mountain » Matharu's Rants and Raves

Mud protection for the RockShox Reverb seatpost

Apr 142013

I have a RockShox Reverb seatpost on my mountain bike and it is a great piece of technology for remotely adjusting the height of the saddle.

However, some people have expressed concern, as the seatpost is exposed to the elements, that there may be some risk of contamination of the inner mechanism of the Reverb. I think that the seals on the Reverb are good enough to keep the unit contamination-free but there is always that nagging doubt in the back of the mind.

When rides are going to be muddy, people normally attach a full rear mudguard to protect themselves and this would also keep the Reverb clear of mud. But there are some days where a ride just does not warrant a full rear mudguard, such as on hot sunny days, but there may still be a chance of coming across mud.

I decided to get one of those thin mini-mudguards such as the Ass Savers “SmartAss” or Mucky Nutz “Butt Fender” that attach to the saddle rails, with the intent to see if I could modify it to act as a permanent mudguard for the Reverb. So I bought a “SmartAss” http://ass-savers.com/ and re-shaped it with scissors such that I could still attached it to the saddle rails but also bend it through nearly 80 degrees to cover the Reverb. I also use a street-legal rear reflector (with red LED) that mounts on the saddle rails and this was essential to keep the SmartAss bent at that approximately 80 degree angle. I’m sure that there are other solutions to keeping that SmartAss held at that angle. The angle is such that it does not get in the way of attaching a full rear mudguard. The SmartAss is also just clear of the rear tyre when the Reverb is fully down and is still usable with a full rear mudguard and the Reverb all the way down; I still need to test this more fully on the trails.

Today was a nice spring day (finally!) and I wasn’t about to attach a rear mudguard. So I went riding and soon came across a number of muddy holes. No problem. See photo below straight after the ride (note that the white skull is a reflective sticker that I attached on the SmartAss).

Mudguard for RockShox seatpost

As you can see, the modified SmartAss has done a very decent job of keeping the Reverb mud-free. I’m still not convinced at all that the Reverb needs this additional level of protection but the modification is cheap and gives that peace of mind. Result!

I hope to post a long-term review later this year.

Article by Kulvinder Singh Matharu – 2013

Cycling in the snow

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Jan 242013

Had snow over the weekend and so took the opportunity to do some off-road cycling with my mountain bike.

Bike in the snow

Article by Kulvinder Singh Matharu – 2013

A shorter stem for my mountain bike

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Jul 102012

So there I sat, pondering the usefulness of the long stem on my mountain bike. The stem is an Easton Haven EA90. Sure, 90mm. A shorter stem is useful for more downhill stuff and also helps with jumps by moving the centre of gravity rearward. Climbing may become a bit more difficult but I should be able to compensate by leaning forward a little bit more.

Doing some quick calculations, I surmised that reducing the stem from 90mm to 70mm with a 5 degree rise would be good for my intended riding style. I soon found the ideal stem; a 70mm RaceFace Turbine Stem with a 6 degree rise/fall (reversible). Looks gorgeous, seems ideal. So I ordered it!

I soon had the EA90 stem replaced with the RaceFace Turbine stem. Nice!

Except that the Raceface 70mm stem seemed much shorter than my EA90 stem, much shorter than a difference of 20mm would suggest when going from 90mm to 70mm. Belatedly, I measured the EA90 stem…it was 110mm, not 90mm! Oh dear. A 40mm reduction in stem length is rather drastic; I was not sure how the bike was now going to perform.

Taking the bike for a quick spin I noticed the (expected) tendency for the front end to lift but the effect was much more than I expected. I need to ride the bike in proper off-road conditions to assess how it now performs in climbing, downhill, level trails, jumping over obstacles, etc.

It’s very wet and slippery in the UK at the moment and I don’t yet trust the bike out on the wet trails. I guess I’ll have to gingerly push the bike to find its envelope. I do have the option of reversing the stem to give a 6 degree drop or remove some spacers which should help with loading the front end of the bike, but I’m not sure what that will do to my posture! The last resort is to purchase a 90mm stem; I’d go for a Raceface Turbine model again.

I should have measured the EA90 stem in the first place rather than just assuming. What was I thinking!

Article by Kulvinder Singh Matharu – 2012

The noise, stop the noise!

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Jul 092012

I made a huge leap in reducing the noise pollution from my mountain bike a few months ago; I replaced my Hope Pro 2 rear hub with an XTR hub.

Whilst riding, and also in my GoPro HD Hero 2 recordings, I was hearing a lot of clickety-clackety noises when going over very rough ground at speed; I put this down to chain slap. So I added a Bionicon C-Guide V.02 chainguide to my triple-ring setup in the hopes of reducing chain slap. The Bionicon C-Guide is a modern take on the DCD (Dave’s Chain Device) that was so popular in the 1990s.

Before fitting the Bionicon C-Guide I feared that the chain trundling through the plastic guide might cause some additional noise; this fear was unfounded as the device, so far, is silky smooth (the Squirt lube also seems to help). This, combined with the rear hub change, resulted in a very quiet bike when out riding.

However, there were still some mechanical noises in my GoPro camera recordings. I soon pinpointed this to the camera itself and eliminated that noise by opening it up and putting in some foam padding. But mechanical noise in the recording still hadn’t been completely eliminated. I traced these remaining noises to two items that were close to the GoPro camera: the Satmap Active 10 GPS device and the Knog NERD 12 bicycle computer.

On the Satmap Active 10, it was just the rechargeable battery bouncing around in the compartment. I soon resolved that by putting some foam padding in there.

On the Knog NERD 12, the noise appeared to be coming from within the device when I shook it. I took drastic action by cutting open the NERD with a junior hacksaw; this was done by cutting around the sides of the display. I soon had the unit opened. There were a bunch of items in there that could cause noise if shaken so I put some blu-tack padding in strategic locations within the device. I reassembled everything but have, temporarily, used some blu-tack for moisture protection and cello tape (or scotch tape in the USA) to hold the unit together; I’ll be using some epoxy resin to provide a more permanent assembly of the NERD at some point. Anyway, noise gone!

I do have a traditional mechanical bicycle bell that makes a little bit of noise when shaken and I have found no way of eliminating that noise. I could replace the bell but it was a birthday present from my friend’s 4-year old son so I’m unlikely to replace it any time soon! The noise is only slight and not really noticeable in the GoPro recordings so I can live with that.

The only other potential source of noise is that caused by the brake cables and gear cables hitting the GoPro camera housing whilst riding over bumps. Now, that does need some fixing. I’m looking at better placement of the GoPro and somehow fastening the cables so that they don’t hit the camera housing. I’ve not yet found a solution but have some ideas that I need to try out. It’s going to be trial and error I’m afraid.

Funnily enough, my rear disc brakes have just started to squeal a little. Oh dear, when will the noise stop!

Article by Kulvinder Singh Matharu – 2012

GoPro HD HERO2 internal rattle noise fixed!

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Jun 032012

I’d noticed on my GoPro HD HERO2 camera mounted on my mountain bike that there were some clicking noises on the video recordings. I normally mount the camera on the handlebars and, at first, I attributed the noise to my bike; perhaps a cable hitting the camera housing.

But then I came across a passing comment in a forum that complained about the internal noises from GoPro cameras. Intrigued, I searched online. There were some comments regarding the helmet-mount (and similar) and the need to insert the rubber “thingy to stop the camera rattling around in the mount; I already knew about this and it was not relevant. Soon I came across a number of posts and articles about a rattling being generated from within the camera itself. So I picked up my camera, in its housing, and shook it near my ear. Sure enough, I could hear the rattling! It was also very evident on subsequent recordings I made just shaking the camera by hand. Oh dear. So not my bike after all.

However, I found a DIY fix which required opening up the camera and putting some small foam under the shutter button so that the “micro-switch” doesn’t rattle around. I debated whether to just return the HD HERO2 under warranty or attempt the DIY. I went for the DIY. Here’s the fix:

GoPro 2 Internal Rattle fix!
http://www.mazdaspeedforums.org/forum/f429/gopro-2-internal-rattle-fix-101001/

It worked. Dead easy. No more rattling! Very pleased now. The internal rattling issue is not uncommon and I am not sure what GoPro are doing to resolve the issue for existing and future cameras.

I added an additional mod to the above but only in my paranoia about noise and not really based any tests. The power/mode button (not its micro-switch) will rattle when the camera is not in its housing so I added a very small piece of self-adhesive foam (and I mean small) to the “power/mode” switch inside the camera housing; this was to stop any chance of the mode switch rattling around:

This particular mod is probably not required but I had some foam to hand and it only took a few seconds to add. It’s important, though, that the foam not be too thick otherwise it will activate the power/mode switch when closing the cameras housing. Of course this doesn’t stop the power/mode button from rattling when the camera is not in its housing but some tape over the button may help to fix that.

Alternatively, I could have gone the whole hog and put some padding inside the camera for the power/mode switch like this chap:

http://www.youtube.com/watch?v=2SeLBpLHN-Q

Anyway, silence!

Article by Kulvinder Singh Matharu – 2012

Quiet rear hub to replace loud Hope Pro 2 rear hub, or “The racket of the ratchet!”

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Apr 222012

When I ordered my custom-build Santa Cruz mountain bike (MTB) in Q4 of 2010 I specified Hope Pro 2 hubs laced to Stan’s NoTubes ZTR Crest rims. I knew when I ordered these hubs that the rear hub would have a loud (ratcheting) clicking noise when freewheeling. But I think I was rather surprised when I got to hear the thing in person…talk about loud!

I’ve tried to live with the noise but it got that I always worried about causing disturbance to wildlife (such a deer) and to other people such as fellow cyclists and those engaged in quiet activities. Sure, there are some cyclists who love that loud clicking noise, and it’s great in letting people know that I’m coming up behind them (I’ve got a bell that can do that too!), but enough is enough; that noise had to go.

I looked at various ways to quieten the rear hub such as filling the thing full of suitable grease to lessen the ratcheting noise but these are very much a hit-and-miss affair and only temporary in nature; it was time to look at a new rear hub. After much research, looking at high-end hubs such as the DT Swiss “240s” and the lower-priced True Precision “Stealth” models, I opted for the Shimano “XTR M985” rear hub.

I ordered the Shimano XTR M985 rear hub plus a quality CenterLock to 6-bolt adapter (Shimano SM-RTAD10) in order to continue using my existing Formula R1 disc brake rotor (didn’t want to buy a new rotor but may change that in the future). My local bike shop (LBS) changed out the hub on my wheel for a small fee but did a horrible job of taping the rim (but that’s another story). Anyway, after I re-taped the rim, installed brake rotor, cassette and tyre, the bike is all up and running: it was a joy to cycle again without causing noise pollution! Peace and tranquillity at last.

The current highlight specs for the bike:

Frame: Blur XC Carbon (2011), medium size, gloss red
Shock: Fox Float RP23 with ProPedal and Boost Valve
Fork: Fox 32 F120 FIT RLC 120mm Black (15mm Through Axle)
Shifters: Shimano M980 (XTR)
Front derailleur: Shimano M981-D (XTR)
Rear derailleur: Shimano M980 SGS (XTR)
Chainset: Shimano M980 24/32/42 (XTR) 10-speed
Bottom bracket: Included with crankset
Chain: HG-X (XTR M980)
Cassette: Shimano M980, 11-34 (XTR)
Brakes: Formula R1 with 160mm rotors (rear with Shimano SM-RTAD10 adapter)
Bars: Syncros FL carbon 31.8mm
Stem: Easton EA 90 31.8mm
Grips: ODI Ruffian Lock-On (130mm)
Headsets: Chris King 1″ 1/8
Seatpost: RockShox Reverb 380mm (30.9mm dia)
Saddle: WTB Silverado SLT
Front wheel: ZTR Crest rim (with single-layer Stan’s 21mm yellow tape) laced to Hope Pro 2 hub
Rear wheel: ZTR Crest rim (with single-layer Stan’s 21mm yellow tape) laced to Shimano XTR M985 hub
Tyres: X-King 2.2 Race Sport (RS) folding Black Chili
Tubes: not applicable: tubeless with 90ml of Stan’s Tire Sealant per tyre
Valves: Notubes Universal 35mm valve stems
Pedals: Point One Podium
Gear cables: Gore Ride-On sealed low friction
Chainguard: Bionicon C-Guide V.02
Scratch shield: SportsCover Bikeshield (fullpack)

Other bits and pieces as appropriate for weather conditions and riding requirements:

CrudCatcher
SKS Grand M.O.M. rear mudguard
Knog N.E.R.D. 12 computer
SatMap Active 10 GPS
CatEye front light
BioLogic Tail Light- saddle rail-mounted rear reflector (with LED)
Skully rear light on seat-post clamp
GoPro HD Hero2

I have a pair of Continental Rubber Queen 2.2 UST tyres but have not used them much as I haven’t ridden in conditions where these are required (yet!).

Article by Kulvinder Singh Matharu – 2012

Continental X-King Race Sport (RS) – tubeless or not?

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Nov 252011

I installed the X-King 2.2 Race Sport tyres on my mountain bike a few months ago, having been attracted to their low weight and the opportunity to run them tubeless on my UST rims. A number of people have had problems going down this tubeless route as these tyres have highly porous sidewalls plus the odd pin-holes. I was expecting the high porosity and was sure that appropriate sealant would resolve, but the pin-holes were an unexpected surprise. However, it was easy enough for the pin-holes and porous sidewalls to seal so I was very happy with my purchase.

It is important to emphasise that I knew that running tubeless with these tyres would require some preparation in order to be successful. A lot of people have reported problems and I would attribute a lot of their problems to inadequate preparation on their part. I believe that I described these tyres as “tubeless ready” in a blog entry from May 2011. I’m not sure where I heard the term “tubeless ready” but I described the term as “…the beading will fit UST rims but that the tyre sidewalls are likely to be quite porous and let air out”. As far as I am concerned, these tyres are tubeless-ready.

I note that the Continental website (at least today 25 Nov 2011) does not describe these tyres as tubeless-ready or even tubeless. But the website does say that the tyre can “be used on tubeless rims” so I guess I interpreted that as “tubeless ready”.

Bikers aren’t generally stupid so I believe that the inadequate preparations are as a result of some people being led into believing that these tyres are fully “tubeless” as opposed to being “tubeless-ready”. So a huge disappointment to them when these tyre do not meet their sealing expectations.

Article by Kulvinder Singh Matharu – 2011

Test of Hero HD camera mounted on mountain bike

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Nov 182011

I’ve had the GoPro Hero HD for several months but never got around to using it in anger on my bike. So last weekend, I had a chance.

This video is a quick test of the Hero HD camera mounted on the handlebars of my mountain bike. This was in some wooded areas near where I live. At some point I’ll test the helmet-mount and the chest-mount.

Test of Hero HD camera mounted on mountain bike (HD res)
http://www.youtube.com/watch?v=hYr95OxN8_0

This version has HD resolutions which are not available in an earlier upload of the same footage.

Article by Kulvinder Singh Matharu – 2011

Stumpjumper Comp 2009

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Apr 052009

Recently bought the 2009 model of the Specialized “Stumpjumper Comp” hardtail mountain bike to replace my older and heavier full-suspension mountain bike. I don’t really do any jumping but cross-country and marathon activities are the norm. And the Stumpjumper Comp has been perfect for that…it’s been a lot of fun on the trails and I’ve taken this lean & mean machine over rough terrain at speed. Sure, as a hardtail, you painfully feel all the bumps but the lightness and speed make up for it. I may look at getting an upgrade on the saddle or seat post as spending 6 hours on the bike may need some more comfort but I’m having a lot of fun with the bike at the moment. Highly recommended.