Split Handles

Maintenance, accessories, operation. Anything to do with making your erg work.
Sakly
Half Marathon Poster
Posts: 3428
Joined: January 13th, 2022, 10:49 am

Re: Split Handles

Post by Sakly » November 7th, 2024, 1:26 pm

JaapvanE wrote:
November 7th, 2024, 12:43 pm
Sakly wrote:
November 7th, 2024, 9:52 am
Very much, but not definitely :lol:
As my manager typically says: if you aren't sure, mitigate. I'd agree the contact surface is less stressed under perfect conditions in the new setup, but under assymmetric load, I wouldn't be sure.
I definitely think that lifetime is at least 10 fold higher, than compared to the U-shape connector with the standard handle. Before this connection breaks, you probably need a new chain anyway.
Additionally, we have to consider the load in general. It makes a difference if someone pulls a <=2:00 for long sessions frequently or a 2:20.
Anyway, nates could report back in a few years and we would see how it goes :lol:
Male - '80 - 82kg - 177cm - Start rowErg Jan 2022
1': 358m
4': 1217m
30'r20: 8068m
30': 8,283m
60': 16,222m
100m: 0:15.9
500m: 1:26.0
1k: 3:07.8
2k: 6:37.1
5k: 17:39.6
6k: 21:03.5
10k: 36:01.5
HM: 1:18:40.1
FM: 2:52:32.6
My log

nates
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Re: Split Handles

Post by nates » November 7th, 2024, 1:34 pm

Future nate already reporting back after looking at his log book from a few years ago. I had gym rower during covid, then lost my gym. I bought a C model I refurbed, but my wife hated the thing and it sat on the screened porch a couple years until she left and I decided I might as well get skinny because it's me and the kid she left behind and I'm only 4 years younger than dad was when he checked out.

Apparently I rowed a 1 minute pace of 1:50 once upon a time, and 2:20 2k's just a few years ago. Won't win the boards but looking at my current times I had to make sure it wasn't old data from the monitor or something but nope, it was me. New chain is less than a co-pay at the doctor's, if I have to replace it every now and then it's worth it if it keeps me rowing.

Slidewinder
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Posts: 457
Joined: April 6th, 2010, 6:52 pm

Re: Split Handles

Post by Slidewinder » November 7th, 2024, 7:57 pm

nates wrote:
November 7th, 2024, 12:40 pm
The moderation is due to perception that Robert is hawking a product on a manufacturer's forum.
Fifteen years ago I posted a YouTube video about the handle I designed and built. Over the years, to the many inquiries I received asking, do you sell them, and could you build one for me, I always replied, no and no. A couple of years ago I relented and built a few dozen, contacted the people who had expressed interest, and sold them all. For my efforts, when all was said and done, I had made about $10/hour. I am working on other projects now.

nates
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Re: Split Handles

Post by nates » November 14th, 2024, 3:31 pm

I tried again and a 5/16" snagless fits the hole without much slop. There are basically three types of shackles I've found - straight (like this one), circular (like the last one) and wide. I've only found snag free in straight shackle. I think perhaps the ideal might be a 1/4" snagless circular shackle with a bushing through the hole. I've not found any that would work with the factory bushing. This 5/16 straight shackle actually won't slip past the lip of the chain end but I think it's a minor issue. I'm basically done messing with it for now, but if I were reading this thread and trying to do what I did that's probably what I'd look for.

Image

Slidewinder
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Re: Split Handles

Post by Slidewinder » November 15th, 2024, 11:40 am

nates wrote:
November 14th, 2024, 3:31 pm
... I'm basically done messing with it for now, but if I were reading this thread and trying to do what I did that's probably what I'd look for.
You are where I was fifteen years ago - trying to figure out the best way to connect two pivoting linkages to the C2 chain swivel connector. The C2 swivel connector was not designed for this task. It was designed to be part of the bushing/U-bolt/ one-piece-rigid-handle assembly. A chain swivel connector could be designed to connect directly and neatly to two, independent, moveable handles, and maybe someday such will be standard equipment on rowing ergometers, but until that happy time, anyone who wants to put together a split handle set-up has to deal with the problem of how to best make attachment to the C2 swivel connector.

Your shown set-up works for you, but for those with a longer reach at the catch it would be better to get the connection/pivot points location of the left/right handle straps up beside the C2 swivel connector. This would gain (it looks to me) about 1 1/2" of forward clearance. The result would be a more compact split handle assembly, without sacrificing any of your geometry and functionality. I have a fairly long reach at the catch, so retaining as much forward clearance is important, and would be important to others who have a similar forward reach.

To this end, if I were putting together a split handle, strap set-up, I would pass a short, straight 5/16" diameter steel dowel, threaded on each end, through the cross-hole of the C2 swivel connector. Then, on each threaded end of this steel dowel I would screw on an internally threaded (5/16" x 18) eye nut. The left/right strap carabiners would then snap onto the left/right eye nuts. This would bring the left/right strap connection pivot points forward, closer to the C2 swivel connector, thereby gaining that 1 1/2" or so of forward clearance (Nevertheless, someone with a long reach, using this set-up, will still need to remove the two vertical struts on each side of the C2 chain port to open up a corridor down the left side of the flywheel housing to accommodate the forward part of the split handle assembly at the catch - so as to not impair the user's reach, and cramp the user's form.).

Some forum members with fabrication skills, who are interested in putting together a split handle set-up, might want to consider if the eye nut solution just described could also be improved upon - both functionally and aesthetically. Fifteen years ago I thought it could be, and that led me to the machining of two small aluminium (6061) saddle blocks which embrace the C2 swivel connector and are secured there by two 3/16" diameter steel pins that also serve as connection pivot points for the left and right strap arms. This was a tidy solution.

When that was done to my satisfaction, the remaining elements of whole strap/handgrip arrangement came under my scrutiny. I thought that improvements could be made there too. So that was the path down which my thinking and experimentation took me. I had some more insights, but the above comments about the C2 swivel connection problem are sufficient for now.

Slidewinder
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Re: Split Handles

Post by Slidewinder » November 17th, 2024, 10:16 am

Slidewinder wrote:
November 15th, 2024, 11:40 am
I have a fairly long reach at the catch, so retaining as much forward clearance is important, and would be important to others who have a similar forward reach.
More on the important subject of forward clearance: No serious erg user will have any interest in a split handle set-up that cramps one's form by restricting a full arm extension at the catch. A good example: C2, on its website, recommends the SportRower handle for adaptive rowers. It is a split handle device. TrakFitness, the manufacturer, markets it as suitable for everyone. In a promotional video it is shown fitted to a C2 unit. It is demonstrated by a stocky man, and even he looks cramped when using it. It is comprised of a horizontal cross bar to which left and right handgrips and handgrip brackets are pivotably connected. For many many users the crossbar will strike the C2 flywheel housing at the catch. This is not what anyone wants - and there is no practical modification that can be done to the C2 machine that will eliminate the problem.

Fortunately, a split handle set-up of the type shown by 'nates' in this thread, has a better feel than the SportRower handle, and the delta shape of the assembly when in use, under tension, is a shape better suited to obtaining the necessary forward clearance when fitted to the C2 rower. In my previous post I recommended the removal of the two vertical struts on each side of the C2 chain port. This opens up a corridor down the left side of the flywheel housing to accommodate the forward portion of the split handle assembly. For many, this will be sufficient, but some will still find that the large plastic tab protruding from the flywheel housing is in the way. I suggest to those people to do what I did - cut off the tab. Why not? It is your machine, and if you like the split handles better than the C2 stock handle, which is probable, then you do not need that large tab on the flywheel housing. So, remove the flywheel housing, and with a hacksaw, cut off the large plastic tab. Do a careful, neat job. Leave a bit with your saw cut to trim down flush with a sharp chisel. It will look as if the tab had never been there.

This modification will gain yet more forward clearance. But look! We are still trying to fit a delta shaped structure into a non-delta shaped opening. The marriage between the split handle assembly and the C2 RowErg is still not a happy one.

Fifteen years ago I thought about this: How could I modify a strap-type split handle set-up to obtain such forward clearance that no user would have their form cramped, while still retaining all of the desirable geometry and functionality of a strap split handle set-up. I worked on that problem until I had a solution that finally brought the split handle set-up, and the C2 RowErg (Model D at that time), together in harmony.

Slidewinder
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Re: Split Handles

Post by Slidewinder » November 22nd, 2024, 10:47 am

Slidewinder wrote:
November 17th, 2024, 10:16 am
This modification will gain yet more forward clearance. But look! We are still trying to fit a delta shaped structure into a non-delta shaped opening. The marriage between the split handle assembly and the C2 RowErg is still not a happy one.
Anyone planning to put together a split handle set-up should also be prepared to undertake the necessary modifications to the C2 rower so that it and the split handle assembly can function together in harmony. The stock C2 unit is designed for use with a solid, horizontal, single-piece handle, not a split handle. A proper adaptation requires more than just swapping out the stock handle for a split handle. You have to get out the wrenches and remove some of the clutter from the C2 machine.

Unbolt and remove the vertical struts on each side of the C2 chain port. This opens up a corridor down the left side of the flywheel housing. It also deprives the PM of its ostentatious perch. Bur rowing erg hot rodders do not need the PM in our face. It can go at the C2 handle clip location. A simple diy U-bracket replaces the handle clip , secures the PM, and provides tilt adjustment of the PM screen to the user's preference. Next, cut off the large plastic tab that protrudes rearward from the flywheel housing. It's in the way, and it looks ugly. Do a neat job. Saw off the tab and with a sharp chisel pare down the plastic flush with the housing body. After these modifications the C2 rower unit will look much better. We can then turn our attention back to the handle.

We like the feel of the 'nates' type of split handle shown in this thread. It uses straps in tension, forming a horizontal chevron shape when in use. This type, seen from above in a freeze frame at the catch, forms, in coordination with the user's arms and shoulders, a fixed base equilateral triangle - the user's shoulders being the width of the base. It is an immanently stable structure. That's what we want. We want stability at the catch.

But we have a problem. Well, not everyone, just all those who have less than 12" of chain showing at the catch when using the C2 stock handle. That is the distance needed to accommodate the triangular shaped forward structure of a strap-type split handle. Our modifications to the C2 unit opened up some forward space, but the clearance we gained is a non-delta shaped corridor down the left side of the flywheel housing. We need a split handle assembly that is long and narrow at the front to enable it to pass freely down that corridor, thus ensuring full extension at the catch, and no impairment of form, for all users.

So, fifteen years ago there were still a problem to solve to bring the split handle design into physical harmony with the C2 rower. I recall my excitement when I realized that the problem is easily solvable. A split handle could be designed that retains the desirable functionality of the 'nates' type strap set-up, with a long, narrow forward section physically compatible with the bare structure of the C2 unit, enabling an unencumbered forward reach for all users. It was a revelation. I was finally able to experience the true potential of the C2 rowing ergometer. You want to experience that too? I urge you to build your own.

Slidewinder
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Re: Split Handles

Post by Slidewinder » November 29th, 2024, 11:22 am

Slidewinder wrote:
November 22nd, 2024, 10:47 am
Anyone planning to put together a split handle set-up should also be prepared to undertake the necessary modifications to the C2 rower so that it and the split handle assembly can function together in harmony. and no impairment of form, for all users.
The Concept 2 rower, among the many commercially available rowing ergometers, seems to be the only one that can be easily adapted for use with a split handle. It is the only one that can be easily modified to gain the extra forward clearance needed to accommodate the structure of a typical split handle arrangement. The others would require major, disruptive alterations to open up more space in front of the handle. With the C2 rower it's simple - just unbolt and remove some bits and pieces, cut off a large plastic tab, move the PM, and the unit is ready to be fitted with the split handle set up of our choice.

Ideally, to best marry form and function, the split handle assembly should provide all of the desirable functional characteristics of the 'nates' type of split handle shown in this thread, but do this in a handle that will fit for much of its length down the left side of the C2 flywheel housing. Instead of the delta shape of the nates device, we need a split handle assembly that is long and narrow in its front section. We want the nates functionality, but we want for all users, full extension at the catch, no cramping of form - all of the good, none of the bad of a strap-type split handle.

It would be heartening to see forum members with fabrication skills put together split handle set ups, following the above design guidelines. We need to get beyond the cobbled together eyesores that are occasionally displayed here. As ugly as they are, those split handle efforts are baby steps in the right direction, but their proud makers miss the big picture: When I describe how to strip the C2 rower of its fat, and how the new lean profile must then inform the structural design of the split handle that is to be fitted to it, the result conveys a message that crude duct tape and baling wire assemblages do not - it shows that for all of these years, inside the old C2 family sedan, there has been a sports car wanting to get out.

Slidewinder
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Joined: April 6th, 2010, 6:52 pm

Re: Split Handles

Post by Slidewinder » December 10th, 2024, 10:44 am

Slidewinder wrote:
November 29th, 2024, 11:22 am
... for all of these years, inside the old C2 family sedan, there has been a sports car wanting to get out.
The goal of a split handle set-up needn't be to enable hand rotation and movement in as many planes as possible. The 'nates' strap-type split handle enables a myriad of movements, but during use only three are utilized - rotation in a horizontal plane about the front pivot, and rotation in a vertical plane at each of the handgrips. But even if a split handle provides just one plane of rotation - that about the front pivot - it would still be a vast improvement over the stock C2 handle.

Visualize the following (this information is in the public domain): A split handle comprised of two 'L' shaped arms positioned back to back and hinged together at the tip of each 'L'. The short arms of the 'L' s are fitted with handgrips and are ergonomically angled back and down slightly. The overall 'T' shape of the assembly provides the long, narrow front section needed to pass freely down the left side of the C2 flywheel housing so as to not impair the user's reach at the catch.

This described handle, so simple, with just one hinged joint at the front to enable one plane of horizontal rotation of the handle arms, is superior to every handle on every rowing ergometer made. It shows the inexcusable innovation apathy in the field of rowing exercise technology, and it shows how poorly the public has been served.

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