Boom too long - cut it?

counterpoint

Well-Known Member
First up a question: with shoes or barefoot when measuring knee to floor?

Anyway, without shoes my measurement (A) for the boom comes out very close to the 80 cm in the example on p. 5 of the assembly notes.

But I'm finding that fully inserted the boom is still longer than that (87cm).

I guess I need to cut?

boom-silvio(1).jpg width:341px


 

counterpoint

Well-Known Member
I don't get it though: fully

I don't get it though: fully inserted the boom is already 7cm longer than the 80cm in the installation example. It's as far as it will go. And mind you, the other clamp is off and there's nothing impeding the boom from sliding further in.
 

scabinetguy

Well-Known Member
Boom length

I had to cut mine about 2", there was no way to get a shorter fit. That still leaves plenty of length for a taller rider. I'm 5'9" with a 42" x-seam.
 

counterpoint

Well-Known Member
same here

I'm 5'8" and my cruzbike x-seam is 40 (of course, on match.com I'm 6'2)
Sounds like cutting is the way to go. I have a pipe scorer and a good saw at the ready.
 

counterpoint

Well-Known Member
boom inserts max 13"/33cm

I found my glasses and a flashlight and I now know why the boom inserts by at most 13" or 33cm:
The thread insert for mounting a bottle holder prevent it from going in deeper.
No wonder I could not get to 80cm total.

On the plus side it means cutting the boom will not change structural stability: it will still be 13 inches in.
 

John Tolhurst

Zen MBB Master
The thread insert for

The thread insert for mounting a bottle holder prevent it from going in deeper. No wonder I could not get to 80cm total.

On the plus side it means cutting the boom will not change structural stability: it will still be 13 inches in.

Agree.

It was a choice ...

give the convenience of bottle mounts via nutsets
OR
?leave the deep clearance so that customers need never shorten the boom

 

Eric Winn

Zen MBB Master
Ah ha! So that is your

Ah ha! So that is your solution to prevent the boom from getting stuck due to over insertion.
devil_smile.gif


-Eric

 

John Tolhurst

Zen MBB Master
Ha!  The Vendetta boom is

Ha! The Vendetta boom is outer, slider is inner. Silvio is the other way, so any binding at the curve of the boom would be visible.
 

Ivan

Guru
Ah, so 2.1 now has water

Ah, so 2.1 now has water bottle mounts on the boom whereas 2.0 did not. Looks like an average height person will now need to cut the boom...
 

BentBierz

Well-Known Member
I'm Also Curious...

"Interesting. John, what other changes were made to this newer version? The rear cable routing on Scabinet's new frame is on the right side as the original 2.0 frames while it appears Mauler's cable runs through the left side of the frame (like the (Vendetta)?"

I'm curious as well to see what simple modifications I might be able to make to my 2.0 that are now standard on 2.1.
 

counterpoint

Well-Known Member
angle grinder with diamond blade?

Turns out the pipe cutter I own isn't wide enough.
Is it okay to use an angle grinder with diamond blade or should I go out and buy a 2" cutter?
I do own a tool to 'shave" cut pipes (looks like an oversized pencil sharpener so I'll be able to make the edge smooth.
 

John Tolhurst

Zen MBB Master
A hack saw and a nice file is

A hack saw and a nice file is all I would use to cut down a tube. Worth marking the line carefully perhaps.
 

Eric Winn

Zen MBB Master
I used a miter box, some

I used a miter box, some clamps, a hacksaw, a file and some sandpaper to trim my boom. The miter box and clamps are to insure a perpendicular cut. Very easy to cut with the hacksaw.

Also, I trimmed a little bit and then tested fit and then trimmed a little bit and tested fit, etc. I would advise against doing the trimming all at once - work your way down a little at a time.

I also found after riding my Vendetta that my fit ended up working naturally into a bit longer x-seam measurement than what I had originally measured for my body so you might want to keep that possibility in mind too while trimming.

-Eric
 

Charles.Plager

Recumbent Quant
What TrPlay said.
In any


What TrPlay said.

In any case, I'd shorten the boom as little as possible to make it work. If you need to shorten it more later, then that's fine. This way, you'll be able to lengthen it as well.
 

MrSteve

Zen MBB Master
If

-if I'm the third person to ditto Mr. Winns' wisdom, is this a, 'tritto'?

If you must cut, be conservative.

Cut it so that you can adjust for your longer 'bent legs.

If you do cut too much off, you can always back-order a new part.
Maybe.
Or buy a new bike and try again.

Good luck,

-Steve
 

counterpoint

Well-Known Member
Easily said for people with

Easily said for people with long legs but an overextended leg, ankle, foot is not an efficient way to put power on the pedal.
Understand that the old design allowed you to fully insert the boom. The new design has these bottle mount nut sets that prevent it from going all in as John T. confirmed.
In other words to get the recommended fit someone my height must cut.
Hopefully they'll include these instructions in the manual.

This still leaves plenty of overlap (13in/33cm to be exact) should you want to adjust it for Daddy Longleg.
In other words, the only advise here:
Measure twice, cut once. And get a fresh hacksaw blade. You need to get it smooth, not beautiful as it'll be inside.
 

counterpoint

Well-Known Member
Romelman must have used those

Romelman must have used those as his is a 2.0 and he mounted them on the upside. Mine (2.1) are facing down (which might be an issue with inside leg clearance).
I just left my built at the bike shop to get the shift and brake cables installed. The SRAM Force front derailleur with yaw is apparently difficult to install, the disk brakes are new to me, and the cable runs require housing by the foot. So hopefully I'll be able to start riding this beast soon enough.
 

Ivan

Guru
The Topeak CageMount offers a

prod74876_Black_NE_01

The Topeak CageMount offers a more secure system that is not based on velcro like the Biologic. I have used the Topeak CageMount successfully on my Brompton for a long time. It would fit the Silvio boom.

http://www.topeak.com/products/bottle-cages/cagemount




 

John Tolhurst

Zen MBB Master
The Topeak unit as usual is

The Topeak unit as usual is nicely made and is a permanent fixing. The velcro one puts the bottle close to the boom.
 
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