Late 70's Bob Jackson TT build

[benseddon]

Re: Late 70's Bob Jackson TT build WIP

That really was impressive. Love the way Indurain just shoots past Armstrong, reminds me of the 1999 TDF prologue for some reason.

I'm getting inspired to slap some pursuit and aero bars onto my Raleigh/BSA, a TT inspired retro mile muncher.

Do you plan to add bar end shifters or are you going to stick with the d/t shifters?

 

[Jonny69]

Re: Late 70's Bob Jackson TT build WIP

I was looking at bar end shifters but they were surprisingly expensive! I think I'll be sticking with d/t's but I haven't really thought through the logistics of changing gear without taking my arms off the aero bars - which has a habit of unsettling the balance of the bike!

 

[benseddon]

Re: Late 70's Bob Jackson TT build WIP

spa cycles have a good selection of bar end shifters, the cheapest being dia compe friction shifters at £40 plus p+p. There is always good old eBay!!

 

[Jonny69]

Re:

I screwed on a few more things. It's starting to take shape now. Cranks and dérailleurs on and new Tufo tubs instead of the crappy Vittoria Rallys I tried. Need to get some cables and a 6-speed block for the back, set of shifters and some bar tape and it ought to be good to go.

I posted this in the tub thread, but look at the state of these. People complaining about Vittoria Rallys not being round weren't joking:

The Tufos, however, are perfect. They're on and stretching.

 

[Jonny69]

Re:

I've almost finished the modifications to the aero bars. As I said before, they were originally a clone of the old Profile aero bars. I wanted them a bit closer together and also lower, so I've chopped them around a bit:

Original mounting arrangement is at the top of the picture, so the bars were mounted above the handlebars and the elbow pad on top of all of that. To get them lower, I've drilled and tapped the bottom of the bracket so they can be flipped over and the pad screwed in that bit instead, as per the lower arrangement in the picture. The only problem is I'm not sure if the pad will actually be low enough for practical use, but I'll have to see.

I'll probably end up buying a new set of aero bars at some point, but this way I can play around and figure out what I actually want because these ones owe me practically nothing.

 

[benseddon]

Re:

Looking good. Can't wait to see what the look like when mounted on the bike

 

[oonaff]

Re:

m great film. because of big migs short top tube on his standard road bikes i always wondered
about the flatness of his back,but see in the film its well flat .
yes,i think we are lucky to have the brownlee brother 's !
the top of the world at their distance

 

[Jonny69]

Re: Late 70's Bob Jackson TT build WIP

I made a push last night to get this on the road, so revision 1 is complete. I made a couple of changes to the build mainly determined by the parts I had in stock and basically so that I could get it rolling. The handlebars are the cut down drops I was using when it was fixed gear. I know this worked with the aero bars so I used this setup to get me going and banged on some cork tape. I also didn't have any brake cables long enough to do the internal routing with the other bars, but this can be changed later. A work colleague donated some friction bar end shifters but, again, I didn't have long enough cables and I decided to get it going with Suntour ratchet downtube shifters. I opted for Tufo S33 tubulars which are really nice.

I rode it in this morning to get a feel for it, 10 miles, and amazingly I don't feel like I need to tweak too much. I have spent a fair amount of time setting up the riding position, however, by putting the parts on other bikes and seeing how it feels, or simply by sitting on the bike and moving things around. It rides really nicely and most importantly it's FAST! The aero bars work really well and get me into a good tuck position as I'd wanted.

Next step is some incremental tweaks and I'll go out hunting big budget carbon bikes on the local TT circuits.

 

[benseddon]

Re:

Bike looks lovely jonny.

Much prefer it with the cut down drops, looks a lot cleaner. Are you considering getting some aero brake levers or just sticking with the brakes you've got?? It looks like a bit of a stretch to grab the levers.

How do you find using the shifters while your tucked in and whizzing along?

 

[Jonny69]

Re: Late 70's Bob Jackson TT build WIP

Do you mean bar-end brake levers? No plan to get those, but if I stick with these bars then I'll probably drill them so I can run the cable inside the tube instead of sticking out like that. It's not a stretch to get to them because it's a small frame - it's about 53cm long and 50cm tall - so actually about right if I were riding with bullhorns but would be too short for me with conventional drops.

Shifting is actually easier than I thought it would be. The only hitch is the levers are right up by the head tube, so I can't shift one-handed like I do on my other geared bike because I can't get my fingers between the tubes and the levers!