[J Ro]

Can one of the Bontrager experts please confirm which size headset my 1996 ish Race Lite takes. I understand that there are 2 types the JIS and standard. I know that the inside diameter of the fork races are different and i thought that the diameter of the cups were also different.

Thanks in advance

 

[Shayne]

Headtube Size Is The Same

The only difference in a JIS headset is the fork crown race.

 

[floibex]

lower crown race:
inner diameter iso -> 26.4mm / jis -> 27.00 mm.

there is also a difference in the cups.
headtube inner diameter iso -> 30.2mm / jis 30.0mm

i had the same problem with my rock lobster, the suntour headset is a jis model.

the solution: i took shims out of tincan and glued them with loctite 638.

up to now all is tight and true

for serious offroad use i wouldn't recommend this...

ciao
flo

 

[cegrover]

MB-2 headset size

lower crown race:
inner diameter iso -> 26.4mm / jis -> 27.00 mm.

there is also a difference in the cups.
headtube inner diameter iso -> 30.2mm / jis 30.0mm

I think I know the answer, but I want to bounce this off the forum before I risk ovalizing my head tube. I'm putting a headset (ISO) into my 1987 Bridgestone MB-2 frame today and it's giving me MUCH more trouble than I've ever had with one.

Is there any chance the MB-2 has a 30.0 mm headtube ID (JIS headset)? The fork definitely takes a 26.4mm race, so I doubt it. But...I wanted to make sure...

EDIT: I did check with a caliper and it looks like 30.0 dead-on. However, 0.2mm is hard to spot.

 

[laffeaux]

Bridgestone and Bontrager would both have originally come with ISO headsets.

 

[cegrover]

Bridgestone and Bontrager would both have originally come with ISO headsets.

Cool, thanks! I'll just use more 'gentle persuasion'