Titanium Rocket

Can anyone shed some light on XTR wheels:<?: prefix = o ns = "urn:schemas-microsoft-com:office:office" /> They always seem to receive good write ups from credible magazines like What Mountain Bike and MBR. They are well priced compared with other top-end options. Yet there are very few around, in fact you hardly ever see them on bikes in real life?why? Is it because they don?t use sealed cartridge bearings, and Shimano persists with the old cup and cone bearing system? Are they a hassle to run and maintain? Perhaps a question for the Hon JB.

Sorry Chuck, I?m just not the type who is happy with my kit looking tatty?<?: prefix = o ns = "urn:schemas-microsoft-com:office:office" /> One step further on Jughead Dave's idea above is to engrave the XTR logo quite deeply into the crank arm. Then you can polish over the top without affecting the logo. Maybe this scuffing issue is a "planned obsolescence" tactic on behalf of Shimano. How else are they going to sell more XTR cranks, because they do really last a flippin' long time. And XT and SLX rings fit the XTR spider perfectly.

I am disappointed with a basic design oversight on Shimano XTR cranks: the fact that the crank arms scuff so badly where it rotates past your shoe. <?: prefix = o ns = "urn:schemas-microsoft-com:office:office" /> I bought a new XTR crank for the Epic, about R4000 on CRC before prices went zulu. After the Epic, a mere 800-odd km, both crank arms look like they?d done 80 000 km. Now every time I look at them it pisses me off intensely; I like things to look perfect. I have small feet and made a point of setting my cleats as far inwards as possible in the shoe sole, but the shoe still scrapes against the crank arm. For people with big shoes, the problem is more exaggerated. I guess there are no solutions to this scuffing. One could take them to an engineering shop and have the shiny parts re-polished. This would obviously remove the anodised XTR decal, but at least it wouldn?t look so second hand. I thought the Race Face range is less prone because the face of the arm is recessed. I hope someone from Shimano reads this: poor attention to detail guys, especially for the price. Any comments from the wizards out there?

JB, firstly let me acknowledge your huge experience and all your great contributions to this site.......1000%. But why so cynical of the ParkTool CC3 chain measuring device? Surely it is just a (crdue) gadget designed to simply give Joe Home Mechanic an practical idea of the condition of his chain. I.e.: totally buggered, or still fine, or replacement coming soon. End of story. If he wants to know the exact length accurately to two decimal places, (what the hell for guys..??), get a vernier or use your measuring system. So if the 0.75 indicator slips easily between the rollers of a (clean) chain, that's good enough for Joe Home Mechanic. He must then start the process: go buy a new chain, check his cassette, chainrings, etc. The Parktool gadget is not meant to be a precision instrument after all. But is it really so crap that we must throw them away?

MoreTrails, please PM me the same process you sent Jules. I know the Mavic freehub system well, but never too late to learn more tricks from other old sea dogs. Specifically, what solution to the problem of a worn nylon bushing, apart from buying a new freebody at R495 from a LBS? I have 2007 Mavic SL's, but I believe the bushing is the same right across their range except for a the freehub on a few downhill models. Much appreciated.

Help on a 2007 Mavic Crossmax SL freebody please: 1. Where to source the nylon bushing? 2. How does one actually get this nylon bushing out......?? 3. Finally, do the 2 pawls ever need replacing? Thanks fellas.

I have an offroad trailer with a roofrack on top of the lid. I used the usual QR system to take 3 bikes to Lesotho. Within 15 km of sh*t road, the bikes were flopping all over the place....too flimsy, not robust enough, also no good for the forks. Now I turn the bikes upside down, put pieces of 1-inch thick high denity foam under the bars and saddles, and strap them down with ratchet tie-downs, 2 per bike. Sweeeeet... also eliminates the problem of finding space for the front wheels.

Sorry Thomo......missed your plot completely here. I ride with a mob of serious MTB'ers, many kms and many Epics between us, many of whom run their lives with their S720i's. Until your note here, I didn't even know Polar had a power meter unit for the 720i......!!

This is a common problem, particulary with XTR calipers; some sites call it a "lazy piston". Caused by dust particles getting in between the piston wall and the seal. Onetime has it right, but I don't find it necessary to remove the caliper from the mounting. I just remove the pads, and squeeze/pump the brake lever SLOWLY so the pistons come out. Don't squeeze too much or they'll pop out and leak all the brake fluid. You will notice they do not emerge evenly. Push the faster one back with a soft tool (a plastic tyre lever is ideal), squeeze some more until they are evenly out by just 2 - 3 mm. Now blast all the gunk off the pistons with Clean Streak, thread a rag through the caliper and clean/buff throroughly. Finally, put a few drops of oil on the walls of the piston, just to lube the contacts with the seals. Force the pistons all the way back in with your tyre level, replace pads, job complete in 6 minutes. Not sure how much dirt riding you do, but I perform this process about once a month to prevent recurrence.

Thomo, presume you mean a Polar S720i, definitely not a 'power meter'. If it is dropping the HR signal, here are some ideas: 1. Make sure your batteries are good on both the watch and the chest strap. If in doubt, get new ones. 2. Make sure you are washing your chest strap; I wash mine in the shower after every session. Don't use fancy soap containing oils, this affects the contacts and signal transmission. 3. If you put cream on your body in winter or whenever, this really screws up the system. It affects pick up of your heart rate by the chest strap device. Took me a while to work this out; stopped using cream and my Polar worked fine. 4. Wet the chest strap contacts thoroughly before use, and your chest. Rub your chest area to clean off sweat residues or cream; the system needs clean skin. 5. The chest straps don't last forever. The new model is much better, but the old model only lasted me +/- 18 months at a use rate of 7 - 10 hrs per week. I have had my 720i for >4 years; sure it's had its moments, but when I think of what it's been subjected to, I reckon Polar are winners. Their local service in Midrand is absolutely world class too. If you need more advice, speak to Travis or Gideon at 011 8051028

Don't be fooled: there is no such thing as a set of MTB wheels totally free of bearing or freebody problems. No matter which brand or how much you pay, they all need maintenance, end of story. The older Mavic SL's pre-2007 had a reputation of hubs failing with riders >75 kg. I have seen threads on the 'Net claiming this has been addressed on the new SLR's. All Mavic freebodies need frequent cleaning and re-lubing; a 10 minute job a kid can even do. Bearing replacement, front and back, is also a piece of piss. One comment about the new SLR's: the black paint starts looking a bit tatty; easy enough to touch up with Hammerite gloss. I have done 3 x Cape Epics on a set of 2005 Mavic SL's.....still 100% mechanically sound, never broken a spoke, still the original freebody. But I maintain them properly... R8300 is a good price for SLR's, no cheaper on ChainReaction. I say go for them....

Can confirm with Dirtbreath; you need a full fluid replacement about every 18 months. Blobs of water can accumulate in the mineral oil reservoir, plus contaminants, tiny specs of black gunk. God knows how water and contamniants get in, given the system is totally air-sealed...perhaps it finds its way in around the piston seals? I have found that bleeding from the caliper upwards flushes water / contaminants up into the reservoir, where you can suck them it with a syringe.

My only addition to either of the above methods, is to tap both the reservoir and caliper with a screwdriver handle to release any obstinate bubbles that may refuse to flow out of their own accord. XTR can be particularly tricky, and if even one bubble is left behind in the system, braking will be spongy.

Sharkysa, you are on the money. Neither th A2Z or KCNC adaptors align the XTR 160 mm rotor properly, you must increase to a 180 mm rotor. I have decided to go the other way because I want to eliminate the chance of a misfit forever: I have bought a XT post mount calliper. Only R200 more than an XTR 180 mm rotor you are talking about. Post calliper for Post fork - no more incompatibility, end of story, sleep tight.

Have bought many R1000's worth of stuff from CRC over the years. Do not forget to add on their freight charges, and our 14% VAT. Then re-check their prices against your LBS. Generally, they will still be cheaper, but weigh up the online effort versus the instant gratification of the "see/touch/buy" process. Takes about 6 working days to get here. Up until about 2 years ago, the price of Shimano kit on CRC was far, far cheaper than in SA LBS's. The gap has closed considerably as of recent, not sure why. Also, they seem to be out of stock of high-end Shimano kit like XTR much of the time these days........but then so too is the whole of SA.

Sweet stuff Gordon: Is the KCNC SC Bone handlebar that you have used a "flat" bar, or is it a "low rise" bar.....?

My point is not that the whole 29" idea in a crap concept, but I seriously doubt the global MTB market will swing from 26" to 29" in the near future. It certainly holds merit for big fellows like TitusTi above, no argument here. But one unfortunate by-product of today's marketing is that it often distorts the real facts, and makes people believe in anything. Similarly, there are consumers who need convincing that their purchases are absolutley the best, in order to avoid buyer's remorse. The tiny technical benefits in a 29" bike are nowhere near as grand as marketing makes out. Sift out the real stuff from 75% of what's written in bike mags and spoken by bike fundi's, find what works for you, and save yourself a sack-full of cash.

Some of the claims made by 29" lobbysists provoke serious thought: 1. They claim the larger wheels "roll better through / over obstacles". 2. They also claim that bigger 29" wheels re bigger "and therefore make better contact with the ground, and so deliver better traction". If one does some basic trig calculations, these claims are not really substantive. The extra height that 29" diameter wheel offers over a 26" wheel when going over a 150 mm obstacle amounts to a few millimetres...rather improve your handling skills. The extra tyre surface of a 29" wheel versus a 26" is also negligible...rather get your tyres and tyre pressure right. Most of the claims around 29" wheels are technically very thin, aimed at a market hungry to throw money at anything new. A bit like the perceived advantages of Lefty forks over conventional forks which hold 98% of the market...come on.

Morewoodkid: count me in, please SMS me on 082 9027915. Can probably rustle up another 2 guys. What is your proposed format? How about we bring our own fork (FOX of course) and do a demo / tutor session. Nothing like doing the real thing; listening / watching is only 50% as effective.

Thanks for the contributions. Summary: 1. I did mean 160 mm rotor...nit. 2. Have been told by our local Shimano agent that Shimano don't make a 160 mm adaptor for this. Believe I have a generic one. 3. Appears the only way is to change to a 180 mm rotor, and shift the caliper outwards by adding washers / spacers, until it matches the diamter of the rotor. 4. Am a very fussy fellow...possibly rather just buy the correct Post-mount caliper....and do the job properly.

I did the race in 2006 and 2007, and recorded the following ascents on my Polar: Day1: 1250 m Day 2: 840 m I think it varies each year, but it won't be by much.

Difficult to keep this one simple, but here goes: 1. My old Fox fork had the ISIS mount, so I have an ISIS mount XTR caliper which fitted and worked perfectly. 2. Recently acquired a new Fox fork, but with a Post mount for the brake caliper (apparently the more popular system these days). The LBS gave me the appropriate XTR adaptor for a 120 mm rotor; with a few shims, I got it all fitted fine. 3. Now after 6 months of use, and I see that the pads are only making +/- 80% contact with the rotor; the outer 20% of the pad is totally un-touched. 4. The adaptor is obviously setting the caliper too far away to make full contact with the rotor. I have checked: it is the right adaptor for a 120 mm rotor. Also, there are no superfluous washers setting it too far out. I can actually feel that my front brake power is poor. Does anyone have any ideas how I can claim my un-used 20% of potential stopping power: 1. I could file down the post mounts on the fork (obviously highly dangerous). 2. My LBS says "...just buy a new XTR post-mount caliper..." (easy for them to say). 3. Or I could go to an engineering shop and get them to make a precision adaptor (will be costly). Has anyone experienced this problem? JB - any ideas?

Just remember that lubes are like women: one man's beauty is another man's beast. There are so many subjective variables in this debate, there can be no such thing as a perfect lube (or woman). Find what lube works for you, apply and concentrate on what matters. Insert a Quick Link into the chain, remove and clean it in petrol every weekend if you want it to last.

Thanks fellows - I don't think I removed all the screws. 1. Any comments on the liberal use of Clean Streak inside the working parts of these Dual Control Shifters, given they are so extremely complicated? 2. And then just lube with WD40 or simular once the Clean Streak has dried off?

This year's Epic was a seriously dusty affair, and my XTR Dual Control shifters became really "crunchy". My bike shop recommended blasting Clean Streak into them via various orifices; this certainly worked as heaps of dust and crap poured out of them. But I's like to open the covers to do the job properly, apply lube, etc. Can anyone help with removing the covers of the new XTR Dual Control levers, and an ABC on servicing them correctly? I have trawled the Internet, but cannot find any reference or service manual on these shifters. Removing the tiny Philips screws doesn't seem to loosen anything....the plastic covers just stay where they are. (LHS different from RHS).