Need help identifing sporstster forks, what parts to order.

[Silverguy80]

Need help identifing frontend totorder parts for it. This front end has 39mm fork tubes, showa fork tube ends, single disc, 1" stem, and 22.25mm axle hole or .875" axle hole.

So once I know what it came off of. Then I need to know which disc size and specs to order? Which caliper to order and what's compatible? Also what axle to order? I need to rebuild the forks too. There seems to be about 2 different types of fork rebuild kits. How do I decide which one I need to order?

As far as I have been told is that this front end came off a sportster.

 

[figure8]

You mention in your other thread you know and bought these off Hugh. I understand not wanting to bother a guy to much and infringing on a friendship, but you gave him business with the purchase of said front end. Asking him if he knows what it came off of so you can do a deep dive on google doesn’t seem excessive.

 

[BobbedSled]

May help may not but here we go....

Goggle Harley 39mm first gen caliper, I think the brake and mount changed from 2000 up so if you can determine pre or post 2000 everything else should bolt up if you stay in that year range.

I put Harley forks on my bike. As far as I found out from 84 on they all used 11.55" rotors same bolt pattern but the inner diamater was slightly different. so pre or post 2K is key.

If it is sportster then it is narrow glide with axle spacer machined into the axle bolt on one side and spacer on the other side. I bought a custom wheel for sportster 1200, ordered used axle and spacers from ebay from 883 and bought an oem rotor for the wheel year. I replaced my lowers with polished ones from who knows what year and the rebuild kits seemed the same from mid 80's up to about 14.

I used 06 front brake. It all bolted up. The tell would be the front brake mount, early ones were single pot, the mounts are way different than the later brakes. If you an figure out pre or post 2000 it should be easy from there, pretty much anything. I just guessed and it all fit staying 2000 and up for parts for 39mm sportster forks.

Good luck!

 

[kshansen]

I can tell you that is for a 1988 Sportster. I also think that they did use the same part on other bikes but the 45900-88 is the part number for the right side fork slider and tube assembly on a 1988 Sportster.

The right side is the one with the split at the bottom with the allen head clamp bolt.

Front caliper for a 1988 is a Harley number 44046-84 and is mounted on the left leg. Stock disc is a 44136-84A, this is the same number for a cast or wire spoke front wheel.

Just happen to have a 1988 Sportster out in the garage and the parts book as well.

One note for anyone not familiar with Harley Part numbers the last two digits for the most part are the year the part was first used. The letter after the last two digits indicates a change or update to the original part but for the most part it will directly replace the former number.

Let me know if I can be of any other help.

One more thing looking at the lower triple tree/bracket being it is aluminum it would be off a 1200 as the 883 used steel/cast iron lower. The rest of the front end parts were identical.

 

[Silverguy80]

Sorry for delay in responding fellas. Works been insane. Suffered from actual heat stroke after breaking down on first actual ride on my motorcycle. Pushing up hill. Then kicking for an hour plus in blistering heat with my helmet on was dumb. Was late to meet lady friend for brunch. That was a wild ride. Put my 1.5 year old dog down because of heart failure. I need some cycle therapy bad!

So it sounds like I have 1988 1200 sportster forks and triple trees. Which is awesome to now know. When ordering a brake lever master cylinder, Do I need to get a specific bore size or will about anything work? Also fork oil? I have searched for alternative fork oil or upgraded fork oil from the Harley stuff and seeing mixed opinions on what to use. Or should I just bite the high price for HD fork oil and get it. Just want to get what will perform the best in the corners. I know I have knobby tires. Got the bike that way and will be changing those even though they look cool.

As far as asking Hugh I did. He wasn't sure what they came off of. Just that they were 39mm sportster frontend.

Oh any idea what axle I will need? I can probably figure it out now that I know year and model.

Thanks for everything y'all! I have made two or 3 similar posts in chopcult with zero response from anyone. I was quite surprised by this as I figured it would have been the opposite in the beginning. Glad there's a good group of people here who are willing to help one another. Makes me even more proud to be an xs650 owner. Keep up the good work fellas. I hope I can help some people in here someday soon.

 

[kshansen]

I just took a quick look my self and see what you mean about all kinds of different answers to what should be a simple question on fork oil!

I think if it was me for a starting point I would use any good 10W fork oil. As this is a custom set-up and everyone's riding style is different what might be too stiff for you might be too soft for someone else. Amount or oil varies depending on if you are just draining and refilling or rebuilding and cleaning all parts. Wet as they call it for just a change calls for 9 oz. Dry as if you disassembled and cleaned off all oil calls for 10.2 oz.

Stock 1200 1988 Sportster axle is part number 43895-87. Note that the Sportster front wheel has a seal spacer on the right side and the speedometer drive that doubles as the seal spacer on the left. Depending on what wheel you are going to be using you will need to adapt for what that wheel needs.