Playing with Spanners

Last Saturday I invested some time into the best bike shop in Manchester. It was a chance to catch up with the staff and some old friends and customers, including Conrad who is currently testing computer games and Chris Hamer who is recovering from having his jaw broken in a scuffle and and subsequent beating in Hulme on his way home from Sandbar.

One of the Manchester based bike paramedics dropped in for the mechanic to give his bike some attention. The Ambulance station they’re based at is at the Sport Village and they cover the entire inner city of Manchester. The bikes have to carry a horrendous weight and they hammer bike parts. On average the crew cover 100 miles a week, but all have reported losing up to 2 stone sweating it out in their distinctive yellow bike gear.

In preparation for the trip out to the alps in a few weeks I’ve replaced my cranks as it was only slightly more expensive that a full new set of rings and the old one have certainly served me well. The new XTR cranks and BB are a fairly different design, but I had thought that the bottom bracket cups had remained unchanged.

This turns out not to be true. Previously you could save a bit of money by running Dura Ace Bottom Brackets and suitably swapping spacers and internal sleeves. I’d had Tim at Sideways upgrade mine to Phil Wood Bearings too, so I was loathe to take them out and put something of lower spec back in.

New Mountain BB is different width

After much faffing it became apparent that I really should have checked them out more closely. As you can see in the photo above, the shell casing of the new unit is about 1.5mm narrower than the predecessor and it just does not fit. the only conceivable way of achieving this is to solve the issue with some narrower shell spacers.

The second task was to upgrade the disc rotors to floating rotors. I am a big believe in these after their sterling performance last year on the transalp and had a spare 180mm rotor to get me started. The rear is a 160mm rotor which with reshimming the calliper to frame mounts went on a treat. Not so the front 180mm disc. The rivets that hold the steel disc to the alloy spider were fouling the calliper body.

After a closer look out came the file set and after some careful work it was possible to cut away the necessary material on both sides of the body. About 2mm needs to be taken off in total as the photos show the fit is tight, but having been tested works fine.

Marta SL Calliper modified for 180mm Hope floating rotors

In all a fairly unique setup with the Magura Marta SLs and Hope rotors, but I was interested to see if it could be done and now I know!

Close fit, but enough

I’m really looking forward to getting out to the Alps again now the weather here is just too damp…

Author: Cris Bloomfield

Usually mountain biking in the North.

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