Moped forks on bicycle?

May 20, 2009
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OK, so I'm cruising eBay for a headlight and I run across this triple tree suspension fork by Puch for a moped.

Here's some of the specs:
head tube is 180mm (~7") with 55mm (~2.1") of threading
thread OD is 26mm x 1mm (~1")
They're 27" long overall, so it looks like a 24 or 26" wheel would fit with a fat tire
There's also cool headlight brackets on it already
Now, at ~$135.00 shipped, they're not cheap (they're also new, a used one would be WAY less), but with the cheap Monark repops are going for ~$120, they're not a bad option, if they'd work.
Has anyone out there ever tried a moped fork? I can't tell from the pic how the bars/stem would mount, but where there's a will.....
I know from cruising TretHarley.de that our european colleagues run a lot a motorcycle/moped parts on their bikes.

any thoughts???

Dr. T
 
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Apr 23, 2009
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I worked on a friends 1950`s German Tandem that had a triple tree fork, it would have been off of a moped or small motorcycle. Worked fine,but if you`re retro fitting to an existing frame, head tube length will be a concern...
 
Aug 9, 2009
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I think most people haven't tried a moped fork being that they usually use a smaller wheel so tossing a 24-26 wheel onto it won't fit. Even if it did, once it compressed it would most likely hit the wheel. Not to mention if a bicycle headset would fit onto mopeds fork or if the mopeds headset would fit into a bicycle frame. I guess buy one and find out.
 
Aug 3, 2008
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couple few of the folks here (from the other side of the pond) have used moped forks on there builds.
 

SSG

Oct 6, 2008
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There really is no standard to moped forks, so some will work, others may not. Most modern moped forks have clamps for 7/8 bars, so bicycle bars with the 1" lump in the center won't work. You can however remove the clamps, run a hollow top nut and use a bicycle stem. Ebay is full of cheap stock forks. This is a set I sold to be used on a motorized cruiser.

Here's a set on a schwinn frame.
 
May 20, 2009
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Thanks for all the feedback.
From what I'm reading the answer is a definite maybe. :D
I really like the looks of a triple tree for a chopper build (with a Basman or Firebike type of frame), but would like to have some sort of suspension for my aging bones.
Could get a MTB downhill fork, but have you seen the prices on those! :shock: Gimme a break!
Besides, who needs 10-12" of travel for a cruiser? :roll:

I would think with most of the loaded weight of a chopper-type bicycle, with rider, towards the rear and the rake of the headtube compared to a moped, the chances of bottoming out a fork designed for a MUCH heavier, forward engined, machine would be be quite low. Think of how little fork travel is utilized on other springer-type or 'comfort' forks. I guess if were an issue, a stop could be added to prevent tire rub. Handlebar mounting doesn't concern me, there are plenty of 7/8" bars that would work or a set of 1" mounts with a corresponding bar could be used.

I'll keep you posted if I end up going this route. I'd love to see more pics of bikes that utilized this idea.

Thanks again,man I love this place.

Dr. T
 
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Mar 17, 2010
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I have somewhere between 10 to 20 complete sets of "triple tree" type mountain bike front ends - VERY similar to the set-up's pictured above. I have used a couple of these sets.

One set stock length, on a stock frame 26" bike - still sprung / suspended. Front suspension is nice on this bike, but could easily live without it.

One set on a chopped and raked (around 40 - 45 degrees) Schwinn-style 26". I replaced fork tubes with some approximately 12" longer, still retaining suspension.

I had the same concerns as you, which is why I went the extra mile to retain the suspension on the chopper. I'm now convinced I could have made the front end rigid (no suspension), saved myself some time and work, and still have been satisfied. Due to rake, trail, wheelbase, weight distribution, etc, etc, etc, front suspension really doesn't come into play on the chopper.

As soon as I get some decent pictures and Photobucket account, I'll post some pictures.

I'm going to list a few of these front ends under "for sale" as well.

Stay tuned...
 

Ace

Oct 17, 2008
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I'm very partial about suspension on cruisertype bicycles. For a start, the suspension movement costs energy, and comes from peddling power. When springs are in use, they get warm, thus cost energy. In other words, you have to peddle harder to make up for energyloss. The only source of energy on a pushbike is your legs, hence my assumption. Second, I do dig MTB suspension by way of elastomeres combined with springs, but that takes more of the trembling away than it actually suspends. But please correct me if I'm wrong here ! :!:

In my opinion, if you want to save your aging bones, you're better off with a decent sprung (gel)seat. I know I love mine. :lol:
 
Apr 20, 2009
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Suspension forks for bicycles should be too stiff move on smooth surfaces, due to the aforementioned considerations. Once you actually hit something, or fall from the sky, the more they can travel, the better. :wink: If the moped fork is fairly light, and the springs can be pre-loaded with a spacer, it could work. :| I used to ride with an early Rock Shox, and it made it possible to haul buns where I couldn't even go with a rigid fork. When I quit doing wilderness trails, (older, lazier :lol: ), I took it off because the stock wishbone was noticeably lighter and more precise, much less effort on long rides.
 

Ace

Oct 17, 2008
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Exactly. That's why I think moped springs are too soft for a bicycle, they will probably move with every push of the peddles.
You might need something as stiff as MTB springs, but apart from Floyd doing half pipes, what are the chances you will be doing a 6' jump on a cruiser ? :mrgreen:
 
May 5, 2009
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I got a set of bicycle triple trees off of a bike my bro gave me. They are more narrow than the moped forks but they're pretty cool. I'm using them on my cruiser now, but when it's time for me to build another motorized bike, they are going to be on that for sure. I guess if you are trying to figure out if the moped forks would work, you would need to measure between the holes for the axle and the bottom tree while the forks are fully compressed. If it is 13" or less, then you might want to reconsider regarding a 26" wheel and tire. 12" or less applies to 24" rim and tire. Moped wheels are usually 14" if that helps any.
 
Mar 17, 2010
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I think one distinct advantage of going with a triple tree frontend, at least from a custom / rat / cruiser perspective, is (in my opinion) they make most customs look extra cool.

That's really the only reason I stuck one on one of my choppers.
 
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Feb 20, 2018
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I will revive this quite old thread.
I saw this yesterday:
70509448_714752812271771_8472178378428907520_o.jpg

The guy said he just used a "holland bike" headset and fit perfectly. I don't know about the hb though - would it be a moped hub laced in a bicycle rim?
Now, I think the most fascinating about these forks is that they go on a 1" headtube frames, and every usable bicycle suspension tripple tree (double crown) fork is for 1 1/8" frames.
What I am really interested in is a leading link fork. Here is what a german fellow member did:
66810797_2344976235547988_1980897362830163968_o.jpg

I must admit that the Basman might not be visually the best frame for this fork, it would look terrific on Felt or a Porucho, or a Lucky frame tough.
I am also curious if the fork would take a bicycle hub - it looks that way thouugh since moped wheels usually have that fat drum brake. He didn't elaborate, just said it was a nightmare to fit the fork to the frame, but if I am not mistaken the Basman has a 1 1/8 tube and the fork would be (around) 1".
I do think that if matching a moped leading link fork to a 1" bike frame is reltively trouble-free it would be the holy grail of rat rod bikes. Also moped forks even new are much cheaper than even an used triple tree bicycle suspension fork. And yes, I know for a welder it'd be really easy to make a leading link fork, but I can't weld and even if I could I don't have the conditions for it (I live in a flat).
As far as the weight concerns go I wouldn't be too worried - I think a moped weighs around 60-80 kilos. This is a Balkan bike (no pedals) and it weighs just 60 kilos:
mk50 2ju25.jpg


Most mopeds, where these forks come from, wiegh less than that.
A Puch Maxi weighs 44 kilos:
1024px-Puch_Maxi_Special_by_Foxy_Thing.jpg

I don't think the forks would bottom out, because the engineers must have taken into consideration the different riders' weight. I for example weigh almost 100 kilos... If a girl rides a moped she might weigh 50 kilos. The fork should be actually able to handle the weight of a heavy rider as well as a light rider. The only problem might be a too stiff suspension because bicycles are much lighter... On the other hand my electric Felt clocks around 30 kilos (probably around 26 without the fork) - total weight 125 kilos - the same as a 80 kilos rider on a Puch Mxi.
 
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Feb 20, 2018
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Also, just found this on the motorized bikes forum:
"Your 26" tires should fit fine. Msrfan has used Puch forks on his Briggs builds with 26" tires. To be sure, shoot him a PM. I have Suzuki forks, Tomos and a set of Hercules, all moped forks and all accept the 26" wheel without a problem. All of these are for a 1" head tube."
There is hope, it seems! :)

P.S. I found something, I don't know whether it is ok to post a link to another forum, though. :43:
 
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Feb 20, 2018
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It would seem that the headtube is not an issue, but the fork droputs are too much apart to be used with a bicycle hub. I saw a few beautiful builds and they all had moped hubs. A moto guy says that Basman probably has a fat bike hub to accomodate that leading link fork. Otherwise I guess one must relace a bike rim to a moped hub.
Or...
Is swapping a normal solid axle (yes, I finally memorized how to spell "axle" LOL) an option? Do fat bike hubs use a regular solid axle that could be bought separately? Can the axle on a drum brake front hub be replaced?
Funny enough I could get a moped, but simply don't want to ride on two wheels in the traffic, especially after two road accidents.
 
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