this is really a big problem. The electric motor touches the brake. Please advise.

flecc

Member
Oct 25, 2006
48,191
25,876
I may be wrong, but if your std mount is for a 140mm disc, then a 180mm (+20mm) adapter will allow you to fit a 160 disc, not a 180. Please feel free to correct me on this.
I'm a little more confused now :)
As VFR400 says, 20mm radius.

That means the diameter of the disc is a gain of twice that, 40mm, the difference between the diameter of a 140 and a 180 mm disc.

If you buy the part VFR400 recommended from ebay, you'll be ok.
.
 
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wheeliepete

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As VFR400 says, 20mm radius.

That means the diameter of the disc is a gain of twice that, 40mm, the difference between the diameter of a 140 and a 180 mm disc.

If you buy the part VFR400 recommended from ebay, you'll be ok.
.
Thanks flecc, but don't you use the +20mm adapter to go from 160 to 180? just trying to understand this, no intention of being a PITA;), which I prob. am.
 

dzhem

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May 13, 2021
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Sorry, no intention to make your head ache more o_O, as I said, I could be wrong, but your 140mm disc is a bit unusual. As most start with 160mm , +20 adapter is 1 size up is 180, but 1 size up for you is 160.
Don't get me wrong for saying this. (My English is already very bad) I was afraid that what you said might be true because a 160mm disc won't solve my problem for sure. I am sure I will learn something from all of you here. I am an amateur. I didn't know you had to take that into account when buying the bike. 140mm is really small. Thank you for your interest.
 

wheeliepete

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Don't get me wrong for saying this. (My English is already very bad) I was afraid that what you said might be true because a 160mm disc won't solve my problem for sure. I am sure I will learn something from all of you here. I am an amateur. I didn't know you had to take that into account when buying the bike. 140mm is really small. Thank you for your interest.
Your English is fine my friend, I think it's me speaking the wrong language, I'll get my coat :).
 
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soundwave

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May 23, 2015
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those bolt holes are really close together i just measured mine and there 76mm apart to fit the adaptor i have to the frame.
 

flecc

Member
Oct 25, 2006
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Thanks flecc, but don't you use the +20mm adapter to go from 160 to 180? just trying to understand this, no intention of being a PITA;), which I prob. am.
Think radius Pete, the 20 mm extension is on one side of the disc from the centre.

Half a 140mm disc from the centre is 70mm, half a 180mm disc from the centre is 90 mm.

The difference betwen 70 and 90 is the 20mm extension outwards for the caliper.
.
 

soundwave

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May 23, 2015
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well the only ones i can find with bolt spacings that close together are these. fr2 160mm.



now if you get that the next problem will be the caliper wont fit on to it as the bolt spacing on the adaptor is way wider than what you have.
 
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dzhem

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May 13, 2021
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well the only ones i can find with bolt spacings that close together are these. fr2 160mm.



now if you get that the next problem will be the caliper wont fit on to it as the bolt spacing on the adaptor is way wider than what you have.
so if you have any idea what i should do to fix this problem i would be very grateful.. i am really confused..
 

soundwave

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well my bike guy had a look at the pic and said that bolt spacing size is from like 20 years ago thus why the caliper wont fit with a adaptor mount as the holes will be to far apart for the caliper you have.

he said do you have any spacers that came with the motor that you could use to push the frame apart a bit more and get enough clearance that way.

only other option is get another caliper that will fit the tektro adaptor mount for a 160mm rotor.

note only the tektro adaptor will work as nothing else has the same bolt spacing to attach it to the frame.
 
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dzhem

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May 13, 2021
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well my bike guy had a look at the pic and said that bolt spacing size is from like 20 years ago thus why the caliper wont fit with a adaptor mount as the holes will be to far apart for the caliper you have.

he said do you have any spacers that came with the motor that you could use to push the frame apart a bit more and get enough clearance that way.

only other option is get another caliper that will fit the tektro adaptor mount for a 160mm rotor.

note only the tektro adaptor will work as nothing else has the same bolt spacing to attach it to the frame.

I think I got it. Thank you very much, but isn't it really strange that this bike is designed like this.. I will try to follow a new path by showing this message to a bike mechanic.
 

dzhem

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May 13, 2021
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Your English is fine my friend, I think it's me speaking the wrong language, I'll get my coat :).
My English is very bad my friend. I am writing with the help of google translate. Also, I'm in Ireland right now. I couldn't find a reliable bike mechanic here and I'm confused. I spent as much money as I could. (I just wanted to have a new kit and bike) this is really hard..
 

soundwave

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it is just one of those things that happens when converting bikes or changing rotor size as if you see the one i have on my bike it is made for the caliper that i have so nothing else would work think i paid 30 quid for the one i have and had to get it from Germany at the time pita!

and i got some of these for my xx1 sram rear mech top one was fine but bottom one was solid with the bolts done up.


so it was Dremel to the rescue and grind down the rear metal plate to get clearance for it lol.

i did have the gx version with nylon jockey wheels but one of them exploded snapped the chain and that was that and walking home.

 
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vfr400

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Jun 12, 2011
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There are two standard disc brake mounting points on bicycles. They are IS (side mount) and PM (post mount). Yours is PM. All PM adapters will have the correct spacing. If you want to check, PM mounting holes are 74mm apart.

I don't know why these guys want to confuse you, when I already showed you the correct part that you need.
 

soundwave

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There are two standard disc brake mounting points on bicycles. They are IS (side mount) and PM (post mount). Yours is PM. All PM adapters will have the correct spacing. If you want to check, PM mounting holes are 74mm apart.

I don't know why these guys want to confuse you, when I already showed you the correct part that you need.
42824

that is not 74mm apart and why he has a problem and why standard adaptors wont work because of the bolt hole spacing to attach it to the frame is not standard anymore.

only the tektro ones will work with that frame bolt spacing and max size is 160mm.
 

soundwave

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May 23, 2015
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4cm is 40mm that caliper will not fit any modern adaptor frame mount is mount or anything else bar what i posted.
 
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soundwave

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It's really a pity that we can't find an adapter for it. I was confused what to do.

this will work just not with the caliper you have becose of the bolt spacing.


problem is i can not find it for sale cheap in any bike shop in stock and only on ebay at near £30 and is the only way to fix this problem.

cable caliper also seem to be a lot wider than hydraulic ones but again modern ones wont match the bolt spacing on the frame so you will need that frame adaptor one way or another.

or take a Dremel to the caliper you have to make the space and grind it down to fit if you only need a few more mm.
 

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