The 90s were a different time in term of bicycle design. Mountain biking was a hot topic and every manufacturer tried to be “unique”.

And of course Bianchi had to do it. They released a series of MTBs called “Ragno”, italian for spider, clearly inspired by the famous triple triangle iconic from GT design. But they pushed it a bit further :

img catalogue

There is 6 models ranging from the lowest quality to the highest quality:

  • Meta
  • Thomisus
  • Pholcus
  • Theridion
  • Migale
  • Araneus

I was browsing leboncoin.fr (our version of craiglist) when I saw a Bianchi Thomisus, to be honest my goal was to find a quality steel 90s mtb for a new build. But seeing this frame I never saw before I had to get it.

It was not the quality I was expecting but the weirdness of the frame made me call the seller, 2 days later I got the bike.

(It has been a long time since I rebuilt the bike so I don’t have all the original parts in mind, will update it)

The Thomisus is equipped with : (link velobase)

  • Shimano Exage Long Cage Rear Derailleur
  • Shimano Exage Front Derailleur
  • A Biopace triple chainring
  • Shimano hubs
  • Shimano rims
  • Shimano U brake
  • Shimano front cantilever

Warning : It comes with a 21.1mm steerer tube fork, so you need to either keep the original stem (mine was in a bad visual shape so I changed it) or look into some old BMX stem matching this size. Exactly what I did.

Goal was to make it my daily driver, something confortable, relatively fast and useful for carrying things. I started by removing the triple crankset, the mtb tires and all the useless things for my usage.

I changed the crankset for a Shimano 600 I converted to single I had laying around. Changed the cassette for something with more range to compensate the single chainring.

I put Maxxis DTH 2.15” tires, with those lovely beige sidewalls, it looks so great on vintage MTB !

First iteration of the build was something like this :

I quickly realized that due to the old setup with triple, the chain was not very straight and I got a lot of chain jumps. So I put back the front derailleur, just acting as a chain guard to prevent it from skipping. Works like a charm.

I then removed the leather saddle and added a front rack later on, for more carrying capacity and because I needed that saddle.

And then I got a trailer for it, still need to transform it to a proper bicycle trailer with a wood plank and some metal railing to carry and attach things.

With the trailer came another problem, the ratio on the front was too much and I was only using my lowest gear on the back. So I switched for a new chainring, changing the crankset in the process because the BCD was not matching with my new chainring.