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• #27
Impressive. Must be satisfying to come up with something just right like that!
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• #28
Repurposed this thread to keep track of all my bike related tinkering and projects :)
Next up, fixing my broken Dolan Track Champion! Or more like crack champion...
This is the current state of affairs:
Whatever the solution is, it has to cost me less than £100, as for that price I could easily buy another frame. But the idea is that I'd rather not trash an otherwise perfectly fine frame. Im not counting the hours ive already invested into this, just material / tool costs.
Possible solutions that I've explored:
Machine an insert with 27.2mm outer diameter, 25mm inner diameter, and a collar to take on a standard seatpost clamp. Then glue this insert into the frame. Probably the least complicated solution, but need my mate to do the machining part (hey @hma !), ship it to me...etc. Also not the cleanest look. I'd need further tools to level the top of the seattube.
Make a quill seatpost. Upon closer inspection only the first ~10cm of the frame is bored to 27.2mm, after that it extends into the aero shape, so adjustability would be minimal.
Glue a 27.2 carbon or AL tube into the frame, and use a seatmast topper. Limited adjustability, and apparently seatmast toppers are neither cheap, nor easy to find.
And probably the most complicated version: Create a jig for a dremel that rotates around the seat tube and machines it down to a uniform 31.8mm that will accept a standard seatpost clamp. Ive seen this done on the same frame by Dolan as a warranty job (and on later models of the Track Champion they adopted a seatpost clamp that follows the shape of the seattube).
Here's where I am with the jig design:
First there's a quill mechanism that fixes itself into the seattube, and has a collar on top to provide a level surface to rotate on. The jig itself is 3D printed and assembled with some standard M5 nuts and bolts. It has a stopper to avoid accidentally machining it smaller than the desired diameter, and it will have a spring (tensioned by a screw from behind) pushing on the sliding dremel mount to force it in the direction it needs to machine off.
Ignore the rectangular protruding thingies, thats a leftover from a previous version that was only 2mm thick (to bring the dremels head as close as possible to the working surface), so it was a place for some steel rods to hold it all together. The dremel head is plenty close, so made the body 10mm thick at the end.
I'll probably finalize this design and do some prints over the next few days, lets see how it goes! If anyone has any suggestions design-wise, Im all ears! Im not an engineer, just played a lot with Legos as a kid :P
PS: .....Anyone has a Dremel I could borrow for a weekend in January? :D
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• #29
you could also melt it down and cast a new frame with that pla mould-making technique you found... :D
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• #30
Anyone has a Dremel I could borrow for a weekend in January? :D
Got one, in SE24 if that's convenient?
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• #31
That would be awesome! But gotta postpone it as I've had to come to Hungary for a while while Covid runs its course. Left most of my stuff in London though, so time to dig up some older projects!
Im currently riding this when in Hungary, 2008 (?) Orbea Onix with a mixed ultegra group. Hoops are from on here, Reynolds tubs on white industries hubs.
Onto the current project! This BMC bike has been about 8 years in the making. Bough it with a cracked top tube, and missing seatpost. The seatpost was quite pricey -which is understandable, its sub 200g for an aero seatpost-, so because of the sunk cost I just HAD TO build it up at some point. Ive finally had the frame repaired last year, and now its time to put it together.
Waiting for a derailleur hanger, and I'll put on an 11sp Campagnolo Chorus groupset on it that Ive bought on there for a mate. He was kind enough to lend it to me while Im in Hungary. 3T finishing kit, not the poser one on the pics :)
And why is this not my main bike? Its a tad bit big for me. Had no idea about bike fit stuff when I bought it...
Theres a pics showing the repaired top tube as well.
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• #32
Interesting solution. Looking forward to seeing more!
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• #33
Thanks! Probably gonna print and figure out the jig part while Im in Hungary so that when I go back to London I can get it done straight away.
BMC project: It really annoyed me that there was a gap between the seat tube and the seat post, then I figured probably there was a rubber cover there originally. Given that its long gone, I made up one in Fusion 360 and will try to print it from the same flexible material that I made the cable guides on the Space chicken. It has a 3mm tall and 0.4mm thin edge that should wedge between the seatpost and the frame, and also has a really snug fit on the seatpost so that theres no gap for any water to get in.
First ive taken a pic of the seat tube, and took measurements of the inside of the seat tube, and the seatpost
Then I used this as a canvas with reference points based on the measurements to draw up a quick design
Voila!
Made another version that has an outer lip too so that it fully covers the top of the frame. Once I can borrow a printer I'll try which one works best.
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• #34
Now that the derailleur hanger arrived, I couldnt wait to get my hands on a 11sp cassette for he campa group, so put it together with the mixed group I had on hand. Not that it matters much as Ive got covid last week, so no training for 2 weeks :( Got over it in 2 days, so I consider myself lucky.
Out of nowhere one of my vittoria tubs started leaking air at the bottom of the valve, so changing over to 24mm tufo S33 pros, got a good deal on them, and a spare with a brown wall too.
I'll sort the fork steerer and the tubs next week, and hopefully get my hands on a bolt to put on the front brake, it needs a super long one.
Otherwise the bike is looking good, cant say how well does it ride, we'll see that one...
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• #35
This is cool. I Have also bought a space chicken with a damaged fork and am building up from scratch. I do not need the frame cable lugs as I have replacement blanks which I will spray red. Happy to send you the old ones if you wish
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• #36
This is great, subbed.
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• #37
Hey, sorry for the super late reply, been away from London for a while, but coming back next week :) If youve still got these, I'd really appreciate it, would be happy with a more accurate model lol. Do they also function as cable stopper (and the one at the BB as a guide), or the cable housing runs all the way through?
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• #38
So as I mentioned ive been away from London, and its been eventful :D Ive managed to put together the BMC with the Chorus grouppo, and put a good 2000kms into it for good measure. Bulk of that was in Serbia and California (work stuff, with an extra free week afterwards). Rides awesome, still way too long for me. Sad, but we knew this going into it. Also smashed that Lew carbon rim on the back. Will attempt to repair it for track use, but thats another story.
So I had 2 weeks in Serbia, treated it like a "camp" and put in some quality training. Then US, skipped a week and a half due to work, and when I got back on the bike, put in a good 21 hours in the first 7 days with 1000+ TSS. Didnt stop there... Anyway heres my favourite pics from SF:
Actual current projects: di2 grouppo for racing bike coming along nicely, and theres a chance of a TT bike being built as well, Im super stoked for that. Currently playing around with some di2 hacking stuff, here's a teaser:
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• #39
Alright, its official, Im finally getting a TT bike! I always liked their aggressive look, and the pure speed. Only had a chance to TT twice with a TT bar on a road bike, and I really enjoyed it. Whats great is that this awesome deal just came up when Im in my best cycling form so far, so I can kinda justify it. Just picked up the frameset from a triathlete girl, she was super nice and her dad even gave me a lift to the train station. A very pleasant encounter!
Now, the frameset was a bargain. It was advertised as "seatpost stuck" and "needs work", and I prepared myself for the hassle. As you might guess from my previous build, Im always up for some tinkering, and giving new life to grubby but otherwise functional parts.
The good>>
1, Its a complete frameset with full carbon frame, fork, seatpost, handlebar and TT extensions, with the proper TRP TT brakes as well.
2, The seatpost came out after a soapy water soak, and a gentle tap. The mechanism is completely intact, nothing wrong with it.
3, To my surprise it came with an Ultegra BB which definitely comes handy in the household.
4, I noticed at the rear derailleur that the cable guide is missing from the frame, but I have JUST the solution for that with my 3D printer. But wait...whats that in there?
Did they...did they really just rip out a di2 cable? Oooh the BB hasnt been removed, so they must have. But that means...
That means that ive got a junction box, as well as at least 1 half of a di2 cable to make into climber switches on my road bike. How did they get out the other one going to the shifters up front? And the one to the battery? We'll know once I get my hands on a BB tool.The bad>>
I mean...imagine a bike youve been riding on your trainer all the time covering it in salt, then submerge it gatorade, and repeat this process for the better part of 2 years. Screws to be replaced, and a proper cleaning job needed. The frame has a nice UD carbon finish, I'll probably give it a quick polish to make it look nice. Surprisingly the seals on the bearings held up pretty well and they turn nicely after a good clean.
Fork is cut a liiiittle too short, but its long enough that im comfortable with it. Because of the expander cap, it could only be about 3mm longer anyway, due to the integrated design with the stem. The stem is connected to the fork on the front as well with another two bolts.
The ugly>>
Besides the overall condition of the bike...The stem has a broken bolt thats gonna be a hassle to get out, and its missing a steel insert that the bolts screw into from the top. I'll have to draw that up and get someone to turn it on a lathe for me.Overall, Im super stoked for this project, and I think its gonna make a great looking bike with some work. Here's how it stands on some wheels and with a random saddle thrown on it:
Stay tuned for messing around with di2, filing down 3mm from the corner of a Sram Force crank to fit my powermeter that was perfectly fine on a Rival crank (no im not mad, why are you asking), and other adventures.
Ps: If youve got one of those Zipp 900 rear disc wheels that have both the 10sp cassette, and the track threads on the other side, yeah im interested.
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• #40
Great dedication to getting stuff working, love the drawing something up then getting someone with a lathe to do the work
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• #41
Look, Im just going through life, one day at a time, trying to come up with excuses to buy a 5 axis desktop cnc milling machine. But until then, I gotta find someone who can do it for me :)
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• #42
Yet another day where I failed to come up with an excuse. Ive drawn up the threaded insert I needed, and realized that all I need is a piece of 8mm AL rod, a hacksaw, access to a pillar drill (or a dremel workstation!), and an M5 tapping tool.
While I had Fusion360 fired up, ive designed a jig to hold the stem in a vice under the pillar drill while I get rid of the old insert with the broken in bolt. Ive used the through holes of the bolts that hold the stem to the front of the fork, and there's a flat place surrounding them inside the hollow stem body.
As soon as my micro SD reader arrives, I can print a threadless version of the insert to test if ive got the dimensions right (centre of holes mostly). I will also circle back to the Dolan project!
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• #43
Last year I bought a di2 bar-end junction box on here without any of the mounting hardware. Finally got around designing and printing my own. Anyone needs one just drop me a message.
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• #44
Nice work. Will drop you a line as I'm just doing a Di2 install now and one of those would be perfect.
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• #45
It still bothered me that from one side it looked somewhat bulky (either from the side, or from the top), and wanted to get rid of one of the tabs. Problem was that if I do that, it doesnt really sit flush to the end of the handlebar. I present: V2
Top one is the new version, bottom one is the older. Wrapped it with the thick edge outwards on purpose, it gives it a sharper, better looking end.
So, how does the new version work? It has an inner piece, that latches onto a little hole in the body of the junction (so that it pulls out with the junction if needed), and has two springy extensions creating tension and friction when inserted into the handlebar. Also functions as the part holding the cables in place. On the front of it the "faceplate" part latches onto the top of the junction box as well, and the tension created by the inner part is forcing it to sit against the edge of the handlebar. Rambling over.
Before wrap:
Once given the permanent marker treatment -as I havent got any black material at the moment-it looks rather nice. I can live with this :)
And as I typed out all this, I just thought of V3, where the tension is built into the faceplate by printing the tab at an angle, say 80' instead of 90'. That might work.
And it kinda works with the inside part only, but I wouldnt trust it on some bad roads, might shake out.
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• #46
The angled faceplate+insert works flawlessly with the di2 junction holder. Wont bore you with pics, looks just the same just 1.5mm thinner.
Back to the Dolan Crack Champion project. Redesigned the jig from scratch in a simplified manner, and it seems quite sturdy. Now just need to make the sliding dremel mount and thats where the fun begins! :)
The plan is to mill it down to a 31.8mm diameter and fit a standard clamp on it. Ive got adjustable stoppers (bolts that screw into the nuts glued into the jig) on both sides to ensure consistent diameter.
PS: If you know of anyone whos got a Dolan Track Champion cracked at the same spot (there were plenty of them), let me know, I'd be happy to fix other's frames once the method proves successful :)
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• #47
Small update on the Space Chicken that made it ride infinitely better. The first handlebar on it was literally a "whatever I found at home" bar, and I didnt want to cut the steerer either. Thanks to Amey it now has a Ritchey Butano, and I put the stem all the way down as well. Loving it.
(before pics on the right)
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• #48
Nice work. I love it when busted up shit can be fixed or repurposed.
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• #49
Restaurant got flooded a bit, so some time on my hands. Finally got around to finish the Dolan.
First, I cut out the chunks with a hacksaw (I just picked up my dremel the next day)
Rough shape after some filing
Bits and pieces that came out
Then an hour of grinding, sanding, and filing later:
At some point ill clean up around it, and give it a lick of paint, but for now, it'll have to do. Probably I'll do my track accreditation in Lee Valley in the near future.
ps: thanks @hippy !
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• #50
this is a pretty tidy fix, gj at saving it
Thanks guys!
Today I spent better part of my morning messing around with an aero headset cover. This is just a trial for my road bike, but wanted to see if I can even model it. And of course it will look a lot better in black PLA.