Custom build advice on WIP - 2500 £ budget

Tactica

Greetings BikeRadar users. I had to join here after about a week of searching the internet and magazines for many answers and finding only few.

I'm a first timer at bike building, and I think that I have learned a lot over the past weeks, but still have some issues I'm looking clarification and help with.

I want to build a fast and light (<22lbs) urban mtb/trail hardtail bike with great parts with a budget of 2500£. Building the bike is a key part of my hobby and I'm not looking advice on readymade bikes.

I currently have a Mavic 2012 Crosstrail UST wheelset with Kenda Smallblock Eight 1.9 26" UST tyres and Avid Elixir 9 Carbon brakes with 160 mm HS1 rotors ready, so I don't need advice with wheels and brakes.

I was looking at On One 456 Carbon frame to build my bike around, since it has recieved pretty good reviews and is affordable and light. I must admit that selecting a suspension fork and headset have been difficult for me, mainly because all of those different steerer choices (tapered or straight?) and different frames and headset configurations. I'm also under the impression that On One headsets are not that great. On the other hand, it would be so much easier to order the frame and pre assembled headset from On One.

The  On One 456 Carbon takes a suspension fork with 150 mm travel, I was looking at the Rock Shock Revelation 150 Dual Air. I'm willing to take suggestions on the fork aswell, but that looks good review and budget wise. This set even comes with some extra bits and would make my headset choosing troubles go away. Thoughts?
http://www.on-one.co.uk/i/q/ZXOOCAR456B ... ork_bundle

With those parts I would have a great rolling frame to continue my build.

Sram XX/XO or Shimano XTR shifters and derailleurs?

I'm split between these two sets. I like SRAM looks better and they could be MatchMade with my Avid brake levers possibly saving few grams of weight, but would using SRAM controls mean that I need to choose a whole new drivetrain from them aswell?

I'm pretty confident that I would go with XT crankset with XT casette and XTR shifters and Derailleurs from Shimano(if they can work together well), but I would like to get some insight from you guys from a similar quality SRAM set.

My biggest questions are:

Which kind of derailleurs to choose? I noticed that there are several versions of the same derailleurs with low, straight, medium or high mounting options and different pulls. How can I tell which one to choose?

Is it best to use same maker shifter-derailleur combos with cranks bottom rings and rear casettes or can or should I mix and match?

Bottom bracket and headset selection. These two are the most difficult parts for me to grasp. How much I should  invest in these parts to be on par with the rest of the bike? 

I'm inclined to go with On One 456 Carbon frame and I could order the headset pre installed from them, but they do not carry a wide selection of brands. I would appriciate if someone who knows their headsets could take a look and suggest a proper and reliable headset from them.

warpcow

Rear shifters and derailleurs must be of the same make. Front can be mixed. Chainset and casette can be mixed too, so pick whatever suits you.

You realise that the headset that comes with the package you linked to is a 'slackset'? That means it changes the geometry by 1 or 2 degrees. You may find that more fun, but maybe not. Any Hope, Cane Creek, FSA, etc headset that fits would be fine and reliable. In my opinion, as long as they fit, and work, headsets are uninteresting parts. Unless you're an extreme weight-weenie or brand-whore then there's not much difference between any of them once you start paying about £30. The same goes for BBs (except the price would be around £20). XTR BBs are cheap, light and reliable, but depending what chainset you choose, you might need a different one. Chris King and Hope just aren't worth the money for anything but the name.

Parktools website has a lot of good information about compatability and installation of parts.

supersonic

Hi, welcome to bike radar!

I take it you are looking at 10 speed groupsets: in which case the rear shifter and derailer MUST be from the same brand. The cassette has to be 10 speed of course, but can be from any brand, as can the chainset and front derailer (9 speed ones work here!). Go for a 10 pseed chain - again any brand will work.

The front derailer type you need depends on the frame - email the retailer.

Bottom brackets and headset type also depend on the frame. Many chainsets come with the bottom braacket, so make sure is compatible.

In the case of the 456, it uses a standard 73mm threaded bottom bracket shell. I would take the 456 bundle and use the headset supplied - they work fine, just look after it.

Tactica

Here we go. Limited Edition On One 456 Carbon and RockShox Revelation RLT Dual Air 150mm Suspension Fork ordered.
Rolling Chassis is complete.

All I need now is the drive train, shiters and derailleurs...too many options.

bluechair84

Shimano SLX is a relaible as everything else, XT weighs only slightly less. SLX is the Ford Focus of the drivetain world, it's pretty much everything 98% of people need 98% of the time (facts and figures made up in my head). Shadow is best as it hangs under the cassette, not outside the frame as older models did. They have a clutch version you don't need. If you got a complete drivetrain it will all be compatible.

Tactica

bluechair84's comment couldn't be more on the spot. XTR cranks and cassettes just seem way too expensive for their benefits for a non competive rider like myself. I have read so many posts about XTR mech being able to last a life time, so I think I should invest to them straight ahead, since the difference in price is not that massive.

So far I'm looking at this 3 x 10 Shimano XT/XTR Dyna Sys set:
Cassette: Shimano XT M771 10-Speed
Chainset: Shimano XT FC-M780 Black (comes with 76 mm bottom bracket)
Chain: Shimano XTR M980 HG-X (might be too much of an overkill here though)
Rear Derailleur: Shimano XTR Rear Mech 10sp M985 (this is with clutch, of which function I looked at and thought to be useful)
Front Derailleur: Shimano XTR Front Mech Conventional 10sp M981
Shifters: Shimano XTR Shifters 10sp M980

I got in touch with On One and they will fit my 456 carbon frame with their On-One Smoothie Mixer headset and crown ring to the fork. They also told me that the frame supports any top or dual pull front mech with a 34.9mm clamping diameter. So here we are. The yet confirmed specs. I was looking at the Front mech variations from Shimano and I'm still unsure which one I should buy. Some of the front mech seem to hang quite far down from the clamp, some are really compact with clamp under them or somewhere in the middle of these.

styxd

Dont know whether anyones mentioned it yet but building a hardtail up with 150mm forks that weighs less than 22lbs is surely pointless. It'll break if you are subjecting it to the kind of riding that warrants 150mm forks.

supersonic

Depends what parts - and long travel doesn't automatically mean a bike that needs to be doing huge drops and jumps. Plwnty run light, long travel rigs for the extra front end traction rather than all out big hit quashing.

The frame, forks and wheels are all relatively light, but tough, as is the XT/XTR kit. Add some bars like carbon Havens, a stemm like a Gusset Staff, Koryak seatpost and you keep the theme. Not jump bike tough, but still a very capable bike.

Tactica

styxd has a point. but I only wish to build a bike once (unless bike fever hits me again) and wan't to spend money on future proof, high quality and durability parts aswell. Relatively cheap On-One 456 carbon seems like a decent frame to build new, perhaps over the top parts on, until I seek a full suss frame and transfer my parts to that.

styxd

I know what you're saying supersonic, I just thought I'd raise a point.

I only think an LT hardtail is useful if you're riding proper downhill tracks, they are a bit ropey for anything else.

I think my Dialled probably weighed close to 35lbs when I built it up for the downhilling in the Alps! It was bloody heavy but solid, I would never have used it for anything other than riding downhill tracks though (for which it was suprisingly good)

Tactica

I feel like a newbie, but again, I would really value your expertise on the mechs - last thing I'm still trying to get right.

Front mech: Which type of XTR I need? There seems to be many to choose from even with 34.9 mm clamps. Others are more compact while other hand below the clamp.
Rear mech: Does Shadow-arm do anything more than tuck the chain closer to frame to protect it? Has Shimano removed the wording from their newest line, or does myt previously mentioned 10sp M985 have it, or is the clutch doing the thing?
XTR Shifter and derailleurs with XT Chainset and cassette: Compatible? Which chain?

I thank you, and promise to supply pics of the build.

supersonic

You need a top pull or dual pull front derailer, 34.9: both high and low (top swing/bottom swing) clamps will fit according to OnOne. I'd go XT.

Shadow is lower profile and itself is less likely to get hit. The clutch adds tension to the cage to prevent chain slap. I have this mech, it is great! The M985 is Shadow Plus, the plus referring to the clutch.

All compatible if the same speed. 10 speed SRAM chains are good.

Tactica

Thank you supersonic. Are there any real reasons to go top swing or down swing other than looks? Would you go with XT because XT chainset compatibility or just purely because XTR wouldn't really make a noticable difference?

Rear Mech issues: solved

Why SRAM? I was under the impression that Shimano has made some great improvements on chain technology with getting rid of mud etc. Not questioning your advice, I just would like to understand the reasoning.

supersonic

High clamps allow for a more solid and stiffer construction, the lower can be lighter (and often used on bikes were space is a premium such as full sussers). The XTR is no better really.

I find SRAM chains to be a bit more reliable overall.

Tactica

Damnation! I thought I was through with all the details but two new concerns have risen!
I'm now trying to learn about gear tooth count and crank length.

XT FC-M780 Chainset comes with fixed 24 x 32 x 42 teeth, but I need to select crank length...170 mm is the standard I guess? How do longer or shorter cranks affect theoretical speed at the same cadence?

Rear cassettes have three different options. The biggest chainring is either 32, 34 or 36 teeth, so the bigger the largest ring, the smaller the gear is, right? Which of these is the standard? I have rarely used the smallest possible gear on 3x9 builds, I doubt I need to go "extra" small now.

cooldad

'Standard' crank length is probably 175mm, but TBH I doubt you could tell the difference without looking.

njee20

I'd get the 11-36 cassette, may as well go 9 speed otherwise, and consider a double crank if you don't think you want the ultra-low gears.

styxd

I'd go 1x10 gearing with a 32 or 34 tooth chainring and an 11/36 cassette. Would save a bit of weight which would make sub 22lbs more achievable.

Tactica

Thanks for your input. sub 22 lbs seems to be unachievable within my budget and specs. One can dream though. From the calculations I've made, I predict that we're talking about a 24 lbs total weight at the moment even with pretty light weight, yet reliable components. I'm not complaining since this build seems to be a good compromise between money spent, weight, durability and performance. Shaving the last 2 pounds would mean investing many many hundreds more for very minor upgrades from the looks of things.

2x10 or even 1x10 could be sufficient, I just have never ridden one so I can't say. Must test these configurations before buying the crankset.

Tactica

About steerer tubes: What are the most common headset tube sizes? When cutting the forks steerer tube to length, I would like to leave some extra to it so it could be fitted to another frame later on, rather than cutting it perfectly to size. Stem clamp heights seem to be pretty much the same size, so few spacers either on top of the stem (if even possible) or under it, should not make a difference?

njee20

Steerers have all been 1 1/8" for about 15 years, then 1.5" came along on longer travel forks, now we have 1 1/8"-1.5" tapered.

No issue having spacers above and or below the stem, makes sense for the very reason you mention.

Your wheels are heavy, you could save a massive chunk of weight there if you wanted to get closer to 22lbs.

Tactica

And here I was thinking that 1685 grams for a pair of wheels including hubs, QR's and spokes was light! I'm going to run tubeless so that saves some weight compared to inner-tubed tires...

Imperial system measurements don't come natively to me since I'm used to a metric system, but I was referring to the steerer tube length, not the diameter of the tube. So my question still remains: what are he most common lengths of head tubes on frames? Should I calculate let say for a 100 mm clearance when cutting the steerer to length to future proof?

Northwind

You're not going to hit 22lbs, not unless you get one of those special internet lbs that some people use My C456 is using comparable or lighter kit and tips the scales at just under 25lbs, IIRC, without the Gravity Dropper. Which is a good weight for a 5 inch hardtail-

Trouble is you're a little split, you're speccing a troublemaker bike rather than a weightweenie bike- and if you want the strength of components to cash the cheques that the frame and fork can write, you either need to throw mad money at it or take a weight hit. TBH I think you're doing the right thing though, a balanced slightly heavier build makes a lot more sense than a weird hard-hitting frame, XC-race kit mixup.

Your wheels are a sensible weight- certainly not "heavy" for a 5 inch bike! The Smallblocks, mmm. I love the 2.1 on the rear, but I wouldn't dream of putting a 1.9 on the front of my 456!

C456 has a short steerer and the slackset is low stack, so you'd be smart to allow some room to maneuvre there, good call. I'd leave a lot of steerer on it, maybe as much as 50mm of spacers on it initially, til you find out where you want the bars. Then maybe cut it down a little.

supersonic

I think 22lbs is doable, but would need a little more budget as you say. But not much! Basically all that seperates the bike from an XC bike is longer forks, larger tyres and tougher wheels. The rest of the parts pot is much the same, and even sttonger bars and stem are pretty light now.

Actually I reckon I could spec up a 22lbs 456 with some decent light but tough parts for 2.5k!

Tactica

22lbs is certainly not a goal set in stone. It was a goal I tried to achieve at first, but reality has stepped in. I'm not going to worry too much about that. I'd rather have a good solid and reliable build that is in balance all round.

Thank you for the information on the headtube. I was going to adjust stem and bar height before cutting of course, but understanding that C456 actually has a shorter than normal headtube is valuable knowledge which I can use when choosing and installing spacers.

Tactica

Just a quick question about front mechs. I'm getting ready to order the parts and I noticed that Shimano XTR front mech comes in very different specs. At first I had Shimano XTR Front Mech Conventional 10sp M986 http://www.chainreactioncycles.com/Mode ... elID=54889 in my basket, but then I noticed it was labeled "dual". Is this for 2 x 10 drivetrains and what I actually should buy for 3 x 10 drivetrain is Shimano XTR Front Mech Conventional 10sp M981 http://www.chainreactioncycles.com/Mode ... elID=54890 which is labeled triple?

supersonic

Dual are for 36/22 chainsets. You need a triple.

Tactica

I want to thank everyone who were kind enough to help me out on my novice problems and questions. I have now ordered all parts except pedals and can not wait to get to building and most of all riding.

Here is what I ended up with:

Frame: On-One 456 Carbon Limited Edition matte black w/ black decals 18" - 1500 grams 370 €
Headset: On-One Smoothie Mixer - 209 grams 49 €
Wheels: Mavic 2012 Crosstrail Disc 6-Bolt Wheels - 760 grams front, 925 grams rear, 453 € for the pair
Tires: Kenda Small Block Eight UST Tyre 1.9 - 694 grams, 38 € per tyre
Front suspension: RockShox Revelation RLT Dual Air 150mm Suspension Fork - 1620 grams, 495 €
Brakes: Avid Elixir 9 Carbon Disc Brake - Grey 2012 - 385 grams per side, 141 € per side
Stem: On-One Ultralight CNC Stem 70 mm - 110 grams, 25 €
Spacers: Hope Space Doctor Spacers Pack - no idea about weight, 10 €
Handlebar: Easton Haven Alu Bar - MTB 2011 710 mm, 270 grams, 80 €
Grips: Lizard Skins Logo Lock-On Bonus Pack - Peaty - No idea about weight, 23 €
Gearshifters: Shimano XTR Shifters 10sp M980 - 250 grams for the pair, 160 € for the pair
Front derailleur: Shimano XTR Front Mech Conventional 10sp M981 - 140 grams, 56 €
Rear derailleur: Shimano XTR Rear Mech 10sp M980 - 175 grams, 160 €
Chainset: Shimano XT Chainset 10sp M780 (includes bottom bracket) - 860 grams, 195 €
Rear Cassette:Shimano XT Cassette 10 Speed M771 - 286 grams, 59 €
Seatpost: Thomson Elite InLine Seatpost, 250 grams, 80 €
Seatpost clamp: Thomson Seat Clanp, no idea about weight, 22 €
Saddle: Selle Italia C2 Genuine Gel Saddle 2011 - 245 grams, 63 €

Total 10150 grams, 2715 Euros
or 22.37 lbs and 2 258 GBP

supersonic

A nice looking build! It will weigh more than the suggested weights, as you need to add in cable, rotor bolts and mounts, grease and so on.

Certainly scope to knock more off for not much money! These are great grips:

http://www.westbrookcycles.co.uk/compon ... ack-p94936

Could put an exotic carbon seatpost on:

http://www.carboncycles.cc/?p=801&

And tyres with sealant could drop some more! But depends what you want, 22lbs is easily doable.

Tactica

Sealant in tyres is something I didn't really grasp. I've been reading on them, but I though they were for tubeless conversions mostly. My rims and tires are tubeless already so what would I gain from sealant? Puncture protection I guess?

supersonic

UST tyres tend to weigh more than a tyre with sealant - but UST is easier to use and mount generally.

There are various kits and combos should you choose. A light tyre and tube could be am option too. I have UST rims but have gone back to tubes.