Light(ish)weight Pompetamine

Sorry - my mistake. Will try and check out the older version.

Pompe frame looks good, cheap, but heavy at 2kg+ without forks...I'd rather stretch the cost than have regrets on spec.

Have a read through the Pompino thread. Do you see a lot of regret*? On-One frames are a bit porky, but they work. My Pompetamine gets ridden more than any of my other bikes because its fast enough on the road but I can throw it at the scenery without worry. I haven't weighed it, but I'm sure it's over 12kg. If you wanted it light, a carbon CX fork might knock the best part of ½kg off, and you could easily knock a whole kilogram off my wheels and tyres, plus my brakes are far from light. With careful shopping, you could build a singlespeed Pompetamine or Kaffenback at about 10kg, probably for less than the £1100 mine cost. If you can live with rim brakes, a Pompino would be even lighter and cheaper, but there's still no way you're going to build something tough and sub 8kg for under £1k new.

*Poloengers excepted

Some quick calculations, prices found lazily from on-one or CRC, first suitable part I found for each...

With some extra effort in the part choice and a little ebaying you should be able to hit 8kg at something close to your £800 budget, using a Pompetamine.

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That 'not included' list adds up to quite a bit of weight...

sub 8kg velocipede if you take off the cranks

Of course, but you can see a lot of the build items I've already included aren't the best weight for the money and there's £200 left in the budget.

Half a kilo off the forks should be easy, the bars, stem and post could be lighter at the same price for some eBaying effort, and I'd choose an External BB for my build.

My polo bike is 8.75kg, starting with a 2kg steel frame. I've previously guestimated all the other parts to cost be about £500 to replace if they were stolen, so on a cheap pomp, you've got £200 to add another brake and lose a kilo.

Ok, a kilo is about 12% of the bike. Meh.

Really once the core of the bike is built as light as possible, then saddle, pedals etc. comes down to personal preference vs. weight. I think the provisional spec above is a really good starting point - thanks Emyr.

I can certainly see a very nice bike at or around 9kg within reach of my budget, which gives me hope. In fact, considering Emyr's spec comes in at sub £600, I think 8.5kg all in, if one stretched the budget to £850 - £900 is very doable.

I'm no weight weenie by any means, but if I'm in the hills I certainly feel a big difference between 12kg and 8kg. I'm under 11 stone (10.5 at fighting weight) but sadly lacking in grunt, which means those extra kgs mean a lot to me.

Wheel weight is without skewers (>200g for the stock ones), Alfine cranks might be more like 900g with BB, they're certainly not 500g on their own. Chain is 300g, pedals the same, 300g+ for tubes, 100g cables, 50g tape + 50g sprocket and your 8.3kg becomes ~10kg, as I said.

I'm building a pompetamine at the moment and I'm struggling to get it under 9 kg with a 1000 £ budget. And that's with carbon forks and 1540 g wheelset.
The frame alone is about 2454 g in large.

I couldn't find and meaningful weight savings without spending lots of money on the bars, stem and seatpost, restricting myself to actual shops.

edit: swaped (bargainous) shimano wheels for self-built, spotted no Centre-lock rotors included but I think CRC's BB7 weight includes a 6-bolt?

Need to leave work now, find some lighter cranks!

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You didn't include the second tube, and TN719 probably aren't really 510g, so we're still around 9.6kg.

That's the weight for two tubes.

find some lighter cranks!

Find some better cranks would be first priority, lighter will probably look after itself. 640g sounds like Italian scales for cranks + chainring, but you're still at 950g complete with BB, which shouldn't be hard to beat with external cups. Even Omnomnom boat anchors are in that area.

That's the weight for two tubes.

Have you weighed any 32c butyl tubes lately? Conti Supersonic 18/20c are 50g each, so 70g 32c would needs be condom-thin.

Is there really a need for 700x32 tyres? You could probably get lighter cross tyres if the thing actually went off road.

Is the quoted weight for two?

Tyre weight is for two.

Seeing as this is MTB-SS chain line, M770 + BB70 = 862g according to CRC, about £100 for both on eBay as of about 4 months ago. Then take some rings off.

Tyres are easily changed, depending on the planned route. For all weather road riding, you could go to 700x25 Open Pave at about 500g, or get muddy on 700x35 Conti CX-King at nearer 800g

Chainline on my Pompetamine doesn't need an MTB crank, just the usual Campag UltraTorque outer ring and the sprocket close to the flange on Hope Trials hub. Anything based on multi-speed cassette hubs will have plenty of space on the cassette rotor to accommodate any road or track crank.

The hubs I've chosen are trials hubs, fixed or free with a disc mount, for a 51mm chain line.

The trouble with that is that using a screw on freewheel limits gearing choice and they are not light or cheap, e.g £35 and 190g (18t only). If you want a couple of different gears, a Hope Pro 2 Trials starts to look like a bargain, even more so when you start wearing out sprockets.

Many thanks Howard.

Do you mean this:

http://www.specialized.com/gb/gb/bikes/road/tricross/tricrosselitedisccompact

Ah, no - as above I meant the older, single speed version that is out of production now.

http://www.evanscycles.com/product_image/image/9f2/fff/86e/33454/product_page/specialized-tricross-singlespeed-2009-road-bike.jpg

Assuming you wanted to go single speed you could turn the in-production Tricross Disc into a neat, tensioner free single speed rig with a White Industries Eno hub rear wheel, but it would be a pricey way to do it.

Hope Pro 2 Evo front 185g £55
Hope Pro 2 Evo Trials rear 295g £139
Stans Iron Cross 780g £126
Some spokes & nipples 300-350g £20 (ACI or DT Comp) to £130 (CX-Rays)

Total 1560-1610g + skewers, about £340-£450. Add another £200[£180] to drop 100g using DT240[American Classic] hubs, so that's low on the weight weenie priority list at £2/g. For 60g less, if you want to sacrifice the strength benefit of a proper SS hub, Novatec's best XC hubs are $129 which will be about £100 landed, so 1550g wheels for ~£250

The Hope version with the cheaper spokes adds £100 to Emyr's build sheet (+120 for the wheels, -20 for using a splined sprocket rather than a freewheel) and drops 120g off the wheels and another 150g as the difference between a splined sprocket and a freewheel. You also get a great set of wheels which will be a joy to keep but easy to sell, lower running costs as you'll be wearing out cheap sprockets and more flexible gearing. On the minus side, the only way to run fixed with these wheels is to take off the back brake and use a bolt on sprocket. If your budget is £800 going on £1k, I'd go for the Hope option, should get you to a genuine 9.5kg without blowing through the £1000 barrier or running the wrong tyres just to get the weight down.

Not sure how light the Genesis bikes are - I'm guessing not terribly. Couple of friends ride the Flyer as their main road bike, but they're fitter than me.

I'm under 11 stone (10.5 at fighting weight) but sadly lacking in grunt, which means those extra kgs mean a lot to me.

...so you really think an unfit person on an 8kg bike is going to be considerably faster than an unfit person on a 10kg bike? Just ride and develop grunt.
If it were me I'd just buy a complete Pompino and make it faster by swapping out the bars for some road drops, sell the wheels and buy some lighter ones and most importantly: tyres with low rolling resistance.
You *will *be faster on a 10kg bike with something like Michelin Pro 4 than on an 8kg bike with entry level Schwalbe Lugano or Vittoria Zaffiro.

I've heard that Spanish steak is good for dropping a few pounds without losing any grunt.

Find some better cranks would be first priority, lighter will probably look after itself. 640g sounds like Italian scales for cranks + chainring, but you're still at 950g complete with BB, which shouldn't be hard to beat with external cups. Even Omnomnom boat anchors are in that area.