adding suspension

[fjb]

Hello. I have two bicycles; one a mountain bike and the other a hybrid. The hybrid currently has static forks and the need has come to replace them with suspension forks. In itself, not a difficult task as I've done a fair bit of bicycle maintenance to date. However all my maintenance skills are gained from hands on and watching youtube alone with an engineering background. Enough bragging now and my issue is this. I've noticed that the head tube on my hybrid is different to the one on my mountain bike as in the hybrid has a longer head tube. The top tube and down tube on the mountain bike are connected to the head tube in a single weld whereas on the hybrid, they are separate with about an inch between them. I also notice that the outer diameter of the head tube on the mountain bike is wider. I am thinking that these factors limit the options for putting front suspension forks on my hybrid. Am I correct? If so, how can i bypass this issue.




Thank you

FJB

 

[Angelfishsolo]

Hello. I have two bicycles; one a mountain bike and the other a hybrid. The hybrid currently has static forks and the need has come to replace them with suspension forks. In itself, not a difficult task as I've done a fair bit of bicycle maintenance to date. However all my maintenance skills are gained from hands on and watching youtube alone with an engineering background. Enough bragging now and my issue is this. I've noticed that the head tube on my hybrid is different to the one on my mountain bike as in the hybrid has a longer head tube. The top tube and down tube on the mountain bike are connected to the head tube in a single weld whereas on the hybrid, they are separate with about an inch between them. I also notice that the outer diameter of the head tube on the mountain bike is wider. I am thinking that these factors limit the options for putting front suspension forks on my hybrid. Am I correct? If so, how can i bypass this issue.




Thank you

FJB

Put simply you will need to get suspension forks that have the same tube diameter and length (or longer as it can be cut down) as that on your Hybrid. You also need to be aware that the style of fork will alter the bikes geometry.

As an aside why does the Hybrid need suspension forks?

 

[Cyclist33]

To put it more complicatedly, the diameters which must be the same are the outer diameter of the fork's steerer tube and the inner diameter of the headtube.

The relative gaps between the top and down tubes on each bike would seem irrelevant to me for this task. Hybrid's top/down tubes are probably narrower in diameter anyway so even if the headtube was the same length on both bikes the welds would likely be differently-spaced.

I echo Angelfish's question. Why bother? If you've already got springs on the mountain bike just use that for suspension days.

How about upgrading the hybrid's forks to static carbon forks, either road or mountain bike style can be got for a good price.

Stu

 

[Cyclist33]

As an aside, why do we say "forks" when we mean "fork"? A single front fork has two tines, but it isn't two forks.

Stu

 

[Angelfishsolo]

To put it more complicatedly, the diameters which must be the same are the outer diameter of the fork's steerer tube and the inner diameter of the headtube.

The relative gaps between the top and down tubes on each bike would seem irrelevant to me for this task. Hybrid's top/down tubes are probably narrower in diameter anyway so even if the headtube was the same length on both bikes the welds would likely be differently-spaced.

I echo Angelfish's question. Why bother? If you've already got springs on the mountain bike just use that for suspension days.

How about upgrading the hybrid's forks to static carbon forks, either road or mountain bike style can be got for a good price.

Stu

I was thinking of suggesting Carbon Forks but as I have not tried them I thought it unwise to base a suggestion on hearsay.

 

[Angelfishsolo]

As an aside, why do we say "forks" when we mean "fork"? A single front fork has two tines, but it isn't two forks.

Stu

Very good question. Why do you say a pair of trousers? Why do you never see a baby pigeon?

 

[Cyclist33]

I was thinking of suggesting Carbon Forks but as I have not tried them I thought it unwise to base a suggestion on hearsay.

Conversely, I've not tried alu or steel forks on a road bike so don't know if/how much better carbon ones are.

the fact that you routinely ride twice as far as me leads me to think there isn't too much advantage in carbon up-front.

Stu

 

[Angelfishsolo]

Conversely, I've not tried alu or steel forks on a road bike so don't know if/how much better carbon ones are.

the fact that you routinely ride twice as far as me leads me to think there isn't too much advantage in carbon up-front.

Stu

I don't much about the pain in my elbows or left wrist (I dislocated it and didn't bother getting proper medical treatment) though Maybe there could be benefits in using Carbon forks.

 

[fjb]

Put simply you will need to get suspension forks that have the same tube diameter and length (or longer as it can be cut down) as that on your Hybrid. You also need to be aware that the style of fork will alter the bikes geometry.

As an aside why does the Hybrid need suspension forks?

Because I go cycling with someone, this someone uses my hybrid and the route where we go is to put it politely, "country". I've already had to replace a couple of spokes on that bike and the route is a bone shaker for that bike even though there is pertinent pressure in the tyres.

 

[fjb]

To put it more complicatedly, the diameters which must be the same are the outer diameter of the fork's steerer tube and the inner diameter of the headtube.

That's putting it more complicatedly?

The relative gaps between the top and down tubes on each bike would seem irrelevant to me for this task. Hybrid's top/down tubes are probably narrower in diameter anyway so even if the headtube was the same length on both bikes the welds would likely be differently-spaced.

I echo Angelfish's question. Why bother? If you've already got springs on the mountain bike just use that for suspension days.

How about upgrading the hybrid's forks to static carbon forks, either road or mountain bike style can be got for a good price.

Stu

I use the mountain bike for rough tracking but the person i go with uses the hybird. Bone shaker.

 

[fjb]

As an aside, why do we say "forks" when we mean "fork"? A single front fork has two tines, but it isn't two forks.

Stu

Good point.

 

[fjb]

I was thinking of suggesting Carbon Forks but as I have not tried them I thought it unwise to base a suggestion on hearsay.

Wouldn't you use carbon forks for a road bike because of their weight?


I've never ridden a carbon bike as they are all too expensive, besides.. i don't do much "Road" cycling.

 

[RecordAceFromNew]

Your question is not an easy one to answer well, but with your engineering background, you might find the references I linked to here useful for helping you figuring out what suspension forks configuration you need.

Separately chance is your mtb has 1-1/8" steerer and 26" wheels, while the hybrid has 1" steerer and 700c wheels. Further they probably have aheadset (or their variants) and threaded headset respectively. You might want to read this and associated links to confirm. You will also have to pick forks that will work with the braking system you are going to use. If still unsure you will probably need to provide a lot more info/spec/photo here or in Knowhow and ask.

Good luck!

 

[PpPete]

much as it will be a fascinating project to convert a bike from rigid forks to suspension the different frame geometries could make it less than pleasant to ride .... and it will probably work out far cheaper overall just to buy a cheap MTB, there are plenty of bargains to be found if you look around.

 

[Moodyman]

Get fatter tyres if you can fit 'em