Bullhorn and Dropbar Options

[ratz]

Parts in da house

Mister Postman delivered Brakes; Paul's thumbies, shift cables, a host of other supplies. And...... The Wife's Silvio. We shall see if this weekend is about building a Bike or playing with Bullhorn layouts. Still waiting on Brake cables; so I'll probably have to be the wise husband first; and the experimenter second.

 

[Charles.Plager]

 Photos of failures can be

Photos of failures can be just as useful as those of successes.

 

[ratz]

Some good, Some bad

Well I couldn't resist doing some testing; sleep is optional

The bar end brakes from profile-design are beautiful, comfy, and powerful. They are easy to use with one finger. One of the best brake levers I have played with on a bike and I've had a lot. Unfortunately the pauls thumbies don't work with the SRAM R2C shifters the new SRAM shift head is too big. So while I've got a nice brake layout with the right reach and comfortable. I have no way to use the shifters. But not to be deterred I dug through the junk drawer and found an old 9spd sram bar end shifters. Put it on the thumbies and started experimenting for mock shifters.

After much fiddling I can arrive at one conclusion. There is not a good place to mount the thumbies and bar-end brakes on 440mm wide bars at the end of the horn. Maybe if the bar where custom 480mm. But at 440 it's either in a poor leverage spot; interferes with the brake lever or hits the legs inside the bars. So that configuration is a non starter.

There are a couple of places where the thumbies would work if they are not co-located with the brakes. Both, at the boom mount and at the 90degree forward sweep turn work. While both of those work, I am currently still aiming for a collocated control setup for the cockpit.

Based on John's comments, I discarded any combinations that placed both controls in tight to the waist (hamster style). I believe that wouldn't allow for consistent MBB upper body recruitment. Being limited to using a trainer for fiddling makes it hard to confirm some ideas, but that one seems obvious from what I have read. I could always revisit that after real road experimentation with hand placement. (we got a foot of snow last night; so that will delay road testing yet again)

I moved on to some testing with the shifters back on the ends. First the OzeroTT work nice and clean upstide down with brifters. Should be able to get some photos of that generated this weekend. The brifters are comfortable but that might be lacking a third hand position. It is not that the 3rd position is required, but rather that my brain is hardwired ,from years of riding with brifters, to expect the 3rd position to be there. The leg clearance in that configuration is wonderful; and holding on to the flat bar section is quite nice. This leads back full circle to Ivan zipp clone with cut off drops. The only difference is I have the flats mounted at a 10-15 degree incline and the brifters are much more vertical due to less curve in the bar. I should be able to shoot a photo this weekend comparing those two ideas.

The first take home point is that the flat bar sections that you can see in Ivan's photos are surprising comfortable a complete win. The bars that have the flat sections have had a better fit with every test I have done. They are also quite good at that 10-15 degree upward angle. Based on leg travel you get better leg clearance in a tight cockpit and I can't see any aero disadvantage. That would be one for John to play with his is mad scientist lab.

With the bar end shifters on the ends; the length of the stock horns is indeed a bit short. It is comfortable but the hands do seem to yearn for about 80-100mm more reach. The Curve on the OzeroTT is less sharp than the T2 Wing bar. Both are ok and don't pose a problem; but the OzeroTT is the better of the two.

The shortfall in reach could be adjusted for with the boom position. Setting it a tad more forward would work. That might bring the legs into contention as John noted (it will be close) I will try that this weekend. Beyond the interference issue I am more concerned with the "length of the lever" behind the pivot clamp. It could be that I will not have enough leverage for low effort steering (again the trainer limits the evaluation).

To further test I need to get a set of "cross" inline brake levers and add real brakes to the configuration to see if it is viable. There are no clamp-on reverse-pull brakes that fit the 24mm bar diameter that I have been able to locate. I will likely try Tektro RL720 Cross Levers since they have springs; and are configurable as cable pull or housing push brakes.

What are the dimensions of the cruzbike bull horns? I am curious how much my 80mm short compares to the delta between these bars and the ones designed for the bike.

More later this weekend with photos of the useful non failures. (and for Charles "PhotoMan" Plager I will re-setup some failure and photograph them if time allows)

 

[ratz]

Discarded options for Charles.

Ok So here are some of the configurations I'm passing on. Since I'm redoing this at Charles behest I'm not mounting them back on the bike to save time. All of them were put on the bike and tested.

This first one uses a thumbie to mount the shifter with a bar end brake. Problem with this layout is that the bars would need to be just a touch wider for leg clearance. And the reach on the horns needs to be about 10mm longer. Also not the shifter I really want to use don't fit the thumbies. Here are 3 photos. The thumbie bracket is not a problem even on the bare bar, with tape or a foam grip installed it is is cover too.

To avoid the legs the shifter can be moved back to the bend in the bar. This works on any of the 90deg bar I have on hand. Inside or outside mounting is possible. A foam grip would be needed to truly remove the bracket from arm interferance. or a longer bar. None of these appealed to me. In this case outside is better. inside again the bars would have to be wider. Minimum of 260mm.

The up top mounting is one that I liked. There is no bracket interference; you could run naked bars, taped bars, or foam grips with this layout. There is plenty of clearance. Unfortunately I don't have the right shifters to fully test this one; but I might get some in the future. This is a too be considered later. A 8-10mm longer reach on the horns would make this a keeper.

You have to also know the shape of your bars; some of the carbon are not round and the thumbie can't be install unless you fashioned a ruber gasket of some sort. Here are some zipp arrow bar that don't have round tubes. notice the non fit.

A traditional thumbies position would work; at the collar; and bar end brake. At this time I do not want my control seperated but this would work just fine. with an traditional round tube bullhorn/pursuit bar. You can get $26 ones from someone like fyxation.com. They don't list wide ones on the site but you can order custom; or just do this with cruzbike horns. I dummied up the configuration with the stock bars and it works; and shifting would be comfortable.

All for these thumbies configuration would have some sharp cable turns. I would us flexible Noodles with a liner. You can get those for $5.00 us. I will put some picks of those noodles into this thread as they are useful for a a lot stuff.

I'll be revisiting these with the Return to center shifters as soone a the Tektro brake levers arrive.

 

[ratz]

Brifters as bullhorns

Ok here are a few that worked; and are going to be road tested for sure.
The first of these is the inverted hydroformed aluminum with the brifter as the horn. This very comfortable and notice how high above the boom the leg clearance is. Ignore the cables they are too short at this time.

Wrapping the tape will be a bit tricky; I have played with them pull back a bit and that works too. taping will likely dictate a final position.

I did also look a Ivan's configuration to see if I could get that third hand position back. These base are the short and shallow variety. The stand positions would be too low for me with the extension installed. It might work on Mrs. Ratz Silvio because she won't have the extension (yes you can see her building it in previous pictures)

However if you mount them at the extreme top of the mounting area

And then rotate the bars up. you can get a similar angle to the inverted TT bars.
Hack off the bottom of the bars and you have a good brifter as a bullhorn configuration with 3 hand positions.

Looking at the side by side you won't have as much leg clear with the third hand position nor as high of a reach; but without the extension this right side would be equivalent to the left. As soon as Mrs. Ratz finishes her's I'll validate that. Cable routing on the right side one would be cleaner as these are made for brifters.

 

[John Tolhurst]

I'm seeing all the reasons I

I'm seeing all the reasons I went ahead with our internalised cable bar end shifter, as part of the bull horn bar set. Cumbersome to set up, but ergonomically right in the pocket.

 

[ratz]

Inspiration back to the starting point

So let night as we worked on Mrs Ratz's build Something occurred to me while I sat across the room looking at the lines on her build. I realized that another bike I had looked at in the last month had similar lines to the Silvio 2.0. So I grabbed the laptop and pulled up these Zockra Prototypes: TD700 Angle1 and TD700 Angle2; while the steering geometry is different; the implied boom angle on the TD700 is comparable to a Standard Silvio 2.0. I held up the laptop and starred at the bike across the room and the light bulb went on.

If we backup for a second; my Build has the extension on it; but I'm short. That was intentional to get my arms down a bit; to help with coping with my bad shoulder. I wanted the Vendetta's cockpit but with suspension for my neck injury (yes I'm falling apart, or rather have fallen from too many DF's). Ivan's build is what led me to pursue it extension and ultimately to buy the Silvio over the Vendetta.

I know from experience that the bullhorn position is more comfortable for me thanks to my messed up shoulder (brifters are low enough for comfort. but straight arms are way better). It always seemed that the stock bullhorns would be too high for me from the stock Silvio boom angle at my height. However I had never consider doing Bullhorns with a huge drop; the ones on the prototype TD700 look to be about 60mm. which brings the hands back down from the higher boom.

So time to play yet again (sleep is optional). I removed the extension from my Build and retested the bars.

I now found that all of the bars now have the correct forward reach. Without the extension everything shifts forward about 8-10cm (didn't measure) and it aligns with my arm length. The leg clearance is higher, (as designed). The bike is also easier to balance at a stand still; I expected that last one and was pleased to confirm it. (Yes John you can point out here that your base designed is really optimal).

So now grip/reach on various configuration work very well. The SRAM R2C shifters are extremely comfortable to hold on to by the way. Unfortunately except for the Drop Bars and Brifters; everything is indeed too high for my shoulder. I sat in the cockpit for 15 minutes last night and my arm quickly seized up and began to hurt. But this is major progress for me. Perhaps with a Bullhorn that has a that serious drop in it (60mm); I can get back the lower arm position my shoulder need and which I have confirmed is comfortable when the extension is installed;

So I did a bunch of searching and found these bars Deda Crononero Low Rider TT Base Bar 46cm x 31.7mm. Wide enough for the Silvo and my legs, a 31.7 clamp. and a 60mm drop. So We'll see if I can use those to forgo the extension and have the best of everything so far.

Here are some pictures of what we tried last night.

 

[ratz]

Internalized Cables - definately.

John,

This has been very educational so far. Besides killing off the dead season here; I'm getting the bikes far more dialed in that I could during the riding season. I always tinker. Example it took two years to get my trike dialed in; I think the Silvios will be pretty set out of the box when we roll the first few weeks. More time to enjoy riding them and less time in the garage.

I can definitely see why on the horns why you went internal on the shifters; and placed the brakes further down. That is certainly going to be comfortable for most people. I did looked high and low for a SRAM compatible indexed shifter that has internal cable routing, but couldn't find any; unless I use TT Extensions (could cut a base bar short and glue extensions into the arms). In the end I could use the ones from the bullhorn kit in friction mode; but I haven't given up yet; more configuration to play with. That's what led me to examine brakes with internal cable runs; get 1/2 the problem in the tube and figure out how to get the other cleanly dealt with. In the end if I have an external cable I'll make a plastic mold for it make the grip area a smooth contoured area.

On the topic of internal cable routing. I'm wonder what your thoughts are about running final cabling in side the Silvio boom. I'm pretty sure I can dampen and rubbing sounds. Would cutting an exit slot just past the pivot clam compromise the boom strength? Is that some thing you have do in your workshop?

I did make an interesting change of direction last night; as I'll post next.

 

[John Tolhurst]

With your bullhorn assembly,

With your bullhorn assembly, watch out for the case where the cables wrapped under the tape distort the grip profile and cause unintended stress in the finger tendons. If you are pulling on the bars for extended periods, this becomes and issue. If you round it up the diameter becomes too large or the feel becomes too spongy.

 

[ratz]

Cables

With the prototyping and testing on the trainer; I can see how the cable can be an issue for a firm grip and pull, I'm not a masher but when I do it become immediately apparent. Unfortunately there are not much in the way of options for center pull SRAM compatible indexed barcons; which leaves just friction ones.

Being stubborn however, I did figure out how to reverse the SRAM mountings. That allows the cable to run on top of the bar for the first 40mm and then enter the bar through a hole in the top. I haven't found any hand placement that grips the cable firmly in that orientation; maybe some light resting, but no firm gripping and pulling with average to small hands. So that solves the SRAM indexing problem. The one negative to that solution is that when doing that the front deraileur control is on the right; and the rear is on the left. I figure that would take about 2-3 rides to get use to. If really annoying someone would just have to machine mounting brackets that were reversed or hack of a pair flop them and weld them back together. The R2C shifters are nice but the shifting action take a bit more force that I like. I've been told that improves with use; regular shifter might be better and if they are reversed they have the same preferred pointed forward orientation.

So as of now I have one setup that will work with the extension installed, SRAM shifters that will work without the cable problem; and cross pull levers that work much the same as the stock ones; although these units can be mounted forward or backwards. I'm sure extend testing will reveal why you reversed them. That same configuration should transfer to the non-extension setup with the bullhorn drops. Those are bars are delayed by weather and will need to be verified when they arrive.

Going to take an tangent now and look into a custom bar end adapter / mount that could hold both the shifter and a proper reverse pull brake. We'll see where that goes.

 

[John Tolhurst]

Interesting tactic, to get

Interesting tactic, to get the cable on the top side ... lay it right between the tips of the fingers and the base of the palm.

My gear lever reversing tactic allowed the cable feed to run down the centre. You swapped the entire units, I kept the levers in place and swapped the bodies to get the internal cable solution. I edged to the internal cable because of looks and aero. It can be questioned.

 

[ratz]

It's not backwards it's reverse flipped

Eric posted some nice pictures of your shifter setup for me. I had started to suspected that you had swapped the bodies when I noticed the offset spindle positions. Very clever.

I thought about doing the same with the R2C shifters but they have a large warning on them not to take them apart because the springs fall out; and the inside is complicated. This morning however I did find some detailed photos of the inards and decided to give it ago. Turns could you can disassemble them and reassemble them if you are careful. I will put a photo of how when I get home. One of the units I got removed without incident the other I had to re-assemble the springs setup; not bad if you are mechanically inclined, but definitely putzy work.

So here are the findings on that swap out:

1) The R2C has a much bigger diameter spindle. Because of that when it's reverse the cable still can't feed down the center. It's close and you could probably bore out the mounting tube to make it work; but the potential wear on the cable probably isn't worth it.

2) By swapping the shifter handles. The levers are now right side up when mounted in the upside down mounting hardware. That gives the top cable routing; but restores the up/down ergo comfort feel on the shift lever. They are heavily sculpted because of the return to center concept. This is worth leaving them flipped in and of itself.

3) Because they are return to center shifters they have a "gear" indicator. That's now visually in the correct place to be seen from the cockpit. I had to rotate the barrel housing 180 degrees when i swapped the lever bodies to make that happen. The hardware is compatible with the rotation. That's also a positive.

4) The one remaining item that isn't perfect is that the shifter arms are also "shaped" left to right. If the rear control is on the right and the front control is on the left per normal convention, they are comfortable but not perfect and they are tad bit wide on the outside. If invert them and put the rear control on the left; they are sublimely comfortable. Since I will be swaping in and out different controls for testing I will leave them conventional for the sake of the wiring. If they become the final controls I'll probably ride them non standard with the rear control on the left.

So the R2C controls do work. However, I would recommend if someone that wanted to use them; get the ZIPP branded versions. They are functionally the same but the ZIPP ergo shaping left to right is uniform so you would be able to side step item (4). I think these R2C levers would work well on the that Aero Tuck bar configuration built for RAM. Although Di2 probably would be even better.

I'm going to go borrow a set of SRAM 500 TT levers from a friend. Will try the reversing trick with those and see if we can get a center cable run out of those. Worth the effort to see if index shifting from SRAM can be done with a center pull.

Results to follow and picture of relevance.

 

[Eric Winn]

For the photos Bob (ratz) is

For the photos Bob (ratz) is referring to, see this thread over on BentRider.

-Eric

 

[ratz]

Center pull SRAM shifters for bull horns.

Ok so I did get my hands on a used pair of SRAM 500 TT aero levers; and was able to successfully convert them to center pull cable routing. It took the better part of about 5 hours with fits and starts and dead ends. But the result are better than the R2C levers and these will be the ones that go on the final bullhorns if I choose shifters and not brakes on the end of the bars.

After having done this; I could do it again in about 1 hour. If you have the following info; should take about about 2 hours; most of that trying different orientations for your preferred ergonomics. Having held 900 TT levers my hand; I'm pretty sure the same conversion would work with them.

For this test I actually had 3 shifters, 2 front and 1 rear to play with. That gave me a reference lever to compare to when I made mistakes that was most helpful. I was also able to confirm that you can use two front levels on a 10speed drive train and have an all friction setup if you prefer that. Although at that point you could save your self the hassle can just get the Cruzbike kit for that.


Front Shifter

Here is the front lever before the conversion:

After the conversion

The first thing to notice is that I had to move the lever and the spindle both over to the other body. This leaves the sweep of the handle to the out side of the spindle instead of over the spindle. Here is a side by side.

Keeping the front lever with the front body is required because the left and right levels are 1 mm different in thickness. The front lever is thing thinner. The white friction washer that makes the front shifter work makes up the difference in width. Pairing the other lever with the front assembly did not work because it was too wide.

After the conversion you can see where the cable end goes; and there the exit end enters the body. John's design calls for a metal cable end Ferrell inside the body. I will mimic that and I think it will be necessary to keep the wire in place.

Here's the parts that make up a front shifter.

There are two fiddly parts of the assembly that took me all the time to figure out. The First is setting the orientation and the rotation length of the shifters. Rotation is control by the washer circled in blue above. There are 4 settings for that. 2 for front Double Ring, and 2 for a Triple.

The second part controls the cable spindle alignment and the start and finish position of the levers. The spindle must wind up in the correct position to function as a center pull. When that orientation is set correctly how you re-attach the lever via the three position triangle (circled in green) controls the final position of the lever on the bars. You pretty much have to install into your bars to figure this out.


Rear Shifter

The rear assembly goes similar; there are however 3 springs in the spindle and an alignment bracket. Take a photo when you open the cover; or plan on 20 minutes of trial and error learning how that goes back together. The plastic bracket at the bottom sort of fits in 3 different positions but only 1 is correct. The correct one has no left and right "play" when it's installed. The lack of a photo for that tells you what happened to me; and once it was back together I was not interested in opening it back up for photos. Sorry.

Inside the housing controlled by the springs is a small gear; the underside of that gear has two ridges that function as the travel stops. This is what gives you 10 discrete gears and a stopping points at the extreme end of each rotation. These gears stops match two stops on the plastic spacer at the bottom of the housing. This gear can be installed in 1 of two starting positions. If you can't get the correct travel on your leveler for your handle bar orientation; placing this gear in the other orientation will solve the to problem. My install reversed the default position.

For the rear one you have to make sure that all 10 travel positions work. You can again set 3 different handle orientation But only two will work and give you full 10 gears. So between the lever orientation and the gear position you can have 4 different alignments.

My final configuration has both shifters configured to run high gears when the level is pointed straight back and over my hands. I prefer to push the levers to shift to bigger sprockets.

Finalizing

Lastly to complete the conversion you can, if you like, cut off the extra metal from the external cable stop. The bracket is aluminum and a hacksaw and file make quick work of it. Took me 10 minutes to cut off the end; file it smooth and round it smooth.

Here they are before painting,

While it's more "fiddly" I would suggest doing the front shifter first; there are more combination but it is less difficult. Having successfully completed the front you should have no problems doing the rear one.

If someone didn't want the internal cable routing; this exact same reversing trick can be use to get the cables to be top routed on the bar; AND have lever positions that make sense on bullhorn bars.

 

[ratz]

Had to scrap the R2C shifters

The R2C shifters I think will have to be abandoned right when they seemed so close. In the reversing process to get the cable on top I had an internal stop bracket incorrectly installed. That resulted in an 11 position shifter; on a 10 gear drive train. The last thing I want is the ability to over shift into the fork or into the spokes. Unfortunately that incorrect setup is the what made them work so well with the cable on top.

So to get the cable on top would require installing them truly upside down; but their ergo shape makes that less desirable; a cable on the bottom would of course work. Perhaps the ZIPP version wouldn't have that problem. I'll leave that for someone else to look at.

What I did next following John's lead was better anyhow.

 

[Eric Winn]

Just to clarify - Cruzbike

Just to clarify - Cruzbike bullhorn shifters are friction FD (left), indexed RD (right):

For this test I actually had 3 shifters, 2 front and 1 rear to play with. That gave me a reference lever to compare to when I made mistakes that was most helpful. I was also able to confirm that you can use two front levels on a 10speed drive train and have an all friction setup if you prefer that. Although at that point you could save your self the hassle can just get the Cruzbike kit for that.

-Eric

 

[ratz]

Doesn't the rear do....

Eric,

Does the rear one not have an optional friction mode setting? I thought it did, but I don't remember where I thought I saw that..

 

[Eric Winn]

I don't know Bob. All I know

I don't know Bob. All I know is I confirmed with John before ordering - just to know what I was getting - and then assembled everything and the left is indeed friction and the right is indexed.

I presume if the indexing wears out as I've read some of these things do, then it might still function as a friction shifter.

-Eric

 

[Eric Winn]

The whole way

Hmmmm... What do you mean by " ... so that the cables could be run internally the whole way... "?

On the Vendetta all four cable housings exit at the pivot cage at the top of the headset.

-Eric

 

[ratz]

Just that

Just that Eric; inside the boom until the pivot clamp; keeping them neat and out of the way of the water bottle cage area. You just said it better than me.