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    • CommentAuthorgottobike
    • CommentTimeJun 28th 2016 edited
     
    Graphene-Laced Bike Tires Are Both Stiffer and Softer
    As enamored as I am with the concept of graphene, it will not be taking me off my Black Chili Continental GP 4000S II road tires anytime soon.
    •  
      CommentAuthorPaul
    • CommentTimeJun 29th 2016 edited
     
    gottobike:Graphene-Laced Bike Tires Are Both Stiffer and Softer
    As enamored as I am with the concept of graphene, it will not be taking me off my Black Chili Continental GP 4000S II road tires anytime soon.


    Well into my second set of the new graphene Corsa G+. They are fast as hell, fairly durable (2200-ish miles/4 flats) and as anyone who plays Bike-o-rama knows, the gum walls look classy as hell.
    •  
      CommentAuthorbilld
    • CommentTimeAug 5th 2016
     
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      CommentAuthorbilld
    • CommentTimeAug 7th 2016
     
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      CommentAuthorSigurd
    • CommentTimeAug 11th 2016
     
    I am looking to convert a classic (fully rigid) mountain bike to drop dirt bars: Who, or which bike shops, in San Diego can provide quality advice on such conversion?

    I need help with decisions such as bar, stem and lever make/models, as well as bar and stem dimensions - thanks for ideas.
  1.  
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      CommentAuthorbatmick
    • CommentTimeAug 12th 2016
     
    •  
      CommentAuthorSigurd
    • CommentTimeAug 12th 2016
     
    batmick:
    Shut Up Legs:Cycle Quest?
    That would have been my first pick as well. The guy knows his stuff.
    http://www.cyclequestsd.com/

    Good to know - I will talk with them.
    • CommentAuthorShady John
    • CommentTimeAug 21st 2016
     
    Sigurd,

    Are you converting your '86 Stumpjumper? I think for geometry considerations, there are many forums where conversions have been discussed (search "MTB drop bar conversion"), and you could also check out the geometry of bikes such as the 26" wheel Surly LHT:

    http://surlybikes.com/bikes/long_haul_trucker

    I understand that getting the geometry right can be a challenge. I've spent a fair amount of time trying to get road and mountain components to work together, and it can be a challenge. I think the typical way people deal with MTB/drop bar component compatibility is to use bar end friction shifters, though there might be some other options now that allow STI shifting if you're willing to buy a new drivetrain.

    Are you set on 26" wheels? If you're willing to consider new or "recent used," particularly 29er/700c, you might be pretty happy with some of the offerings from Salsa/Surly/Soma, or maybe Black Mountain Cycles in Marin (http://blackmountaincycles.blogspot.com/). Many other more mainstream manufacturers have put out steel 29ers over the past 10-12 years, as well, including Raleigh, Kona, Marin, GT, etc.
    •  
      CommentAuthorSigurd
    • CommentTimeAug 21st 2016
     
    Shady John:Sigurd,Are you converting your '86 Stumpjumper?
    Yes. It's not much of a "mountain" bike, anyways, by modern standards, so I might as well have some fun with it and focus on uses around gravel and dirt roads. I would of course keep the current bar setup, so the conversion is entirely reversible without any fuss.

    Sky is sending me some original WTB MTB dirt drop bars and Barcons. So what I need some guidance on is, I think:

    - What kind of stem and dimensions (1" threaded)
    - What kind of levers (need to work with cantis

    This is the sort of thing I am going for:

    • CommentAuthorerik
    • CommentTimeAug 29th 2016
     
    Yes. It's not much of a "mountain" bike, anyways, by modern standards, so I might as well have some fun with it and focus on uses around gravel and dirt roads. I would of course keep the current bar setup, so the conversion is entirely reversible without any fuss.

    Sky is sending me some original WTB MTB dirt drop bars and Barcons. So what I need some guidance on is, I think:

    - What kind of stem and dimensions (1" threaded)
    - What kind of levers (need to work with cantis

    This is the sort of thing I am going for:

    Levers for cantis are pretty easy. Any road lever should work. Just make sure you get the right yoke height/pad angle. Sometimes when you go from mountain brake levers to road brake levers you have to shift that around a bit to get the most mechanical advantage. If you want Vs, that is a different story.

    For this kind of conversion, I usually go with a threaded to threadless stem adaptor. It makes it much easier to find the right stem length. If you want to keep a more classic look, you will need to do some careful thinking to get the right stem geometry, but if you can use threadless stems you can swap things out pretty easily. I happen to like the look of modern, threadless stems on beefier frames like mountain bikes, so I never have a problem with this, but I know some people like to keep their threaded stems looking threaded.

    Either way, you probably want to bring the bars up and in compared to the mountain geometry. I always found that counter-intuitive, but it makes sense considering that drop bars intrinsically stretch you out more than flat bars. Nitto makes the MT-10, which I think was designed for this kind of thing. There must be others out there though.
  2.  
    Tour de France Champion Greg LeMond Signs Groundbreaking Carbon Fiber Agreement with Oak Ridge National Laboratory
    New manufacturing process yields high volume, low cost carbon fiber for transportation, renewable energy, and infrastructure
    August 29, 2016 businesswire.com
    OAK RIDGE, Tenn.--(BUSINESS WIRE)--Three-time Tour de France champion Greg LeMond is partnering with carbon fiber manufacturing pioneer Connie Jackson and Oak Ridge National Laboratory (ORNL) to bring the most significant development in carbon fiber production in over 50 years to the global markets.

    LeMond Composites, a new company offering solutions for high-volume, low-cost carbon fiber, has secured a licensing agreement with U.S. Department of Energy’s ORNL. The agreement will make the Oak Ridge-based LeMond Composites the first company to offer this new industry-disrupting carbon fiber to the transportation, renewable energy, and infrastructure markets.

    A breakthrough process invented by Jackson and a research team at ORNL’s Carbon Fiber Technology Facility (CFTF) will reduce production costs by more than 50% relative to the lowest cost Industrial grade carbon fiber. Incredibly this new carbon fiber has the mechanical properties of carbon fiber costing three times as much. Until now, manufacturing carbon fiber was an extremely energy-intensive process. This new method reduces energy consumed during production by up to 60%.
    •  
      CommentAuthorbikingbill
    • CommentTimeAug 31st 2016
     
    That will be important for the large wind turbines. Reduction in cost of those, which already are one of the cheapest electrical generating sources, could be a tipping point.
  3.  
    More carbon fiber for everyone!
    Greg's gonna make a shitload of dough
    Im curious what the breakthrough was, 50% and more in savings?
    •  
      CommentAuthorbilld
    • CommentTimeSep 9th 2016
     
    • CommentAuthorgottobike
    • CommentTimeSep 16th 2016
     
    Product | COBI
    https://www.cobi.bike/product?_ga=1.90347804.767114061.1474074602
    COBI is helping to revolutionize the overall cycling experience by connecting your smartphone to your bike. This award-winning modular system brings out the best in any bike by providing it with intelligent assistance. The result is more safety, convenience and fun – no matter where your journey takes you.

    Smartphone mount with headlight/taillight, battery pack, available dyno-hub charging cable, electronic bell, alarm system, nav and weather. Very smart!
    • CommentAuthorShady John
    • CommentTimeSep 16th 2016
     
    gottobike:Product | COBI
    https://www.cobi.bike/product?_ga=1.90347804.767114061.1474074602
    COBI is helping to revolutionize the overall cycling experience by connecting your smartphone to your bike. This award-winning modular system brings out the best in any bike by providing it with intelligent assistance. The result is more safety, convenience and fun – no matter where your journey takes you.

    Smartphone mount with headlight/taillight, battery pack, available dyno-hub charging cable, electronic bell, alarm system, nav and weather. Very smart!


    Kind of cool, but no thanks. My smartphone resides deep inside a backpack, or in a jersey pocket zipped inside a thick ziplock bag. If my phone rode out on the handlebars it would be cracked and splintered within a matter of days or weeks.
    • CommentAuthorgottobike
    • CommentTimeSep 17th 2016 edited
     
    Good point, Shady John. With many of today's more common smart phones, it does seem like the COBI would be geared more to an uptown style of flair weather riding. If durability of the smartphone is the limiting factor, maybe it's time for something a little more rugged?

    Best Rugged Smartphones (Unlocked) 2016
    http://www.toughgadget.com/best-rugged-smartphones-unlocked/

    These are not cheap; however, with the 6/6+ running 6-800 USD and then another ~200 USD to replace the flimsy touch screen every few months, one of these ruggedized phones may be a better choice, especially if it is using an internal waterproofing technology like HZO http://www.hzo.com and subscribes to ingress protection standards.
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      CommentAuthorbatmick
    • CommentTimeSep 17th 2016
     
    I've been using this case/mount combination for a couple of months now and really like it. Tested the waterproofing in one of the few rainstorms we had earlier in the year and dropped it once at about 5mph because I had taken it off the holder while riding.

    Not sure if I would trust my iPhone 6s to it for real off-road action but fire roads etc. shouldn't be a problem.

    https://www.amazon.com/gp/product/B00VZGTQZ8
    •  
      CommentAuthorSigurd
    • CommentTimeSep 17th 2016
     
    batmick:Not sure if I would trust my iPhone 6s to it for real off-road action
    Pretty sure I wouldn't trust myself not checking my phone every two minutes...
    •  
      CommentAuthorbatmick
    • CommentTimeSep 18th 2016 edited
     
    Sigurd:
    batmick:Not sure if I would trust my iPhone 6s to it for real off-road action
    Pretty sure I wouldn't trust myself not checking my phone every two minutes...


    Good point. But I use mine as a cycle computer after my Garmin died, so I needed something to have it in front of me and weather-protected. So I am constantly checking it but, so far, I have been able to resist the temptation of email.
    •  
      CommentAuthorbikingbill
    • CommentTimeFeb 6th 2017
     
    Capitan Obvious: Replacing Warped Rotors makes you go FASTER

    Longish story.

    My Bacchetta Giro recumbent originally came with BB5 disc brakes. Long and fast descents glazed the pads and warped the rotors.

    This was replaced with BB7's. The pads held up fine. The rotors appeared to be fine, but it was always a compromise between no-contact (rubbing) and braking effectiveness. Then last week some rider on a recumbent trike was pulling wheelies (riding on two wheels) just before the start of a ride, and managed to crash into my rear wheel.

    Tried to find a replacement, ended up having to buy two new wheels AND new rotors, as these wheels were not 6-bolt ones.

    The shop (Adams Ave) suggested better rotors (thicker) and that was that.

    So, yesterday on a ride I decided to push in on one stretch and set a PR:

    https://www.strava.com/activities/855243706/segments/20836837236

    23.7mph average and I wasn't pushing it that hard. Prior PR was 20.8mi/h in 2012.

    The new wheels (from Adams Ave. Bikes):



    Oh these are Deore hubs sans ratchets. They use some sort of clutch mechanism for coasting. That should be an interesting experiment.
    • CommentAuthort.e.d
    • CommentTimeMar 9th 2017
     
    Has anyone tried the Compass "supple" tires?

    I've ridden Panaracer Paselas for many years and was curious how the casing of the Compass compares.
    •  
      CommentAuthorbikingbill
    • CommentTimeMar 9th 2017
     
    t.e.d:Has anyone tried the Compass "supple" tires?

    I've ridden Panaracer Paselas for many years and was curious how the casing of the Compass compares.


    They ride great, but the ones I had (26") had a tread pattern that make a lot of noise above 20mph. So I switched to slicks. Since then Compass has changed to a better pattern.

    I do think Compass makes some amazing tires, and when the stock of these slicks run out ... I'm going to try these ... probabily tubeless:

    https://www.compasscycle.com/shop/components/tires/26-inch/compass-26-x-1-8-naches-pass/
    • CommentAuthort.e.d
    • CommentTimeMar 23rd 2017
     
    bikingbill:
    t.e.d:Has anyone tried the Compass "supple" tires?

    I've ridden Panaracer Paselas for many years and was curious how the casing of the Compass compares.


    They ride great, but the ones I had (26") had a tread pattern that make a lot of noise above 20mph. So I switched to slicks. Since then Compass has changed to a better pattern.

    I do think Compass makes some amazing tires, and when the stock of these slicks run out ... I'm going to try these ... probabily tubeless:

    https://www.compasscycle.com/shop/components/tires/26-inch/compass-26-x-1-8-naches-pass/


    Thanks, Bill. Is there a shop locally that carries the Compass tires? I really just want to feel the tire to get an idea of the difference between the Paselas (Besides about $50) since they're both made by Panaracer.
    •  
      CommentAuthorSigurd
    • CommentTimeMar 23rd 2017
     
    t.e.d: Is there a shop locally that carries the Compass tires?
    I am pretty sure MJ's Cyclery (Park and Uni) orders them, but I am not sure if they carry any inventory - I would check with them.
    •  
      CommentAuthorbikingbill
    • CommentTimeMar 23rd 2017
     
    I had to mail order them. I still have the 26'ers in my garage, not worn down ... but I knew with that volume of sound I was losing watts ... and Strava pretty much verified this with various PR's.

    I had 559-32's Panaracers and they were FAST. But I wore the rear to threads in about 1000 miles.

    That happens on the climbs. Big rider + double digit grades + heavy bike + cargo = rear tire wear.
    •  
      CommentAuthorPaul
    • CommentTimeMar 23rd 2017
     
    Sigurd:
    t.e.d: Is there a shop locally that carries the Compass tires?
    I am pretty sure MJ's Cyclery (Park and Uni) orders them, but I am not sure if they carry any inventory - I would check with them.


    MJ's will order. They come in 2-3 days and you'll save shipping. I just got some Switchback Hills that way.
    • CommentAuthorgottobike
    • CommentTimeApr 21st 2017
     
    QUARQ SHOCKWIZ
    https://www.quarq.com/shockwiz
    Just heard about this from ABR today.
    • CommentAuthort.e.d
    • CommentTimeJul 19th 2017
     
    Can anyone recommend a spot to fix a broken rear dropout?
  4.  
    t.e.d:Can anyone recommend a spot to fix a broken rear dropout?

    What is the frame material?

    If it's steel, check out Hub & Spoke Cycleworks in National City (right off of the 5 next to the naval base).
    • CommentAuthort.e.d
    • CommentTimeJul 21st 2017
     
    JayOtheMountains:
    t.e.d:Can anyone recommend a spot to fix a broken rear dropout?

    What is the frame material?

    If it's steel, check out Hub & Spoke Cycleworks in National City (right off of the 5 next to the naval base).


    Yeah, steel dropout. I'll call them. Thanks!
    • CommentAuthorShady John
    • CommentTimeJul 21st 2017
     
    Joe Bell in Spring Valley
    •  
      CommentAuthorSigurd
    • CommentTimeJul 22nd 2017
     
    Hub and Spoke did an incredible job repairing and color matching a broken dropout on my Stumpy:

    https://www.instagram.com/p/BLAJxN5DuUa/?taken-by=sdbikecommuter
    https://www.instagram.com/p/BM4b4AqDHFX/?taken-by=sdbikecommuter

    Joe Bell, as well, of course.
    • CommentAuthort.e.d
    • CommentTimeJul 24th 2017
     
    Sigurd:Hub and Spoke did an incredible job repairing and color matching a broken dropout on my Stumpy:

    https://www.instagram.com/p/BLAJxN5DuUa/?taken-by=sdbikecommuter
    https://www.instagram.com/p/BM4b4AqDHFX/?taken-by=sdbikecommuter

    Joe Bell, as well, of course.


    That looks like great work. I recomended them to my friend with the broken dropout. I'll look up Joe Bell as well.

    Thanks for the help!
    •  
      CommentAuthorbikingbill
    • CommentTimeNov 25th 2017
     
    Is Hub and Spoke good at resetting steel dropouts that have been slightly bent?
    • CommentAuthort.e.d
    • CommentTimeNov 27th 2017
     
    bikingbill:Is Hub and Spoke good at resetting steel dropouts that have been slightly bent?


    Hub and Spoke is the only place I'd take framework. They are honest and do good work.
    •  
      CommentAuthorbikingbill
    • CommentTimeDec 17th 2017
     
    On my used Bacchetta, the rear derailleur had come lose and locked the rear wheel.

    Local shop did a wheel rebuild and installed a new derailleur.

    Told me the dropout needed to be aligned, I asked if they had this Park tool for the job:



    They said yes. I've had this alignment done on my prior bike and with the right tool it works well.

    When I got the bike back I could see a mark where (in hindsight) they probably used a crescent wrench and visual alignment.

    I know they didn't have the tool or just didn't use it right because I couldn't get the shifting right.

    Well, the LBS went out of business.

    So rather than roll the dice again, I spent $75 on the tool, watched the Park youtube video and did it myself.

    Bike's rear shift is wonderful now. Better than when I got it.
  5.  
    bikingbill:So rather than roll the dice again, I spent $75 on the tool, watched the Park youtube video and did it myself.
    Good info Bill. Here's the link to the Park Tool and video.
    • CommentAuthorShady John
    • CommentTimeDec 17th 2017
     
    As regards bikes, I've long preferred to spend the money on the tool rather than pay someone else to do the work. There are a few exceptions--wheel building, for example. And frame repair. And internals of a rear shock. But simpler stuff is better done by yourself.
    • CommentAuthorgottobike
    • CommentTimeDec 24th 2017
     
    If anyone has experienced less than stellar results from rattle canning paint onto a bike frame as I have, Spray.Bike might be the answer:
    https://us.spray.bike/
    Instagram: #spraydotbike
    colors
    • CommentAuthorgottobike
    • CommentTimeJun 5th 2018
     

    Mobike reveals Apple Watch shortcut at WWDC 2018
    https://www.mobike.com/us/blog/post/wwdc_applewatch
    • CommentAuthorgottobike
    • CommentTimeJun 27th 2018 edited
     
    New independent test ranks bicycle helmet safety
    EDIT: Moved to Helmets on this SDBIKECOMMUTER board.
    •  
      CommentAuthorSigurd
    • CommentTimeSep 9th 2018 edited
     
    What’s your take on this? Despite the bolt being tightened as much as it can, the bar slips by a few mm when exposed to an impact, for example when I hit a bump in the road (it’s not catastrophic, but pretty disconcerting): So there is some element of friction between the Cinelli stem and Cinelli bar that no longer works the way it was intended. Hoping not to have to scrap this stem.

  6.  
    Shim the stem.
    • CommentAuthort.e.d
    • CommentTimeSep 10th 2018
     
    JayOtheMountains:Shim the stem.


    I've used beer can shims in the past. They're great because you can wrap to the exact thickness that you need? Make sure to check the stem for cracks first.
  7.  

    Different stem configuration than the Cinelli 1R

    So much wrong here. Sorry about that. I assumed a different type of clamp arrangement, as shown above.

    If the bolt is bottoming out on a blind hole, maybe a simple flat washer (or two) under the bolt head will effectively shorten the bolt so it doesn't do that. It's a simple test just to see if it helps in gaining any more purchase on the clamping action. If so you could remove the bolt and washers, then grind (file/sand) the bolt length down a millimeter or two (or three) and reinstall without the washers.

    The expander bolt is duralumin to save weight.
    Make sure to use a little dab of grease on the threads so the hardened bolt doesn't gall the soft aluminum threads internally on the stem. With all the torquing and repeated removal/installation, there's a good chance of ruining the internal threads on that nice stem.


    Shimming is a possibility. I've read some comments suggesting a sliced bit of Aluminum can. Not sure of the thickness but it definitely sounds doable. I was going to suggest a heavy duty Aluminum foil. It's similar metal so you don't have to worry about electrolysis. It's soft enough to compress and conform to irregularities between the bar and stem, and it might be easy to install if you pry the clamp open enough.

    Rivendell Nitto Shim: These look to be about 0.3 mm thick. (X2 = 0.6 added diameter.) Makes 25.4mm handlebar sleeves fit 26mm stem clamps. Two halves. Stainless steel, made by Nitto. Some people put a dab of glue in the stem, then stick in the shims before sliding the handlebar in.
    (I might have a set in the garage.) So maybe some shim stock in the 0.05 - 0.2 mm range could work.) You might be able to buy some shim stock from an auto parts store. You just have to know the thickness you're looking for.

    If the bar surface is very smooth under the clamp, maybe a good roughing up with #80 grit emery cloth would help to increase the coefficient of friction. You could rough up the interior of the clamp as well. Of course it would be removing material, so that might compound the existing problem. You would have to remove the bars and all that that entails. (It's like when turning a few thousandths of material off of automobile brake rotors to remove the 'glazing' off the polished metal surfaces after 30K miles of braking. It helps to increase the friction between rotors and new brake pads.)

    When reassembling, maybe some Loctite or similar product could add a level of assurance. You'd have to research those products. I've only used the Red Loctite on bolts and such.

    That's a nice stem for sure. Proceed with caution.

    PS: I really enjoyed seeing your Daccordi on Instagram. Chapeau! Nicely done.
  8.  
    I had never seen this type of clamping mechanism before. I just assumed a typical pinching, compression type clamping force usually seen on stems. After finding info (that you referenced) on VeloBase.com I see now the unique architecture of this mechanical clamping set-up. The expander bolt of the quill is duralumin to save weight. Use grease on the threads and inside of steerer tube as well.

    Make sure to use a little dab of grease on the threads so the hardened bar-clamp bolt doesn't gall the aluminum threads internally on the pivot-nut. With all of the repeated removal/installation and torquing, there's a good chance of ruining the threads on the internal bits of that nice stem.


    The 1R along with the similar designed XA aero styled stems from Cinelli were introduced in the late 1970's and 1980's. The 1R's bar clamp design is different from that of the XA and other Cinelli stems. It's bolt pulls a nut down against the bar-clamp from the back side, securing the handle bar in place. The tightening bolt and the pivot-nut it screws into are both very fine thread with seemingly shallow threads. It's easy to strip these so don't over torque them. Again I'm guessing here so bear with me, as the pivot-nut is drawn downward against the angled moment-lever on the back side of the moving bar-clamp, it causes compression of the clamp into the bar. I'm not sure if there is any meaningful increase of mechanical advantage gained by all this. It seems more like a way of transferring the vertical force of the bolt into a horizontal force on the clamp.

    How the pivot-nut fits into the stem housing and how it interacts with the angled moment-lever is hard to discern. The rounded ends of the nut would seem to fit into the rounded opening at the rear of the bar space. That leaves the flat surface of the nut to push against the angled moment-lever. There's not much material there and might easily ware through the very thin wall to where the internal threads of the nut are. Also: for every applied force, there is an equal and opposite force in response. As the nut pushes against the lever arm of the clamp, the clamp pushes back, causing the bolt to deflect away from the clamp. Unless there is a 'seat' (machined into the back of the cavity) for the nut to rest against, that resists this backward deflection, the applied force on the clamp will be diminished. I would make sure that both the flat surfaces on the nut be greased as well as the rounded surfaces. That way there is minimal friction on the movement of the nut inside the stem and minimal friction at the lever arm, allowing all force from the bolt to be transferred into the horizontal clamping forces. Minimal friction losses in transferring force through the mechanism, maximizing resultant force on the clamp. You will not have to torque the bolt as much for the same resulting clamping force.


    New Old Stock Cinelli 1R stem clamp. Avoid getting any grease on the clamp face-grooves and inside the stem shell grooves as well. I'm thinking you want a dry fit of the handle bar so as to help secure the bar without slippage.



    The above image seems to show the groves in the clamp as being in relatively good condition. The teeth seem sharp, clean of any debris and deep enough to get a 'good bite' on the bar.


    Cinelli 1R stem with bars installed. Notice the fine grooves in the bars that help to secure the grip of the stem's bar-clamp. If these are worn or full of metal-debris, grease or grime, the gripping is diminished and the bars may rotate more easily.
  9.  
    (cont.)



    This image shows the grooves somewhat dirty, shallow and filled with debris. Maybe this occurs over time from normal ware and usage. If the bar has rotated inside the stem clamp, you can be sure the 'teeth' inside the stem cavity and on the moving clamp have been rolled over and worn down. The 'sharp bite' into the bar material has been diminished. (Like a toothless geezer trying to gum his food!) The grooves in the bar that the 'teeth' once sunk into are also damaged and less effective at holding the bar in place. It will only get worse as such movement continues. It's analogous to worn teeth on cogs not engaging the chain links in an efficient manner. Not much holding power when added force is applied, increased slippage and over time it just gets worse.


    Another stem and bar-clamp showing Aluminum metal residue, residual grease or never-seize, dirt and grime in grooves.

    A good cleaning with a stiff wire brush and some cleaning agent/solvent (NO ACID; so as to protect the pantographing/engraving and red anodizing on stem) might go a long way to removing the filler-debris and thus deepening the grooves. Stubborn residual metal could be scraped out with a sharp, pointed tool like a dentist pick.

    This should be done on both the stem shell and the tightening clamp.

    If the cleaning doesn't restore the grooves enough, a jewelers file or fine machinist's file could be used to deepen the groves while at the same time restoring the sharp edge to the teeth. The restored "bite' of both the stem shell teeth, and the clamping mechanism teeth, might then be enough to hold the bar securely in place. (You might want to smooth the bar a bit so the troughs in the clamp are not filled by existing high spots on the bar from past clamping. The newly sharpened teeth will then have a 'fresh, deep bite' on the smoothed bar surface.)

    You might utilize a jewelry shop, watch repair shop, machinist, boat maker machine shop, transmission repair shop, gunsmith etc. etc. They would have ready access to fine files to do the job. Maybe buy a set of fine files and keep for routine thread cleaning and such.

    A good bike shop like Hub and Spoke (web-site gone ??) would have, and know how to use, such fine files for this type of work. (Don't they deal in Italian frames and components? They may have come across similar problems with any past Cinelli stems they've dealt with. They might also have spare internal components - Italian threaded - for this type of stem in their bits-box.)

    I think adding a shim to this set-up would be counter productive and actually increase the chance of slippage. If the clamping teeth are compromised anyway, they're not going to get much bite on the shim. The shim itself will have no bite on the bar, act like a bushing, and thus provide another place for slippage. No Bueno.

    Having said that, others may disagree and may have had success with shimming the bars. I'm just conjecturing here.


    Shim inside of Cinelli 1R stem bar-clamp.


    Cinelli 1R stem bar-clamp with shim inserted.


    Close up of shim inside Cinelli 1R stem bar-clamp.

    One last point. Upon further consideration, I think Loctite shouldn't be used. It makes adjusting the bars to the proper angle and orientation more problematic. If there are repeated adjustment sets and resets of the bars, the hardened Loctite will interfere with the process as well as acting as a filler in between the grooves on the bars and clamp surfaces. Again, one man's opinion.
    • CommentAuthorgottobike
    • CommentTimeSep 28th 2018 edited
     
    Question for all you bicycle frame design experts and industry pros:
    If the steep seat tubes (74 degrees or more) and slack head tubes (71 degrees or less) we see on the smaller frame road bikes are so great, why not just continue that geometry into the larger sizes?

    The road frames that handle well and I am able to get comfortable on have 73/72 degree tubes and bb drop ~72mm. For 700c designed bikes, this geometry is only available in larger sizes. Seems it would be cheaper to maintain this fantastic 74/71 geometry promoted by the bicycle industry across all frame sizes instead of having to refixture for the smaller sizes.

    Example:
    Trek has a great new Checkpoint with ~73/72 degree geometry in 56cm and above:
    https://www.trekbikes.com/us/en_US/bikes/road-bikes/checkpoint/checkpoint-alr-4/p/22628/

    However, this quickly erodes to an unrideable ~74/71 geometry in smaller sizes.