Converting road bike to TT bike

lennymc

so I have a dolan bike, which looks like it could be converted to a semi TT bike. Its low at the front, and has a short TT so that, coupled with something like a fast forward seatpost should give me something approaching TT geometry.



Im thinking fast forward seat post, aero cockpit, brakes, shifters and a change to the gearing should do it. Anyone any other suggestions?

Lumen

Looks like the saddle is only about 6cm behind the BB, so not sure you need to change the seatpost.

lennymc

Lumen wrote: »

Looks like the saddle is only about 6cm behind the BB, so not sure you need to change the seatpost.

anyway of measuring the angle? there is a set back on the seatpost thats on there at present.

Lumen

lennymc wrote: »

anyway of measuring the angle? there is a set back on the seatpost thats on there at present.

Not sure angles are relevant. You want the saddle tip to be as close to 5cm behind the BB as possible.

lennymc

ok. whys that?

Lumen

lennymc wrote: »

ok. whys that?

The further forward your saddle, the more aero you can get without losing power.

This is restricted by the 5cm rule (UCI), which you may or may not care about. If you don't care you can consider yourself a triathlete.

lennymc

Lumen wrote: »

The further forward your saddle, the more aero you can get without losing power.

This is restricted by the 5cm rule (UCI), which you may or may not care about. If you don't care you can consider yourself a triathlete.

cheers for that lumen. Ill look at getting some bars and see about setting it up. I really care about the 5cm rule. Honestly!!

I have a set of profile design TT clipons, and was looking at getting a base bar and using that with the clipons.

Beasty

Lumen wrote: »

The further forward your saddle, the more aero you can get without losing power.

This is restricted by the 5cm rule (UCI), which you may or may not care about. If you don't care you can consider yourself a triathlete.

... or old - the IVCA don't bother with UCI rules

The only time I'm aware it's checked is for national (and World;)) Championships. No-one got a tape measure out for the Leinster 10m TT Championships this year for example

Beasty

Then there's the 75/80cm rule - the tips of the TT bars (excluding shifters) cannot be more than 75cm in front of the centre of the BB. This is increased to up to 80cm if a morphology test is passed (only really relevant for taller riders)

Interestingly in the World Masters you could pretty much get your bike checked at any time during the session - perhaps an hour or so before you were due to ride. I assumed the bike would then be quarantined, but they let you take it away and never checked it again.

I had the TT bars about 78cm in front of the BB, and they didn't even bother with the morphology test - so long as it was no more than 80 they were happy with it.

Then I noticed some riders were wearing overshoes, which had theoretically been banned (for indoor events) a week or so previously. I asked whether they were allowed and was informed the new rule was in place but not yet being enforced ....

lennymc

morphology?



so if no one checks the bikes, I only need to worry about the rules if Im not considering triathlons.

I think.

Lumen

lennymc wrote: »

so if no one checks the bikes, I only need to worry about the rules if Im not considering triathlons.

I've never been drug tested in the club league, but I wouldn't use that as an excuse for a "Wednesday refill".

lennymc

many thanks to Fago who donated some parts to operation makethedolanattbike.

put the tt cockpit on today - I need to see about setting it up properly and adjusting it. Ill spend some time on the trainer and get it comfy and in a position that means I can ride it! I took it for a spin round the block. It feels fast but twitchy on the aero bars (fine on the base bars) which is understandable. Ill have to get used to the handling. I think it could go lower at the front - i certainly think I could. Would need a new stem with a more aggressive angle - ill see what I have in the shed. The shifters are 9 speed, but work with the 10 speed with the indexing turned off. The brakes are quite good aswell. I wasnt too happy with them on another bike, but they seem to work better with these levers. It was previously running an 8 speed, with a 9 spd sora derailer, so for the crack i chucked in a 10 speed wheel and chain, and that seems to work fine. happy days - it will take my power meter and or aero wheels.

its running a compact chainset, but with 50/11 gearing I think ill be ok. If not ill get a double chainset. Maybe ill just get a double anyway. Ill see how the finances are

Things I need:
front braze on derailler
cables
pedals
bar tape
a good clean
cut the steerer
a couple of hours on the turbo fine tuning the position.

once I get those bits I should be at least able to use it on the road and get a feel for it. Happy days.

Any tips on setting up the position?

its a crap picture, but ill get some better ones when its finished.

hf4z6sqo7vjngi

A side picture of you in the TT position with foot at 6 o clock would help.

lennymc

Tenley Bumpy Label wrote: »

A side picture of you in the TT position with foot at 6 o clock would help.

ill get one tomorrow. It might be about 10 o clock in the morning tho. is that ok?

Ill wait until I have pedals and shoes etc on so i can get a good guesstimate on the saddle height.

Lumen

lennymc wrote: »

Any tips on setting up the position?

Don't do it on the turbo. Go out on a quiet road with a couple of allen keys. Everything feels different on the road.

colm_gti

Lumen wrote: »

Don't do it on the turbo. Go out on a quiet road with a couple of allen keys. Everything feels different on the road.

Couldn't agree more!

Bike looks good Lenny

lennymc

so spent an hour pootling about on the bike today, playing with the position and seeing if i could ride the thing. Its a bit twitchy, but I would imagine that all TT bikes are gonna be a bit twitchy. I dont mind that, and to be honest didn't notice it by the end of the spin. Seems comfy enough, a few more bits of fine tuning then ill bring it out for a proper 10k tt. Thanks for the help all.