Measuring a hub

Imagine you have a hub. You don’t know anything about it and can’t find any manufacturer specifications. However, it’s a really great hub that you love, and want to build a wheel on it!

You can jump online and see how to find the parts you need to measure – this screen grab from the ProWheelBuilder.com spoke length calculator shows what you need to know.

The key observations are PCD – or the diameter of the spoke flanges; OLD – or the distance between the two hub end caps; locknut to flange – or the distance from each end cap to flange centres; and flange to centre – or the distance between the centre of the hub and the centre of each flange. For reference, the DT Swiss spoke calculator uses the same data.

But how do you get these data if you can’t look the hub up online?

I use a few simple tools. Here, I have some hubs; a pretty basic set of calipers, a right angle rule, a piece of corrugated card, and things to write with. It helps if the card has at least two edges at a proper right angle.


First thing is to measure PCD. That’s simple – use the caliper. You could also create a tool to measure this out of card – get creative!

Notice I’m not trying to measure the middle of the hole – just measure between the top of  the hole on one side and the bottom of the hole on the other. It’s the same as centre-to-centre difference.

These hubs have different sized flanges, so I had to do this four times. Unlucky!

Next, measure the flange to flange difference. This is where the card comes in.

Here, since the flanges are different diameters I have the large flange off the edge of a table, pushed up hard against the edge of the card. I’m pressing down on the hub body hard enough that the smaller flange makes an impression in the card – you can mark each edge and hey presto – you can measure flange to flange!

Measure from the card edge to the far edge of the impression; and add the flange thickness (use the caliper to measure that).


If your hub has identical flanges, you can just push both into the card at once and make your life easier. Just ensure that your impressions are far enough into the card to allow for the whole hub to be measured up each side.

Next, taking the flange to locknut distance for one side. Here, use the right angle rule to ‘drop’ the end of your hub on the small flange side down to the card.

Again, for hubs with symmetrical flanges you can do this for both ends while the hub is still in it’s ‘impressions’ and save a bunch of effort. This time, however, we need to do it the long way and do some quick maths. Now that we know our OLD (hub spacing from end to end), our flange to flange distance and one locknut to flange distance we can infer the rest.

Mark out a couple of ‘axles’ and transfer your measurements across. From here, you can work out the hub centre; then the flange to centre from both sides.

In this picture, the rear hub is marked out at the top, and the front hub at the bottom. Note, I’ve transferred my measurements of the partial hub (from one flange across) from the other side of the card. This side also has a neat right angle to work from (upper right corner). Lining the hub up, it looks pretty good.

…and you’re done! Combined with your PCD measured at the start, you can go to a spoke calculator and determine which spokes you need!

So how did I go? I made:

PCD: (rear) 49/58 (front) 45/58

Brake side locknut to flange: (rear) 36 (front) 25

Drive side locknut to flange: (rear) 50 (front) 14

Flange to flange centre: (rear) 54 (front) 58

Flange to centre (brake/drive): (rear) 20/34 (front) 23/36

…and Novatecs own specs are here (from weightweenies.com). Note Novatec’s F2F measurement is from the outside of the flanges – not centres.

So not too bad! What’s the next step?

I usually use both prowheelbuilder.com and the DT Swiss calculator. If both are around the same, I go ahead and order spokes! If not, I check my measurements and try again.

For reference, I always use and recommend double butted spokes at a minimum. Because engineering that you can googlify because it’s over my head.

 

Happy birthday, Fuego del Fuego!

My Fuji Altamira CX 1.3 is just about 9 000 km old now. 8 700 officially on strava, and quite a few off the books – so not precisely 9000, but very nearly or maybe more.

So it’s time for a big birthday service! And a look at what 9 000 km of commuting and gravel riding does to a carbon fibre wonderbike with curly wurly bars. My pre-rebuild photo in the workstand came out blurry, so here’s one from out on the trail.

Commuting in Canberra
The Altamira CX 1.3 in fine form

Far from the highly tuned racing life this bike is made for, she’s (yes, it’s a girl!) been my daily driver – logging kilometres in all sorts of weather conditions, on all sorts of trail surfaces. I haven’t done any epically long rides, but with new slighly lower gearing coming that will probably change. So what’s happened to it over nearly 9000 km?

Drivetrain

The first part of the drivetrain to go was the bottom bracket. I replaced the SRAM unit with a wheels manufacturing/enduro BB set at about 3 500 km (after the first winter). The replacement is still spinning like the day it was installed, and has remained creak-free. It’s been through 3 chains – two KMCs and a shimano Ultegra chain that I threw on because I couldn’t get anything else at the time. All shifted acceptably on the SRAM cogs.

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Enduro/wheels manufacturing BB – it stays

 

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SRAM Force 1 chainring vs 9000 km

 

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Some pretty worn cogs.

The chainring and cassette have had an extraordinary life! I was expecting to change both at around 5 000 km. So well done SRAM, the 1170 cassette and Force CX chainring have gone the distance. The cranks have had no issues – no creaks, no oddness, just reliable transmission of power.

I should mention the clutched rear mech. This is a superb addition to a 1x drivetrain on what is essentially a rigid MTB-lite. SRAM were exactly on point transferring their mountain bike system to a cyclocross oriented group.

Frame and forks

Not much to say here. No cracks – only a few stone chips and and unfortunate loss of clearcoat after catching a nail in my rear tyre. I’ve had minor niggles with the headset vibrating loose, because the tensioning nut slips loose inside the carbon steerer. I’ve replaced the alloy topcap bolt with a steel one, so if I notice any play I can quickly and easily fix it. This is not surprising, given the rattling Fuego gets out on the trails. Headset bearings still smooth, no unusual wear on any internal surfaces. Good work, Fuji!

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Nails in tyres don’t make carbon frames happy. Fortunately just a clearcoat chip.

 

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Normally you only ever see Yoan Barelli’s CX bike from this angle! Undercarriage check, all good.

Wheels and tyres

The Oval 527s have been excellent. They still roll like new, no crunching or grinding. The rims are true and strong and easy to set up tubeless tyres on. I haven’t cracked the rear hub open before – it was nice to see clean grease in there. One minor niggle is that the drive side endcap works loose every now and then, which lets a little moisture in and contributes to minor corrosion on the axle (shown below). The freehub bearings could use replacing soon, although the main wheel bearings are still rolling like the day I built this bike. I replaced the rear wheel spokes with DT Alpine IIIs, because I mashed the drive side spokes with my chain at about 3000 km old. Since then, lots of abuse and no dramas at all.

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Inside the CX 527 hub. Rolling on a nice fat axle! Yes, those spokes are not the factory versions, they’re DT Alpine IIIs. Correct tools for the job. Bearings still rolling like a boss.

 

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3 pawls, nice and simple. The grease in here was still clean – but those bearings were not 100% happy.

Tyres – I’ve used a few sets. The OEM Challenge Grifos lasted about 1500km, then their replacement Vittoria GX Pro did around 2 000 km, then some Maxxis locusts for about another 1 000 km, some random cheap tyres just for fun for another 500 -1000km, and for the last 3500 km I’ve been using Vittoria Revolution city G+ tyres. These have been great for daily driving on all surfaces, even mountain bike tracks. I would not race CX on them and can’t run them tubeless, but I am very happy with 3 500 km and one puncture. Yes, just one! I’m looking forward to Vittoria’s new G+ semi slick CX tyres, but I’ll stay on the revolutions until then.

Cockpit, controls, brakes

I really, really like SRAMS exaggerated horns out front. When I’m riding down hills that are not made for CX bikes, I can stay confidently on the hoods or go to the drops – either way feels safe. The Oval bar tape has held up exceptionally well, and the 310 bars are still comfortable.

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Lots of hand on bar tape time – it’s held up well, and so have SRAM’s hoods.

 

Braking is still precise – I haven’t felt the need to bleed the brakes yet. Gear shifting is still precise, and I’ve finally stopped accidentally up shifting on the double tap or looking for something to rest my left fingers on.

My butt did not like the Oval Concepts 710 saddle, it was replaced early on with a Pro Condor – essentially a touring perch – which has been much more agreeable.

 

Upgrade time – what’s going on, what’s coming off

So now it’s time for a full drivetrain swap, what’s the program? Given the durability of the SRAM driveline, it’s another PG-1170 cassette in 11-28. I also really like the ratios used on this one. Up front is an absoluteBLACK 42t oval direct mount chainring. I’ve really liked how the oval ring has worked on my mountain bike, so I’m looking forward to some less stressed knees and hips on the daily driver.

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Oval 42 vs round 44.
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Close up – absoluteBLACK use a shorter, broader tooth. Let’s see how it goes.
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Direct mount – it’s pretty!
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Installed!

Also, dropping a couple of teeth from the front will open up new horizons. I’ve avoided long rides in the hills around Canberra simply because 44/28 is a hard ratio to push up a hill at the end of a long ride. I’m not brave enough to go much faster than I can pedal the current gears, so I’m pretty happy that I’ll be OK on the downhills too. Connecting them up is a SRAM red 22 chain.

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New cassette stacks are also pretty, especially this part. Worth appreciating before it gets hidden away.

New rotors and brake pads have been installed front and rear. The rear 140mm had a fair bit machined off it in 9 000 km. The front rotor is still safe to use, but it’s birthday time and I’ll keep the old one as a spare.

Finally, a new gear cable and housing is a good excuse for new bars! I wanted to go a little wider so I’ve gone from 44 cm Oval concepts 310 bars to 46cm Oval concepts 310 bars. I was happy with the stock bars, and they’re great value. The new bars also feel slightly lighter, have a deeper groove for cables, and a 4 degree outward sweep on the drops as well as the 4 degree sweep on the top. I’ve also used Oval concepts bar tape again, it was excellent.

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New 310s, 46cm

 

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All taped up! Job done.

Would I recommend this bike to my mother in law?

Oh yes I would!

 

Summary – 9 000 km of Altamira CX

This bike is designed for CX racing. It is very light, stiffer than the equivalent road version (far less buzz absorption in the seat stays), very quick handling, and strong. I’ve repurposed it as a daily drive/gravel grinder, and it has been truly amazing at that job as well – making commuting a lot more diverse and fun than it would otherwise have been. I really don’t know how I’d improve this bike – maybe put thru axles in, but I’ve never felt the need for more direct steering out on the trails. Very occasionally I get a small brake rub, which thru axles might help. But really, it’s been a no nonsense machine that is very capable and a lot of fun.

I’ve found the ride excellent, and the geometry really sorted – quick handling but not twitchy, stable at speed, and predictable in absolute rocky chunder.

I don’t ever catch the external brake hose (and to be honest, I prefer it there). As a ‘buy it and ride the hell out of it’ proposition, all the bits are in place on this machine. For the cash outlay, though, it’s what you would expect. If you can make the stretch to get a hold of one, it will take you further than a road bike should, while letting you travel the world efficiently and in style.

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Finished

Where can you buy it?

These beasties can be had from any Fuji dealer, or click and collect from the importer Oceania Bicycles. Unfortunately Oceania don’t have any 2017 CX bikes in the standard lineup, but you can get a great deal on remaining 2016 and 2015 models. And a brand new aluminium frame gravel ride is coming in – the Fuji Jari. These actually look pretty exciting as an all terrain, all the time cycle riding machine – and would tick the ‘can I tow trailers’ box that the Altamira CX is way too badass for.

Mine was supplied by Cycle Canberra – who can help you to source one too.

Disclaimers

When I built this bike I worked for Cycle Canberra, who sell Fuji bikes. I left in January 2016 because PhD = done! I’m not obliged to write anything either good or bad about Fuji products, and I’m not being paid by the shop to write about Fuji bikes. However – I do like to support people who support me, and Cycle Canberra still give me pro deals on parts.

I am on the absoluteBLACK ambassador program – so I am supposed to write about my experiences (good or bad) with them.