Fitting ISIS hub to Pashley MUni frame

Has anyone successfully fit an ISIS splined hub to a classic Pashley MUni frame (rather than a square tapered hub, for which the frame was designed)?

I just acquired a used 26" Pashley MUni from the early 2000’s. It’s in fine working order with the original Suzue square tapered hub, but has a very narrow (18 mm internal width) single-walled aluminum rim. Ideally, I’d like to run a wider double-walled rim (30-35 mm internal width) for a stronger wheel and better tire profile.

Rather than lacing a new rim to the Suzue hub or building an entirely new wheel around a UDC square-tapered CroMo hub, I am considering trying the following approach to fit an ISIS hub to this frame:

STEP 1: Use Impact 22-32-14RS bearings with aluminum shims to achieve a 35 mm outer diameter so that each Impact bearing can be securely pressed into the Pashley lollipop bearing housings. (See the picture below for a sketch showing how these pieces would fit together.)

  • The Pashley lollipop bearing housing is built for use with a 6003-2RS bearing (17x35x10).

  • Unfortunately, I cannot seem to find any standard cartridge bearings with both a 22 mm inner diameter (which would fit an ISIS axle) and 35 mm outer diameter. The Impact bearings are the closest size I could find.

  • The only real downside I can see, is that when fully seated in the Pashley lollipop, there will be a 4 mm overhang for the Impact bearing. This is because the lollipop housing seat-depth in only 10 mm. (See the lower right-hand drawing in the picture below.)

STEP 2: Cold-set the Pashley frame to accommodate the wider 100 mm ISIS hub with Impact bearings.

  • The Pashley frame was built for a Suzue hub, which I believe has a 97 mm bearing-to-bearing width.

  • Therefore, the frame will need to be spread by about 11 mm to accept a 100 mm ISIS hub with 14 mm wide bearings (rather than the 10 mm wide 6003-2RS bearings originally used for the Suzue hub).

  • To accomplish this, I would cold-set the frame by spreading it, while attemping to keep the ends of the fork parallel to minimize stress on the bearings and hub axle.

QUESTIONS:

  1. If others have successfully used an ISIS hub with a Pashley MUni frame, what approach did they use to accomplish it?

  2. For the proposed approach I have outlined above, do any potential issues stand out? For instance, might the Impact bearing fail prematurely (or catastrophically) due to the 4 mm it will extend from the lollipop housing once seated?

I did try to find old threads related to this idea of retrofitting one of these Pashley MUni frames with an ISIS splined hub, but didn’t have any real luck.

The closest I could find was this thread from 2006: Splined Hub Compatability...Pashley Frame

However, no real solution seemed to come of it.

Unless you are really in love with this frame save the money you would spend on building this out and put it toward a modern muni. I know supplies are short right now but there are good used ones that pop up. I’ve just bought my 5th used uni on ebay. All have been awesome buys.

My preference would be to breathe more life info this old frame.

I am a bit compulsive about rebuilding old steel bicycle frames, and it turns out that obsessive tinkering has spilled over to unicycles now that I’ve gotten ahold of this Pashley. Really, most everything I ride (whether one wheel or two) was acquired used, stripped down to bearings and rebuilt from parts.

Besides, if I could successfully update the hub interface on this frame, not only would it likely improve strength and ride quality, but it also means I could eventually swap out wheelsets and cranks with other modern frames.

See if Udc will sell you the bearing housings. then weld them in. The rest will be building a wheel with an Isis hub. although My opinion is a modern frame will be stronger for muni and take a wider tire. I would doubt it if you could do a proper rebuild with bearing housings, a wheel, tire, hub and cranks for less than $300. Then throw in a decent seat and seat post. I think the rounded crown nimbus frame is only $65 new. I would start there if you want to build something.

Also check out my post on pashley unicycle / UMX and read the thread. There is a lot of good info on pashley Munis. You own a nice historical uni, you should consider preserving it as is. Just my opinion. Good luck in whatever route you choose.

Thanks for posting! That is a great article and thread. I definitely read through that while researching Pashley MUn’s a few weeks back after first discovering unicyclist.com.

I found my Pashley on Ebay while trying to find an affordable 26" to continue learning on and to try my hand at some light muni (up until that point I had been borrowing a friend’s cheap 20" as a starter). The Ebay seller had the Pashley posted as a “unicycle.com” unicycle because of the UDC stickers on the inside of the fork blades. The Pashley MUni stickers had been removed by a previous owner.

It wasn’t until I had bought it and was waiting for it to arrive that I learned about Pashley unicycles and early MUni’s. I was trying to identify the make/model before it arrived so that I had a head start on understanding what I might need to do from a refurb perspective.

Actually, it was the “III. Equipment” section of this great old FAQ on MUni from the late-90’s that finally allowed me to identify it as a Pashley MUni: Mountain Unicycling Frequently Asked Questions

It was the bottlecage bosses visible in the Ebay auction photos that allowed me to piece it all together :thinking:

Then, I discovered unicyclist.com later that week and started reading through all the threads I could find on Pashleys, including that one you posted!

The only work I really needed to do after receiving the Pashley was replacing the bearings and truing the wheel (for which I needed to replace a few deformed spoke nipples).

As for the preserving it “as is” vs. trying to modify it. I am definitely torn.

I have some time to think it over, because I’ll probably continue to ride it on its existing wheel until my skill level reaches a point where I want something more than the current narrow single-walled rim and cotterless setup.

I totally get the “historical” aspect of the frame. The two bicycles I ride are a 1993 Bridgestone XO-1 (which I’ve needed to strip to the bearings and rebuild a few times since acquiring it used and abused in the early 2000’s) and a 1987 Dahon folder (also rebuilt from the bearings to become my current commuter after someone gave it to me in unridable condition a couple years ago). The Bridgestone is a true piece of cycling history. The Dahon too, just of a different sort.

I have to admit, I was happy to discover the historical significance of Pashley MUnis after inadvertently buying one on Ebay before even realizing what it was.

I’m with you on fixing up the old stuff. I just did a150 miles trail ride on my Mid 1990s used GT Talera mountain bike, and I drive A 1972 beetle, hence my forum name. I have 2 UDC Unicycles with cotterless cranks. My 29er trainer I have put well over 1000 miles on. Best of luck with your pashley.