Hubs and Drums Ready

Thanks to JELE surface technology services near Berlin, my alloy Borrani wheels look just like new. Jens, the brain behind JELE, grinded and polished them nicely, realizing a mirror-like finish. The shiny wheels really stand out from the rest of the bike which is why also treated the hubs and brake drums with some TLC. Therefore, I used the following materials step by step:

  • Foamed sandpaper 120
  • Wet 600 sandpaper
  • Wet 1000 sandpaper
  • Polish with 150 chaulk
  • Final Polish with 855 chaulk

My new polishing machine, powered by 400 V and revving up to 2.850 rpm @ 25 cm diameter, works perfectly under these conditions. The old 230 V engine did not even come close that performance. No loss in power at all when you push the part on the polishing disk…

All unsprung parts; hubs, brake drums, shaft casing and drum covers received a proper cleaning and several polishing stages. But I did not want to overdo it. The appearance of a chrome finish was definitely not my intention for the Guzzi, being more a daily draiver rather than a showroom diva.

The brake shoes (Guzzi 12620800) were also replaced, followed by new tapered roller wheel bearings (Guzzi 92201420) and standard sealing rings (32 x 48 x 7 mm). The brake shoes had to be adapted slightly because they did not align with their joints completely. Two mill grinded off the shoe and things worked well…

Springs, levers and the shoes were mounted with high-end suspension grease and PTFE spray (“Teflon”), allowing for maximum durability and movability. The bearings were filled with appropriate grease. Honestly, I am still wondering about the fact stat one brake shoe in the front wheel had to be shorter than the other three. My supplier had only one size in stock – so I re-used one old shoe in the future front wheel.

A torch was a big help to heat and widen the mounts of the bearing cases in the hubs. Punching the cases into the wheels was tricky though. Luckily, the old crown wheel of the shaft drive could be used as a matching tool, hammering the bearing case deeper and deeper into the hub.

The day was exhausting over all: Standing in front of the polishing machine for hours, and slamming hammers onto wheel bearings. But the final result – completely new hubs and drums with a shiny finish – make up for that work. The final assembly and brake adjustment will be done when the hubs are back from re-spoking. Urban Motor is currently taking care of that process, using stainless steel spokes and according nipples.

Advertisements

Leave a Reply

Fill in your details below or click an icon to log in:

WordPress.com Logo

You are commenting using your WordPress.com account. Log Out / Change )

Twitter picture

You are commenting using your Twitter account. Log Out / Change )

Facebook photo

You are commenting using your Facebook account. Log Out / Change )

Google+ photo

You are commenting using your Google+ account. Log Out / Change )

Connecting to %s