you.” But because of my age (darn those calendars), I’m keeping an eye on articles like yours on hearts and blood thinners, just in case.
I’ll try not to miss any more columns again!
I’m impressed that you have found a solution that keeps you enjoying the open road like that!
Just a word of caution on moving cleats too far back towards the midfoot. If you are just spinning, it is not a problem. Standing and climbing could put too much stress on the plantar fascia ligament causing heel and arch pain. This would be similar to seeing patients that work construction and standing on a ladder all day. They stand with the rung through the midfoot and produce the same symptoms.
— Alan G. Shier, D.P.M.
Foot Care & Surgery Center
Thanks. In my experience, having my cleat under my medial arch makes it super uncomfortable and awkward-feeling to stand out of the saddle anyway; I think the only way to ride with a mid-foot cleat is to sit and spin.