Steering Head

[Retyred1]

When I purchased my Haibike Sduro Hardnine I knew it was their budget model so I intended to upgrade a few bits as time and $ permitted.

The Suntour forks were high on my upgrade list. I have been offered some Pikes off a new bike at a great price but just checked to make sure they would fit. The steering head on my bike had a large taper from bottom to top so thought this was ok but dropped the forks to be sure. The stem was straight!

There was a smaller Crown race bearing top and larger on bottom and I guess inserts inside the head.

Wondering if this is a true taper head with inserts to allow the fitting of the straight stem or a straight head just made to look good? Never seen this on a factory setup but I guess was done to save a few dollars on the fork setup.

 

[Rick Bullotta]

I'm not entirely sure what you're asking, but this definitely is a tapered fork setup from what you've described (1.5" bottom 1.25" top). When replacing the fork you want to be sure that it is also a tapered steerer (1.5/1.25), consider axle-to-crown distance of the original vs the replacement (will affect handling and is a function of fork travel and fork design), and also fork "rake" or offset. Both will affect handling to some degree. Generally best to err on a more slack geometry versus something that can make your bike too twitchy (e.g. putting a 120mm fork on a frame designed for 150mm would be scary).

Also be sure to use only the original fork crown race (the part of the headset that gets pressed on top of the fork crown) that mates with your headset.

 

[Rick Bullotta]

Highly unlikely that there are inserts of any kind other than the headset wedge that goes between the steerer tube and the top headset bearing.

 

[argoose]

The crown race will be a reducer, from 1 1/5 (head tube) to 1 1/8 (steerer tube).
Your LBS will have a 1 1/5 crown race.
Exact same thing with brothers Cube. £3 from LBS.
Heated it up with blow torch dropped on steerer let cool job done.

 

[Rick Bullotta]

The crown race will be a reducer, from 1 1/5 (head tube) to 1 1/8 (steerer tube).
Your LBS will have a 1 1/5 crown race.
Exact same thing with brothers Cube. £3 from LBS.
Heated it up with blow torch dropped on steerer let cool job done.

Just be careful though, since not all crown race(s) have the same profile. A mismatch could lead to anything from annoying noises to a failure of the bearing or headtube. Make sure it is an exact match of the correct one for your headset. Or better yet, just remove the one from your old fork!

 

[argoose]

If Retyred is putting a tapered fork on, his old crown race wont fit

 

[Retyred1]

Thanks guys, I think I have my head around what you have said.

I guess one of my queries was is it normal for a bike manufacturer to have a tapered head on the frame yet install a straight steerer. I can only assume at this stage that the head is a normal size.

 

[Rick Bullotta]

Thanks guys, I think I have my head around what you have said.

I guess one of my queries was is it normal for a bike manufacturer to have a tapered head on the frame yet install a straight steerer. I can only assume at this stage that the head is a normal size.

Not very normal at all, but nothing surprises me with what manufacturers do these days. Measure the bearings. If the bottom bearing has an inside diameter of 1.5" and the top bearing is 1.125" then it is a tapered headtube/headset.

 

[soundwave]

 

[Rick Bullotta]

View attachment 22163

Actually it's the inside diameter that should be 1.5 and 1.125, but that's definitely a tapered headset that Soundwave took a picture of!

@Retyred1 : can you take a picture of the steerer tube and headset race mounted on your original fork? That will answer everything.