Showing posts with label chain. Show all posts
Showing posts with label chain. Show all posts

Wednesday, August 15, 2012

And so the Legacy begins

In the absence of any project bikes, and despite my recent experience with bits falling off the P3 frame (must buy torque wrench). I decided to start work on my hybrid bike. Over the past couple of months I have been assembling a series of spares to overhaul the quite frankly knackered shifters and the aging drivechain parts. The experience of changing gears has reached the top end of tempermental. Which is to say the occasional inconvenience of forgetting your house keys as opposed to the Alzheimer memory loss.

This bike is a Ridgeback Adventure SX120 - bought back in the early 90's and still going strong. When it was relatively new there was an inadvertant upgrade of wheels and hubs which looks to have been a very positive move as they run as smooth as the day they were fitted. It will also allow me to fit a 9 speed to them taking the range for the cassette from its lowly to 7 and adding a bit of low climbing gears for my tired old legs.

In my previous round of parts purchasing I had picked up some Shimano LX mechs and although I had planned to put these on an MTB build, I have decided that these should be the basis of the equipment change. Should these second hand parts fail then I have the option of buying a new part that will slot into the system. As this is to be a workhorse bike I wanted all the parts to be of a decent level of mechanical soundness. Most LX parts are relatively cheap and the shifters were easily located at a low price due to discontinuation of the items. A 9 speed chain and an HG50 cassette make up the drivechain parts.

The brake levers were also a little tatty and quite frankly as the levers themselves are plastic, I decided that replacement with some Avid Juicy 7's was a nice touch. Finally to complete the comfort rating I am going to add some Ergo grips and a new saddle (the old ones have been on from new, and I'm sure I deserve it).

My first task will be to strip down the bike and clean, I will leave the cantilevers on the bike. I'm not sure I want to go as far as a bare frame rebuild, but when I look at the bike I may change my mind.

Wednesday, June 1, 2011

Replacement of chainring

I have now received the Goldtech chainring from BETD, very prompt dispatched Tuesday and here the next day, so being free for half an hour fitted it. It is a simple job as there was no need to remove the bottom bracket and adjust the front derailleur. Simplicity does have its merits. I do need to work at getting the chainretention device to fit cleanly though. I think over the rougher downhill sections it will save me from spinning my legs in a futile attempt to provide drive when required.

A few points for future reference though - SRAM powerlinks are a life saver! I rerouted the chain after shortening the chain for the smaller chainring. This new route through the jockey chain was clearly going to do nothing for the chain or the noise levels as I cycled. Ooops! Undoing the masterlinks though was almost literally a snap. Clearly, if ever I should desire to move back to the larger chainring I am going to need a new chain. I have saved the old links, but I am not convinced despite assurances that they will do anything but act as an emergency link to get me home. Finally, summer dust is much harder to remove from the drivetrain than mud.

Sunday, February 6, 2011

Cry "Havoc!" and let slip the dogs of war.

Finally, the bike is complete! There are a few niggles, like the fact that it is unrideable in its current configuration, but it is complete and I am hoping that the issues can be overcome quickly and cheaply.

brake boss line up
Finally, I have brake bosses that at least partially work with the XT brake arms. If you look in the photograph you can see the three versions that I managed to get. Look at the different size of the lip next to the screw and if you can compare the profile of each boss fitting. Not all bosses are the same and so when you get to adding brake arms it is clearly a question of the right ones for the job. I'm keeping the others in my spares box for anyother job. The one to the right is from Tiawan and made of titanium, but is far better quality and has a better profile than the others. Even so it does not provide a perfect fit for the brake arms, with a small 3mm gap between the frame and the arm. I am hoping that this will not cause to much strain in braking, because if it does I will need to see if the adaptor kit works any better.
just a small gap

Confident that I would at least have some braking potential, and finding my Sunday afternoon surprisingly free, I continued on completing the last jobs on the bike. First up chain onto the bike. Simple enough, I'm not going to explain the ins and outs as it is done well enough in Zinn and in other bicycle maintance books. I had not appreciated how much you need to be an octopus though. I was most pleased that I was fixing the chain together with a powerlink and not having to force a pin into place with a chain tool. Really simple, but a little more fiddley was the task of aligning the rear derailleur (mech). Setting the high and low screws to match the limits of chain movement is simple in theory. I found that holding the derailleur over the low position and looking at where the limit screw was holding gave me more confidence that this phase was set up.

powerlink
I then needed to cut the housing for both the brakes and the gears. I wish I had a proper wire cutter for this as it was hard work with the cutter on my old pliers, but they worked adequately. Fighting to not strip the wire as you thread it through the housing is also a must. Not only does it make it difficult to thread, it will also weaken the cable.  Finally, I fitted the handlebar grips, (some lizardskin ones which have lock down bolts) and adjusted the shifter and brake levers into position.

I have however, created a bike that is a little overdeveloped in the tyre department. There is an alignment issue with the rear wheel which I think is easy to sort, but there is one major problem that is preventing me from riding the P3 today. The tyres are too fat. Inflated the rear tyre is one large balloon wedged between the downstays. Not so bad at lower pressures, but it still rubs the frame badly. The original tyres that came with the wheels, I seems to remember, were fine. So I will try a switch back. In the short term there is a potential to borrow some from Uncle Riotous who is storing a load of spares. The ultimate will be a rebuild of the hub on a narrower rim. Whilst I have enjoyed assembling a bike from its components and I even feel that framebuilding might one day be an option- I have visions of being an old man with a shed in the Welsh mountains building custom frames. Wheel building is an art that requires specialisr equipment, much patience and many hours. So to rebuild the wheel I think I may need to employ my local bike shop.

The beast nearly ready for action