Dec 082013

There I am, enjoying a mild and sunny December on my mountain bike today and I begin accelerating for maximum speed, clicking up the rear gears, and then a problem. It’s suddenly got awfully hard to pedal, and I try going down a gear but nothing happens. In dread, remembering the time when my Shimano RD-M980 rear derailleur had ended up in the spokes of my wheel this year, I stopped the bike and had a look at the rear derailleur (RD-M986).

The chain had become unseated from the jockey-wheel and was jammed between the cage and the outside of the jockey-wheel. Also, the Bionicon C.Guide had rotated 180 degrees so that it was now sitting above the chainstay, and one of the C.Guide barrel legs had snapped; the three remaining functional cable-ties meant that the C.Guide was probably still functional though.

This all looked fairly easy to fix, but when I managed to reseat the chain onto the jockey-wheel, the jockey-wheel would not rotate easily. To compound it all, I had neglected to bring any tools (this was only meant to be a short fun ride!).  The hub was still freewheeling, so I walked the bike home.

The first thing I did when I got home was to remove the jockey-wheel. Unfortunately, the jockey-wheel bolt/screw seemed to be stuck so the Allen hex tool just ended up rounding out the head on the bolt. Oops. I needed some help now but we managed to drill the bolt and remove the tapered head, which then allowed the cage to be removed, and then the bolt could be removed with pliers. Whew!

I could see why the jockey-wheel wasn’t turning. The bushing had been displaced by a couple of millimetres so that the jockey-wheel was off-centre and rubbing against the rear derailleur cage. This probably happened when the chain became unseated and had applied a force against the side of the jockey-wheel when I was pedalling (the jockey-wheel was heavily lacerated by the chain but still useable). Judicious use of a vice soon had the bushing centred correctly in the jockey-wheel. Of course I had sacrificed the bolt, but luckily I was able to scavenge a bolt from my older broken RD-M980 rear derailleur which fit perfectly. Result!

I soon had everything reassembled. But I decided to completely remove the C.Guide as I wasn’t convinced that it was really needed on a bike with Shadow Plus technology. Shadow Plus had arrived on my bike in the guise of the RD-M986 which had replaced my broken RD-M980 earlier this year. Anyway, I should really see how Shadow Plus works on its own, and I have a sneaky suspicion that the C.Guide had ended up on top of the chainstay as a result of it getting caught in my Five10 shoes whilst pedalling furiously, and that this had then unseated the chain from the jockey-wheel. It’s just a suspicion.

Nov 172013

Had a quick blast on the mountain bike yesterday. Part of the ride was next to a river which sometimes gets flooded when the river breaks its bank. Going down hill and around a corner, a quick glimpse ahead indicated that the area was not flooded although it looked a bit damp. No problem. Except that I ended up in three inches of accumulated river silt; the black, gloopy and smelly kind! Having misjudged the situation going in, I did not have enough speed or momentum to take me through this gloop and out uphill. I soon ground to a halt and had to walk my way out. Oh my poor Five 10 Impact shoes!

I got out of the gloop soon enough, trying not to slip walking uphill, but now both the bike and myself were like mobile masses of glue; leaves and other plant detritus sticking to us and not shifting! I normally don’t mind riding through mud, it’s a lot of fun actually, but this black gloop was something else!

Come to think of it, I hadn’t been this way for a couple of months and I do recall that the area had been flooded for an extended period of time…it’s entirely possible that it has remained flooded until quite recently, and that this has given enough time for the black, gloopy silt to accumulate and trap the unwary or foolhardy.

When I got home I immediately washed everything down; that decaying stink had to go! The Five 10 Impact shoes will take longer to dry out being the older model that soaked water and never let go, like those super absorbent kitchen towels. I do have Teva Links shoes that I can use in the meantime.

I guess it’s also time to change my tyres to something more suited to wet winter conditions. Rather than go for an all-out mud tyre like a Specialized Storm Control or Continental Baron, I’ll probably try a Continental Mountain King II 2.4 ProTection on the front in a tubeless configuration to replace the X-King 2.4 RaceSport, and leave the rear on the X-King 2.2 RaceSport (also in a tubeless configuration). The Mountain King II can be used in a wider variety of conditions than the Baron and I really do not want to constantly keep changing tubeless tyres for specific trail conditions. Last winter I used a pair of older Rubber Queen 2.2 UST tyres but I’d like to see how the Mountain King II stacks up.

Nov 132013

I’ve seen quite a few reports over recent years indicating that the police do not care about bike thefts. Even if the victim goes to all the trouble of tracking down the stolen bike or the thief, there just isn’t any positive reaction from the police. The post below is one such case:

Just a heads up really, I took a last minute decision to go and ride at Swinley tonight. I pulled into the car park and parked up. Got changed and then got the bike out and lent it against the back of the van. I noticed whilst i was getting changed that an red Ford Fiesta pulled into the car park and drove up to the visitor centre which i couldn’t quite see from where i was, then within a couple of minutes left the car park. I thought the car looked dodgy but I didn’t really think anything off it too much. I then knelt into the back of the van to get my shock pump and i suddenly realised that a guy in a black beanie was getting on my bike. I shouted and instantly took chase. Luckily it was in a lowish gear so it took him a while to get going and I managed to grab his arm as he shifted under massive load making the gears jump! I pulled him down on to the ground. The downside was i also ended up on the floor and he managed to get up quicker being on the opposite side of the bike and leg if off down the car park! I probably then should have given chase to get the scum bag but just decided that I was very lucky to still have my bike!

I then decided that I may be would still go for a ride but I would move the van into the Water World car park, I drove into the car park and couldn’t believe my luck but the Fiesta was in there with the guy who tried nicking the bike being in the back seat still wearing his beanie along with another 4 people. So i got the registration number and called the Police, who didn’t seem that bothered even though I mentioned they was CCTV in The Lock Out car park that would have captured all this!

I got the impression that they have tried to do this before (may be even been successful) so don’t leave your bikes unattended in the car park at night. I was half a metre at the very most when he grabbed it! If you are on your own take extra care as it makes you a very easy target because there is no one to give chase on another bike.

The car registration number was T608 PRJ – Colour Dark Red.

If you also know anyone this happened to please let them know about this post!

My own interest in this, apart from being a bike owner, is that I do use Swinley for cycle rides although not at night. Are our police forces so stretched that they are unable to investigate even if all the work has been done for them? Or do the police have a standing policy of not investigating ANY bike crime as 9 out of 10 lead nowhere?

Sep 082013

Following routine maintenance on the threadless headset and fork on my mountain bike, I placed the stem back on the fork steerer and set the torque wrench to 8 N-M (the stem instruction manual recommends between 8.5 N-m and 9 N-m). I tightened one steerer clamp bolt easily enough, but the second bolt just kinda snapped, the head flying off at high speed cutting my hand.

Brolen steer stem clamp bolt.

That’s a pretty unusual failure mode for a high-grade part; it suggests that either the bolt had a flaw or that the torque wrench was incorrectly setup/used. I’ve rechecked the settings on the torque wrench and everything looks fine.

As an interim arrangement, I’ve borrowed a bolt from another stem that I had lying around; their recommendation is 4-5 N-m and that’s as far as I’ve taken it. I’m hoping that the warranty on the stem is still valid and so I have contacted the stem manufacturer to ask if they can send some spare bolts. This being the weekend, not much is happening and I’ll have to wait till Monday, but at least I can keep riding.

Article by Kulvinder Singh Matharu – 2013

Sep 072013

After the mangling of the mech hanger, the mech cage and the chain on my mountain bike, I finally got round to installing the new parts: new Santa Cruz hanger, new Shimano XTR RD-M986 (SGS) rear mech, new Shimano XTR CN-M981 HG-X chain, and a 10-spd KMC “Missing Link” re-useable quick link. With a three-ring setup I pretty much had to go for the long cage (SGS) version of the RD-M986. At some point in the future when I need to replace major elements of the drive-train I may consider a two-ring 11-speed setup. We’ll see.

The damaged parts…

Broken bike

Close-up of the new rear mech, new chain and new quick link…

New parts

A better overview, now also showing the mech hanger…

New parts

The keen-eyed may have spotted that I opted to retain usage of the Bionicon even though the new rear mech sports a directional clutch. The two should work well together, but some may consider it overkill; I don’t disagree but I already had the c-guide on the bike and I couldn’t resist the new tech on the RD-M986 Smile

I’ve taken the bike for a few quick spins to make sure that all was well. So far so good, but I will need to test on rougher terrain. I’ve engaged the clutch and left it on the default settings for now; the shifting seems unaffected which did surprise me, so I’ll see what happens over the next few rides.

Article by Kulvinder Singh Matharu – 2013

Aug 182013

I had a bit of an inconvenience yesterday with my Santa Cruz Blur XC Carbon bike. I had just started off on my ride and somehow the rear mech (Shimano XTR RM-M980) was pulled into the spokes of my wheel; the rear mech hanger bent through 90 degrees.

Broken bike

The rear mech suffered some damage; the metal part of the cage highly warped, and the carbon part of the cage cut through and fractured. Both the cage and the rest of the rear mech all with deep scratches.

The chain (CN-M980 HG-X) was also broken with a couple of links twisted and snapped. I’m lucky that the spokes were undamaged! The mech hanger, as a sacrificial part, stopped any major damage to the carbon frame. The Formula R1 160mm dia disc brake rotor was a bit warped too but not too bad.

Although I could have repaired the rear mech, the carbon cage is quite expensive. So I’m taking this opportunity to purchase a new rear mech with a clutch mechanism to reduce chain-slap; the Shimano Shadow Plus XTR RD-M986 SGS for a 3-ring setup. I also decided to get the new Shimano CN-M981 HG-X chain as it seems to have some improvements over the CN-M980.

Anyway, whilst I’m waiting for the new parts, I dusted off my old Stumpjumper HT Comp yesterday afternoon. I’ve not ridden this steed in three years and it needed some work to get it fit again:

  • Chain and drivetrain cleaned and degreased, and then treated with Squirt Lube.
  • Tyres resealed with Stan’s NoTubes Tire sealant. I had to wait overnight to make sure that I had sealed the tyres properly. The tyres on this steed are the Continental Rubber Queens 2.2 Black Chili folding (non UST), but at some point I’ll need to put on something lighter and faster rolling such as the Continental X-King RaceSport.
  • The rear hub was loose for some reason so I had to tighten this up. Easily done.
  • The fork was also loose and moving around…very disconcerting when braking! It turns out that I needed a bigger gap above the steerer tube to the headset cap…I had a headset spacer lying around that soon fixed the problem. Such a simple thing and it took me the best part of an hour to finally realise that a bigger gap was needed. I probably forgot to put that spacer in three years ago when I changed the handlebar!
  • The gears were re-indexed.
  • The brakes (Avid Elixir R SL)…hmmm…the rear brake pad is always touching the rotor and squeals at low speed. I’ve done what I could to push the pistons back, so most likely there may be too much fluid in the brake lines; not really sure. The front brake also seems squishy. It’s probably best to re-bleed these brakes, and perhaps also clean and re-bed the braking pads. We shall see, so I’ve ordered an Avid-compatible bleed kit with DOT 5.1 brake fluid.
  • The brake levers and gear levers were rotated on the handlebar for a more ergonomic fit.

Anyway, the Stumpy is eminently ride-able and I am now happy to trust it on longer rides. I took the Stumpy out for a quick ride today to make sure everything was bedded in. It was a real blast, and it brought a smile to my face. Even when shod with the Rubber Queen 2.2 tyres, the Stumpy is a proper pocket rocket. I may ride it more; I forgot how good a bike this is!

Article by Kulvinder Singh Matharu – 2013

Jul 142013

Just over a week ago I reported that I had changed my front tyre from a 26” Continental X-King 2.2 RaceSport to a 2.4 version of the same tyre. The installation was for a tubeless setup on ZTR Crest rims using Stan’s NoTubes Tire Sealant.

This is the easiest tubeless installation that I’ve done to date. The tyre has held up well over the last week or so, although there was a significant decrease in tyre pressure on Sunday morning. My current suspicion is that this decrease in tyre pressure was due to me leaving the tyre pressure at 40 PSI after the installation and not reducing it to the 20 PSI that I would normally ride at; at these high pressures the air either escaped through the tyre sidewalls as the sealant hadn’t yet completed its job, or that I had burped the tyre somewhere. Anyway, I could find no leaks, and further rides have not shown any further problems; I was running at the intended <20 PSI this time.

My steed with a 26” Continental X-King 2.4 RaceSport front tyre, and a 26” Continental X-King 2.4 RaceSport rear tyre:

X-King RaceSport tyres on Santa Cruz bike

The X-King 2.4 RaceSport is a little bit heavier than the 2.2 version it replaces but I’m expecting that the larger volume will allow me to run lower pressures for increased grip, and that the larger width and potentially larger diameter will allow better rollability over rough terrain. Well, that’s the plan!

Article by Kulvinder Singh Matharu – 2013