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Rear Hoop Clearances Help

Posted: Sun Jun 17, 2012 8:54 pm
by cartierusm
OK, so I built a custom frame and ended having to chop it to fit the wheels I got, I got a smokin' deal on some genuine harley rims.

First question should I offset the rear hoop so the clearance is correct on each side of the wheel, so that the hoop is actually offset from the bike? Or should I make both side equidistant?

Next question what clearances do I need between the outer edge of my drive pulley on the wheel to the inside edge of the axle plate? Also clearance from the outer edge of the disc rotor and the inside edge of the axle plate, I"ll be using a brake caliper that mounts onto the axle.

Thanks, here's a pic of the frame I built, before I had to chop it.

Re: Rear Hoop Clearances Help

Posted: Mon Jun 18, 2012 8:20 am
by gww25
For almost all Harley rims a space of 8.5-inches between the rails will work unless your running a belt drive. Keep the distance equal on each side of the centerline but I'd wait until you have the parts in hand to get real accurate measurements. Most Harley rims are designed for either 130 or 150 tires so you need the rim measurments at a minimum.

Re: Rear Hoop Clearances Help

Posted: Mon Jun 18, 2012 10:13 am
by hansgoudzwaard
cartierusm wrote:OK, so I built a custom frame and ended having to chop it to fit the wheels I got, I got a smokin' deal on some genuine harley rims.
What does the frame look like since you "chopped" it? Could we see a picture?

Maybe I'm missing something here.

Re: Rear Hoop Clearances Help

Posted: Mon Jun 18, 2012 1:13 pm
by cartierusm
Sure I'll post a pic when the chopping is done, but I need clearance dimensions first.

That still doesn't answer my question. I need to know the distance between the outer edge of the pulley and the frame so I know what inner width to make the hoops. Thanks.

Re: Rear Hoop Clearances Help

Posted: Mon Jun 18, 2012 1:20 pm
by hansgoudzwaard
What is the distance between the axle plates on the present frame? What did you use for a guideline measurement when you built it?

Re: Rear Hoop Clearances Help

Posted: Mon Jun 18, 2012 3:23 pm
by gww25
Maybe we're all missing something here. You have the rims and sprockets and disk and you have the frame so what dimensions do you need that you can't measure? Most folks usually use an eighth of an inch for 'clearances' between the parts. I suppose you can use a quarter if preferred and to be on the safe side. You need to post up some mock up pics of all of the parts. For a 130 your original frame looked just fine and if you wanted to use a 'standard' chain you most likely could have done it with a 150 on that frame to begin with. What make and model are the wheels you bought. Kind of sounds like you built a frame without having any plan dimensions to start with or modified some before you had the final parts. What motor/tranny is in the frame as you may have offset issues that you haven't figured out yet either. Looks like a Sporty but who knows nowadays.
Hope the wheels are for a Sportster.

Re: Rear Hoop Clearances Help

Posted: Mon Jun 18, 2012 3:28 pm
by Maxthegardener
Good question Hans...Garys on the money as per ;)

what your going to use sprocket or pully,, whats the size of the rims whats size tyre etc, on my frame eg was made for a 200 tyre with a sprocket..its 10.5 betwwen the centre marks of the tube (1.5" tube).. but Iam running a 150 tyre on a 3.5" rim, 10mm spacers on the sprockets so there's loads of room untill I can afford a bigger rim lol

Can you not mock up what youve got??

Re: Rear Hoop Clearances Help

Posted: Mon Jun 18, 2012 7:20 pm
by cartierusm
Ok, we all seem confused. But I appreciate the thought everyone is giving.

The frame I had i built from scratch with the tires and rims that I had on hand. Then I bought some nicer rims for cheap so I'm going with those. So I chopped my new frame to account for the new rims and drive line, no biggie.

Specs: It is a Sportster Evo Motor, the new wheels are Harley off a 2000 Soft Tail - a standard wheel 16" x 3", I'm going to put a 150 Tire on it, I'm going to use the pulley that came on the wheel which is for a belt, I already got the belt pulley for the motor. The motor mounts are only tacked in place and I will adjust the motor for balance and position once the new wheel is on.

All I'm asking is what is normal clearance between the pulley and the frame. I mean for chain you have to account for the chain and so forth, I just wanted to make sure I wasn't missing anything that needs to go on. I figure a 1/4" should do the trick between the outside edge of the pulley and the tubing (so the clearance to the axle plate is a little bit more).

Here's a pic of what i have now.

P.S. I wrote this then went and took a pic, forgot I already setup the frame back on the frame jig. SO I put the wheel on so you can see it.

Re: Rear Hoop Clearances Help

Posted: Mon Jun 18, 2012 8:17 pm
by hansgoudzwaard
clearance shot
clearance shot
DSCN1282 (640x480).jpg (153.8 KiB) Viewed 7926 times
3/16 in. clearance

10 1/2" inside measurement, swingarm.

5 1/2" rim.

170/60 x17" wheel.
DSCN1284 (640x480).jpg
DSCN1284 (640x480).jpg (238.75 KiB) Viewed 7925 times
DSCN1285 (640x480).jpg
DSCN1285 (640x480).jpg (193.31 KiB) Viewed 7925 times

Re: Rear Hoop Clearances Help

Posted: Mon Jun 18, 2012 8:33 pm
by cartierusm
Sweet thanks. So I'll go 1/4" on the drive side and make the hoop equidistant on each side. Thanks for the help. Will post update pics once it's welded up. I also just finished my copper oil tank. I'll start a new thread for that.