# Axle mounted trailer and sliding dropouts question



## komekomegaijin (Nov 9, 2008)

Hi IGH riders,

Has anyone ridden an axle mounted bike trailer, like a BOB trailer, mounted on a sliding dropout frame?

I've been commuting for over a year with a BOB Yak mounted using a BOB skewer on a derailleured Trek 26" commuter. I'm thinking about building a new commuter with an Internal Gear Hub, possibly using sliding dropouts. I'm wondering if there's any issues with the weight of the trailer on a sliding dropout, like a Surly frame. I've never used a sliding dropout and don't know how prone they are to slipping.

This is also posted in the commuter thread.

Any thoughts appreciated.


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## pursuiter (May 28, 2008)

I am confused about the question. AFAIK, Surly only has horizontal dropouts, no sliding dropouts. 

- Currently you install the BOB on a vertical dropout frame with a QR hub.

- You want to run an IGH and the BOB.

- You're looking at frame options and there's four choices for chain tension:
Vertical dropouts and chain tensioner
Vertical dropouts and EBB
Vertical dropouts that slide
Horizontal dropouts

Which chain tension option are you considering?


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## komekomegaijin (Nov 9, 2008)

Sorry, my bad pursuiter. By sliding dropouts I was thinking of both sliding dropouts, like the popular Paragon units, AND horizontal, like Surly...

I have my Alfine in a Niner with a EBB which I like, but haven't, and maybe won't ever, wet weather tested it.

I was thinking of trying a frame with either sliding dropouts or horizontal dropouts. 

I've since thought about it some more and come to the realisation that if the dropouts (in either form) don't move with the weight of the bike and rider on them then a trailer shouldn't be any problem. Probably a waste of a thread, sorry!

By the way - 5th option: vert dropouts, and eccentric BB in a normal BB shell!


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## SurfHenk (Dec 13, 2005)

Hi,

My new bike has the exact configuration you are thinking about, sliding dropouts that are used together with a trailer. You can see the bike here
In fact the trailer in question is a kid's trailer used daily for school/daycare, which means it is quite heavily loaded with the two kids plus their stuff, locks and sometimes additional heavy groceries. In fact I am pretty sure I am sometimes at the limit of the recommended maximum load, meaning the trailer weighing 50kg in total.

While the trailer does indeed "pull" in the same line as the sliding dropouts, this has shown to be no problem whatsoever. Even when crossing small sidewalk steps, which obviously are a rather heavy shock in line with the dropouts.

As a matter of fact, the most critical area has shown to be the axle bolt securing the rear axle and trailer-mount to the dropout. If this bolt is fastened with too little torque, the trailer-mount has a tendency to rotate. And if this bolt is torqued too tight, the Rohloff hub can have slight shifting issues, which is known for this hub. Luckily there is a correct torque in between both that addresses both issues. And obviously this has nothing to do with the sliding dropouts themselves, conventional dropouts would require the same attention.

I too hesitated between sliding dropouts and an EBB by the way. In the end I chose the sliding dropouts because in my mind it's the "cleanest" solution and am now happy with this choice.

Good luck with your build!


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## komekomegaijin (Nov 9, 2008)

Thanks for that great reply SurfHenk. 

Man, that commuter of yours is very, very sweet indeed! My budget, should I go ahead with a new bike, wouldn't even allow anything like that, yet, still the same principle in being as maintenance free as possible. The thing is, this year I built a Niner Sir9 to be my "do everything" bike - including commuting duties. It's Alfine equipped. Since building it I've become too precious about it to take it and leave it in the school car parks everyday, so I want a cheaper bike that also looks less blingy (not that mine is all that blingy) to use everyday.

Anyhow, SurfHenk, I could ask you a million questions about your commuter but I'll leave it at two, itf that's ok.

1. What fenders are they?

2. How are the Schwalbe Big Apples? Do they have a noticeable rolling resistance with that size? Heavy feeling to ride?

Thanks again!


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## SurfHenk (Dec 13, 2005)

You are of course welcome to ask as many questions as you wish. It is the least I can do for this forum, where I too get a lot of very useful information.

1. Ahaahhhh the fenders  Well, let me start by saying they are one of the most particular items on this bike. Initially, I planned to use a pair of the very nice Japanese made Honjo fenders. But unfortunately I was unable to find these anywhere locall or even in Europe, not in shops and not online. I hesitated to order some from the States, where I found a source online, but the shipping costs and fragile nature put me of of this.
Since the bike had (yes seriously, it had) to be built up with as much titanium as possible :winker: and since I was paying the shipping costs for the frame anyway, I in the end decided to have the fenders custom manufactured together with the frame. The advantages are of course that they fit the bike perfectly, are stronger than concrete (seriously, they are extremely stiff and thick) and that they will never rust 
But they are also heavier and much more expensive than aluminium ones, even Honjo's. In the end the fenders were a bit of a crazy decision, but they should last a lifetime just like the rest of the bike...
I took a quick look at your profile and you are apparently based in Japan. In that case, I would try to trace down some Honjo's if your budget permits...

2. I really love the Big Apples. For their looks. But also for their other characteristics. I tend to inflate these to very low pressures, which gives surprisingly supple rides on our typically Belgian/Flemish Cobblestones. They also seem very hard wearing, since they are also fitted to my kid's trailer and show no significant wear after quite some kilometers/years. I have never ridden real skinny tires though, since I have an MTB background and I can imagine really skinny tires to have even lower rolling resistance, but I find them very performing. The reason I chose this tire is that I did not want any "real" suspsension for maintenance reasons, so any added softness from the tire is welcome. There also seems to be a consensus that while high pressure skinny tires are obviously the fastest on perfect road conditions, wide low pressure tires actually have less rolling resistance on rough (tire deforming) terrain. Since, as already said, so called coublestones are very widespread here in Brussels, I am pretty sure these wide tires at low PSI will be very close to the efficiency, if not better, than skinnier tires. And all of that at a much higher comfort level of course.

So, that leaves me with 999998 questions to go...


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## Wombat (Jan 25, 2004)

SurfHenk, I can't see from the pictures how you can mount the belt so that it passes through the seatstay, and where did you get the cog for the Rohloff?

Thanks

Tim


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## SurfHenk (Dec 13, 2005)

Hi Tim,

The connection where the belt goes trough the frame is indeed almost invisible.
If you look carefully, you can see a thin line where the seatstay opens up, immediately behind the dropout:

From Comoutant
You can also see the hollow end of the seatstay, which allows to insert and tighten the hex bolt that connects both ends.
Both sections have a cone-shaped interface, one male and one female, such that the bolt does not have to transfer all loads.

Since I live in Europe, I bought all belt related items from the German distributor, g-boxx.com . They are actually related to the bike brand Nicolai, which you may be familiar with.


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## Wombat (Jan 25, 2004)

SurfHenk

Thanks. That's a really neat bike. You obviously put a great deal of thought into getting what you wanted.

Tim


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