Horizontal Dropout with Derailleur Hangar, need help with wheel placement.
#1
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Horizontal Dropout with Derailleur Hangar, need help with wheel placement.
I'm in the process of putting together a bike and I have a question about the horizontal dropouts I have. It has an attached RD hangar and I was wondering what my wheel placement should be?
This is what it looks like. I'm assuming I should push it all the way towards the front.
Any help would be awesome
Thanks
Neil
This is what it looks like. I'm assuming I should push it all the way towards the front.
Any help would be awesome
Thanks
Neil
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Generally just behind the derailluer pivot point. That is where it was in this frame you can see the marks on the drop out where the wheel was tightened previously. Roger
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Most bikes I have seen have the axle in front of the pivot point. I think the way it is should be fine. The existing marks could have been from a fixed/SS build.
#4
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I'd say the axle just goes all the way forward as well. Being slightly ahead of the derailleur pivot is the norm if you look at bikes with vertical dropouts. And the amount of axle lead ahead of the derailleur looks darn close to what you would have if it were a vertical dropout.
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I'd say the axle just goes all the way forward as well. Being slightly ahead of the derailleur pivot is the norm if you look at bikes with vertical dropouts. And the amount of axle lead ahead of the derailleur looks darn close to what you would have if it were a vertical dropout.
Thanks for the info everyone!
Neil
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As you can see, there's a certain amount of debate here, and the truth of the matter is that it really doesn't matter as far as the derailleur is concerned, but there are differences.
Further forward, shortens the wheelbase making for snappier handling, but can adversely affect handling on steep climbs, especially on tall frames, because the rear axle will be forward as compared to the center of gravity. Also farther forward, improves chain wrap which will help prevent skipping on the smaller sprockets as the chain and cassette wear out, maybe buying you a few hundred miles at the end of their lives (this can always be done later.
One consideration may be chainstay clearance. The clearance gets narrower as you approach the bottom bracket, so pushing the wheel forward will reduce tire clearance, which may be a consideration depending on wheel alignment and tire width.
Those are some of the considerations, and you can make your own informed decision. Just remember that you'll need to re-center the wheel every time you remount it.
Further forward, shortens the wheelbase making for snappier handling, but can adversely affect handling on steep climbs, especially on tall frames, because the rear axle will be forward as compared to the center of gravity. Also farther forward, improves chain wrap which will help prevent skipping on the smaller sprockets as the chain and cassette wear out, maybe buying you a few hundred miles at the end of their lives (this can always be done later.
One consideration may be chainstay clearance. The clearance gets narrower as you approach the bottom bracket, so pushing the wheel forward will reduce tire clearance, which may be a consideration depending on wheel alignment and tire width.
Those are some of the considerations, and you can make your own informed decision. Just remember that you'll need to re-center the wheel every time you remount it.
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An ounce of diagnosis is worth a pound of cure.
Just because I'm tired of arguing, doesn't mean you're right.
“One accurate measurement is worth a thousand expert opinions” - Adm Grace Murray Hopper - USN
WARNING, I'm from New York. Thin skinned people should maintain safe distance.
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Modern racing style road bikes with vertical dropouts have very little clearance between the rear wheel and the seat stay.
Steering trail has much more to do with handling than wheelbase, most older road bikes have more relaxed head tube angles and more trail than modern road bikes. I would bet that this bike has plenty of trail to offset any quicker steering that shortening the wheel base could cause.
I don't see any problem with moving the axle forward. Just be sure the chain is properly sized.
Steering trail has much more to do with handling than wheelbase, most older road bikes have more relaxed head tube angles and more trail than modern road bikes. I would bet that this bike has plenty of trail to offset any quicker steering that shortening the wheel base could cause.
I don't see any problem with moving the axle forward. Just be sure the chain is properly sized.
Last edited by Al1943; 10-19-10 at 10:57 AM.
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I've read this claim numerous times from many posters and writers but have always wondered if there is any validity to it. The change in wheelbase from all the way forward to all the way back in most horizontal dropouts is, perhaps, 15 mm or less than 1.5% of a typical 1000 mm wheelbase. Is that enough to make any difference in responsiveness?
#10
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I've read this claim numerous times from many posters and writers but have always wondered if there is any validity to it. The change in wheelbase from all the way forward to all the way back in most horizontal dropouts is, perhaps, 15 mm or less than 1.5% of a typical 1000 mm wheelbase. Is that enough to make any difference in responsiveness?
#12
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The best shifting-performance is achieved with the cogs as close to the upper-pulley as possible. Different frame & dropout as well as derailleur designs will vary the position in the actual slots, but as long as you place the cogs as close to the upper-pulley as possible, it will shift best.
As for handling, I've haven't been able to tell the difference with rear-wheel only adjustments. I've noticed that bikes with shorter overall wheelbase tends to handle better.
As for handling, I've haven't been able to tell the difference with rear-wheel only adjustments. I've noticed that bikes with shorter overall wheelbase tends to handle better.
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I have varied the position of the axle in my horizontal dropouts. You can detect a slight difference in handling due to wheelbase.
BTW those are "track ends" not dropouts.
BTW those are "track ends" not dropouts.
#14
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IT matters little, try various placements and see your personal preference.
A rear opening fork end is one way to build a short wheel base rear end.
More suitable to be set up as a fixed gear street bike than a vertical rear dropout would be, or a lot better than a Track frame ,
that you kids naively buy, and then want know how to drill a brake hole in a carbon composite track fork for a front brake.
A rear opening fork end is one way to build a short wheel base rear end.
More suitable to be set up as a fixed gear street bike than a vertical rear dropout would be, or a lot better than a Track frame ,
that you kids naively buy, and then want know how to drill a brake hole in a carbon composite track fork for a front brake.