Raleigh Dyna Tech appreciation and information thread

[averagebiker]

Anyone know the seatpost diameter for Dynatech Road bikes? The restoration of my 1994 Corsa 405ti has begun and I am not sure the seatpost it came with is original/correct.
Cheers

 

[Markybeau]

it varies depending on the year and the material, most of the mt3 - mt4 range with tims titanium is 28.4mm. spme of pro range, like my 2070 tt lo-pro, with reynolds 653 has 28mm. some of the later mtrax range has larger 31.2mm... the mtrax 27.5`s and 29ers are 31.8mm .. how ever for yours, id say would be same as an mt3/4 28.4mm, anybody else, want to add anything?

MT4 is 26.4 -26.6mm. They take a 28.6mm front derailleur. Although this is not helpful to the OP. Best not to confuse internal with external measurements.

Post in thread '1992 Raleigh Dyna-Tech MT4'

Feb 10, 2024

Seatpost size test to end any speculation. Working on the basis that it could be anywhere between 26.8 and 26.4 I assembled three to try for size;
26.8mm XT post
26.6mm Kalloy post
26.4mm Post Moderne post



It’s worth noting that there is clear ‘step’ at the very top of the seat tube where the lug(?) wraps the the titanium tube - and this gives false hope that a larger seatpost is going to fit.



First up, the 26.8mm Deore XT post; enters the lug without issue - but that’s as far as it goes;


Second up, the 26.6mm Kalloy post; again no problem...

• Once A Hero

• 

@averagebiker your best bet is using a vernier / micrometer.

 

[Mark south wales]

MT4 is 26.4 -26.6mm. They take a 28.6mm front derailleur. Although this is not helpful to the OP. Best not to confuse internal with external measurements.

Post in thread '1992 Raleigh Dyna-Tech MT4'

Feb 10, 2024

Seatpost size test to end any speculation. Working on the basis that it could be anywhere between 26.8 and 26.4 I assembled three to try for size;
26.8mm XT post
26.6mm Kalloy post
26.4mm Post Moderne post



It’s worth noting that there is clear ‘step’ at the very top of the seat tube where the lug(?) wraps the the titanium tube - and this gives false hope that a larger seatpost is going to fit.



First up, the 26.8mm Deore XT post; enters the lug without issue - but that’s as far as it goes;


Second up, the 26.6mm Kalloy post; again no problem...

• Once A Hero

• 

@averagebiker your best bet is using a vernier / micrometer.

yup, i`ll delete my post now, to avoid confusion, as you rightly say