Sizing up a TT bike from road bike measurements...

[drgav2005]

Hi,

Looking for some help to determine the correct sized TT bike. My local bike stores have *very* limited selection (try one size/model!) so it is difficult to gauge what sized bike I should order in. I am tempted by the Specialized Shiv and used Specialized's sizing chart (based solely on height). I'm 1.88m (6'2") and tested an XL Shiv at my LBS but it felt absolutely massive.

I've just had a Retul bike fit on my road bike but don't really know how to convert these figures into the correct size for a TT bike, so apologies in advance if this has been covered elsewhere… Is there a (fairly) simple way to take these measurements and work out what sized TT bike to try?

Saddle height 786mm
Saddle setback -72mm
Frame stack 591mm
Frame reach 404mm
Handlebar reach 549mm
Handlebar drop -63mm
Grip reach 699mm
Grip drop -14mm
BB to Grip reach 627mm
Handlebar stack 677mm
Handlebar reach 477mm
Thigh length 433mm / 454mm
Shin length 430mm / 436mm
Inside leg measurement 910 mm

I suspect the best course of action is to wait until the expo at the next triathlon I'm at (September) and try as many bikes as possible there but if there are any key measurements which I've taken (or could take) to help narrow down the choices then that would be really helpful…

Thanks in advance!

[graeme4130]

You road bike position won't correlate too closely with a TT bike set up
Best bet is to get the Retul fit done for a TT bike on their generic Jig rather than an actual bike (Velomotion in MK had one there when I was last set up on my tri bike there)
To be honest, if you're spending Shiv money, then getting a retul set up done would be a natural stage anyway
Enjoy the bike, Shiv's are wonderful bits of kit

[anonymous-user]

speak to the guys on www.timetriallingforum.co.uk and see what they say, some of them are pretty clued up on sizing.

[khushy]

graeme4130 said:

You road bike position won't correlate too closely with a TT bike set up
Best bet is to get the Retul fit done for a TT bike on their generic Jig rather than an actual bike (Velomotion in MK had one there when I was last set up on my tri bike there)
To be honest, if you're spending Shiv money, then getting a retul set up done would be a natural stage anyway
Enjoy the bike, Shiv's are wonderful bits of kit

^THIS^ all day - every day!

khushy

[drgav2005]

I'll certainly get another Retul bike fit for the tri bike. I was fitted at the only Retul fitter in Scotland (athelite in Hamilton, South Lanarkshire) and Colin managed to turn my road bike from an instrument of torture into a comfortable flying machine! I don't think he has the generic rig though so I'll have to travel further afield for a tri-specific fit. I reckon a good scout about at the Virgin London Triathlon expo should help and then narrow down the bike / fit from there…

I did also find this site which looks pretty useful: http://www.competitivecyclist.com/za/CCY?PAGE=FIT_...