Front brake / suspension problem

MagneO

Member
Hello!

Today a rode my first longer ride on the cruz-bike (kit), about 18 km I think. I have a serious problem related to the front brake and suspension. I presume this is an ordinary problem with any front suspension bike but I have newer owned one. The thing is that the bike brakes due to the suspension travel. I noticed this early so I ride slow over all bumps, still I almost got thrown off the bike. The cable seems to have enough play but still this happens.

Any tips?

Regards,
MagneO
 

JonB

Zen MBB Master
MagneO wrote: Hello!

Today a rode my first longer ride on the cruz-bike (kit), about 18 km I think. I have a serious problem related to the front brake and suspension. I presume this is an ordinary problem with any front suspension bike but I have newer owned one. The thing is that the bike brakes due to the suspension travel. I noticed this early so I ride slow over all bumps, still I almost got thrown off the bike. The cable seems to have enough play but still this happens.
Try to lie ontop of the handlebar and press it down to see what happens.
 

MrSteve

Zen MBB Master
MagneO wrote: Hello!

Today a rode my first longer ride on the cruz-bike (kit), about 18 km I think. I have a serious problem related to the front brake and suspension. I presume this is an ordinary problem with any front suspension bike but I have newer owned one. The thing is that the bike brakes due to the suspension travel. I noticed this early so I ride slow over all bumps, still I almost got thrown off the bike. The cable seems to have enough play but still this happens.

Any tips?

Regards,
MagneO
Jon is onto something!

From what you describe, it seems like your "brake" problem is really a clearance problem between your front tyre and the top
of your front fork.
Your fork is the motorcycle-type, correct?
Headstock, triple-trees, down tubes and fork sliders, right?

If possible, stiffen your front suspension by adjusting/tightening the suspension springs inside the fork legs.
Alternatively, stiffen the springs by inserting spacers between the fork springs and the forks.

Anyway, that's my opinion.

Good luck!

-Steve
 

MagneO

Member
Hello!

I will try to lean on the steering bar to see what happens. The name of the various components of the front fork are unclear to me (since I am Norwegian and my bike vocabulary is limited), but I have what I believe is an ordinary front suspension fork. I also think the brake is to blame since i clearly shifts to one side after the impact and the noice that is produced is"brake like".

But i will look into it. Tightening up the suspension might be a good idea anyway.

Regards,

MagneO
 

MagneO

Member
Update!

Steve you are most likely right!

I was unable to fully compress the suspension by leaning on the handlebars. However, the oily piece of the fork (on the fixed part) were the rubber gasket push away the dust is probably a good indication of the maximum stroke of the fork. Comparing that to the to actual distance between the tire and the traverse piece that holds the two legs of the fork together, it is evident there may well be a clearance problem.

Thanks for the tip!

Regards,

MagneO
 

Doug Burton

Zen MBB Master
Hi MagneO,

There are couple of things we might need to look into here...

First, did you turn the fork around 180 degrees before mounting the triangle brackets that hold the wheel to the fork? One of the first things we frequently encounter on kits that don't have the fork reversed is that the relocated wheel strikes the brake bridge. This can be dangerous if you hit a significant bump, and probably should be sorted out before you ride any distance.

If the fork is set-up properly, the brakes will be on the BACK side of the fork.

If this is a "triple tree" type fork it might be difficult to reverse, but it is necessary for the wheel to relate properly to the brakes , and for the trail dimension in the steering to be correct.

Please take a look and let me know what you see...

Thanks
 

MagneO

Member
The brake is on the back, I have remembered to turn it around!

How do I adjust the fork? I have looked at it, it has a knob on top of each leg. Is this what I turn? I cannot turn it by hand and it does not appear to fit any standard key or wrench. Or is this simply a cover which need to be removed?

EDIT, I have been down in the basement ( I live in an apartment block) and looked other bikes. There were many were the knobs are easy to turn and look as they are design to be turned. May the cheap bike I bought simply not have an adjustable fork?!?!!!

Regards,

MagneO
 

Doug Burton

Zen MBB Master
Hi Magne,

Peder has referred me to a picture of your bike. It's very nice indeed!

I can see you've installed everything correctly.

Thats a LONG travel on the front fork. Sometimes these forks aren't adjustable by a knob or the like, but you can make them effectively stiffer by shimming the spring or elastomers that are inside the shock tubes. With the inexpensive forks, there is usually a hex nut holding the shock togther that you can reach by removing the plastic plug on top of the shock tube. Sometimes it is good to first wrap something around the fork crown and the brake bridge to hold the fork togther when you remove this nut! Then remove the spring or elastomer and put either an additonal elastomer or a piece of solid hard material (it can even be wood) to take up some of the suspension travel.

It's a nice bike, I'm sure we can get it going!

Peder, thanks for connecting me with the photo.
 

MagneO

Member
Doug,

The supplier (Biltema, if any of you reading this are from the Nordic contries) over the phone confirms the damper is not designed to be adjustable.

I will try to go to the store to talk to one the persons putting these together to find out more about the design. Thereafter I will try to pick it apart to see what it looks like.

Regards,

MagneO
 

MagneO

Member
Today a replaced the front tire with a more road like tire as the manual suggests. This clearly reduced the problem but it didn't completely eliminate it. I will probably ride with this tire and perhaps consider two additional changes. To get a tire with even less pattern, this will perhaps give me an extra millimeter or two. Also I have noticed that the steering tube of the fork sticks out on the under the traverse piece. I think it could be possible to grind off a 2-3 mm large "wedge"of this tube (taking off material at the front end). This could be done without taking anything apart and should only take a half hour. I don't believe this would make the part much weaker and could probably be the last millimeters I need.

If the above doesn't do it I will look into taking the fort apart. It is on the soft side (not that I have much experience to base this judgment on I should add) so when I get to know the bike and start riding harder I will probably need a firmer suspension.

Regards,

MagneO
 

John Tolhurst

Zen MBB Master
loosen the clamps around the fork legs, insert a packer - hard rubber or something - this will rotate the wheel down, creating more clearance :D
 

MagneO

Member
Aha!

I will try that, thanks.

By the way am I getting much better at riding the bike. There is of cource some way to go here but now I am riding much more relaxed and I have ridden only a total of 40 km.

Regards,

MagneO
 

Mark B

Zen MBB Master
The thing I found that worked for me was a rubber sewer pipe coupler bought at Home Depot. It's very thick rubber, yet cuts easily with a sharp utility knife. I cut chunks of it for the fork legs and also used it to make a shim for the front of my seat.

Mark
 
Top