Starting to assemble my Franken-T
- Thread starter Rampa
- Start date
Rampa
Guru
Some bits of significance.
I had to watch Ebay for a bit to get the right 1.5 inch stem at a good price. Someone got the first one I found. 1.5 inch was made for downhill and freeride, but is not super common.
I rotated the seat base 180 to get the seat lower with nose up a bit (better support with higher cranks). It can also go further back. I'll experiment with rearward VS traction. There is some advantage that the seat continues to get lower the more rearward it slides no. Eventually I'll probably go to a different seat.
Lopped a few inches of the seat-stay inner tubes with a tubing cutter. Found one with a low enough knob to be able to rotate around the tube without hitting the other side. Had maybe a millimeter to spare. A hacksaw could also be used.
My ugly, soon to painted silver, pivot clamp. Combination of an adjustable stem and offroad roll-bar accessory mount clamps, with some elbow grease! I need a sexier bolt than the 3/8th bolt holding it together right now!
Slotted the end of my 1.5 inch tube and clamped it with a Gibralter drum-stand clamp. They happen to be perfect and inexpensive! Did have to swap out the bolt, as the one it came with had a head for a tuning wrench.
I had to watch Ebay for a bit to get the right 1.5 inch stem at a good price. Someone got the first one I found. 1.5 inch was made for downhill and freeride, but is not super common.
I rotated the seat base 180 to get the seat lower with nose up a bit (better support with higher cranks). It can also go further back. I'll experiment with rearward VS traction. There is some advantage that the seat continues to get lower the more rearward it slides no. Eventually I'll probably go to a different seat.
Lopped a few inches of the seat-stay inner tubes with a tubing cutter. Found one with a low enough knob to be able to rotate around the tube without hitting the other side. Had maybe a millimeter to spare. A hacksaw could also be used.
My ugly, soon to painted silver, pivot clamp. Combination of an adjustable stem and offroad roll-bar accessory mount clamps, with some elbow grease! I need a sexier bolt than the 3/8th bolt holding it together right now!
Slotted the end of my 1.5 inch tube and clamped it with a Gibralter drum-stand clamp. They happen to be perfect and inexpensive! Did have to swap out the bolt, as the one it came with had a head for a tuning wrench.
Rampa
Guru
Yep. They are 700 by 28. Just enough clearance to fit comfortably at the fork.
I found the 11 speed wheelset with a SRAM 10-42 cassette in the Goodwill last year. So a tiny fix later, I had a really nice wheelset for dirt cheap. I have planned the whole build around them. You'll notice that I did adapt them for shrader. These were not tubeless ready wheels, so I wanted shrader so I could add a little bit of sealent to my tubes easily. I'll balance my wheels as needed, as that will be a few extra grams of valve.
I really wanted regular dropouts, no suspension, and a dynamic boom. The T50 frame meets the first 2 criteria, and the mod is something I knew I could do. Chose the 1.5 inch tube primarily for aesthetics. A 1.25 tube would have been easier (no squeeze-slot cutting).
I found the 11 speed wheelset with a SRAM 10-42 cassette in the Goodwill last year. So a tiny fix later, I had a really nice wheelset for dirt cheap. I have planned the whole build around them. You'll notice that I did adapt them for shrader. These were not tubeless ready wheels, so I wanted shrader so I could add a little bit of sealent to my tubes easily. I'll balance my wheels as needed, as that will be a few extra grams of valve.
I really wanted regular dropouts, no suspension, and a dynamic boom. The T50 frame meets the first 2 criteria, and the mod is something I knew I could do. Chose the 1.5 inch tube primarily for aesthetics. A 1.25 tube would have been easier (no squeeze-slot cutting).
ak-tux
Zen MBB Master
This is really an excellent way to build a cheaper alternative to an S40. Just 700c wheelset, then add nice flared road drop bars, position the seat at between 35 and 40 degrees and voila !
The wheelbase is a little short (109cm T50 vs 114cm S40) but you can get used to it.
A more rigid ribbed composite seat like a Thor Easy model would also get it closer to an S40.
The wheelbase is a little short (109cm T50 vs 114cm S40) but you can get used to it.
A more rigid ribbed composite seat like a Thor Easy model would also get it closer to an S40.
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rx7mark
Guru
Yep, I really like my T50, with Emiljay mod and Thor seat. Makes a great ride, just wish I could buy a longer chainstay.
Mark
rx7mark
Guru
That's a great idea, I am talking to a frame builder and modifier this week, I'll see what a longer part would cost to fabricate vs modifying the stock part.Mark,I think that bottom bracket clevis clamp is pretty standard on many low-end duallies. So find a cheap donor to give you the bits to weld in a new section. Keep the original part safe. It would need some narrowing as part of the re-building process.
Mark
Not as easy as that - the S40 is still THE S40. IMHO this is a workable idea for "S40 like" but the stiffness, etc of the frame is not the same. Will be watching though to see how it goes.
Robert
ak-tux
Zen MBB Master
It's alive!!!!
Evening here, and not fully tuned yet, so just rode around the neighborhood a bit. Pretty nice!
Very nice! Just remember to cover and seal the top opening of that 1.5 inch pipe/boom/steerer. Otherwise water will get to the bottom bracket and cause wear.
Is that a 50T narrow-wide chainring?
I wonder how much the bike weighs as shown.
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ak-tux
Zen MBB Master
Considering the price of an S40 frameset, let's just call this the poor man's S40-like alternative
Rampa
Guru
It's not light! Have not weighed it.
The front ring is a 44 tooth narrow wide. With the 11 speed SRAM 10-42 cassette, thats about 27 to 116 gear inches. There is maybe clearance for a 48 tooth, but I think a 52 would hit the chainstay with my current chainline offset. I'm using a BMX crank with no spacers, and it sets the chain right in the middle of the cassette. The wheelset is actually "29'er" and disc only. The cheap brakes I had sitting around re a little heavy, along with a few other bits.
But mostly I wanted a fun project bike. I'm sure it will keep evolving over time. I would think of it as a Miata instead of the S40 Porsche/V20 Bugatti.
I need to find a nice way to cover the end of the tube. Or maybe learn to play the didgeridoo!
I'll probably just rattle-can the boom a nice silver to match the somewhat textured silver finish of the fork and stays. The black pivot clamp parts and collar clamp will get painted silver too. But the stem and bars will remain black. I have some 31.8 seagull bars on the way to replace the 25.4 ones I've got installed now (taken from my Sofrider).
The front ring is a 44 tooth narrow wide. With the 11 speed SRAM 10-42 cassette, thats about 27 to 116 gear inches. There is maybe clearance for a 48 tooth, but I think a 52 would hit the chainstay with my current chainline offset. I'm using a BMX crank with no spacers, and it sets the chain right in the middle of the cassette. The wheelset is actually "29'er" and disc only. The cheap brakes I had sitting around re a little heavy, along with a few other bits.
But mostly I wanted a fun project bike. I'm sure it will keep evolving over time. I would think of it as a Miata instead of the S40 Porsche/V20 Bugatti.
I need to find a nice way to cover the end of the tube. Or maybe learn to play the didgeridoo!
I'll probably just rattle-can the boom a nice silver to match the somewhat textured silver finish of the fork and stays. The black pivot clamp parts and collar clamp will get painted silver too. But the stem and bars will remain black. I have some 31.8 seagull bars on the way to replace the 25.4 ones I've got installed now (taken from my Sofrider).
super slim
Zen MBB Master
Could you fit a speedo or a Garmin GPS over the 38mm boom, to seal the 38 boom?It's not light! Have not weighed it.
The front ring is a 44 tooth narrow wide. With the 11 speed SRAM 10-42 cassette, thats about 27 to 116 gear inches. There is maybe clearance for a 48 tooth, but I think a 52 would hit the chainstay with my current chainline offset. I'm using a BMX crank with no spacers, and it sets the chain right in the middle of the cassette. The wheelset is actually "29'er" and disc only. The cheap brakes I had sitting around re a little heavy, along with a few other bits.
But mostly I wanted a fun project bike. I'm sure it will keep evolving over time. I would think of it as a Miata instead of the S40 Porsche/V20 Bugatti.
I need to find a nice way to cover the end of the tube. Or maybe learn to play the didgeridoo!
I'll probably just rattle-can the boom a nice silver to match the somewhat textured silver finish of the fork and stays. The black pivot clamp parts and collar clamp will get painted silver too. But the stem and bars will remain black. I have some 31.8 seagull bars on the way to replace the 25.4 ones I've got installed now (taken from my Sofrider).
!
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Rampa
Guru
From the not-terribly-accurate bathroom scale method, it's around 30 pounds.
The pivot clamp may loose a few ounces at some point. The seat and assembly could replaced with something much lighter. I like the durability of the aluminum seat though. I'm keeping an eye out for an old aluminum Slyway adjustable seat. They are no longer manufactured. Every manufacturer has gone to composite, it seems
Drivetrains can almost always get a bit lighter. I didn't go for anything terribly fancy in this department.
I'm sure you can come up with clamps for pretty much any accessory to fit the 38mm boom. Actually, it is 38.1, because it needed a specific ID and wall thickness only available with 38.1 OD.
I need to add some extra chain links. Chain is on the way. Cannot test low gears yet.
The pivot clamp may loose a few ounces at some point. The seat and assembly could replaced with something much lighter. I like the durability of the aluminum seat though. I'm keeping an eye out for an old aluminum Slyway adjustable seat. They are no longer manufactured. Every manufacturer has gone to composite, it seems
Drivetrains can almost always get a bit lighter. I didn't go for anything terribly fancy in this department.
I'm sure you can come up with clamps for pretty much any accessory to fit the 38mm boom. Actually, it is 38.1, because it needed a specific ID and wall thickness only available with 38.1 OD.
I need to add some extra chain links. Chain is on the way. Cannot test low gears yet.
Rampa
Guru
I would be very doubtful of the value for Cruzbike to design a boom system in-between the two they currently have. Although it is quite nice, and was one of my main criteria. It is a less stiff and heavier design than that of the Cruzbike boom. With the pivots and offsets of the connection points. If I were to do another, I would be very tempted to just start with a Q45 frameset with a light air-shock. Perhaps a frame-kit option will be available sometime.
There is an extra degree of freedom-of-adjustment with the handlebar stem as well, giving yet another back and forth option as well as above or below the boom mounting of the bars.
For seat-level or higher cranks, rotating the seat-mount plate 180 degrees is one of the biggest differences. I think Q45 riders might really benefit from it. The lower and nose-up seating position helps with CG, ground reach, and less "recumbum". The angle provides better tushy support. The original Quest bikes used a more nose-up seat mounting.
The seat height on this bike is just a smidge lower than that of my 26 inch wheel Sofrider. This bike is running 700c.
I am going to put a 52 tooth on the front. I think the 52-42 will be plenty low-enough low gear for me. Switching is quick for different needs.
There is an extra degree of freedom-of-adjustment with the handlebar stem as well, giving yet another back and forth option as well as above or below the boom mounting of the bars.
For seat-level or higher cranks, rotating the seat-mount plate 180 degrees is one of the biggest differences. I think Q45 riders might really benefit from it. The lower and nose-up seating position helps with CG, ground reach, and less "recumbum". The angle provides better tushy support. The original Quest bikes used a more nose-up seat mounting.
The seat height on this bike is just a smidge lower than that of my 26 inch wheel Sofrider. This bike is running 700c.
I am going to put a 52 tooth on the front. I think the 52-42 will be plenty low-enough low gear for me. Switching is quick for different needs.
benphyr
Guru-me-not
Men, even Cruzbike men would do better to stay away from speedo's especially near the boom...
couldn't resist twisting your swords.. er.. words. 
