Khs Lightweight on a budget

[vincenth]

While I almost finished my latest project: a beefy overbuild koga miyata which probably weighs in around 14 kg. I thought it would be nice to build something a tad lighter.

I used to have a 1993 khs montana pro which has to be one of the better retro rides I have owned. About a year ago I bought a mostly stock 1993 montana comp in team colours. Sadly the Paint was in much worse condition than I had hoped and put it away in the shed.

Now I think it will make a great franken/rat/go-around-town-maybe-even-trails kind off bike.
These bikes used to weigh 11,5kg
I changed the wheelset to xt/dt hugi on mavic x517 rims with simple smart sam tires and seat(post) to a kalloy post and flite saddle.
These simple changes brought the weight down to 10,8 kg and got me wondering if I could make it sub 10 kg without breaking the bank.
The 'upgrades' I found so far:
Type. Old. New.
Tires 1020. 690
Tubes. 355. 100
Cassette. 300. 240
Saddle. 203. 183
Wheel qr's. 110. 50
Bars. 180. 145

I ordered new tires (kenda klimax lite), tubes (ridenow tpu) and wheel qr's (titanium)
Got a bargain on a ritchey pro lite
Swapped the standard flite for a carbonio
Found an old xt cassette

I am making calculations as I'm doing this write up and realize that the bike sould be close to 10kg.
The calculations are not exact, I might be 10-20 grams off here and there, but so far I am saving 760 gram and spent a total of 90 euro.
I guess now its waiting for the courier and see where I'm at.
Any advice on more cheap weight saving are welcome.
Pics will follow up

 

[My_Teenage_Self]

WOOOOoooooo... Weightweenie!

Everything. Just obsess about everything.

BB and cranks = hunk of weight.
Seatpost & Stem.
What shifters/brakes.

FYI, Shimano is rarely the lightest.

 

[vincenth]

Bb is a bb Un 71, cranks shimano deore lx m560 and so are the brakes/shifters.
The project looks a whole lot different now as I found a much lighter frameset, a marin indian fire trail.
Right now the total weight is just over 10 kg.
Maybe I will reset my goal to sub 9 kg .
the stem is not particulary lightweight but looks way too cool in my opinion to swap.

 

[bikeworkshop]

My favourite cheap weight saving tips from mid 90s mtb racing...
No grips!
Chain too short
Inner tubes two sizes too small

If you spent a little money, you could save weight on the post.
Plastic pedals are light too, and some proper lightweight tyres?

Bb and chainset weight saving would be expensive - more of an investment

 

[Fourbikes]

I use bits from road bikes, rear mechs and hubs for example, which are a bit lighter. As you're running the chainset as a double, a road rear mech will be ok. A 'compact' chainset such as an LX M563 will be quite a bit lighter than the one you've got also, I think.

 

[bikeworkshop]

Older Mtb derailleur's parallelogram is more slanted to allow the top jockey to clear a rear sprocket over 28t. (Newer road stuff is more liberal with the introduction of compact chainsets to offer easy gears for mammils, earlier ones generally did only 27!)

Sometimes with a lucky hanger mount position and careful chain length this can be overcome, but if you compare a 7/8 speed 105 (rd-1051, 238g) to an 8 speed xt (rd-m730, 230g) i don't think you'll find much advantage.
A shorter cage makes it lighter, but denies you wider overall gear range.

As for the hubs, on retro stuff the main difference was that mtb hubs had extra seals around the cones.
If you compare the castings of 7 speed 105/ ultegra and xt, they are basically the same.
A 32 spoke wheel vs 36 probably makes a greater difference.
Or (weak) alloy qrs over (strong) steel.

At least we stopped drilling holes in things

 

[Fourbikes]

If you're 'flexible' about period correctness a later Dura Ace or Ultegra rear mech can be quite light. 7800(185g), 7700(195g), 6600(205g) for example and they should be fine for up to 28 teeth.

 

[bikeworkshop]

Or you could save a kilo with Lightweight tyres

 

[Once A Hero]

Bb is a bb Un 71, cranks shimano deore lx m560 and so are the brakes/shifters.
The project looks a whole lot different now as I found a much lighter frameset, a marin indian fire trail.
Right now the total weight is just over 10 kg.
Maybe I will reset my goal to sub 9 kg .
the stem is not particulary lightweight but looks way too cool in my opinion to swap.

When I built my IFT (see signature) I was disappointed by how heavy the stem was, but it matches the fork/is OEM so it stayed. Mine came in at 9.69kg.

 

[vincenth]

My favourite cheap weight saving tips from mid 90s mtb racing...
No grips!
Chain too short
Inner tubes two sizes too small

If you spent a little money, you could save weight on the post.
Plastic pedals are light too, and some proper lightweight tyres?

Bb and chainset weight saving would be expensive - more of an investment

Lightweight tubes and tires are on their way, I might regret super lightweight tires (345gram!) But we will see if and how many punctures the they will have.
Plastic pedals are too flimsy I think
I should have a ti bb some where but dont know the size.
Supposedly 9 speed chains work fine with 7/8 speed setups, that might save a bit of weight.