Hi
Looking to repair Mrs G’s old Specialized Hardrock D4W, 26in from 2007. Frame seems to go on for ever. It is mostly working but I need a couple of bits, including a seat clamp.
It has a 30.9 seat post and the old clamp (no longer operating, as the QR moving bits all died) has ‘6J 36’ stamped on it. I’ve searched online and am more confused than ever; people online have said that it is a very unusual diameter.
I have the old seat clamp, so I could try and see if there are parts that will work in it; my spare Hope QR bits don’t fit it at all.
There are only 3-4 seatclamp sizes that cover the vast majority of bikes - I would expect yours to be 34.9. Put a ruler/tape across the top of the tube to check?
30.9 is one of the most common seatpost sizes. As above, it will be a 34.9 mm seatclamp.
I have a vague memory of these being a strange size. I used to service fleets of Specialized police bikes and the clamps were forever going missing or getting damaged. I think I sourced some BBB replacements. I’ll nip down to the workshop in a bit and have a look if you can measure the outside diameter as accurately as possible. There are three common sizes now, but not always been the case!
@gribble
@gribble I’ve just been down to the workshop (in me jamas, it’s Sunday), I think the size you need is 35.8. I’ve got a BBB Carbonstrangler here l can post to you for nowt if you think it’s the correct size. Direct message me if you think it’s the badger! Bolt type though, not quick release.
Hope this helps
Thankyou @wheelsonfire1 - that is really helpful. I think you are right; I just measured and the diameter is just over 35mm, so it looks like 35.8mm would be spot on.
I’ll PM you, but very kind.
People thinking they know what seatclamp size is needed based on a seatposts diameter should stop giving advice. Some alloy trek frames have 36.4 clamps for example, who'd have guessed that.
@greeny30 I think that people were only trying to help, they might not be correct but still trying to be helpful. Be nice!
Thankyou to wheelsonfire1 - his advice was spot on and he absolutely nailed the advice. Now fitted to the bike.
Thankyou @wheelsonfire1 – that is really helpful. I think you are right; I just measured and the diameter is just over 35mm, so it looks like 35.8mm would be spot on.
You ain't measured it if you don't know the actual size - these are cheap enough, and then you'll be properly able to get the right size:
https://www.screwfix.com/p/c-k-vernier-callipers-5-130mm/7816x
Thankyou. I need to get myself a pair of those!
