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Old 2017-11-06, 02:44 PM   #2101
UniMyra
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I've sent the question to Sclumpf, but I don't think I'll wait very long for the answer.

I think I will start with 19 on the tension meter, and see how that feels. I'll keep a close eye on the wheel to see how it goes.

I am also thinking that if the spoke tension is too low, there may be to much stress on some of the spokes (and that part of the hub) when you ride, but I don't know.

Regarding the disc brake. Nathan Hoover showes in this video how he modified a KH36 frame to make a Sclumpf hub/disc brake setup work: https://www.youtube.com/watch?v=gtZzcXD2W0s
I'm hoping to do the same.
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Old 2017-11-07, 09:48 AM   #2102
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Quote:
Originally Posted by UniMyra View Post
Regarding the disc brake. Nathan Hoover showes in this video how he modified a KH36 frame to make a Sclumpf hub/disc brake setup work: https://www.youtube.com/watch?v=gtZzcXD2W0s
I'm hoping to do the same.
Cool mod!
Pretty straight forward. I would only worry about the D-Brake being weakened as they removed quite a bit from it. Adding a reinforcement rod like Eric did would be a good thing.

Great handlebar btw!
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Old 2017-11-07, 10:36 AM   #2103
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I would only worry about the D-Brake being weakened as they removed quite a bit from it. Adding a reinforcement rod like Eric did would be a good thing.
My frame (KH 29 2014) has a disc brake mount so I don't have to worry about the D'brake. I checked yesterday, and it looks like everyting will fit. I will probably do a little grinding on the inside of the frame to make sure. 0.5 mm should do.
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Old 2017-11-07, 11:58 PM   #2104
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I'm curious to know the effect of a crank-mounted disc as opposed to a hub one. If the wheel is in high gear... surely the disc is going to require a different amount of power to when it's in low gear, because the cranks are geared down from how the wheel is turning?

I guess it's not an issue in practice, and you'd just learn to apply more or less pressure depending on the gear you're in, but just sounds really unintuitive for me
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Old 2017-11-08, 12:02 AM   #2105
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Also, I had a quick go with the torque wrench today - first time I've checked the bolts since I set the hub up, and it all seems solid! I'm REALLY worried about stripping the ISIS bolts though. With the shifting rod, I feel like I can't quite get a good enough 'grip' with my allen bolt, and had a few slippages.

As these bolts don't seem to be standard ISIS bolt-sized (in terms of the hex key socket), how is it I'm looking at getting replacements, should the need arise? Is there any way I could replace them with bolts with a proper ISIS hex socket, rather than the smaller one?

I've not had the hub too long, just a couple months, so I'm sort of looking towards the future of this component of it and getting worried.
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Old 2017-11-08, 12:21 AM   #2106
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Cool mod!
Pretty straight forward. I would only worry about the D-Brake being weakened as they removed quite a bit from it. Adding a reinforcement rod like Eric did would be a good thing.

Great handlebar btw!
Yes I worried about weakening the adapter too. I think it really depends on your riding style. I use the brake sparingly, and never crank hard on it. Others who brake really hard will surely bend the D-brake, weakened or not. The extreme is Chuck Edwall who loves riding really fast and cranking on the brake so hard that his body is at a 45 degree angle briefly as he slows down.

For me, I am still using the same D-brake we modified for that video back in 2012. Since then it's done over 5k miles and hasn't bent or had any problem.
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Old 2017-11-08, 12:44 AM   #2107
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Note that there are two versions of the dBrake. One is a bit more chunky than the other. I can provide photos if you're interested as I have one of each.
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Old 2017-11-08, 08:45 AM   #2108
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Note that there are two versions of the dBrake. One is a bit more chunky than the other. I can provide photos if you're interested as I have one of each.
Please do! Is it an evolution of the d-brake?
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Old 2017-11-08, 10:29 AM   #2109
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Please do! Is it an evolution of the d-brake?
Yes Pierrox, they are 2 versions of D-brake, second one is reinforced
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Old 2017-11-08, 12:00 PM   #2110
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Originally Posted by Piece Maker View Post
Also, I had a quick go with the torque wrench today - first time I've checked the bolts since I set the hub up, and it all seems solid! I'm REALLY worried about stripping the ISIS bolts though. With the shifting rod, I feel like I can't quite get a good enough 'grip' with my allen bolt, and had a few slippages.

As these bolts don't seem to be standard ISIS bolt-sized (in terms of the hex key socket), how is it I'm looking at getting replacements, should the need arise? Is there any way I could replace them with bolts with a proper ISIS hex socket, rather than the smaller one?

I've not had the hub too long, just a couple months, so I'm sort of looking towards the future of this component of it and getting worried.
Same for me when I took the crank out to install the disk rotor.

I did not take the opportunity to compare to a regular ISIS bolt but my feeling was that it should be fairly the same if you manage to drill the center to let the rod through

I would love to make the experiment but I need to find a friend with a press-drill in order not to murder the bolt (or whatever will maintain the bolt up when trying to hand-drill).
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Old 2017-11-08, 12:12 PM   #2111
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Yes Pierrox, they are 2 versions of D-brake, second one is reinforced
since when is it available? UDC (UK and GER) only shows the standard one that I have had for years now.
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Old 2017-11-08, 08:12 PM   #2112
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since when is it available? UDC (UK and GER) only shows the standard one that I have had for years now.
I think design was improved long time ago
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Old 2017-11-09, 04:03 AM   #2113
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Here are the two dBrakes. Other than the arm profile visible in this photo they are identical. The silver on the bottom one is where I filed it to fit my 36er.
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Old 2017-11-09, 11:38 AM   #2114
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Don't forget that once you're on the uni, you add a lot of tension to the spokes as you are suspended to the top of the wheel from the hub (in summary).
That's a myth - the increase in tension of any one spoke is small when the wheel is under load. The only large change in tension is the decrease in tension of the bottom spokes where the rim bends slightly under the load. A bicycle/unicycle wheel is a pre-stressed structure which doesn't quite work in the obvious way (you actually sit on the bottom spokes rather than hang from the top ones).

The significance of this is that in general too low a tension is more of a problem than too high a tension - it's quite rare for people to build wheels with too high spoke tension, as that's a lot higher than people think. Too low a tension can result in the spokes at the bottom going completely slack, which makes the wheel less strong and also tends to result in the nipple unscrewing and you losing all wheel tension.

There is one obvious exception to that, which needs mentioning on a Schlumpf thread. I think most/all of you have relatively recent Schlumpf hubs, but I have a first generation hub and broke the flange when rebuilding the wheel by overtensioning the spokes (they wouldn't have been overtensioned on a normal hub - I was just bringing them up to the same tension I have on bike wheels with similar rims - but you have to use lower tension with first gen Schlumpfs).
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Last edited by aracer; 2017-11-09 at 11:39 AM.
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Old 2017-11-12, 10:59 PM   #2115
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Just had a go on a G28 earlier today, what a hoot! Took a couple of seconds to get used to the much larger feeling wheel (which wasn't too hard as I'd just got off a 36"). But after that I quickly figured out freemounting in the higher gear.

Tyre was running at 60PSI, which, coupled with the way smaller wheel, feels incredibly responsive. I'm hooked! Really want to build some geared system now...
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