Cycling UK Forum

Tail End Charlie wrote:I'm with 531Colin. A fixed gear bike is great for commuting, with dynamo light, it's a winner. I'd have a back brake as well though.
With that in mind, an On One Pompino would be my choice.

I recently bought a Pompino frame - really impressed with it.

OP said:-
My bike is brand new however I want to upgrade the chain set and cassette.

I know of someone who is 84, and last year did 204 miles in a 12hr time trial! puts us youngsters to shame!!!!
Seriously though, not many 30 year olds could achieve that (though racing men could)

Chain will be correct length. If you add together the largest chainwheel number and the largest sprocket number for the old setup, and compare this to the new setup the difference gives the chain length increase or decrease in teeth for complete rings (if that makes sense) As the chain runs (roughly speaking) over half the teeth of the chainring and sprocket, divide the difference by 2 to get the chain increase in length . For the sizes you have specified 50+27 =77. For new setup 52+25 =77 so no difference. If (as an example) you changed to 60T chainring but kept 27 tooth sprocket the difference would be roughly 5 inches.

If it worked before removal, why change the setup?

better measure it!

Hmm, look what I just found. Looks like they've bought (or copied) Paul.
http://www.singletrackbikes.co.uk/m7b37 ... tAodtW0ASg

Not for skinflints though!

Forgive me if this option has already been suggested..... What about some simple thumb shifters which are available for less than a fiver each. They all appear to be for 22.2 bars, but have simple steel clamps which should easily 'give' to 23.8mm ok it's 1.6mm on the diameter, so should need the clamping screw 5mm longer. An easy solution to our quest? or are the levers too short? Could just use the mounts and a longer lever?

I think I need some Suntour Command's then - They seem the best of all . 531 Colin's settup is great, with the addition of an extra lever it could be operated from the drops like Commands - Maybe someone with TIG welding skills could weld another lever onto the first? I guess they could be machined from solid but not a DIY job ( I agree the TIG welding isn't either, but at least a smaller job.

Something like this idea (please excuse rough diagram, but I didn't know how to move the lever in the image. This idea might need very long fingers though. Anyway, it's another idea

Haven't seen any new posts for a while on this one so...... I've seen (and somewhat admire) the retroshift idea - but note the inability to operate from the drops. Here's a new twist; what about mounting the lever in the same orientation to the retroshifts but on the bar, behind the brake lever so it can be reached from drops or hoods? Should be clear of the brake lever (which would only get close to the bar if the cable was very slack anyway)

I agree with Brucey - In fact my note would have been almost identical If I'd not seen Brucey's first. Most of these have a rolled thread - aside from the issue of the correct diameter (it MUST BE CORRECT TO FORM THE THREAD) a rolled thread is stronger than a cut thread. This is unlikely to be an issue (especially with a front QR) , but should be considered!
I guess these are the ones from SJSC? I bought some as well

My personal opinion (and it's only that) is to always get the OLN dimension of the hub the same as the frame. As long as the axle length doesn't stop the QR working then is should be good, but the aim IMHO is the same dimension as the outside of the dropouts. I know I'm precise (a##l?) about these sort of things, but if I had one of the frames (such as Surly) with an OLN of 132.5, I'd not be happy with a hub of 130 or 135, I'd make sure it's 132.5! Maybe it's just me, but IMHO it's correct engineering.

That looks good Al - Unfortunately I bought a new TorTec rack a few weeks ago. Maybe I should have though of a complete system?

I think the OP refers to the complete axle length as 135, the dropouts do appear to be 120. Where are you? - I have a new complete rear axle with cones/locknuts you are welcome to as I won't be using it, as it appears you may be a student, so I'm willing to help. I am in Norfolk (UK not Virginia!) Ah just thinking the rear axle may be nutted rather than QR, I'll look tomorrow, but let me know anyway.