Road single speed TT hash up

lunar_c
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Road single speed TT hash up

Postby lunar_c » Thu Apr 21, 2016 6:14 pm

I put together a road frame single speed with a Merida I bought cheaply a while back with a magic gear (47x18 or 50x16 with a half link), single speed conversion spacers on an old road wheel, on 3/32" chain and enjoyed riding it so much that it became my main commuting bike.

I love track riding whenever I get the time to get out there and would like to start training for time trial and pursuit events once I get a bit more experience on the track.

So for the hell of it I got a base bar and clip ons at a swap meet and decided to throw them on the Merida and try and come up with a halfway decent position to start getting some experience with that type of position.

It's all a bit of a laugh and an experience but advice would be appreciated on the position..

At present I have a zero offset seat post on its way to get my saddle further forward.

The plan is to build a nice track bike sometime in the future for pursuiting and track use and this will go back to being my commuter.

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dalai47
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Re: Road single speed TT hash up

Postby dalai47 » Thu Apr 21, 2016 9:46 pm

If you have the flexibility, flip the stem to start with...

dalai47
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Re: Road single speed TT hash up

Postby dalai47 » Thu Apr 21, 2016 10:10 pm

Note my torso... Actually dropped out another 2cm of spacers after this run.

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lunar_c
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Re: Road single speed TT hash up

Postby lunar_c » Fri Apr 22, 2016 9:26 am

The stem is -6 in the riding picture.. So to get lower on the front end maybe a -17 and a bit more forward of the BB for a start? Trying to get my back straighter and lower, and was unsure of the elbow angle I should shoot for.

It's an interesting exercise that makes you realise why TT frames have shorter TT/HT and straighter ST angles, well it's a fun afternoons tinkering anyway.

dalai47
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Re: Road single speed TT hash up

Postby dalai47 » Fri Apr 22, 2016 10:34 am

If you want to use the bike to replicate and train for the pursuit, check to see the saddle tip isn't further forward than 5cm behind the BB before pushing the saddle further forward.

Try for your elbow angle from 90 to 120 degrees.

Been keen on the idea of doing some flatter TT's on a fixed gear as is popular in the UK. Unfortunately CA rules require a front and rear brake so can't use one of my track bikes with a drilled front fork.

dalai47
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Re: Road single speed TT hash up

Postby dalai47 » Fri Apr 22, 2016 10:39 am

To get lower, consider buying an adjustable stem if you can score one cheaply. I used one on my first track bike in an effort to combat the too tall head tube...

lunar_c
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Re: Road single speed TT hash up

Postby lunar_c » Fri Apr 22, 2016 11:03 am

Hey that's pretty much what I'd like to do!

I'll be looking for an adjustable stem today, as that's what a lot of the U.K. Fixed TT guys recommend as you said for the taller head tubes of some track frames.

Shorter TT's on a fixed gear are what I plan to build strength in this position with and are much easier to get to for me than the track out in midvale. My physio (herself a gifted triathlete) has been encouraging me to come and do some TT's.

I am looking to build myself a track bike fairly soon (I've been collecting some nice bits - dura ace hubs etc for a wheel build) and am thinking of going with maybe a Dolan track frame or Cinelli vigorelli though I will probably get a quote on a custom frame from some local builders as in quite tall with long legs (845mm saddle to BB) that Merida is. 62cm frame ..

The rear brake issue is definitely a bit of a PITA though.

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MattyK
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Re: Road single speed TT hash up

Postby MattyK » Fri Apr 22, 2016 1:15 pm

Looks cool.

lunar_c wrote:The stem is -6 in the riding picture.. So to get lower on the front end maybe a -17 and a bit more forward of the BB for a start? Trying to get my back straighter and lower, and was unsure of the elbow angle I should shoot for.

It's an interesting exercise that makes you realise why TT frames have shorter TT/HT and straighter ST angles, well it's a fun afternoons tinkering anyway.


TT/Tri setup is all about rotating your whole body around the bottom bracket.
An interesting thing to ponder about road vs TT frame geometry though: if you imagine flipping your seat post around to a forward offset (say from -25 to +25), you are simultaneously increasing your virtual seat tube angle (by about 4 degrees) AND shortening the virtual top tube length (by about 40mm). So a reversed seat post gets you to almost the same hip position AND the same reach as a TT frame... Then you just need to dump the bars lower, which can be done with a track stem or an upside down MTB stem. 8)

I have a shopping list planned for next season when I am hoping to do some more triathlons on my road bike (I have some clip on aero bars already). These were the best bargains I could find:

3T Ionic seatpost 25mm offset, flipped backwards. Currently $59 on CRC. Cheapest reversible post I could find.
Fabric tri saddle $85 from Evans. About the cheapest tri saddle, but personal preference etc.
Cinelli Pista track stem (-25°) ~$30 from wiggle. There are some cheap BBB MTB stems also that could be flipped (35°)

lunar_c
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Re: Road single speed TT hash up

Postby lunar_c » Fri Apr 22, 2016 1:53 pm

That's a good tip, thanks .. I tried to reverse my current setback seat post but can't get a level saddle with it reversed

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MattyK
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Re: Road single speed TT hash up

Postby MattyK » Fri Apr 22, 2016 2:19 pm

Yeah not many posts can do that. The 3Ts with the cylindrical tilt adjuster can (apparently it's a pain to adjust tilt though), as can Thomson layback posts. Probably some others if you search more...

dalai47
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Re: Road single speed TT hash up

Postby dalai47 » Fri Apr 22, 2016 2:33 pm

Limitation with pushing the saddle forward is lunar_c is restricted in how far he can move it forward unlike Tri rules.

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MattyK
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Re: Road single speed TT hash up

Postby MattyK » Fri Apr 22, 2016 2:55 pm

In which case, go searching for the saddle with the shortest nose :)

lunar_c
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Re: Road single speed TT hash up

Postby lunar_c » Tue Apr 26, 2016 11:07 am

Got the chain back on with 50x16, put the 5mm spacer on top of the stem, ever so slightly tilted the arm extensions upward a few degrees, and am trying a different Selle San Marcos saddle slid a further 1cm forward (have an inline seat post coming) .. Now just waiting for it to stop raining.

Will look for a decent adjustable stem soon ..

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