...MTB repair! service mystery  

for the last couple of weeks I had this strange noise coming from the rear wheel. Its a Hope XC hub and Mavic 321 Disc rim, 2mm spokes. The cassette and chain are worn in but not work out. I recently tried to replace the largest of the three front sprockets and replace it with a slightly smaller version (40 teeth instead of 42). The part I bought online was however for single speed use. In addition I had to get my 2004 (and never serviced) Marzocchi Bomber checked out.

So, this noise & feeling that the chain is slipping had been there for many weeks and I decided to do something about it. the front derailleur had been on the bike for around 4 years or more. it had become worn out. I did blame it partially for the general repairs as it had to be fixed. Then the rear shifter developed issues, it wouldn't always grip and shift upwards. but the annoying feeling was more towards the actual chain (partially) slipping off the respective gear. the more force applied the worst the problem got. however, it was not at all times evenly. it would be on and off.

ordered a new front shifter and cables, a new chain, also new front derailleur from chainreactioncycles.com. I didn't get a new rear cassette as the one on was still in good nick. The front fork service (£80) was not done to my or to the mechanic's satisfaction at BikeWorks (East London). The fork was sent back and the bike was complete 1 week later.

However, the rattling noise had not stopped. I went to Jorrin who know's all about bicycles and how to fix em. We both concluded, after some more testing, that it must be the rear hub that's causing the problems. I've never taken a rear hub apart nor did I know how it functions.

Here is how to service a Hope (XC) Rear Hub Freewheel Body (partial courtesy of www.mbro35.co.uk). If you need to take the whole rear hub including bearings apart...click here for detailed instructions

Tools needed

• chainwhip
• cassette lock ring tool & suitable spanner
• flat bladed screwdrivers
• circlip pliers
• terpentine (or other)
• grease

1. Remove the wheel from the bike. Remove the quick release skewer from the axle. Using a chain whip to stop the cassette turning, undo the cassette lockring with a suitable lockring tool and spanner. Remove the cassette from the freehub.

 2. Prise off the drive side spacer. If it is difficult to remove try two flat bladed screwdrivers opposite each other to lever it off. be careful not to damage it. Remove the non drive side (coloured) spacer.

3. Pull the freehub off (a bit of gentle leverage from a screwdriver may be needed). Be careful that you don't loose any of the three pawls and springs - they might come out with the freehub or stay in the hub. Remove the internal spacer from behind the freehub.

 Cleaning

To clean the inside of housing I used a tooth brush and terpentine (just a little of it). You don't want terpenting dropping onto your sealed bearings. I cleaned the paws and the springs also with terp and toothbrush. there was a lot of grit inside the springs, got it out with a little allen key. The task of putting the little pawls and the springs back into the freewheel body is daunting.

 

Putting it all back together

Insert the internal spacer into the drive side of the hub. Put a blob of grease on each of the holes in the freehub that the pawls fit into. Insert the pawls and springs. The grease should hold everything together. Holding the pawls in with your fingers slide the freehub into place. I have read many tips about using elastic bands etc to hold the pawls in but they are not really needed as long as you have at least three fingers and a thumb on one hand! Make sure everything is spinning freely.