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Alternative forks

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Bison

Posts: 19

Joined: Tue Oct 29, 2013 9:02 am

Post Thu Jan 09, 2014 2:10 pm

Alternative forks

Folks,
Just trying to think ahead a bit here. I've collected many 45" parts over the years, so much so that I'm more or less in a position to build what I've always wanted to build, a 45" flat track/bobber style bike. I have a frame, engine,gearbox, clutch etc etc. The one thing I don't have is springer legs, I have springs and rockers etc ,I'm not sold on buying from India, I don't know what the quality would be like. So I wanted to find out if anyone has experience of fitting a telescopic front end?, and if so from what bike?. I'm concerned also about the rake/trail, I read the 45 stock frame is quite shallow 23 degrees , I think that may be too little for road riding, so am I committed to springing for springers?.
No rush because I'm still in the middle of my long time owned stock WLC tidy up
Thanks,
Alan.
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Beachdog

Posts: 766

Joined: Mon Oct 16, 2000 12:01 am

Location: CA USA

Post Thu Jan 09, 2014 2:55 pm

Re: Alternative forks

Alan,
I have used several different front forks over the years. The first was a late 60's XLCH full width drum brake front end. Same size stem. A simple bolt up. Any 7/8" HD stem front fork would work including the dual disc setup. I have also done several different Japanese front forks that required changing the stem to 7/8" - a little more work. The strangest fork I have used was a four leading shoe drum brake front end from a Suzuki 750 water buffalo. This only required knocking the casting roughness from the 45 frame neck bore and honing out the 45 neck races and cups a bit to fit onto the Suzuki stem. Bolted right up after that hand fitting. I never felt that the neck rake was a problem with glide forks. The bike never went that fast to create a problem for me.
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Bison

Posts: 19

Joined: Tue Oct 29, 2013 9:02 am

Post Fri Jan 10, 2014 2:40 am

Re: Alternative forks

Hi Beachdog,
Thanks for the reply. I'm interested to hear the early Sportster/ Glide forks will fit relatively easily, I'll keep an eye open for them. It seems from what I can find on the web that Harley went to a 1" tube when the Evo models came out.
Alan.
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knucklebolt

Posts: 236

Joined: Tue Feb 12, 2013 8:27 pm

Location: Six miles East of Cheney, Wa.

Post Fri Jan 10, 2014 10:45 am

Re: Alternative forks

I've used Sportster front ends on a number of non-sportster bikes in the past, early and later, drum and disc, have one on the UL I just built, and they have always worked well. I don't think the shallow rake will effect handling much more or less than it will/would with a Springer, even though the springer puts the axle ahead of the forks by an inch or so. On a 45, or a light big twin I think that a single disc will work well, dual discs would/might be too much of a good thing. ? Not like you ever want to lock up the front brake. Had a single disc on my Knucklehead and it was more than enough brake, but also had a drum brake front end (sporter) and that didn't seem like enough brake. I use the front brake about 95% of the time, and a single disc seems perfect for me.

On the other hand, dual discs certainly look nice...lots of "wow" appeal. Just seems like they might be a bit "touchy" on a very light bike.

You also have some wiggle-room with the tube front ends as far as adjusting the length by a few inches longer or shorter, without changing the tubes. And they are certainly cheap if you shop around for a while. Always lots of them on ebay.

k.
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45Brit

Posts: 1433

Joined: Tue Nov 27, 2007 2:29 am

Post Sat Jan 11, 2014 11:36 am

Re: Alternative forks

My 45 project over on the "show us your 45 " thread has Shovelhead forks, FLH type wide glides which just required some turning and honing to make a set of neck races. Pics on that thread. I gather that a few WR racers used them, but the lighter K type forks superseded them.

Triumph, BSA, Norton or Ariel forks will fit with some finagling about with spacers.

I certainly agree that the 45 simply isn't fast enough for the 23 degree neck angle to be a problem. Likewise I'd say any British or Japsnese drum or single disk made after 1970, or any British drum over 8" in diameter will be a great improvement on the stock brake.

Use a 19" front rim, or 19" rear and 21" front and improve the ground clearance at the same time
Shoot, a man could have a good weekend in Dallas with all that stuff...
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knucklebolt

Posts: 236

Joined: Tue Feb 12, 2013 8:27 pm

Location: Six miles East of Cheney, Wa.

Post Sun Jan 12, 2014 2:03 pm

Re: Alternative forks

Just a thought, but I'd not over think the rake angle, or angle of rake. Although a steep angle isn't the best for high speed stability, in theory, in actuality, I don't think the bike is going to misbehave at normal speeds, or that you'll really notice much if any difference at normal speeds. Wheel alignment, good tires, proper tire pressure is what is more important I would think.

I have a BMW R100 which does not have much rake, don't know what it is, but it's pretty steep, probably around that 23 degree number, and it's got a pretty short wheel base too. It handles fine at 65-75mph, and on the curves and twisty roads it handles way better than I am capable of riding it. I would describe the way that bike handles as "crisp", but certainly not "twitchy" or unstable. Unless taken to extremes, rake angle probably is not something, or much to worry about.

Just a thought....too much coffee on a nice Sunday morning.

k.
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45Brit

Posts: 1433

Joined: Tue Nov 27, 2007 2:29 am

Post Sun Jan 12, 2014 6:53 pm

Re: Alternative forks

BMWs are an interesting case in that they have quite steep fork angles, they are essentially touring bikes which will carry huge amounts of weight - carefully distributed, of course - and not waddle about like an old spavined mare. I had a BMW R60/6 for a long while and I always found that while not tremendously fast it would set very respectable journey times with all sorts of luggage on board.

Personally, I'd be more concerned to get the riding position right. A lot of HDs have pretty odd riding positions. The 45 is quite a small bike, by Harley standards anyway, and so more sensitive to rider position and balance.
Shoot, a man could have a good weekend in Dallas with all that stuff...
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knucklebolt

Posts: 236

Joined: Tue Feb 12, 2013 8:27 pm

Location: Six miles East of Cheney, Wa.

Post Sun Jan 12, 2014 9:24 pm

Re: Alternative forks

By the way, those forks look great on your 45, 45Brit. I think they'd look good on my UL too. !!!

k.
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45Brit

Posts: 1433

Joined: Tue Nov 27, 2007 2:29 am

Post Mon Jan 13, 2014 3:11 am

Re: Alternative forks

knucklebolt wrote:By the way, those forks look great on your 45, 45Brit. I think they'd look good on my UL too. !!!

k.


I could have had a set of later Sportster ones for around the same cost, but I just fancied the "wide" look and I'm sure they will perform well enough. The bike actually had a set of Japanese USD forks with twin disks, hence the 1" neck conversion, but they were already gone when I bought it as a project.. it had the 16" rear already so I went for the 16" front, seeing as I already had it, along with the banana caliper.
Shoot, a man could have a good weekend in Dallas with all that stuff...
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Bison

Posts: 19

Joined: Tue Oct 29, 2013 9:02 am

Post Mon Jan 13, 2014 12:20 pm

Re: Alternative forks

I'm thinking a set of sporty forks would fit the bill, but the only ones that seem to be for sale are 1" stem. Can it be turned down or replaced I wonder?. I'm lucky enough to have access to a machine shop. Looking at my frame it would seem the best way would be tp turn out the inner diameter of the bearing cups to suit the 1" stem. I'll check the dimensions tomorrow, see if there's enough meat.
Alan
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45Brit

Posts: 1433

Joined: Tue Nov 27, 2007 2:29 am

Post Mon Jan 13, 2014 1:06 pm

Re: Alternative forks

My Shovelhead fork conversion uses a 1" stem, just has adapter cups which I think are off the shelf from one of the after-market supply houses
Shoot, a man could have a good weekend in Dallas with all that stuff...
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Bison

Posts: 19

Joined: Tue Oct 29, 2013 9:02 am

Post Mon Jan 13, 2014 1:41 pm

Re: Alternative forks

AHA!, now if it's possible to buy them then it means I can make them!, get timkin rollers fitted too. I think there's more than one length of Sportster forks too so I'll have to start looking!.
Thanks 45brit, if you remember where you got the conversion from please tell me.
Alan.
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knucklebolt

Posts: 236

Joined: Tue Feb 12, 2013 8:27 pm

Location: Six miles East of Cheney, Wa.

Post Mon Jan 13, 2014 8:53 pm

Re: Alternative forks

Well I think it's going to be a good look (45Brit) and actually I had intended to go with some wider, heavier forks on the UL, and a bigger front tire, but I found that Sporter front end at a price I could not refuse. And I'm happy with it...not complaining!

I always had a 16" on the rear of my 45, but as it was my first Harley, and I was 19 years old at the time, I raked the neck and extended the nice stock VL Springer that was on it out quite a bit. Yes, ouch. Then I had a double loop frame made for it, that used a big twin four speed. Looked like a UL at first glance. Then someone stole it. !!! That was the mid-seventies, I must have been one of the first to do that...or maybe not. It sure worked well.

Bison, it should be easy putting just about any year Sporty front end on your bike. You can always shorten them a bit by cutting the springs down, or putting in a spacer to get a little more length.

Good luck.

k.
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45Brit

Posts: 1433

Joined: Tue Nov 27, 2007 2:29 am

Post Tue Jan 14, 2014 1:39 am

Re: Alternative forks

My bike came with the conversion already fitted, it has Timken rollers. However entering in google produced several suppliers, that shouldn't be a problem by the look of it. Personally I think the Sportster forks and a 19" wheel would be better suited, because lighter, but I was offered the complete front end at a good price so I went that way

Personally, I don't prefer 16" wheels for 45s. The extra weight and rolling resistance don't help, and they don't do anything for the handling, but as the bike already had a 16" rear and the other parts were available, and I already have the Ariel bike with 18"/19" wheels I thought I'd give it a go

The original Super Glide had Sportster forks which were much criticised as being generally not up to the job, whether they would perform on a rigid flathead is up to you, really. My guess is that a rigid flathead with no electric start is probably the same sort of weight as an iron Sportster?
Shoot, a man could have a good weekend in Dallas with all that stuff...
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knucklebolt

Posts: 236

Joined: Tue Feb 12, 2013 8:27 pm

Location: Six miles East of Cheney, Wa.

Post Tue Jan 14, 2014 8:01 pm

Re: Alternative forks

I'm pretty sure that my UL is lighter than a Sporter, iron head or otherwise, but I've not weighed it yet. My son's Sportster, which is a '98 or a '99, or something around there, is also in my garage, which I've ridden, and I'd bet it is heavier, just from handling/moving/pushing both bikes around the garage lately. I'm going to make a wild guess that the UL only weighs in around 525 at most, maybe less. I'll try to weigh it soon and see how much of a liar I am. !!! Anyone know what a stock UL weighs? Or the Sporters, and stock 45's?

I had two different sporter front ends on my Knucklehead, a drum front end and a later single disc front end, and they both worked great, certainly up to the job on that bike. (I even center-punched a '57 chevy with it...chevy looked like it had been hit with a truck)(which is why I had to get front end #2, which was the single disc) It (the knuck) was a stripper, and I don't recall exactly what it weighed, but I remember it was quite a bit less than a stock Shovelhead, and in fact I could usually out-accelerate the shovelheads for that reason. (although the 11.0:1 compression didn't hurt) So, the sporter front ends may indeed be on the light side for a shovelhead, (kind of thinking 625 pounds and up...but...?) but fine on anything lighter, certainly perfect for a 45.

k.
Last edited by knucklebolt on Tue Jan 14, 2014 9:31 pm, edited 1 time in total.
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Pa

Site Admin

Posts: 4753

Joined: Sun Mar 12, 2000 1:01 am

Location: Ohio USA

Post Tue Jan 14, 2014 8:52 pm

Re: Alternative forks

I installed a set of earlier Sportster forks on one of my 1955 KHK's back in the 70's. I also added 6" over to the tubes. Bike rode real well.
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45Brit

Posts: 1433

Joined: Tue Nov 27, 2007 2:29 am

Post Tue Jan 14, 2014 9:21 pm

Re: Alternative forks

Swing-arm, electric-start Shovelhead is a heavy old thing, right enough....
Shoot, a man could have a good weekend in Dallas with all that stuff...

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